GB1073243A - Twisted collagen ribbon - Google Patents

Abstract

A homogeneous aqueous dispersion of substantially pure swollen collagen fibrils is extruded through a slit into a fllowing dehydrating bath consisting essentially of aqueous ammonia and acetone to form a ribbon, and the ribbon is twisted, stretched and dried to form a suture. The extruded ribbons, which may be stretched in two stages, and subsequently tanned consist of collagen fibrils aligned parallel to the longitudinal axis of the ribbon, and having the rectilinearity and landing at intervals of about 640 Angstrom typical of collagen fibrils in the natural state. A multiplicity of extruded ribbons may be bonded together to form a composite structure having the form of a tape or ribbon. In one embodiment, a 1% dispersion of beef tendon fibrils, swollen in aqueous cyanoacetic acid, is extruded as a flat ribbon into a circulating dehydrating bath, washed and tanned during a two-stage stretching process, dried by hot air and wound. The ribbon is stored as such and processed subsequently to form a rounded stand. Extrusion may be horizontal or vertical. The tanning solution may be aqueous formaldehyde containing aluminium ammonium sulphate. The suture may be obtained by heating the dried and tanned ribbon with a bonding agent e.g. dextran sulphate, and twisting together one or more of the ribbons to form a unitary linear structure.ALSO:A homogeneous aqueous dispersion of substantially pure swollen collagen fibrils is extruded through a slit into a flowing dehydrating bath consisting essentially of aqueous ammonia and acetone to form a ribbon, and the ribbon is twisted, stretched and dried to form a suture. The extruded ribbons, which may be stretched in two stages and subsequently tanned consist of collagen fibrils aligned parallel to the longitudinal axis of the ribbon, and having the rectilinearity and landing at intervals of about 640 Angstrom typical of collagen fibrils in the natural p state. A multiplicity of extruded ribbons may be bonded together to form a composite structure having the form of a tape or ribbon. In one embodiment, a 1% dispersion of beef tendon fibrils, swollen in aqueous cyanoacetic acid, is extruded as a flat ribbon into a circulating dehydrating bath, washed and tanned during a two-stage stretching process, dried by hot air and wound. The ribbon is stored as such and processed subsequently to form a rounded stand. Extrusion may be horizontal or vertical. The tanning solution may be aqueous formaldehyde containing aluminium ammonium sulphate. The suture may be obtained by heating the dried and tanned ribbon with a bonding agent e.g. dextran sulphate, and twisting together one or more of the ribbons to form a unitary linear structure.