System for selective release of liposome encapsulated material via laser radiation

• US 4,891,043 A
• Filed: 05/28/1987
• Issued: 01/02/1990
• Est. Priority Date: 05/28/1987
• Status: Expired due to Term

• Current Assignee: Board of Trustees of The University of Illinois
• Original Assignee: Board of Trustees of The University of Illinois
• Inventors: Peyman, Gholam A., Khoobehi, Bahram, Zeimer, Ran C.
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Daley, Kathleen A.
• Application Number:
  US07/055,047
• Time in Patent Office: 950 Days
• Field of Search: 128/1 R, 128/303.1, 128/898, 540/145, 604/20, 604/21
• US Class Current: 604/20
• CPC Class Codes: A61K 41/0028 Disruption, 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
• CPC Class Codes: A61K 49/0043 Fluorescein, used in vivo
• CPC Class Codes: A61K 49/0084 liposome, i.e. bilayered vesicular structure
• CPC Class Codes: A61K 9/127 Liposomes
• CPC Class Codes: A61M 37/00 Other apparatus for introducing media into the body for reproduction or fertilisation A61B17/425; apparatus for iontophoresis or cataphoresis A61N1/30; Percutany, i.e. introducing medicines into the body by diffusion through the skin salt baths A61H33/04
• CPC Class Codes: A61N 5/062 Photodynamic therapy, i.e. excitation of an agent

Abstract

A system for selectively releasing materials, such as drugs or dyes, at a specific site in the body of an animal. The system uses laser radiation to rupture laser light-absorbing and heat-sensitive lipid vesicles containing the drugs or dyes, thereby releasing these materials at the specific site irradiated by the laser. By using this system, the location and concentration of the materials are controlled as well as the duration of the materials'"'"' release and the release can be triggered repetitively. The laser beam used is visible or its location can be made visible to the naked eye so that the location and size of the beam'"'"'s contact with the irradiated tissue can be observed and adjusted.

Claims

1. A method of selectively and repetitively releasing a material at a specific site in the blood stream inside the body of an animal, comprising the steps of

encapsulating the material in heat-sensitive lipid vesicles,

injecting the lipid vesicles into the blood stream of the animal so that the blood stream carries the lipid vesicles throughout the body including the specific site,

generating a laser beam having a wavelength in the visible or infrared part of the electromagnetic spectrum, and

applying the laser beam to the lipid vesicles located at the specific site so as to heat and rupture the lipid vesicles so that the material therein is released within milliseconds therefrom at the specific site.

2. A method according to claim 1, wherein the material in the lipid vesicles comprises a dye.

3. A method according to claim 1, wherein the material in the lipid vesicles comprises a drug.

4. A method according to claim 1, wherein the specific site is in the retina.

5. A method according to claim 1, wherein the specific site is in the eye.

6. A method according to claim 1, wherein

the wavelength of the laser beam is in the blue part of the spectrum.

7. A method according to claim 1, and further comprising the step of

photographing the specific site.

8. A method according to claim 1, wherein

the specific site is in the retina in an eye, and

the applying step is preceded by the step of placing a contact lens on the cornea of the eye to enlarge the spot size of the laser beam inside the eye.

9. A method according to claim 1, wherein

the material absorbs light at a wavelength corresponding to the wavelength of the laser beam.

10. A method according to claim 1, wherein the applying step comprises the steps of

aiming the laser beam at the specific site,

observing the location of the contract between the laser beam and the specific site, and

adjusting the position of the contact relative to the specific site.

11. A method according to claim 1, and further comprising the steps of

observing the size of the contact between the laser beam and the specific site, and

adjusting the size of the contact.