Abstract Macromolecular reconstituted collagen is prepared by treating natural insoluble collagen with an aqueous solution comprised of an alkali sulfate salt and an alkali metal hydroxide for at least 48 hours to saponify fats suspended within the natural insoluble collagen. The fat free collagen is then treated with an aqueous solution comprised of an alkali metal sulfate for at least four hours to stabilize the interfibular bonds between individual polypeptide chains. The collagen is then dissolved in an aqueous acid solution and frozen at a rate of -20° C./hour. The frozen collagen is vacuum dried at 10 -3 to 10 -5 torr for at least 16 hours to produce a biologically active collagen article. Various biologically active materials may be added to the aqueous acid solution prior to freezing. The collagen product may then be implanted into an animal or the like and the medication slowly released. The article can remain within the biological system and it will slowly dissolve due to enzymatic digestion and through other biological processes.
A process of preparing macromolecular reconstituted collagen fiber comprising: (a) treating natural insoluble collagen with an aqueous solution comprised of 0.5 to 1 molar of an alkali sulfate salt and 1.0 to 2.5 molar of an alkali metal hydroxide for at least 48 hours and up to 96 hours to saponify fats suspended within the natural insoluble collagen and to uniformly swell the collagen fibers; (b) treating the fat free collagen with an aqueous solution comprised of an alkali metal sulfate for at least four hours to stabilize the interfibular bonds; (c) dissolving the collagen in an aqueous solution; (d) adding an effective amount of a biologically active substance to said solution; (e) freezing said solution to effect a temperature reduction rate of -18° C. to -24° C./hour to a temperature of -60° C. to -70° C.; and (f) vacuum drying said solution at 10 -3 to 10 -5 torr for at least 12 hours.
Claim 2
Dependent Claim
155 words
A process of preparing macromolecular reconstituted collagen fiber comprising: (a) treating natural insoluble collagen with an aqueous solution comprised of 0.5 to 1 molar of an alkali sulfate salt and 1.0 to 2.5 molar of an alkali metal hydroxide for at least 48 hours and up to 96 hours to saponify fats suspended within the natural insoluble collagen and to uniformly swell the collagen fibers; (b) treating the fat free collagen with an aqueous solution comprised of an alkali metal sulfate for at least four hours to stabilize the interfibular bonds; (c) dissolving the collagen in an aqueous solution; (d) adding an effective amount of a biologically active substance to said solution; (e) freezing said solution to effect a temperature reduction rate of -18° C. to -24° C./hour to a temperature of -60° C. to -70° C.; and (f) vacuum drying said solution at 10 -3 to 10 -5 torr for at least 12 hours.
Claim 3
Dependent Claim
13 words
The process of claim 1 wherein said biologically active substance is a hormone.
Claim 4
Dependent Claim
13 words
The process of claim 1 wherein said biologically active substance is an antibiotic.
Claim 5
Dependent Claim
13 words
The process of claim 1 wherein said biologically active substance is a spermicide.
Claim 6
Dependent Claim
9 words
The collagen product prepared in accordance with claim 1.