CA2110487A1 - Methods for providing localized therapeutic heat to biological tissues and fluids using gas filled liposomes - Google Patents

Methods for providing localized therapeutic heat to biological tissues and fluids using gas filled liposomes

Info

Publication number
CA2110487A1
CA2110487A1 CA002110487A CA2110487A CA2110487A1 CA 2110487 A1 CA2110487 A1 CA 2110487A1 CA 002110487 A CA002110487 A CA 002110487A CA 2110487 A CA2110487 A CA 2110487A CA 2110487 A1 CA2110487 A1 CA 2110487A1
Authority
CA
Canada
Prior art keywords
liposomes
gas
tissue
fluid
liquid
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
CA002110487A
Other languages
French (fr)
Inventor
Evan C. Unger
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
ImaRx Pharmaceutical Corp
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Publication of CA2110487A1 publication Critical patent/CA2110487A1/en
Abandoned legal-status Critical Current

Links

Classifications

    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61KPREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K9/00Medicinal preparations characterised by special physical form
    • A61K9/10Dispersions; Emulsions
    • A61K9/127Liposomes
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61KPREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K41/00Medicinal preparations obtained by treating materials with wave energy or particle radiation ; Therapies using these preparations
    • A61K41/0028Disruption, e.g. by heat or ultrasounds, sonophysical or sonochemical activation, e.g. thermosensitive or heat-sensitive liposomes, disruption of calculi with a medicinal preparation and ultrasounds
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61KPREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K41/00Medicinal preparations obtained by treating materials with wave energy or particle radiation ; Therapies using these preparations
    • A61K41/0052Thermotherapy; Hyperthermia; Magnetic induction; Induction heating therapy
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61KPREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K47/00Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient
    • A61K47/50Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates
    • A61K47/69Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the conjugate being characterised by physical or galenical forms, e.g. emulsion, particle, inclusion complex, stent or kit
    • A61K47/6921Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the conjugate being characterised by physical or galenical forms, e.g. emulsion, particle, inclusion complex, stent or kit the form being a particulate, a powder, an adsorbate, a bead or a sphere
    • A61K47/6925Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the conjugate being characterised by physical or galenical forms, e.g. emulsion, particle, inclusion complex, stent or kit the form being a particulate, a powder, an adsorbate, a bead or a sphere the form being a microcapsule, nanocapsule, microbubble or nanobubble
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61KPREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K49/00Preparations for testing in vivo
    • A61K49/22Echographic preparations; Ultrasound imaging preparations ; Optoacoustic imaging preparations
    • A61K49/222Echographic preparations; Ultrasound imaging preparations ; Optoacoustic imaging preparations characterised by a special physical form, e.g. emulsions, liposomes
    • A61K49/223Microbubbles, hollow microspheres, free gas bubbles, gas microspheres
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61KPREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K49/00Preparations for testing in vivo
    • A61K49/22Echographic preparations; Ultrasound imaging preparations ; Optoacoustic imaging preparations
    • A61K49/222Echographic preparations; Ultrasound imaging preparations ; Optoacoustic imaging preparations characterised by a special physical form, e.g. emulsions, liposomes
    • A61K49/227Liposomes, lipoprotein vesicles, e.g. LDL or HDL lipoproteins, micelles, e.g. phospholipidic or polymeric
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61KPREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K9/00Medicinal preparations characterised by special physical form
    • A61K9/10Dispersions; Emulsions
    • A61K9/127Liposomes
    • A61K9/1277Processes for preparing; Proliposomes
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61KPREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K9/00Medicinal preparations characterised by special physical form
    • A61K9/10Dispersions; Emulsions
    • A61K9/127Liposomes
    • A61K9/1277Processes for preparing; Proliposomes
    • A61K9/1278Post-loading, e.g. by ion or pH gradient
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61NELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N7/00Ultrasound therapy
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61NELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N7/00Ultrasound therapy
    • A61N7/02Localised ultrasound hyperthermia
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00Surgical instruments, devices or methods, e.g. tourniquets
    • A61B2017/00681Aspects not otherwise provided for
    • A61B2017/00707Dummies, phantoms; Devices simulating patient or parts of patient
    • A61B2017/00716Dummies, phantoms; Devices simulating patient or parts of patient simulating physical properties
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00Surgical instruments, devices or methods, e.g. tourniquets
    • A61B17/22Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for
    • A61B2017/22082Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for after introduction of a substance
    • A61B2017/22088Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for after introduction of a substance ultrasound absorbing, drug activated by ultrasound
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M2202/00Special media to be introduced, removed or treated
    • A61M2202/04Liquids
    • A61M2202/0468Liquids non-physiological
    • A61M2202/0476Oxygenated solutions
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61NELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N7/00Ultrasound therapy
    • A61N7/02Localised ultrasound hyperthermia
    • A61N2007/025Localised ultrasound hyperthermia interstitial

Abstract

Gas filled liposomes (19) prepared by a vacuum drying gas instillation method and/or gas filled liposomes (19) substantially devoid of liquid in the interior thereof, are presented as novel potentiators for ultrasonic hyperthermia. The liposomes (19) of the present invention, which may be administered into the vasculature, interstitially or into any body cavity are designed to accumulate in cancerous and diseased tissues. When therapeutic ultrasonic energy is applied to the diseased region heating is increased because of the greater effectiveness of sound energy absorption caused by these agents.

Description

,. . , .wo g2/2224g ~ ' 'PCr/USs2'iO2610 ` 211û~7 METHOD8 FOR PROVIDING LOCALIZ~D THERAPEUTIC HEAT
TO BIOLOGICAL TI88~E8 AND FL~ID8 ~8ING
GA8 FILL~D LIP080ME8 RELAT~D APPLICATION
This application is a continuation-in-part of copending application U.S. Serial No. ~81,027, filed September 11, 1990, and a continuation-in-part of copending application U.S. Serial No. 569,828, filed August 20, 1990, which in turn is a continuation-in-part of application U.S. Serial'No. 455,707, filed December 22, ~;. ;
1989, the disclosures of each'of which are hereby incorporated herein by reference in their entirety.

BAC~GRO~ND OF T~E INVENTION
Field of the Invention ~ - ~'`The''present'invëntion relates to the use of `ultrasonic`energy"~to'iheat'biological tissues and fluids, and more specificàlly, to the use of hyperthermia potentiators, such as gas filled liposomes prepared by a vacuum drying gas instillation method, and/or gàs filled liposomes^substàntially devoid of liquid in the interior thereof, in combination with ultrasound to facilitate the selective heating of the tissues and fluids.
Description of thé Prior Art The usefulness of heat to treat various inflammatory and arthritic conditions has long been known.
The use of ultrasound to generate such heat for these as ,~, ,, ,.WO g2/22249 ~'PCI~/US92io2610 21 1~ - 2 -well as other therapeutic purposes, such as in, for example, the treatment of tumors has, however, been a fairly recent development.
Where the treatment of inflammation and arthritis is concerned, the use of the ultrasound induced heat serves to increase blood flow to the affected regions, resulting in various beneficial effects. Moreover, when ultrasonic energy is delivered to a tumor, the temperature of the tumorous tissue rises, generally at a higher rate than in normal tissue. As this temperature reac~es above about 43C, the tumorous cells begin to die and, if all goes well, the tumor eventually disappears. Ultrasound induced heat treatment of biological tissues and fluids is known in the art as hyperthermic ultrasound.
The non-invasive nature of the hyperthermia ultrasound technique is one of its benefits. Nonetheless, in employing hyperthermic ultrasound, certain precautions must be taken. Specifically, one must be careful to focus the ultrasound energy on only the areas to be treated, in an attempt to avoid heat-induced damage to the surrounding, non-targeted, tissues. In the treatment of tumors, for example, when temperatures exceeding about 43-C are reached, damage to the surrounding normal tissue is of particular concern. This concern with over heating ~5 the non-target tissues thus places limits on the use of hyp-rthermic ultraso~nd. Such therapeutic treatments would clearly be more effective and more widely employed if a way of targeting the desired tissues and fluids, and of maximizing the heat generated in those targeted tissues, could be devised.
` The present invention is directed toward - `improving the effectiveness and utility of hyperthermic ultrasound by providing agents capable of promoting the selective heating of targeted tissues and body fluids.

W0 92/22249 2 1 1 o ,~ 8 ~cr/us92/0261o 811~1ARY OF THE INV~NTION
The present invention is directed to methods for heat treating biological tissues and fluids which comprise administering to the tissue or fluid to be treated a s thera-peutically effective amount of a hyperthermia potentiator comprising gas filled liposomes prepared by a vacuum drying gas instillation method, and then applying ultrasound to that tissue or fluid.
The present invention is also directed to methods for heat treating biological tissues and fluids which comprise administering to the tissue or fluid to be treated a therapeutically effective amount of a hyperthermia potentiator comprising gas filled liposomes substantially devoid of liquid in the interior thereof, and then applying ultrasound to that tissue or fluid.
By using the potentiators of the present invention, hyperthermic ultrasound becomes a better, more selective and more effective therapeutic method for the treatment of tumors, inflammation, and arthritis, as well as other various conditions.
.
BRI~F DE8CRIPTION OF T~B FIG~RE~
FIG~RE 1 shows an apparatus according to the present invention for preparing the vacuum dried gas instilled liposomes and the gas filled liposomes;`
25 ~ substantially~deYoid of liquid in the interior théreof prepared by the vacuum drying gas instillation`method.
FIG~RE 2 is a graphical representation of the dB
reflectivity of the vacuum dried gas instiiled`liposomes and the gas filled liposomes substantially devoid of ~ liquid in the-interior thereof prepared by the vacuum drying gas-instillation method. The data was obtainéd by scanning with a 7.5 megahertz transducer using an Acoustic Imaging~ Model 5200 Scanner (Acoustic Imaging, Phoenix, Arizona), and was generated using the system test software to measure reflectivity. The system was standardized ~W092/2224s ~ ; PCT/US92io2~l0 .

21'10~87 -~-prior to each experiment with a phantom of known acoustic impedance.
.
DEq!AIL~D DB8CRIPTION OF T~ NTION
The present invention is directed to a method for heat treating biological tissues and fluids comprising administering to the tissue or fluid to be treated a therapeutically effective amount of a hyperthermia potentiator, and then applying ultrasound to said tissue or fluid.
The hyperthermia potentiators described herein comprise gas filled liposomes prepared by a vacuum drying gas instillation method, and/or gas filled liposomes substantially devoid of liquid in the interior thereof.
The vacuum drying gas instillation method, which lS may be employed to prepare both the gas filled liposomes prepared by the vacuum drying gas instillation method, and the gas filled liposomes substantially devoid of liquid in the interior thereof, contemplates the following process.
First, in accordance with the process, the liposomes are placed under negative pressure (that is,- reduced pressure or vacuum pressure). Next, the liposomes are incubated under that negative pressure for a time sufficient to remove substantially all liquid from the liposomes, thereby re~ulting in substantially dried liposomes. By re~oval of substantially all liquids, and by substantially .... i. . ~
dried~liposomes, as those phrases are used herein, it~is ~eant that the liposomes are at least about 90% devoid of liquid,~preferably at least about 95% devoid of liquid, ;~m~ost~preferably about 100% devoid of liquid. Finally, the liposomes are instilled with selected gas by applying the gas~to the liposomes until ambient pressures are achieved, thus resulting in the subject vacuum dried gas instilled , liposomes of the present invention, and the gas filled liposomes of the invention substantially devoid of liquid in the interior thereof. By substantially devoid of liquid in the interior thereof, as used herein, it is W09~22249 2 1 1 0 4 ~ 7 PCT/US92/026to meant liposomes having an interior that is at least about 90% devoid of liquid, preferably at least about 95% devoid of liquid, most preferably about 100% devoid of liquid.
Unexpectedly, the liposomes prepared in accordance with the vacuum dried gas instillation method, and the gas filled liposomes substantially devoid of liquid in the interior thereof, possess a number of surprising yet highly beneficial characteristics. The liposomes of the invention exhibit intense ecogenicity on lo ultrasound, result in good heating of surrounding tissues and/or fluids on ultrasound, are highly stable to pressure, and/or possess a long storage life either when stored dry or suspended in a liquid medium.
The ecogenicity of the liposomes allows the monitoring of the liposomes following administration to a patient to determine the presence of liposomes in a desired region. The ability of the liposomes to result in heating of the surrounding region is of obvious importance to the therapeutic applications of the invention.
~ The ~tability of the liposomes is also of great practical importance. The subject liposomes tend to have greater stability during storage than other gas filled liposomes produced via known procedures such as pressurization or other techniques. At 72 hours after formation, for example, conventionally prepared liposomes often are essentially devoid of gas, the gas`having ~diffu~ed~out of the~liposomes 'and/or-the"liposomes`~'aving ruptured and/or fused, resulting in a concomitant~ loss in heating potential. ~In comparison, gas filled liposomes of the present invention generally have a shelf life stability;of`greater than about three weeks,'preferably a shelf life ~tability of greater than about four weeks, more preferably a shelf life stability of greater than about five weeks, even more preferably a shelf life ;-stability of greater than about three months, and often ashelf life stability that is even much longer, such as over six months, twelve months or even two years.

; .' ~ !J~' SwOg2/22~9~ PCT/US92/02610 211~ 48 1 6 --Also unexpected is the ability of the liposomes during the vacuum drying gas instillation process to fill with gas and resume their original circular shape, rather than collapse into a cup-shaped structure, as the prior art would cause one to expect. See, e. g., Crowe et al., Archives of BiochemistrY and BioPhysics, Vol. 242, pp.
240-247 (1985); Crowe et al., Archives of Biochemistry and Biophvsics, Vol. 220, pp. 477-484 (1983); Fukuda et al., J. Am. Chem. Soc., Vol. 108, pp. 2321-2327 (1986); Regen et al., J. Am. Chem. Soc., Vol. 102, pp. 6638-664~ (1980).

The liposomes subjected to the vacuum drying gas instillation method of the invention may be prepared using any one of a variety of conventional liposome preparatory techniques which will be apparent to those skilled in the art. These techniques include freeze-thaw, as well as techniques such as sonication, chelate dialysis, homogenization, solvent infusion, microemulsification, spontaneous formation, solvent vaporization, French pressure cell technique, controlled detergent dialyzing, and others. The size of the liposomes can be adjusted, if decired, prior to vacuum drying and gas instillation, by a variety of procedures including extrusion, filtration, sonication, homogenization, employing a laminar stream of a core of liquid introduced into an immiscible sheath of liquid, and similar methods, in order to modulate - -re~ultant liposomal biodistribution and clearance, with 1 - extrusion under pressure through pores of defined size ¦ being the preferred means-of adjusting the size of the liposomes. The foregoing techniques, as well as others, are discu~sed, for example, in U.S. Patent No. 4,728~578;
U.K. Patent Application GB 2193095 A; U.S. Patent No.
4,728,575; U.S. Patent No. 4,737,323; International Application PCT/US85/01161; Mayer et al., Biochimica et Biophvsica Acta Vol. 858, pp. 161-168 (1986); Hope et al., Biochimica et BioPhysica Acta. Vol. 812, pp. 55-65 (1985); U.S. Patent No. 4,533,254; Mayhew et al., Methods .

W092/22249 2 1 1 ~ ~ 8 ~CTiUS92/026l0 in EnzYmoloqy. Vol. 149, pp. 64-77 (1987); Mayhew et al., `
Biochimica et 8iophysica Acta. Vol 755, pp. 169-74 (1984);
Cheng et al, Investiaative RadiologY. Vol. 22, pp. 47-5s (1987); PCT/US89/05040, U.S. Patent No. 4,162,282; U.S.
Patent No. 4,310,505; U.S. Patent No. 4,921,706; and Liposome TechnoloqY, Gregoriadis, G., ed., Vol. I, pp. 29-37, 51-67 and 79-108 (CRC Press Inc., Boca Raton, FL
1984). The disclosures of each of the foregoing patents, publications and patent applications are incorporated by reference herein, in their entirety. Although any of a number of varying techniques can be employed, preferably the liposomes are prepared via microemulsification techniques. The liposomes produced by the various conventional procedures can then be employed in the vacuum -drying gas instillation method of the present invention, to produce the liposomes of the present invention.
The materials which may be utilized in preparing liposomes to be employed in the vacuum drying gas instilla-tion method of the present invention include any of the materials or combinations thereof known to those skilled in the art as suitable for liposome construction.
The lipids used may be of either natural or synthetic origin. Such materials include, but are not limited to, lipids such as fatty acids, lys~lipids, dipalmitoylphosphatidylcholine, phosphatidylcholine, - phosphatidic acid, sphingomyelin, cholesterol, cholesterol - ~ hemi~u¢cinate, tocopherol-^hemisuccinate,;
phosphatidylethanolamine, phosphatidyl-inositol, ~?
lysolipids, sphingomyelin, glycoæphingolipids, glucolipids, glycolipids, sulphatides, lipids with ether ~ and ester-linked fatty acids, polymerized lipids, diacetyl ; phosphate, ~tearylamine,! di~tearoylphosphatidylcholine, phosphatidylserine, sphingomyelin, cardiolipin, phospholipids with short chain fatty acids of 6-8-carbons in length, synthetic phospholipids with asymmetric acyl chains (e.g., with one acyl chain of 6 carbons and another acyl chain of 12 carbons), 6-(5-cholesten-3~-yloxy)-1-W092/22U9. ! P~T/US92/02610 .. . .. .
2110~87 thio-~-D-galactopyranoside, digalactosyldiglyceride, 6-(5-cholesten-3~-yloxy)hexyl-6-amino-6-deoxy-1-thio-~-D-galactopyranoside, 6-(5-cholesten-3~-yloxy)hexyl-6-amino-6-deoxyl-1-thio-~-D-mannopyranoside, dibehenoyl-phosphatidylcholine, dimyristoylphosphatidylcholine,dilauroylphosphatidylcholine, and dioleoyl-phosphatidylcholine, and/or combinations thereof. Other useful lipids or combinations thereof apparent to those skilled in the art which are in keeping with the spirit of the present invention are also encompassed by the present invention. For example, carbohydrate bearinq lipids may be employed for in vivo targeting, as described in U.S.
Patent No. 4,310,505. Of particular interest~for use in the present invention are lipids which are in the gel state (as compared with the liquid crystalline state) at the temperature at which the vacuum drying gas instillation is performed. The phase transition temperatures of various lipids will be readily apparent to those skilled in the art and are described, for example, in Li~osome Technolooy, Gregoriadis, G., ed., Vol. I, pp.
1-18 (CRC Press, Inc..Boca Raton, FL 1984), the disclosures of which are incorporated herein by reference in their entirety. In addition, it has been found that the incorporation of at least a small amount of negatively charged lipid into any liposome membrane, although not required,.is beneficial to providing highly stable liposomes. By!at least a~mall amount, it is meant-about 1 mole.:percent of the total lipid.; Suitable negatively charged lipids will be readily apparent to those skilled 30-.. in the art, and include, for example phosphatidylserine . and fattyJacids. Most.preferred for the combined reasons of ultimate~hyperthermia potentiation, ecogenicity, and stability..following the vacuum drying gas instillation process are liposomes prepared from dipalmitoylphosphatidylcholine.
By way of general guidance, dipalmitoyl-phosphatidylcholine liposomes may be prepared by . ! wo 92/22~9 2 1 1 0 4 8 ~CTiUS92/02610 suspending dipalmitoylphosphatidylcholine lipids in phosphate buffered saline or water, and heating the lipids to about 50-C, a temperature which is slightly above the 45-C temperature required for transition of the dipalmitoyl- phosphatidylcholine lipids from a gel state to a liquid crystalline state, to form liposomes. To prepare multilamellar vesicles of a rather heterogeneous size distribution of around 2 microns, the liposomes may then be mixed gently by hand while keeping the liposome solution at a temperature of about 50-C. The temperature is then lowered to room temperature, and the liposomes remain intact. Extrusion of dipalmitoylphosphatidylcholine liposomes through polycarbonate filters of defined size may, if desired, be employed to make liposomes of a more homogeneous size distribution. A device useful for this technique is an extruder device (Extruder Device , Lipex Biomembranes, Vancouver, Canada) equipped with a thermal barrel so that extrusion may be conveniently accomplished above the gel state-liquid crystalline transition temperature for lipids. - ' `"
Alternatively, and again by way of general guidance, conventional freeze-thaw procedures may be used to produce either oligolamellar or unilamellar 25 dipalmitoyl-phosphatidylcholine liposomes. After the `~' -- freezè-thaw procedures, extrusion procedures as described -;above may then be performed on'the`liposomes'.' -- - The liposomes thus prepared may then be subjected to the vacuum drying gas instillation process'of`the present invention, to produce the vacuum dried gas - instilled liposomes, and the gas filled liposomes ~ubstantially devoid of-liguid in the interior thereof, of -the invention. In accordance with the process of the invention, the liposomes are placed into a vessel æuitable for subjecting to the liposomes to negative pressure (that is, reduced pressure or vacuum conditions). Negative pressure is then applied for a time sufficient to remove W092/22249 '~PCT/US92io2610 - 2110~8 1 -^`

substantially all liquid from the liposomes, thereby resulting in substantially dried liposomes. As those skilled in the art would recognize, once armed with the present disclosure, various negative pressures can be employed, the important parameter being that substantially all of the liquid has been removed from the liposomes.
Generally, a negative pressure of at least about 700 mm Hg, and preferably in the range of between about 700 mm Hg and about 760 mm Hg (gauge pressure) applied for about 24 to about 72 hours, is sufficient to remove subst~ntially all of the liquid from the liposomes. Other suitable pressures and time periods will be apparent to those skilled in the art, in view of the disclosures herein.
Finally, a selected gas is applied to the .
liposomes to instill the liposomes with gas until ambient pressures are achieved, thereby resulting in the vacuum dried gas instilled liposomes of the invention, and in the gas filled liposomes substantially devoid of liquid in the interior thereof. Preferably, gas instillation occurs 20 slowly,..that is, over a time period-of at least about 4 hours, most preferably over a time period of between about 4 and about 8 hours. Various biocompatible gases may be employed. Such gases include air, nitrogen, carbon dioxide, oxygen,-argon, xenon, neon, helium, or any and a}l combinations thereof. Other suitable gases will be apparent to.those skilled in the art, the gas chosen being only limited by the proposed application of the liposomes.
.; .~ .~T;he above.described method for production of liposomes is referred to hereinafter as the vacuum drying gas.instillation process.
.~ If desired, the liposomes may be cooled, prior to subjecting the liposomes to negative pressure, and such cooling is preferred. Preferably, the liposomes are .cooled to below 0-C, more preferably to between about -10-C and about -20-C, and most preferably to -10-C, prior to subjecting the liposomes to negative pressure. Upon reaching the desired negative pressure, the liposomes ,~ W09~22249 PCT/US92/02610 --- 2:110487 temperature is then preferably increased to above ooCl more preferably to between about lO-C and about 20-C, and most preferably to lO C, until substantially all of the liquid has been removed from the liposomes and the negative pressure is discontinued, at which time the temperature is then permitted to return to room temperature.
If the liposomes are cooled to a temperature - below 0C, it is preferable that the vacuum drying gas instillation process be carried out with liposomes either initially prepared in the presence of cryoprotectants, or liposomes to which cryoprotectants have been added prior to carrying out the vacuum drying gas instillation process of the invention. Such cryoprotectants, while not -mandatorily added, assist in maintaining the integrity of liposome membranes at low temperatures and also add to the ultimate stability of the ~embranes. Preferred cryoprotectants are trehalose, glycerol, polyethyleneglycol (especially polyethyleneglycol of molecular weight 400), raffinose, sucrose, and sorbitol, with trehalose being particularly preferred`.
It has also been surprisingly discovered that the liposomes of the invention are highly stable to changes in pressure. Because of this characteristic, extrusion of the liposomes through filters of defined pore size following vacuum drying and gas instillation can be ' carried out, if desired, to create liposomes of reIatively homogeneous-and defined pore size. ' '`
For storage prior to use, the'liposomes of the pre~ent invention may be ~uspended in an aqueous solution, ~uch as a.saline ~olution (for example, a phosphate `
- buffered ~aline ~olution), or simply water, and 'stored preferably at a temperature of between about 2-C and about lO-C, preferably at about 4-C. Preferably, the water is 35 sterile. Most preferably, the liposomes are stored in a hypertonic saline solution (e.g., about 0.3 to about 0.5 NaCl), although, if desired, the saline solution may be W092~22249 PCT/USs2/026l0 0 ~ 12 -isotonic. The solution also may be buffered, if desired, to provide a pH range of pH 6.8 to pH 7.4. Suitable buffers include, but are not limited to, acetate, citrate, phosphate and bicarbonate. Dextrose may also be included s in the suspending media. Preferably, the aqueous solution is degassed ~that is, degassed under vacuum pressure) prior to suspending the liposomes therein. Bacteriostatic agents may also be included with the liposomes to prevent bacterial degradation on storage. Suitable bacteriostatic lo agents include but are not limited to benzalkonium chloride, benzethonium chloride, benzoic acid, benzyl alcohol, butylparaben, cetylpyridinium chloride, chlorobutanol, chlorocresol, methylparaben, phenol, potassium benzoate, potassium sorbate, sodium benzoate and sorbic acid. One or more antioxidants may further be included with the gas filled liposomes to prevent oxidation of the lipid. Suitable antioxidants include tocop~erol, ascorbic acid and ascorbyl palmitate.
Liposomes prepared in the various foregoing manners may be stored for at least several weeks or months. Liposomes of the present invention may alternatively, if desired, be stored in their dried, unsuspended form, and such liposomes also have a shelf life of greater than several weeks or months; Specifically, the liposomes of the present invention, stored either way, generally have a shelf life stability of greater than about three weeks, preferably~a ~helf life stability of greaterithan about ~ four weeks, more preferably a shelf life stability of greater than~about five weeks, even more preferably a shelf life stability of greater than about three months, and often a shelf life stability that is even much longer, such~as over six months, twelve months or even two years.
As another aspect of the invention, useful apparatus for preparing the vacuum dried gas instilled liposomes, and the gas filled liposomes substantially devoid of liquid in the interior thereof, of the invention is also presented. Specifically, there is shown in Figure wos2/2224s ' Pcr/uss2io26l0 ~ 2110487 1 a preferred apparatus for vacuum drying liposomes and instilling a gas into the dried liposomes. The apparatus is comprised of a vessel 8 for containing liposomes 19.
If desired, the apparatus may include an ice bath 5 containing dry ice 17 surrounding the vessel 8. The ice bath 5 and dry ice 17 allow the liposomes to be cooled to below 0C. A vacuum pump 1 is connected to the vessel 8 via a conduit 15 for applying a sustained negative pressure to the vessel. In the preferred embodiment, the pump 1 is capable of applying a negative pressure of at least 700 mm Hg and preferably a negative pressure in the range of about 700 mm Hg to about 760 mm Hg (gauge pressure). A ~anometer 6 is connected to the conduit 15 to allow monitoring of the negative pressure applied to ~5 the vessel 8.
In order to prevent liquid removed from the liposomes from entering the pump 1, a series of traps are connected to the conduit 15 to assist in collecting the liquid (and liquid vapor, all collectively referred to herein as liquid) drawn from the liposomes. In a preferred embodiment, two traps are utilized. The first trap is preferably comprised of a flask 7 disposed in an ice bath 4 with dry ice 17. The second trap is preferably comprised of a column 3 around which tubing 16 is helically arranged. The column 3 is connected to the - conduit 15 at its top end and to one end of the tubing 16 - at its bottom end. The~other end of the tubing l6''is connected to the conduit l5. As shown 'in Figure 1, an ice bath 2 with dry ice 17 surrounds the column 3 and tubing 16. If desired, dry ice 17 can be replaced with liquid nitrogen, liquid air or other cryogenic material. The ice baths 2 and 4 assist in collecting any liquid and' - condensing any liquid vapor drawn from the liposomes for collection in the traps. In preferred embodiments of the present invention the ice traps 2 and 4 are each maintained at a temperature of least about -70C.

WO g2/22249 ~, ~ PCr/USg2/02610 '"'21'10'4~87 A stopcock 14 is disposed in the conduit 15 upstream of the vessel 8 to allow a selected gas to be introduced into the vessel 8 and into liposomes 19 from gas bottle 18.
Apparatus of the present invention are utilized by placing the liposomes 19 into vessel 8. In a preferable embodiment, ice bath 5 with dry ice 17 is used to lower the temperature of the liposomes to below ooc, more preferably to between about -10C and about -200C, and most preferably to -lo-C. With stopcocks 14 and 9 closed, vacuum pump 1 is turned on. Stopcocks lo, 11, 12 and 13 are then carefully opened to create a vacuum in vessel 8 by means of vacuum pump 1. The pressure is gauged by means of manometer 6 until negative pressure of at least 700 mm Hg and preferably in the,range of between about 700 mm Hg and about 760 mm Hg, is achieved. In preferred embodiments of the present invention, vessel 7, cooled by ice bath 4 with dry ice 17, and column 3 and coil 16, cooled by ice bath 2 with dry ice 17, together or 20 individually condense liquid vapor and trap liguid drawn from-the liposomes so as to prevent such liquids and liquid vapor from entering the vacuum pump 1. In preferred embodiments of the present invention, the temperature of ice traps 2 and 4 are each maintained at a :
temperature of at least about -70-C. The desired negative pres~ure is.generally maintained for at least 24 hours as liquid and liquid vapor is r.emoved from;the-liposomes 19 . in vessel~.8-and frozen in vessels 3 and .7. Pressure -within-the system is monitored using manometer 6 and is generally maintained for about 24 to about 72 hours, at which time substantially all of the liquid has been-removed~:from~.the liposomes. At this point,:stopcock 10 is slowly clo~ed and vacuum pump 1 is turned off. Stopcock 14 i8 then opened gradually and gas is slowly introduced into the system from gas bottle 18 through stopcock 14 via conduit 15 to instill gas into the liposomes 19 in vessel 8. Preferably, the gas instillation occurs slowly over a ; W092/22249 2 1 1 o ~ ~ 7PCT/US92/02610 time period of at least about 4 hours, most preferably over a time period of between about 4 and about 8 hours, until the system reaches ambient pressure.
The vacuum dried gas instilled liposomes and the gas filled liposomes substantially devoid of liquid in the interior thereof of the present invention have superior characteristics for use as hyperthermia potentiators. The subject liposomes provide good heating of surrounding tissues and/or fluids on ultrasound, are highly stable to pressure, and/or generally possess a long storage life either when stored dry or suspended in a liquid medium.
In use, the hyperthermic potentiators of the present invention are administered to a biological tissue or to biological fluids, whereupon ultrasound is then applied to the biological matter. The methods of the invention are particularly useful when employed in relation to such biological matter as tumor tissue, muscle tissue or blood fluid.
The liposomes employed may be of varying sizes, but preferably are of a size range wherein they have a A~ mean outside diameter between-about 30 nanometers and about lO microns, with the preferable mean outside diameter being about 2 microns. As is known to those skilled in the art, liposome size influences biodistribution and, therefore, different size liposomes are selected for various purposes. For intravascular use, or,example,~liposome~size is generally no larger than about 5 microns, and generally no smaller than about 30 nanometers, in mean outside diameter. For non-vascular uses, larger liposomes, e.g., between about 2 and about lO
- micron mean outside diameter may be employed, if desired.
- ~ The lipids employed may be selected to optimize the particular therapeutic use, minimize toxicity and maximize shelf-life of the product. Neutral liposomes composed of either saturated or unsaturated phosphatidyl-choline, with or without sterol, such as cholesterol, function quite well as intravascular hyperthermia . W092/22249 ~';PCT/US92io2610 ` 2~ 87 potentiators entrapping gas. To improve uptake by cells .such as the reticuloendothelial system (RES), a negatively charged lipid such as phosphatidylglycerol, phosphatidyl-serine or similar materials is added. For even greater s liposome stability, the liposome can be polymerized using polymerizable lipids, or the surface of the liposome can be coated with polymers such as polyethylene glycol so as to protect the surface of the vesicle from serum proteins, or gangliosides such as GMl can be incorporated within the lipid matrix. Liposomes may also be prepared with attached receptors or antibodies to facilitate their targeting to specific cell types such as tumors. Most preferred for reasons of their hyperthermia potentiation and stability are liposomes prepared from dipalmitoylphosphatidyl choline.
Where the usage is in vivo, administration may be carried out in various fashions, such as intravascularly, intralymphatically, parenterally, subcutaneously, intramuscularly, intraperitoneally, interstitialiy, 20 hyperbarically, orally, or intratumorly.using a variety of dosage forms, the particular route of administration and the dosage used being dependent upon the type of therapeutic use sought, and the particular potentiating agent employed.- For example, in tumors with a principal dominant.arterial supply such as the kidney, these - hyperthermic.:potentiating agents may be administered intraarterially. LTypically, dosage is initiated at~-lower levels and-~increased until~the desired temperature --increase effect is achieved. Generally, the contrast agents of the invention are administered in the form of an aqueous suspension such as in water or a saline~solution (e.g.,^.phosphate buffered saline). Preferably, the water is sterile.: Also preferably the saline solution is a ~ hypertonic saline solution (e.g., about 0.3 to about 0.5%
:: 35 NaCl), although, if desired, the saline solution may be isotonic. The solution also may be bu$fered, if desired, to provide a pH range of pH 6.8 to pH 7.4. In addition, ~ WOs2/22~9 PCT/US92/02610 211~87 dextrose may be preferably included in the media.
Preferably, the aqueous solution is degassed (that is, degassed under vacuum pressure) prior to suspending the liposomes therein.
For in vivo usage, the patient can be any type of mammal, but most preferably is a human. The method of the invention is particularly useful in the treatment ~f tumors, various inflammatory conditions, and arthritis, especially in the treatment of tumors. The gas filled lo liposomes prepared by a vacuum drying gas instillation method and the gas filled liposomes substantially devoid of liquid in the interior thereof accumulate in tumors, particularly in the brain, because of the leaky capillaries and delayed wash-out from the diseased tissues. Similarly, in other regions of the body where tumor vessels are leaky, the hyperthermic potentiating agents will accumulate.
The hyperthe~mic potentiators of the present invention may be used alone, in combination with one another, or in combination with other therapeutic and/or diagnostic agents. In tumor therapy applications, for example, the hyperthermic potentiators may be administered in combination with various chemotherapeutic agents.
Any of the various types of ultrasound imaging devices can be employed in the practice-of the invention, -;the^particular type or model of the device not being critical to the method of the invention. Preferably,-however, devices specially designed for administering ultrasonic hyperthermia are preferred.- Such devices are described U.S. Patent Nos. 4,620,546, 4,658,828, and 4,586,512, the disclosures of each of which are hereby incorporated herein by reference in their entirety. `The use of a-device designed for administering ultrasonic - hyperthermia and incorporating resonant frequency (RF) spectral analyzer is particularly preferred.
Although applicant does not inte~d to be limited to any particular theory of operation, the hyperthermic WOg2/22249 PCT/US92/02610 2110~8~

potentiators employed in the methods of the present invention are believed to possess their excellent results because of the following scientific postulates.
Ultrasonic energy may either be transmitted through a tissue, reflected or absorbed. It is believed that the potentiators of the invention serve to increase the absorption of sound energy within the biological tissues or fluids in which they are present, which results in increased heating, thereby increasing the therapeutic effectiveness of ultrasonic hyperthermia.
Absorption of sound is believed to be increased in acoustic regions which have a high degree of ultrasonic heterogeneity. Soft tissues and fluids with a higher degree of heterogeneity will absorb sound at a higher rate than tissues or fluids which are more homogeneous acoustically. When sound encounters an interface which has a different acoustic impedance than the surrounding medium, there is believed to be both increased reflection of sound and increased absorption of sound. The degree of absorption of sound is believed to rise as the difference between the acoustic impedances between the two substances comprising the interface increases. The potentiators of the present invention provide high acoustic impedance differences between the potentiators and any surrounding liquids and tissues.
Intense sonic energy is also believed to cause cavitation and,~when cavitation occurs, this in turn is thought to cau~e intense local heating.~ Gas bubbles are believed to lower the cavitation threshold, that is, accelerate the process of cavitation durinq sonication.
- Since the potentiators of the present invention ~ ~provide high acoustic impedance differences-between the -~ potentiators and the surrounding liquids and tissues, as well as decrease the cavitation threshold, the subject potentiators may act to increase the rate of absorption of ultrasonic energy in the surrounding tissues and fluids and effect a conversion of that energy into local heat.

W092/22249 ;PCT/VSg2/026l0 - 19- 211~
Additionally, the low thermal conductivity of gas may serve to decrease local heat dissipation, with the result that there is both an increase in the rate of heating and an increase in the final equilibrium temperature.
The potentiators of the present invention may serve to increase the acoustic heterogeneity and generate cavitation nuclei in tumors and tissues thereby acting as a potentiator of heating in ultrasonic hyperthermia.
Because the gas creates an acoustic impedance mismatch lo with adjacent tissues and adjacent fluids, the g~s acts to increase the absorption of sound and conversion of the energy into heat in the surrounding tissues and fluids.
The liposomes of the present invention are believed to differ from the liposomes of the prior art in a nùmber of respects, both in physical and in functional characteristics. For example, the liposomes of the invention are substantially devoid of liquid in the interior thereof. By definition, liposomes in the prior art have been characterized by the presence of an aqueous medium. see, e.g., Dorland's Illustrated Medical Dictionarv, p. 946, 27th ed. (W.B. Saunders Company, Philadelphia 1988). Moreover, the present liposomes surprisingly result in good heating of surrounding tissues and/or fluids on ultrasound, and posses a long storage life, characteristics of obvious importance to the hyperthermic potentiator applications of the invention.
There are various!other applications for ~
- liposomes of the invention beyond those described in detail herein. Such-additional uses, for example, include such application as drug delivery vehicles and as contrast agents for ultrasonic imaging. Such additional uses and - other related subject matter are described and claimed in Applicant's patent applications filed concurrently herewith entitled "Novel Liposomal Drug Delivery Systems"
and "Gas Filled Liposomes And Their Use As Ultrasonic Contrast Agents", the disclosures of each of which are incorporated herein by reference in their entirety.

,j~,..WOg2~22~9 PCT/US92/02610 211048~

The following examples are merely illustrative of the present invention and should not be considered as limiting the scope of the invention in any way. These examples and equivalents thereof will become more apparent to those versed in the art in light of the present disclosure, and the accompanying claims.
Examples 1-8 are actual examples that describe the preparation and testing of the vacuum dried gas instilled liposomes, the gas filled liposomes being i.
substantially devoid of any liquid in the interior thereof, of the invention. Examples 9-13 are prophetic examples meant to be illustrative of how the invention would operate under the specified conditions.

~XAMPL~8 lS Exam~le 1 Dipalmitoylphosphatidylcholine (1 gram) was suspended in 10 ml phosphate buffered saline, the suspension was heated to about 50-C, and then swirled by hand in a round bottom flask for about 30 minutes. The heat~source was removed, and the suspension was swirled for two additional hours, while allowing the suspension to cool to room temperature, to form liposomes.
The liposomes thus prepared were placed in a vessel in an apparatus similar to that shown in Figure 1 cooled to ab.out -lO-C, and.then subjected to high negative vacuum~pressure.~ The-~temperature o.the 1iposomes was the~n~raised~to about lO-C.. High negative vacuum pressure was maintained for about 48 hours. After about 48 hours, nitrogen gas was gradually instilled into the chamber over a period.of about 4:hours, after which time the pressure . .returned to ambient pressure. The resulting vacuum dried :~ gas instilled liposomes, the gas filled liposomes being substantially devoid of any liquid in the interior ~ :
thereof, were then suspended in 10 cc of phosphate buffered saline and stored at about 4C.for about three months.

WO92/2224g PCTiUS92/02610 ` 2110(1~7 Example 2 To test the liposomes of Example l ultrasonographically, a 250 mg sample of these liposomes was suspended in 300 cc of degassed phosphate buffered saline (that is, degassed under vacuum pressure). The liposomes were then scanned in vitro at varying time intervals with a 7.5 mHz transducer using an Acoustic Imaging Model 5200 scanner (Acoustic Imaging, Phoenix, AZ) and employing the system test software to measure dB
reflectivity. The system was standardized prior~to testing the liposomes with a phantom of known acoustic impedance. A graph showing dB reflectivity is provided in - Figure 2.
Example 3 Dipalmitoylphosphatidylcholine (l gram) and the cryoprotectant trehalose (l gram) were suspended in lO ml -~
phosphate buffered saline, the suspension was heated to about 50-C, and then swirled by hand in a round bottom flask for about 30 minutes. The heat source was removed, and the suspension was swirled for about two additional hours, while allowing the suspension to cool to room temperature, to form liposomes.
The liposomes thus prepared were then vacuum dried and gas instilled, substantially following the procedures shown in Example l, resulting in vacuum dried gas instilled liposomes, the gas filled liposomes being substantially devoid of any liquid in the interior i~
thereof. The liposomes were then suspended in lO cc of phosphate buffered saline, and then stored at about 4C
for several weeks.
~ Example 4 ; To test the liposomes of Example 3 ultrasonographically, the procedures of Example 2 were substantially followed. The dB reflectivity of the liposomes were similar to the dB reflectivity reported in Example 2.
Example 5 10 ~8~ ~ 22 -Dipalmitoylphosphatidylcholine (l gram) was suspended in lO ml phosphate buffered saline, the suspension was heated to about 50-C, and then swirled by hand in a round bottom flask for about 30 minutes. The suspension was then subjected to 5 cycles of extrusion through an extruder device jacketed with a thermal barrel (Extruder Device~, Lipex Biomembranes, Vancouver, Canada), both with and without conventional freeze-thaw treatment prior to extrusion, while maintaining the temperature at about. 50 C. The heat source was removed, and the suspension was swirled for about two additional hours, while allowing the suspension to cool to room temperature, to form liposomes.
The liposomes thus prepared were then vacuum dried and gas instilled, substantially following the procedures shown in Example l, resulting in vacuum dried gas instilled liposomes, the gas filled liposomes being substantially devoid of any liquid in the interior thereof. The liposomes were then suspended in lO cc of phosphate buffered saline, and then stored at about 4-C
for several weeks. --` -Example 6 To test the liposomes of Example 5 ultrasonographically, the procedures of Example 2 were : 25 substantially followed. The dB reflectivity of the liposomes were similar to the dB reflectivity reported in Example.~2~ t 5~ . t '` ' ` ~ f ,, Example 7 ~
- -In order to test the stability of the Iiposomes ..
of the invention, the liposomes suspension of Example l :. was passed through 2 micron polycarbonate filters in an extruder device (Extruder Device~, Lipex Biomembranes, Vancouver,~Canada) five times at a pressure of about 600 psi. After extrusion treatment, the liposomes were studied uItrasonographically, as described in Example 2.
Surprisingly, even after extrusion under high pressure, ~ ~W092/22249 PCT/US92/02610 ~llO~S7 the liposomes of the invention substantially retained their echogenicity.
Example 8 The liposomes of Example 1 were scanned by s ultrasound using transducer frequencies varying from 3 to 7.5 mHz. The results indicated that at a higher frequency of ultrasound, the echogenicity decays more rapidly, reflecting a relatively high resonant frequency and higher energy associated with the higher frequencies.
The following examples, Examples 9-13, are prophetic examples.
Example 9 A patient with cancer is administered a dose of gas filled liposomes prepared by a vacuum drying gas instillation method, the liposomes being substantia~ly devoid of liquid in the interior thereof. Accumulation of the liposomes in the tumor is verified ultrasonigraphic-ally. Focused ultrasonic hyperthermia is then administered to the tumor and the liposomes therein. The 20 tumor has an increased rate of heating compared to -;
treatment using ultrasonic hyperthermia without the liposomes.
~xample 10 An ultrasonic device designed for administering ultrasonic hyperthermia and incorporating an RF spectral analyzer was employed. After--gas filled liposomes prepared by a-vacuum drying-~gas~instillation method,-the liposomes being substantially devoid of liquid in the interior thereof, are delivered intravenously, the R~
30 - signal in a lesion in the~patient is monitored by the ultrasonic hyperthermia RF~spectral analyzer. Even though the concentration-of gas filled liposomes may be too dilute to visualize on an image ultrasonographically, the - RF spectral analyzer detects a change in the peak of the RF spectrum. The peak in the RF spectrum reflects the harmonic frequency of the gas filled liposomes. This data enables the operator to the ultrasonic hyperthermia W092/22249 , PCT/US92/02610 ~ 2~ -equipment to adjust the application of the ultrasonic energy to coincide with the maximal intra-lesional concentration of the gas filled liposomes and to evaluate the disappearance of the gas filled liposomes as hyperthermia progresses. Assessment of the resonant frequency also allows the operator to adjust the frequency, amplitude, duration and pulse repetition rate to be maximally effective at heating the tumor through the augmenting effects of the bubbles. Further, the presence lo of the gas filled liposomes in the lesion allows-the operator to assess the blood flow through the diseased tissues, information of great value in determining the rate of washout of heat from the tumor. Information regarding blood flow can be obtained either from simple lS subjective assessment of the images under real time ultrasound or by quantitative assessment through integration of the peaks in the RF spectrums reflecting the resonant frequencies of the gas filled liposomes.
~ ple 11 Gas filled liposomes prepared by a vacuum drying gas instillation method, the liposomes being substantially devoid of liquid in the interior thereof and entrapping oxygen gas, are administered intravenously to a patient with cancer. Ultrasonic hyperthermia is performed with pulses of high energy ultrasound and cavitation occurs at the sites of the bubbles. The oxygen increases the rate ~ of formation of free radicals which help to destroy the - tumor~tissue.
Example 12 -- 30 - In a patient with cancer, gas filled liposomes prepared by a vacuum drying gas instillation method, the liposomes being substantially devoid of liquid in the interior thereof and entrapping oxygen, are administered intravenousIy and the patient is then scanned via ultrasound. When the peak concentration of liposomes is in the tumor, the tumor is simultaneously treated with hyperthermia and radiation therapy. The effect of the WOg2/22249 r~ c ~ ~c ~ PCT/USg2/02610
2.ll~487 - 2s -liposomes and hyperthermia magnifies the effectiveness of the radiation therapy by releasing oxygen to form free radicals generated by the ionizing radiation and also formed by cavitation to improve the response of the tumor to combined radiation and hyperthermia.
Various modifications in addition to those shown and described herein will be apparent to those skilled in the art from the foregoing description. Such modifications are also intended to fall within the scope of the appended claims.
Exa~ple 13 Gas filled liposomes prepared by a vacuum drying -gas instillation method, the liposomes beingrsubstantially devoid of liquid in the interior thereof and entrapping argon gas, are administered intravenously to a patient with cancer. Ultrasonic hyperthermia is performed with pulses of high energy ultrasound and cavitation occurs at the sites of the bubbles. The argon increases the rate of formation of free radicals which help to destroy the tumor tissue.

..~
:

.; :

Claims (16)

- 26 - What is claimed is:
1. A method for heat treating biological tissues and fluids which comprises:
(i) administering to the tissue or fluid to be treated a therapeutically effective amount of a hyperthermia potentiator comprising gas filled liposomes prepared by vacuum drying gas instillation method; and (ii) applying ultrasound to heat said tissue or fluid to a temperature of at least about 43°C.
2. A method of claim 1 wherein said liposomes are comprised of lipid materials selected from the group consisting of fatty acids, lysolipids, dipalmitoyl-phosphatidylcholine, phosphatidylcholine, phosphatidic acid, sphingomyelin, cholesterol, cholesterol hemicsuccinate, tocopherol hemisuccinate, phosphatidyl-ethanolamine, phosphatidylinositol, lysolipids, sphingomeylin, glycosphingolipids, glucolipids, glycolipids, sulphatides, lipids with ether and ester-linked fatty acids, and polymerized lipids.
3. A method of claim 2 wherein said liposomes are comprised of dipalmitoylphosphatidylcholine.
4. A method of claim 1 wherein said liposomes are filled with a gas selected from the group consisting of air, nitrogen, carbon dioxide, oxygen, argon, xenon, helium, and neon.
5. A method of claim 4 wherein said liposomes are filled with nitrogen gas.
6. A method of claim 1 wherein said liposomes are suspended in an aqueous medium.
7. A method of claim 6 wherein said aqueous medium is phosphate buffered saline.
8. A method of claim 1 wherein said liposomes are admininstered to tissue or fluid selected from the group consisting of tumor tissue, muscle tissue, and blood fluid.
9. A method for heat treating biological tgissues and fluids which comprises:
(i) administering to the tissue or fluid to be treated a therapeutically effective amount of a hyperthermia potentiator comprising gas filled liposomes substantially devoid of liquid in the interior thereof; and (ii) applying ultrasound to heat said tissue or fluid to a temperature of at least about 43°C.
10. A method of claim 9 wherein said liposomes are comprised of lipid materials selected from the group consisting of fatty acids, lysolipids, dipalmitoyl-phosphatidylcholine, phosphatidylcholine, phosphatidic acid, sphingomyelin, cholesterol, cholesterol hemicsuccinate, tocopherol hemisuccinate, phosphatidyl-ethanolamine, phosphatidylinositol, lysolipids, sphingomeylin, glycosphingolipids, glucolipids, glycolipids, sulphatides, lipids with ether and ester-linked fatty acids, and polymerized lipids.
11. A method of claim 10 wherein said liposomes are comprised of dipalmitoylphosphatidylcholine.
12. A method of claim 9 wherein said liposomes are filled with a gas selected from the group consisting of air, nitrogen, carbon dioxide, oxygen, argon, xenon, helium, and neon.
13. A method of claim 12 wherein said liposomes are filled with nitrogen gas.
14. A method of claim 9 wherein said liposomes are suspended in an aqueous medium.
15. A method of claim 14 wherein said aqueous medium is phosphate buffered saline.
16. A method of claim 9 wherein said liposomes are admininstered to tissue or fluid selected from the group consisting of tumor tissue, muscle tissue, and blood fluid.
CA002110487A 1991-06-18 1992-03-31 Methods for providing localized therapeutic heat to biological tissues and fluids using gas filled liposomes Abandoned CA2110487A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US07/716,793 US5209720A (en) 1989-12-22 1991-06-18 Methods for providing localized therapeutic heat to biological tissues and fluids using gas filled liposomes
US716,793 1991-06-18

Publications (1)

Publication Number Publication Date
CA2110487A1 true CA2110487A1 (en) 1992-12-23

Family

ID=24879461

Family Applications (1)

Application Number Title Priority Date Filing Date
CA002110487A Abandoned CA2110487A1 (en) 1991-06-18 1992-03-31 Methods for providing localized therapeutic heat to biological tissues and fluids using gas filled liposomes

Country Status (10)

Country Link
US (1) US5209720A (en)
EP (1) EP0660687B1 (en)
JP (1) JP3053217B2 (en)
AT (1) ATE172625T1 (en)
AU (1) AU661701B2 (en)
CA (1) CA2110487A1 (en)
DE (1) DE69227468T2 (en)
DK (1) DK0660687T3 (en)
ES (1) ES2124733T3 (en)
WO (1) WO1992022249A1 (en)

Families Citing this family (172)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5542935A (en) 1989-12-22 1996-08-06 Imarx Pharmaceutical Corp. Therapeutic delivery systems related applications
US5585112A (en) 1989-12-22 1996-12-17 Imarx Pharmaceutical Corp. Method of preparing gas and gaseous precursor-filled microspheres
US5705187A (en) * 1989-12-22 1998-01-06 Imarx Pharmaceutical Corp. Compositions of lipids and stabilizing materials
US6088613A (en) 1989-12-22 2000-07-11 Imarx Pharmaceutical Corp. Method of magnetic resonance focused surgical and therapeutic ultrasound
US5656211A (en) 1989-12-22 1997-08-12 Imarx Pharmaceutical Corp. Apparatus and method for making gas-filled vesicles of optimal size
US5773024A (en) * 1989-12-22 1998-06-30 Imarx Pharmaceutical Corp. Container with multi-phase composition for use in diagnostic and therapeutic applications
US5149319A (en) * 1990-09-11 1992-09-22 Unger Evan C Methods for providing localized therapeutic heat to biological tissues and fluids
US5733572A (en) 1989-12-22 1998-03-31 Imarx Pharmaceutical Corp. Gas and gaseous precursor filled microspheres as topical and subcutaneous delivery vehicles
US5580575A (en) 1989-12-22 1996-12-03 Imarx Pharmaceutical Corp. Therapeutic drug delivery systems
US5922304A (en) 1989-12-22 1999-07-13 Imarx Pharmaceutical Corp. Gaseous precursor filled microspheres as magnetic resonance imaging contrast agents
US5469854A (en) * 1989-12-22 1995-11-28 Imarx Pharmaceutical Corp. Methods of preparing gas-filled liposomes
US5305757A (en) 1989-12-22 1994-04-26 Unger Evan C Gas filled liposomes and their use as ultrasonic contrast agents
US6146657A (en) 1989-12-22 2000-11-14 Imarx Pharmaceutical Corp. Gas-filled lipid spheres for use in diagnostic and therapeutic applications
US6551576B1 (en) 1989-12-22 2003-04-22 Bristol-Myers Squibb Medical Imaging, Inc. Container with multi-phase composition for use in diagnostic and therapeutic applications
US5352435A (en) * 1989-12-22 1994-10-04 Unger Evan C Ionophore containing liposomes for ultrasound imaging
US5776429A (en) 1989-12-22 1998-07-07 Imarx Pharmaceutical Corp. Method of preparing gas-filled microspheres using a lyophilized lipids
US6001335A (en) 1989-12-22 1999-12-14 Imarx Pharmaceutical Corp. Contrasting agents for ultrasonic imaging and methods for preparing the same
US6613306B1 (en) 1990-04-02 2003-09-02 Bracco International B.V. Ultrasound contrast agents and methods of making and using them
USRE39146E1 (en) 1990-04-02 2006-06-27 Bracco International B.V. Long-lasting aqueous dispersions or suspensions of pressure-resistant gas-filled microvesicles and methods for the preparation thereof
US20040208826A1 (en) * 1990-04-02 2004-10-21 Bracco International B.V. Ultrasound contrast agents and methods of making and using them
US20010024638A1 (en) * 1992-11-02 2001-09-27 Michel Schneider Stable microbubble suspensions as enhancement agents for ultrasound echography and dry formulations thereof
US7083778B2 (en) * 1991-05-03 2006-08-01 Bracco International B.V. Ultrasound contrast agents and methods of making and using them
US5578292A (en) 1991-11-20 1996-11-26 Bracco International B.V. Long-lasting aqueous dispersions or suspensions of pressure-resistant gas-filled microvesicles and methods for the preparation thereof
US6989141B2 (en) * 1990-05-18 2006-01-24 Bracco International B.V. Ultrasound contrast agents and methods of making and using them
US5445813A (en) * 1992-11-02 1995-08-29 Bracco International B.V. Stable microbubble suspensions as enhancement agents for ultrasound echography
IN172208B (en) 1990-04-02 1993-05-01 Sint Sa
AU636481B2 (en) * 1990-05-18 1993-04-29 Bracco International B.V. Polymeric gas or air filled microballoons usable as suspensions in liquid carriers for ultrasonic echography
US20030194376A1 (en) * 1990-05-18 2003-10-16 Bracco International B.V. Ultrasound contrast agents and methods of making and using them
US5569180A (en) * 1991-02-14 1996-10-29 Wayne State University Method for delivering a gas-supersaturated fluid to a gas-depleted site and use thereof
EP0732106A3 (en) * 1991-03-22 2003-04-09 Katsuro Tachibana Microbubbles containing booster for therapy of disease with ultrasound
US5205290A (en) 1991-04-05 1993-04-27 Unger Evan C Low density microspheres and their use as contrast agents for computed tomography
US5874062A (en) 1991-04-05 1999-02-23 Imarx Pharmaceutical Corp. Methods of computed tomography using perfluorocarbon gaseous filled microspheres as contrast agents
MX9205298A (en) 1991-09-17 1993-05-01 Steven Carl Quay GASEOUS ULTRASOUND CONTRASTING MEDIA AND METHOD FOR SELECTING GASES TO BE USED AS ULTRASOUND CONTRASTING MEDIA
US5409688A (en) * 1991-09-17 1995-04-25 Sonus Pharmaceuticals, Inc. Gaseous ultrasound contrast media
DE69230885T3 (en) * 1991-09-17 2008-01-24 Ge Healthcare As GASOUS ULTRASONIC CONTRASTING AGENTS
US6723303B1 (en) 1991-09-17 2004-04-20 Amersham Health, As Ultrasound contrast agents including protein stabilized microspheres of perfluoropropane, perfluorobutane or perfluoropentane
IL104084A (en) * 1992-01-24 1996-09-12 Bracco Int Bv Long-lasting aqueous suspensions of pressure-resistant gas-filled microvesicles their preparation and contrast agents consisting of them
IL108416A (en) 1993-01-25 1998-10-30 Sonus Pharma Inc Phase shift colloids as ultrasound contrast agents
US5798091A (en) 1993-07-30 1998-08-25 Alliance Pharmaceutical Corp. Stabilized gas emulsion containing phospholipid for ultrasound contrast enhancement
JP3559849B2 (en) 1993-07-30 2004-09-02 アイエムシーオーアール ファーマシューティカル カンパニー Stabilized microbubble compositions for ultrasonic technology
US5433204A (en) * 1993-11-16 1995-07-18 Camilla Olson Method of assessing placentation
CA2154867C (en) * 1993-12-15 2007-05-29 Feng Yan Gas mixtures useful as ultrasound contrast media
US5588962A (en) * 1994-03-29 1996-12-31 Boston Scientific Corporation Drug treatment of diseased sites deep within the body
US5736121A (en) 1994-05-23 1998-04-07 Imarx Pharmaceutical Corp. Stabilized homogenous suspensions as computed tomography contrast agents
US6743779B1 (en) 1994-11-29 2004-06-01 Imarx Pharmaceutical Corp. Methods for delivering compounds into a cell
US20020048596A1 (en) * 1994-12-30 2002-04-25 Gregor Cevc Preparation for the transport of an active substance across barriers
US5830430A (en) 1995-02-21 1998-11-03 Imarx Pharmaceutical Corp. Cationic lipids and the use thereof
US6210356B1 (en) * 1998-08-05 2001-04-03 Ekos Corporation Ultrasound assembly for use with a catheter
US6176842B1 (en) * 1995-03-08 2001-01-23 Ekos Corporation Ultrasound assembly for use with light activated drugs
US5558092A (en) * 1995-06-06 1996-09-24 Imarx Pharmaceutical Corp. Methods and apparatus for performing diagnostic and therapeutic ultrasound simultaneously
US5997898A (en) 1995-06-06 1999-12-07 Imarx Pharmaceutical Corp. Stabilized compositions of fluorinated amphiphiles for methods of therapeutic delivery
US5804162A (en) * 1995-06-07 1998-09-08 Alliance Pharmaceutical Corp. Gas emulsions stabilized with fluorinated ethers having low Ostwald coefficients
US6231834B1 (en) 1995-06-07 2001-05-15 Imarx Pharmaceutical Corp. Methods for ultrasound imaging involving the use of a contrast agent and multiple images and processing of same
US6521211B1 (en) * 1995-06-07 2003-02-18 Bristol-Myers Squibb Medical Imaging, Inc. Methods of imaging and treatment with targeted compositions
US6033645A (en) 1996-06-19 2000-03-07 Unger; Evan C. Methods for diagnostic imaging by regulating the administration rate of a contrast agent
US6139819A (en) 1995-06-07 2000-10-31 Imarx Pharmaceutical Corp. Targeted contrast agents for diagnostic and therapeutic use
ATE265863T1 (en) * 1995-06-07 2004-05-15 Imarx Pharmaceutical Corp NEW TARGETED AGENTS FOR DIAGNOSTIC AND THERAPEUTIC USE
US5840276A (en) * 1996-01-11 1998-11-24 Apfel Enterprises, Inc. Activatable infusable dispersions containing drops of a superheated liquid for methods of therapy and diagnosis
US5611344A (en) * 1996-03-05 1997-03-18 Acusphere, Inc. Microencapsulated fluorinated gases for use as imaging agents
NZ331460A (en) * 1996-03-05 1998-12-23 Acusphere Inc Microencapsulated fluorinated gases for use as imaging agents
DE69736981D1 (en) 1996-05-01 2007-01-04 Imarx Pharmaceutical Corp IN VITRO PROCESS FOR INTRODUCING NUCLEIC ACIDS INTO A CELL
US5837221A (en) * 1996-07-29 1998-11-17 Acusphere, Inc. Polymer-lipid microencapsulated gases for use as imaging agents
US6414139B1 (en) 1996-09-03 2002-07-02 Imarx Therapeutics, Inc. Silicon amphiphilic compounds and the use thereof
US5846517A (en) 1996-09-11 1998-12-08 Imarx Pharmaceutical Corp. Methods for diagnostic imaging using a renal contrast agent and a vasodilator
DE69718519T2 (en) 1996-09-11 2003-11-06 Imarx Pharmaceutical Corp IMPROVED METHODS FOR DIAGNOSTIC IMAGE GENERATION USING A CONTRAST AND VASODILATOR
US5827533A (en) * 1997-02-06 1998-10-27 Duke University Liposomes containing active agents aggregated with lipid surfactants
US6143276A (en) 1997-03-21 2000-11-07 Imarx Pharmaceutical Corp. Methods for delivering bioactive agents to regions of elevated temperatures
US6537246B1 (en) 1997-06-18 2003-03-25 Imarx Therapeutics, Inc. Oxygen delivery agents and uses for the same
US6090800A (en) 1997-05-06 2000-07-18 Imarx Pharmaceutical Corp. Lipid soluble steroid prodrugs
US6120751A (en) 1997-03-21 2000-09-19 Imarx Pharmaceutical Corp. Charged lipids and uses for the same
US6676626B1 (en) 1998-05-01 2004-01-13 Ekos Corporation Ultrasound assembly with increased efficacy
US6582392B1 (en) 1998-05-01 2003-06-24 Ekos Corporation Ultrasound assembly for use with a catheter
US6416740B1 (en) 1997-05-13 2002-07-09 Bristol-Myers Squibb Medical Imaging, Inc. Acoustically active drug delivery systems
US6548047B1 (en) 1997-09-15 2003-04-15 Bristol-Myers Squibb Medical Imaging, Inc. Thermal preactivation of gaseous precursor filled compositions
US6050943A (en) 1997-10-14 2000-04-18 Guided Therapy Systems, Inc. Imaging, therapy, and temperature monitoring ultrasonic system
US6500121B1 (en) 1997-10-14 2002-12-31 Guided Therapy Systems, Inc. Imaging, therapy, and temperature monitoring ultrasonic system
US6623430B1 (en) 1997-10-14 2003-09-23 Guided Therapy Systems, Inc. Method and apparatus for safety delivering medicants to a region of tissue using imaging, therapy and temperature monitoring ultrasonic system
US6123923A (en) 1997-12-18 2000-09-26 Imarx Pharmaceutical Corp. Optoacoustic contrast agents and methods for their use
US20010003580A1 (en) 1998-01-14 2001-06-14 Poh K. Hui Preparation of a lipid blend and a phospholipid suspension containing the lipid blend
US6200598B1 (en) * 1998-06-18 2001-03-13 Duke University Temperature-sensitive liposomal formulation
US6726925B1 (en) 1998-06-18 2004-04-27 Duke University Temperature-sensitive liposomal formulation
ATE216875T1 (en) 1999-01-27 2002-05-15 Idea Ag NON-INVASIVE VACCINATION THROUGH THE SKIN
ES2173679T3 (en) 1999-01-27 2002-10-16 Idea Ag IMMUNIZATION / TRANSNASAL TRANSPORTATION WITH HIGHLY ADAPTABLE VEHICLES.
AU5409699A (en) * 1999-07-05 2001-01-22 Idea Ag A method for the improvement of transport across adaptable semi-permeable barriers
US7914453B2 (en) * 2000-12-28 2011-03-29 Ardent Sound, Inc. Visual imaging system for ultrasonic probe
US7179449B2 (en) * 2001-01-30 2007-02-20 Barnes-Jewish Hospital Enhanced ultrasound detection with temperature-dependent contrast agents
US20030003144A1 (en) * 2001-05-01 2003-01-02 Keller Brian C. Sustained release formulations for nifedipine, dextromethorphan, and danazol
US7220239B2 (en) 2001-12-03 2007-05-22 Ekos Corporation Catheter with multiple ultrasound radiating members
US8226629B1 (en) 2002-04-01 2012-07-24 Ekos Corporation Ultrasonic catheter power control
US7473432B2 (en) * 2002-10-11 2009-01-06 Idea Ag NSAID formulations, based on highly adaptable aggregates, for improved transport through barriers and topical drug delivery
US6921371B2 (en) * 2002-10-14 2005-07-26 Ekos Corporation Ultrasound radiating members for catheter
US20060058708A1 (en) * 2003-12-24 2006-03-16 Gill Heart Method and apparatus for ultrasonically increasing the transportation of therapeutic substances through tissue
US7341569B2 (en) * 2004-01-30 2008-03-11 Ekos Corporation Treatment of vascular occlusions using ultrasonic energy and microbubbles
US8235909B2 (en) 2004-05-12 2012-08-07 Guided Therapy Systems, L.L.C. Method and system for controlled scanning, imaging and/or therapy
US8012457B2 (en) * 2004-06-04 2011-09-06 Acusphere, Inc. Ultrasound contrast agent dosage formulation
US7393325B2 (en) 2004-09-16 2008-07-01 Guided Therapy Systems, L.L.C. Method and system for ultrasound treatment with a multi-directional transducer
US7824348B2 (en) * 2004-09-16 2010-11-02 Guided Therapy Systems, L.L.C. System and method for variable depth ultrasound treatment
US9011336B2 (en) 2004-09-16 2015-04-21 Guided Therapy Systems, Llc Method and system for combined energy therapy profile
US8535228B2 (en) 2004-10-06 2013-09-17 Guided Therapy Systems, Llc Method and system for noninvasive face lifts and deep tissue tightening
US10864385B2 (en) 2004-09-24 2020-12-15 Guided Therapy Systems, Llc Rejuvenating skin by heating tissue for cosmetic treatment of the face and body
US7530958B2 (en) * 2004-09-24 2009-05-12 Guided Therapy Systems, Inc. Method and system for combined ultrasound treatment
US20080071255A1 (en) * 2006-09-19 2008-03-20 Barthe Peter G Method and system for treating muscle, tendon, ligament and cartilage tissue
US8444562B2 (en) 2004-10-06 2013-05-21 Guided Therapy Systems, Llc System and method for treating muscle, tendon, ligament and cartilage tissue
US8690778B2 (en) 2004-10-06 2014-04-08 Guided Therapy Systems, Llc Energy-based tissue tightening
US8663112B2 (en) 2004-10-06 2014-03-04 Guided Therapy Systems, Llc Methods and systems for fat reduction and/or cellulite treatment
US11235179B2 (en) 2004-10-06 2022-02-01 Guided Therapy Systems, Llc Energy based skin gland treatment
ES2705758T3 (en) * 2004-10-06 2019-03-26 Guided Therapy Systems Llc System for controlled heat treatment of human surface tissue
US11883688B2 (en) 2004-10-06 2024-01-30 Guided Therapy Systems, Llc Energy based fat reduction
US7758524B2 (en) 2004-10-06 2010-07-20 Guided Therapy Systems, L.L.C. Method and system for ultra-high frequency ultrasound treatment
US8133180B2 (en) 2004-10-06 2012-03-13 Guided Therapy Systems, L.L.C. Method and system for treating cellulite
US9694212B2 (en) 2004-10-06 2017-07-04 Guided Therapy Systems, Llc Method and system for ultrasound treatment of skin
JP2008522642A (en) 2004-10-06 2008-07-03 ガイデッド セラピー システムズ, エル.エル.シー. Method and system for beauty enhancement
DE202005022028U1 (en) 2004-10-06 2012-07-09 Guided Therapy Systems, Llc Ultrasonic tissue treatment system
US20060111744A1 (en) * 2004-10-13 2006-05-25 Guided Therapy Systems, L.L.C. Method and system for treatment of sweat glands
US9827449B2 (en) 2004-10-06 2017-11-28 Guided Therapy Systems, L.L.C. Systems for treating skin laxity
US20060079868A1 (en) * 2004-10-07 2006-04-13 Guided Therapy Systems, L.L.C. Method and system for treatment of blood vessel disorders
US11207548B2 (en) 2004-10-07 2021-12-28 Guided Therapy Systems, L.L.C. Ultrasound probe for treating skin laxity
US11724133B2 (en) 2004-10-07 2023-08-15 Guided Therapy Systems, Llc Ultrasound probe for treatment of skin
US20080095722A1 (en) * 2004-11-12 2008-04-24 Idea Ag Extended Surface Aggregates in the Treatment of Skin Conditions
EP1874197A4 (en) * 2005-04-12 2010-02-10 Ekos Corp Ultrasound catheter with cavitation promoting surface
EP1875327A2 (en) * 2005-04-25 2008-01-09 Guided Therapy Systems, L.L.C. Method and system for enhancing computer peripheral saftey
JP2009506873A (en) * 2005-09-07 2009-02-19 ザ ファウンドリー, インコーポレイテッド Apparatus and method for disrupting subcutaneous structures
US9486274B2 (en) 2005-09-07 2016-11-08 Ulthera, Inc. Dissection handpiece and method for reducing the appearance of cellulite
US9358033B2 (en) 2005-09-07 2016-06-07 Ulthera, Inc. Fluid-jet dissection system and method for reducing the appearance of cellulite
US9011473B2 (en) 2005-09-07 2015-04-21 Ulthera, Inc. Dissection handpiece and method for reducing the appearance of cellulite
US10548659B2 (en) 2006-01-17 2020-02-04 Ulthera, Inc. High pressure pre-burst for improved fluid delivery
US8518069B2 (en) 2005-09-07 2013-08-27 Cabochon Aesthetics, Inc. Dissection handpiece and method for reducing the appearance of cellulite
US7967763B2 (en) * 2005-09-07 2011-06-28 Cabochon Aesthetics, Inc. Method for treating subcutaneous tissues
US20080200864A1 (en) * 2005-12-02 2008-08-21 Cabochon Aesthetics, Inc. Devices and methods for selectively lysing cells
US7885793B2 (en) 2007-05-22 2011-02-08 International Business Machines Corporation Method and system for developing a conceptual model to facilitate generating a business-aligned information technology solution
US20080195036A1 (en) * 2005-12-02 2008-08-14 Cabochon Aesthetics, Inc. Devices and methods for selectively lysing cells
US20080200863A1 (en) * 2005-12-02 2008-08-21 Cabochon Aesthetics, Inc. Devices and methods for selectively lysing cells
US20080197517A1 (en) * 2005-12-02 2008-08-21 Cabochon Aesthetics, Inc. Devices and methods for selectively lysing cells
US20080014627A1 (en) * 2005-12-02 2008-01-17 Cabochon Aesthetics, Inc. Devices and methods for selectively lysing cells
US9248317B2 (en) * 2005-12-02 2016-02-02 Ulthera, Inc. Devices and methods for selectively lysing cells
US20070232987A1 (en) * 2006-02-22 2007-10-04 Vicente Diaz One-hand-operated ultrasound transducer and method for delivering a controlled and uniform distribution of a sterile or a non-sterile topical reagent to skin for use in diagnostic, therapeutic, and aesthetic therapies
WO2007127176A2 (en) * 2006-04-24 2007-11-08 Ekos Corporation Ultrasound therapy system
US9566454B2 (en) 2006-09-18 2017-02-14 Guided Therapy Systems, Llc Method and sysem for non-ablative acne treatment and prevention
US9241683B2 (en) 2006-10-04 2016-01-26 Ardent Sound Inc. Ultrasound system and method for imaging and/or measuring displacement of moving tissue and fluid
JP5975600B2 (en) * 2007-05-07 2016-08-24 ガイデッド セラピー システムズ, エル.エル.シー. Method and system for coupling and focusing acoustic energy using a coupler member
US20150174388A1 (en) 2007-05-07 2015-06-25 Guided Therapy Systems, Llc Methods and Systems for Ultrasound Assisted Delivery of a Medicant to Tissue
JP2010526589A (en) 2007-05-07 2010-08-05 ガイデッド セラピー システムズ, エル.エル.シー. Method and system for modulating a mediant using acoustic energy
ES2471118T3 (en) 2007-06-22 2014-06-25 Ekos Corporation Method and apparatus for the treatment of intracranial hemorrhages
US8439940B2 (en) 2010-12-22 2013-05-14 Cabochon Aesthetics, Inc. Dissection handpiece with aspiration means for reducing the appearance of cellulite
US20090187137A1 (en) * 2007-12-14 2009-07-23 Kim Volz Ultrasound pulse shaping
KR102147455B1 (en) 2008-06-06 2020-08-24 얼테라, 인크 Ultrasound treatment system
GB0811856D0 (en) * 2008-06-27 2008-07-30 Ucl Business Plc Magnetic microbubbles, methods of preparing them and their uses
CA2762562A1 (en) * 2009-05-19 2010-11-25 Endra, Inc. Thermoacoustic system for analyzing tissue
US11096708B2 (en) 2009-08-07 2021-08-24 Ulthera, Inc. Devices and methods for performing subcutaneous surgery
US9358064B2 (en) 2009-08-07 2016-06-07 Ulthera, Inc. Handpiece and methods for performing subcutaneous surgery
JP5463548B2 (en) * 2009-09-08 2014-04-09 学校法人福岡大学 Liposomes for ultrasound therapy and liposomes for promoting ultrasound therapy
JP5463549B2 (en) * 2009-09-08 2014-04-09 学校法人福岡大学 Liposomes for ultrasound therapy and liposomes for promoting ultrasound therapy
US8715186B2 (en) 2009-11-24 2014-05-06 Guided Therapy Systems, Llc Methods and systems for generating thermal bubbles for improved ultrasound imaging and therapy
CA2798205A1 (en) * 2010-05-03 2011-11-10 University Health Network Imageable activatable agent for radiation therapy and method and system for radiation therapy
US8845624B2 (en) 2010-06-25 2014-09-30 Alcon LexSx, Inc. Adaptive patient interface
US9504446B2 (en) 2010-08-02 2016-11-29 Guided Therapy Systems, Llc Systems and methods for coupling an ultrasound source to tissue
EP2600937B8 (en) 2010-08-02 2024-03-06 Guided Therapy Systems, L.L.C. Systems for treating acute and/or chronic injuries in soft tissue
US8857438B2 (en) 2010-11-08 2014-10-14 Ulthera, Inc. Devices and methods for acoustic shielding
US8858471B2 (en) 2011-07-10 2014-10-14 Guided Therapy Systems, Llc Methods and systems for ultrasound treatment
KR20190080967A (en) 2011-07-11 2019-07-08 가이디드 테라피 시스템스, 엘.엘.씨. Systems and methods for coupling an ultrasound source to tissue
US9263663B2 (en) 2012-04-13 2016-02-16 Ardent Sound, Inc. Method of making thick film transducer arrays
US9510802B2 (en) 2012-09-21 2016-12-06 Guided Therapy Systems, Llc Reflective ultrasound technology for dermatological treatments
CN204637350U (en) 2013-03-08 2015-09-16 奥赛拉公司 Aesthstic imaging and processing system, multifocal processing system and perform the system of aesthetic procedure
WO2014146022A2 (en) 2013-03-15 2014-09-18 Guided Therapy Systems Llc Ultrasound treatment device and methods of use
BR112016023889B1 (en) 2014-04-18 2023-02-07 Ulthera, Inc ULTRASOUND TRANSDUCTION SYSTEM FOR LINEAR FOCUSING ULTRASOUND
KR102618877B1 (en) 2014-12-31 2023-12-28 랜티우스 메디컬 이메징, 인크. Lipid-encapsulated gas microsphere compositions and related methods
CN107708581B (en) 2015-06-10 2021-11-19 Ekos公司 Ultrasonic wave guide tube
PT3405294T (en) 2016-01-18 2023-03-03 Ulthera Inc Compact ultrasound device having annular ultrasound array peripherally electrically connected to flexible printed circuit board and method of assembly thereof
KR20220165808A (en) 2016-05-04 2022-12-15 랜티우스 메디컬 이메징, 인크. Methods and devices for preparation of ultrasound contrast agents
EP3452052A4 (en) * 2016-05-06 2020-04-01 WRS Nutraceuticals Pty Ltd Agent delivery system
US9789210B1 (en) 2016-07-06 2017-10-17 Lantheus Medical Imaging, Inc. Methods for making ultrasound contrast agents
KR20230149878A (en) 2016-08-16 2023-10-27 얼테라, 인크 Systems and methods for cosmetic ultrasound treatment of skin

Family Cites Families (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4162282A (en) * 1976-04-22 1979-07-24 Coulter Electronics, Inc. Method for producing uniform particles
DE2967287D1 (en) * 1978-08-28 1984-12-13 Ricoh Kk Electrophotographic copying machine
US4310505A (en) * 1979-11-08 1982-01-12 California Institute Of Technology Lipid vesicles bearing carbohydrate surfaces as lymphatic directed vehicles for therapeutic and diagnostic substances
SE7909819L (en) * 1979-11-28 1981-05-29 Karl Thore Sterner DEVICE FOR Separation of excrement and feed residues in a fish-breeding container
US4657756A (en) * 1980-11-17 1987-04-14 Schering Aktiengesellschaft Microbubble precursors and apparatus for their production and use
US4533254A (en) * 1981-04-17 1985-08-06 Biotechnology Development Corporation Apparatus for forming emulsions
EP0068961A3 (en) * 1981-06-26 1983-02-02 Thomson-Csf Apparatus for the local heating of biological tissue
EP0111386B1 (en) * 1982-10-26 1987-11-19 University Of Aberdeen Ultrasound hyperthermia unit
US4900540A (en) * 1983-06-20 1990-02-13 Trustees Of The University Of Massachusetts Lipisomes containing gas for ultrasound detection
FR2563725B1 (en) * 1984-05-03 1988-07-15 Dory Jacques APPARATUS FOR EXAMINING AND LOCATING ULTRASONIC TUMORS WITH A LOCALIZED HYPERTHERMAL TREATMENT DEVICE
US4728575A (en) * 1984-04-27 1988-03-01 Vestar, Inc. Contrast agents for NMR imaging
JPS60255728A (en) * 1984-05-31 1985-12-17 Mochida Pharmaceut Co Ltd Preparation of magnetic vesicle composition for carcinostatic use
US4620546A (en) * 1984-06-30 1986-11-04 Kabushiki Kaisha Toshiba Ultrasound hyperthermia apparatus
US4921706A (en) * 1984-11-20 1990-05-01 Massachusetts Institute Of Technology Unilamellar lipid vesicles and method for their formation
US4689986A (en) * 1985-03-13 1987-09-01 The University Of Michigan Variable frequency gas-bubble-manipulating apparatus and method
US4865836A (en) * 1986-01-14 1989-09-12 Fluoromed Pharmaceutical, Inc. Brominated perfluorocarbon emulsions for internal animal use for contrast enhancement and oxygen transport
US4737323A (en) * 1986-02-13 1988-04-12 Liposome Technology, Inc. Liposome extrusion method
DE3614657A1 (en) * 1986-04-30 1987-11-05 Dornier Medizintechnik LIPID VESICLES CONTAINING PHARMAKA, METHOD FOR THE PRODUCTION AND INTRODUCTION THEREOF IN THE BODY OF A LIVING BEING AND RELEASE OF THE PHARMACA CONTAINING IN THE LIPID VESICLES
US4728578A (en) * 1986-08-13 1988-03-01 The Lubrizol Corporation Compositions containing basic metal salts and/or non-Newtonian colloidal disperse systems and vinyl aromatic containing polymers
DE3741201A1 (en) * 1987-12-02 1989-06-15 Schering Ag ULTRASONIC PROCESS AND METHOD FOR IMPLEMENTING IT
US4893624A (en) * 1988-06-21 1990-01-16 Massachusetts Institute Of Technology Diffuse focus ultrasound hyperthermia system
US5149319A (en) * 1990-09-11 1992-09-22 Unger Evan C Methods for providing localized therapeutic heat to biological tissues and fluids
US5088499A (en) * 1989-12-22 1992-02-18 Unger Evan C Liposomes as contrast agents for ultrasonic imaging and methods for preparing the same
US5215680A (en) * 1990-07-10 1993-06-01 Cavitation-Control Technology, Inc. Method for the production of medical-grade lipid-coated microbubbles, paramagnetic labeling of such microbubbles and therapeutic uses of microbubbles

Also Published As

Publication number Publication date
EP0660687A1 (en) 1995-07-05
ATE172625T1 (en) 1998-11-15
JPH06508277A (en) 1994-09-22
US5209720A (en) 1993-05-11
JP3053217B2 (en) 2000-06-19
AU661701B2 (en) 1995-08-03
EP0660687B1 (en) 1998-10-28
DK0660687T3 (en) 1999-07-12
ES2124733T3 (en) 1999-02-16
DE69227468D1 (en) 1998-12-03
AU2149692A (en) 1993-01-12
DE69227468T2 (en) 1999-03-25
EP0660687A4 (en) 1996-06-26
WO1992022249A1 (en) 1992-12-23

Similar Documents

Publication Publication Date Title
EP0660687B1 (en) Methods for providing localized therapeutic heat to biological tissues and fluids using gas filled liposomes
US5305757A (en) Gas filled liposomes and their use as ultrasonic contrast agents
AU667471B2 (en) Gas filled liposomes and their use as ultrasonic contrast agents
EP0639067B1 (en) Use of perfluorcarbons for the preparation of potentiators of the ultrasound induced hyperthermia treatment of biological tissues
Schroeder et al. Ultrasound, liposomes, and drug delivery: principles for using ultrasound to control the release of drugs from liposomes
CA2110490C (en) Drug delivery systems comprising gas-filled liposomes at least 90% devoid of liquid in their interior
US5800833A (en) Method for loading lipid vesicles
Al Sawaftah et al. Ultrasound-mediated drug delivery in cancer therapy: A review
JP2015528441A (en) Neuroprotective liposome compositions and methods for the treatment of stroke
US20180243418A1 (en) Systems and methods for targeted cancer therapies
US20010025144A1 (en) Gas filled liposomes and their use as ultrasonic contrast agents
EP1255533A2 (en) Magnetoliposome composition for targeted treatment of biological tissue
CA2110491C (en) Gas filled liposomes and their use as ultrasonic contrast agents
CA2211517C (en) Uses of compositions comprising gaseous precursors as potentiators for ultrasonic hyperthermia
EP1104678A2 (en) Method for hyperthermic potentiation of tissue
Lin Interactions between ultrasound and liposomes
AU9136998A (en) Method for hyperthermic potentiation of tissue

Legal Events

Date Code Title Description
EEER Examination request
FZDE Discontinued