Patent ID: 6309454
Filing Date: 2001-10-30
Classification: A61L,A61M

Abstract:
A method of manufacture of a freeze-dried sponge pad comprising the steps of:providing an acidified paste of purified collagen fibers, wherein the collagen is less than 10% denatured;providing oxidized regenerated cellulose fibers, wherein at least 80% of said fibers have lengths in the range of 20 .mu.m to 1000 .mu.m;combining said collagen and said ORC fibers in a homogeneous aqueous dispersion in a weight ratio of 60:40 to 40:60 collagen:ORC, said aqueous dispersion being acidified to a pH in the range of 2.8 to 3.2 and having a total solids concentration of 0.8 to 1.2% by weight;pouring said aqueous dispersion into trays to a depth greater than 1 cm;freezing the dispersion to a temperature below -30.degree. C., followed by a temperature programmed freeze drying and dehydrothermal cross-linking to a final moisture content of 5-15% by weight;splitting the freeze-dried dispersion to remove surface layers and leave one or more pads; andsterilizing the one or more pads by gamma-irradiation.