GB606427A - Improvements relating to collagenous strands and method of making the same - Google Patents

Abstract

Filaments are produced by extruding a fibre-free solution of collagenous material in an organic acid into a coagulating bath. The collagenous substance may be obtained from hides, skins, fascialata, or muscles of vertebrates. Green-salted calf skin or kip skin may be used. This may be prepared by removing the flesh and hair, leaving the clean corium, which is that lamination of the animal hide containing the greatest proportion of collagen. The corium may be cut into strips and covered with a dilute solution of an organic acid with pH of 2 to 4, e.g. 0.05 to 0.10 normal formic acid or 0.5 to 1.0 normal acetic acid. The corium is allowed to swell for several hours in the acid solution at 10 DEG -30 DEG C. The mass is then mechanically disintegrated, e.g. in a shredder and the collagen gradually dissolves in the acid. Any insoluble matter such as elastin, and hair fragments, is removed from the solution, e.g. by centrifuging and filtering. The spinning solution preferably contains 5 to 15 per cent of collagen. The coagulating bath may be formed by a strong salt solution such as a 35 per cent saturated solution of ammonium sulphate with sufficient ammonia to maintain a pH of 7.8, or a 25 per cent magnesium sulphate solution buffered to a pH of 7.8 by means of triethanolamine. The filaments may be stretched during coagulation and setting, and by stretching in stages an extension of 700 per cent may be obtained. When the wet filaments from the coagulating bath are twisted to form a strand considerable coalescence of the filaments occurs so that a unitary strand may be obtained. The filaments or strands may be tanned and they may be used as surgical sutures or ligatures.ALSO:A fibre-free solution of collagenous material in an organic acid is extruded into a coagulating bath to form artificial threads. The collagenous substance may be obtained from hides, skins, fascialata, or muscles of vertebrates. Greensalted calf skin or kip skin may be used. This may be prepared by removing the flesh and hair, leaving the clean corium, which is that lamination of the animal hide containing the greatest proportion of collagen. The corium may be cut into strips and covered with a dilute solution of an organic acid with pH of 2 to 4, e.g. 0.05 to 0.10 normal formic acid or 0.5 to 1.0 normal acetic acid. The corium is allowed to swell for several hours in the acid solution at 10-30 DEG C. The mass is then mechanically disintegrated, e.g. in a shredder and the collagen gradually dissolves in the acid. Any insoluble matter such as elastin, and hair fragments, is removed from the solution, e.g. by centrifuging and filtering. The spinning solution preferably contains 5 to 15 per cent of collagen.