Novel naturally crosslinked electrospun nanofibrous chitosan mats for guided bone regeneration membranes: material characterization and cytocompatibility

Guided bone regeneration (GBR) barrier membranes are used to prevent soft tissue infiltration into the graft space during dental procedures that involve bone grafting. Chitosan materials have shown promise as GBR barrier membranes, due to their biocompatibility and predictable biodegradability, but degradation rates may still be too high for clinical applications. In this study, chitosan GBR membranes were electrospun using chitosan (70% deacetylated, 312kDa, 5.5w/v%), with or without the addition of 5 or 10mm genipin, a natural crosslinking agent, in order to extend the degradation to meet the clinical target time frame of 4-6months. Membranes were evaluated for fibre diameter, tensile strength, biodegradation rate, bond structure and cytocompatibility. Genipin addition, at 5 or 10mm, resulted in median fibre diameters 184, 144 and 154nm for uncrosslinked, 5mm and 10mm crosslinked, respectively. Crosslinking, examined by Fourier transform infrared spectroscopy, showed a decrease in N-H stretch as genipin levels were increased. Genipin-crosslinked mats exhibited only 22% degradation based on mass loss, as compared to 34% for uncrosslinked mats at 16weeks in vitro. The ultimate tensile strength of the mats was increased by 165% to 32MPa with 10mm crosslinking as compared to the uncrosslinked mats. Finally, genipin-crosslinked mats supported the proliferation of SAOS-2 cells in a 5day growth study, similar to uncrosslinked mats. These results suggest that electrospun chitosan mats may benefit from genipin crosslinking and have the potential to meet clinical degradation time frames for GBR applications. Copyright (c) 2012 John Wiley & Sons, Ltd.