Biocompatible and degradable scaffolds based on 2-hydroxyethyl methacrylate, gelatin and poly(beta amino ester) crosslinkers

Abstract

Gelatin hydrogels have great potential in regenerative medicine but their weak mechanical properties are a major drawback for the load-bearing applications, such as scaffolds for tissue engineering. To overcome this deficiency, novel biodegradable hydrogels with improved mechanical properties were prepared by combining gelatine with 2-hydroxyethyl methacrylate (HEMA), using a double network synthetic procedure. The first, superporous and mechanically strong network, was obtained by free radical polymerization of HEMA at cryogenic temperature, in the presence of gelatin. Degradable poly (β-amino ester) (PBAE) macromers of different chemical composition or molecular weight were used as crosslinkers to introduce hydrolytically labile bonds in PHEMA. The second gelatin network was formed by crosslinking gelatin with glutaraldehyde. For comparison, a set of biodegradable PHEMA networks was obtained by polymerization of HEMA at cryogenic temperature. All samples were characterized revealing that mechanical strength, swelling behavior and degradation rate as well as high biocompatibility of new IPNs are in accordance with values required for scaffolds in tissue engineering applications and that tuning of these properties is accomplished by simply using different PBAE macromers.