Abstract: Biodegradable dextran based hydrogel suitable for biomedical application is produced by subjecting polysaccharide substituted with unsaturated moiety, e.g. dextran methacrylate, in aqueous medium to UV or visible light irradiation in the precense of riboflavin/L-arginine or riboflavin/chitosan to cause photocrosslinking of polysaccharide substituted with unsaturated moiety.

Abstract: Biodegradable hydrogels are formed by photocrosslinking dextran-maleic acid monoesters in which the average degree of substitution of each glucose unit of each &agr;-D-glucopyranosyl of dextran by maleic acid ranges from 0.60 to 1.6 and which have a weight average molecular weight ranging from 40,000 to 80,000 on a dextran basis. The hydrogels at pH 7 have maximum swelling ratios ranging from 500 to 1,500 percent. The hydrogels are characterized by increase in swelling ratio as average degree of substitution increases. The hydrogels are useful, for example, for drug delivery and solubility enhancers of drugs, as protective encapsulators of viruses used in gene therapy, and for conventional uses of hydrogels.

Abstract: A controlled release doxorubicin containing composition comprises doxorubicin physically entrapped in a dextran-methacrylate biodegradable hydrogel. The composition provides a rapid initial release of doxorubicin over a period of 5 to 7 hours followed by slow release. Increased degree of substitution in the dextran methacrylate decreases cumulative doxorubicin release. The composition provides higher cumulative release in acid pH (e.g., the stomach) than at physiological pH at lower degrees of substitution. The composition allows administration alternatives to the bolus intravenous and continuous intravenous methods of administration now used for doxorubicin. The composition can be prepared without the use of heat (which can result in heat destruction of doxorubicin) and is prepared without chemical cross-linker such as glutaraldehyde and the toxicity associated therewith.