IMPLANT FOR SUBCUTANEOUS OR INTRADERMAL INJECTION
The invention concerns an injection implant for filling up wrinkles, thin lines, skin cracks and scars, for reparative or plastic surgery, aesthetic dermatology, and for filling up gums in dental treatment. The invention concerns the use of biologically absorbable polymer microspheres or microparticles suspended in a gel. Said suspension is produced either ready-for-use or freeze-dried. The biological absorbability of the microspheres is controlled and enables the production of implants having well defined persistence and deliberately limited to 3 years.
1 . A method of performing reparative or esthetic dermatologic surgery which
comprises subcutaneously or intradermally injecting into a subject a bioresorbable injectable
implant consisting essentially of bioresorbable microspheres or microparticles suspended in a gel, wherein said microspheres or microparticles consist of at least one polymer selected from the group consisting of lactic acid polymers, glycolic acid polymers, and
lactic acid-glycolic acid co-polymers.
2 . The method according to claim 1 wherein said surgery is for filling wrinkles, fine lines, skin cracks or scars.
3 . The method according to claim 1 wherein said surgery is for filling the gums for dentistry.
4 . The method according to claim 1 wherein said implant consists essentially of materials of non-animal origin.
5 . The method according to claim 1 wherein said microspheres or microparticles have a mean diameter greater than 5 μm and less than 150 μm.
6 . The method according to claim 1 wherein said microspheres or microparticles have a mean diameter greater than 20 μm and less than 80 μm.
7 . The method according to claim 1 wherein said microspheres or microparticles have a mean diameter greater than 20 μm and less than 40 μm.
8 . The method according to claim 1 wherein said polylactic acid has a molecular mass of between 70,000 and 175,000 Daltons.
9 . The method according to claim 1 wherein said polylactic acid has a molecular mass of between 120,000 and 170,000 Daltons.
10 . The method according to claim 1 wherein said polylactic acid has an intrinsic viscosity of between 3 and 4 dl/g.
11 . The method according to claim 1 wherein said polylactic acid has an intrinsic viscosity of between 3.35 and 3.65 dl/g.
12 . The method according to claim 1 wherein said microspheres or microparticles are present in said gel at a concentration of from 50-300 g/l.
13 . The method according to claim 1 wherein said microspheres or microparticles are present in said gel at a concentration of from 60-200 g/l.
14 . The method according to claim 1 wherein said gel consists essentially of water, from about 0.1 to about 7.5% (wt/wt) of an injectable gelling agent, and a surfactant.
15 . The method according to claim 1 wherein said gel consists essentially of water and 0.1 to 7.5% by weight carboxymethylcellulose (CMC) or hydroxypropylmethylcellulose.
16 . The method according to claim 14 wherein said gelling agent is a cellulose derivative.
17 . The method according to claim 16 wherein said cellulose derivative is selected from the group consisting of carboxymethylcellulose and hydroxypropylmethylcellulose.
18 . The method according to claim 14 wherein wherein said gelling agent is synthetic hyaluronic acid.
19 . The method according to claim 14 wherein wherein said surfactant is selected from the group consisting of polyoxyethylene sorbitan monooleate and pluronic acid.
20 . The method according to claim 1 wherein said microparticles consist of a polymer selected from the group consisting of poly-L-lactic acid, poly-D-lactic acid, and mixtures thereof.