Preparation of interpenetrating networks of gelatin and dextran as degradable biomaterials

Gelatin and dextran were blended and crosslinked to form enzymatically degradable interpenetrating polymeric networks (IPNs) as materials for degradable implants. Several crosslinking methods were investigated including treatment with glyceraldehyde, thermal hardening, and chelation of dextran by divalent metal cations. IPNs were characterized by an equilibrium swelling method. Gelatin/dextran IPNs were stable at 25°C and reached peak volume equilibrium swelling ratios up to 17 and peak weight swelling ratios up to 15. When swollen at 37°C, the gels dissolved denoting that a network had been formed by physical and not chemical crosslinks.