Genipin-crosslinked chitosan scaffolds and its efficacy in releasing anti-inflammatory medicine

Controlled release carriers are often made into microspheres or tablets. Systematic and quantitative characterization of porous tissue engineered scaffolds as release carriers have not been done. Chitosan and chitosan crosslinked with various concentrations of genipin were made into porous tissue engineered scaffolds. Their thermal and enzymatic stabilities, hydrophobicities, porous structures, swelling and release properties, and compressional moduli were measured. The effects of scaffolds loaded with pentoxifylline (PTX) in suppressing inflammatory reactions in vitro were quantified. Fourier Transform Infrared spectra showed new bond formation after crosslinking chitosan with genipin. As genipin increased from 0.01% to 0.1%, the crosslinked chitosan scaffolds swelled 0.5% to 1.8% less, had 1.9-5% decrease in PTX release efficiencies, became less wettable, were less favorable for initial cell attachment, had 4-20% increase in Young's modulus and were more resistant to enzymatic degradation. In vitro tests showed that when PTX was released more slowly from crosslinked scaffolds, PTX became more effective in suppressing macrophage cells from releasing IL-6 and TNF-alpha.