Hydrolytically labile microspheres of polysaccharide crosslinked with cyanogen halide and their application in wound dressings

摘要

A water swellable and hydrolytically labile (and therefore potentially biodegradable) non-toxic crosslinked polysaccharide in microsphere or bead form. The crosslinked polysaccharide comprises polysaccharide chains and crosslinking groups which are imidocarbonate groups, carbonate groups or a mixture thereof. The microspheres are predominantly in the range of about 1 micron to about 100 microns in diameter, preferably about 2-50 microns. The crosslinked polysaccharide polymer, which is preferably a crosslinked dextran, is formed by treating a water soluble non-crosslinked polysaccharide with a cyanogen halide (preferably cyanogen bromide) in an aqueous alkaline medium which is the disperse phase of a water-in-oil dispersion. The microspheres are useful in the treatment of wounds, in particular as an absorptive agent for wound exudates. The microspheres may be formed into a wound dressing which includes a blend of the microspheres and a hydrophobic adhesive matrix material on a waterproof backing sheet.