Silk fibroin/polyacrylamide Semi-interpenetrating network hydrogels for controlled drug release

The present study describes a semi-interpenetrating network hydrogel fabricated using silk fibroin/polyacrylamide for controlled drug delivery applications. Hydrogels were synthesized using varied ratios of silk fibroin/acrylamide mixtures crosslinked by N,N'-Methylenebisacrylamide. Fourier Transform Infrared analysis was performed suggesting beta sheet transition of silk fibroin with hydrogels. Scanning electron microscopy revealed microporous surface with maximum pore size of 50 +/- 11 mu m. Rheological properties along with swellability, degradation, sol fraction estimation, equilibrium water content and swelling kinetics were evaluated. Compressive strength of 241.9 +/- 5.5 kPa was observed suggesting mechanically stronger gels. MTT assay showed biocompatibility and absence of deleterious effects of hydrogel on cell viability and functionality. In vitro release studies using two model compounds i.e. trypan blue dye and FITC-inulin reveal their sustained release from the fabricated hydrogel constructs. (C) 2009 Elsevier Ltd. All rights reserved.