Photo cross-linked biodegradable hydrogels for enhanced vancomycin loading and sustained release.

A series of biodegradable hydrogels based on dextran and poly(L-glutamic acid) were fabricated for effective vancomycin loading and release. The preparation of hydrogels was simply achieved by photo cross-linking of methacrylated dextran and poly(L-glutamic acid)- g-hydroxyethyl methacrylate (PGH) in the presence of photoinitiator I2959. The structures of hydrogels were characterized by FTIR and SEM. The swelling and enzymatic degradation behaviors of hydrogels were examined to be dependent on the poly(L-glutamic acid) content in the hydrogels. The higher content of poly(L-glutamic acid) in the gel, the higher swelling ratio and quicker degradation were observed. More interestingly, the hydrogel with higher PGH ratio showed higher vancomycin (VCM) loading content, which might be due to the electrostatic interaction between carboxylate groups in hydrogel and ammonium group of VCM. In vitro drug release from the VCM-loaded hydrogels in aqueous solution exhibited sustained release of VCM up to 72 h, while the in vitro antibacterial test based on the VCM-loaded hydrogel showed an efficient Methicillin-Resistant S. aureus (MRSA) inhibition extending out to 7 days. These results demonstrated that the biodegradable hydrogels which formed by in situ photo-cross linking would be promising as scaffolds or coatings for local antibacterial drug release in tissue engineering. [ABSTRACT FROM AUTHOR]