Hydrophilic, water-swellable, crosslinked, copolymer gel and prosthesis employing same

• US 4,138,382 A
• Filed: 05/01/1978
• Issued: 02/06/1979
• Est. Priority Date: 05/01/1978
• Status: Expired due to Term

• Current Assignee: Dow Corning Corporation (Dow, Inc.)
• Original Assignee: Dow Corning Corporation (Dow, Inc.)
• Inventors: Polmanteer, Keith E.
• Primary Examiner(s): Michl, Paul R.
• Application Number:
  US05/901,954
• Time in Patent Office: 281 Days
• Field of Search: 260/29.6 H, 260/29.6 TA, 260/29.7 H, 526/279, 528/32, 3/36
• US Class Current: 523/113
• CPC Class Codes: A61F 2/12 Mammary prostheses and implants
• CPC Class Codes: A61L 27/16 obtained by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: A61L 27/52 Hydrogels or hydrocolloids
• CPC Class Codes: C08F 230/085 the monomer being a polymerisable silane, e.g. (meth)acryloyloxy trialkoxy silanes or vinyl trialkoxysilanes
• CPC Class Codes: C08L 39/06 Homopolymers or copolymers of N-vinyl-pyrrolidones
• CPC Class Codes: C08L 43/04 Homopolymers or copolymers of monomers containing silicon
• CPC Class Codes: Y10S 128/21 Silicone

Abstract

A hydrophilic, water-swellable, crosslinked gel is produced by copolymerizing a water soluble vinylic constituent in aqueous solution with olefinic hydrolyzable silanes which contain low molecular weight alkoxy groups. Copolymerization is via the unsaturated groups and crosslinking is by condensation reactions. The copolymer is swellable to a finite extent or to an infinite extent depending upon the water/vinylic monomer volume ratio and upon the vinylic monomer:silane mole ratio. Non-toxic embodiments of the gel are especially useful as prosthesis fillers. Such gels can be used to fill the prosthesis before implantation or the prosthesis can be swollen with an aqueous solution after implantation.

Claims

1. A water swellable hydrophilic gel comprising a crosslinked copolymer of a water soluble vinylic constituent in aqueous solution and an olefinic hydrolyzable silane having the formula X_m R_n Si(OR'"'"')_4-(n+m) wherein X is an unsaturated group, m is at least 1 and R'"'"' and R are organic radicals, n being 0 to 2, wherein the volume ratio of water to vinylic constituent is from about 0.5 to about 10 while the mole ratio of vinylic constituent to hydrolyzable silane is from about 50 to about 600, wherein copolymerization is via the unsaturated groups and wherein crosslinking is by condensation reactions.

2. The gel of claim 1 wherein the volume ratio of water to vinylic constituent and the mole ratio of vinylic constituent to hydrolyzable silane are selected to produce a gel which is water swellable to an infinite extent.

3. The gel of claim 1 wherein the volume ratio of water to vinylic constituent and the mole ratio of vinylic constituent to hydrolyzable silane is selected to produce a gel which is water swellable to a finite extent.

4. The gel of claim 1 wherein the volume ratio of water to vinylic constituent and the mole ratio of vinylic constituent to hydrolyzable silane is selected to produce a slowly soluble gel.

5. The gel of claim 1 wherein the vinylic constituent is selected from the group consisting of n-vinylpyrrolidone and copolymers and terpolymers of n-vinylpyrrolidone with minor amounts of comonomers selected from the group consisting of 2,4-pentadiene-1-ol;

acrylamide derivatives of the formula ##STR4## wherein R is --H or CH₃ and R'"'"' and R" are H, --CH₃, --C₂ H₅ or --CH₂ CHOHCH₃ ; and

hydroxylalkylmethacrylates of the formula ##STR5## wherein R is --CH₂ CH₂ OH; and

wherein the olefinic hydrolyzable silane is selected from the group consisting of vinyltrimethoxy-silane, vinyltriethoxysilane, ethylvinyldimethoxysilane, allyltrimethoxysilane and 3-trimethoxysilylpropylmethacrylate.

6. A surgically implantable mammary prosthesis which comprises:

(a) a flexible container made of surgically implantable material having an outer surface shaped to approximate the general form of the human breast; and

(b) a filling within the container of the gel of claim 1.

7. The prosthesis of claim 6 wherein the filling within the container comprises the gel of claims 2, 3 or 4.

8. The prosthesis of claim 6 wherein the filling within the container comprises an amount of the gel of claim 3 insufficient to support the prosthesis and wherein the container is adapted to supply the gel with an amount of aqueous fluid after the prosthesis has been implanted, the amount of aqueous fluid being sufficient to swell the gel so that the prosthesis is supported.

9. The prosthesis of claim 8 wherein the container includes a silicone gel valve for supplying a sterile aqueous fluid to the gel.