The invention provides a method of treating a chronic ulcer, such as a diabetic ulcer, comprising administering a therapeutic amount of a hydrogel matrix to the ulcer, the matrix composition comprising gelatin and a long chain carbohydrate. The matrix may further include polar amino acids, nitric oxide inhibitors and super oxide inhibitors. Injection is a preferred method of administration. The matrix may be injected into one or more locations within the ulcer, underneath the ulcer and/or around the periphery of the ulcer.