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

Abstract

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, 312 kDa, 5.5 w/v%), with or without the addition of 5 or 10 mm genipin, a natural crosslinking agent, in order to extend the degradation to meet the clinical target time frame of 4-6 months. Membranes were evaluated for fibre diameter, tensile strength, biodegradation rate, bond structure and cytocompatibility. Genipin addition, at 5 or 10 mm, resulted in median fibre diameters 184, 144 and 154 nm for uncrosslinked, 5 mm and 10 mm 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 16 weeks in vitro. The ultimate tensile strength of the mats was increased by 165% to 32 MPa with 10 mm crosslinking as compared to the uncrosslinked mats. Finally, genipin-crosslinked mats supported the proliferation of SAOS-2 cells in a 5 day 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.

Genipin-crosslinked electrospun chitosan nanofibers: Determination of crosslinking conditions and evaluation of cytocompatibility

“…In any case, consistent with above SEM results, we found cell viability was sharply enhanced when cultivated on the 0.5%GP crosslinked CTS nanofibers as compared to other GP concentrations, which indicates that CTS-GP0.5% nanofibers could be used as the optimal scaffold for cell growth. Earlier on, Bumgardner's group demonstrated in vitro the cytocompatibility of electrospun nanofibrous CTS membranes crosslinked with GP by culturing with fibroblast, ostoblast, and monocyte cell lines (Norowski et al, 2012(Norowski et al, , 2015. Very recently, it was found that these crosslinked nanofibrous CTS membranes also exhibited similar inflammatory and tissue Fig.…”

Evaluation of biocompatibility and degradation of chitosan nanofiber membrane crosslinked with genipin

“…Genipin at 5 or 10 m M concentration was added to the chitosan solution 30 min before electrospinning. The concentrations of genipin were selected based on our previous studies that showed statistical differences in tensile strengths and in vitro degradation of the membranes . Electrospinning was performed using a plastic 10 mL syringe with a blunt 20 G, 3.81 cm stainless steel needle tip, at a 20 μL/min flow rate, and a voltage of 25 kV.…”

“…Membranes were allowed to dry, were then cut in 1 × 1 cm specimens. Genipin crosslinked and uncrosslinked chitosan electrospun membranes under these conditions have average fiber diameters of 142 and 162 nm, respectively, and average tensile strengths 32.2 MPa (10 m M genipin crosslinked), 22.2 MPa (5 m M genipin crosslinked), and 12.3 MPa (uncrosslinked chitosan) and the membranes produced are approximately 0.05 mm thick . Membranes were sterilized by ethylene oxide gas (24 h exposure, 2 h ventilation, ∼20°C and >35% relative humidity) before implantation (Anprolene Gas Sterilizer, Model AN74i, Andersen Products, NC).…”

“…Our group earlier reported on the mechanical tensile properties, degradation, and cytocompatibility of chitosan and genipin crosslinked chitosan electrospun GBR membranes . Uncrosslinked mats showed 34% degradation based on mass loss compared with 22% for genipin crosslinked mats at 16 weeks in vitro . The ultimate tensile strength of the mats was increased significantly with 10 m M genipin crosslinking as compared with the uncrosslinked mats.…”

Antimicrobial Activity of Minocycline-Loaded Genipin-Crosslinked Nano-Fibrous Chitosan Mats for Guided Tissue Regeneration

“…We have developed electrospun chitosan membranes with genipin cross-linking (natural crosslinker) that have resulted in 12% reduction in mass loss over 16 weeks, and increased the tensile strength of the membranes three fold [9]. We have also demonstrated that the genipin crosslinked chitosan membranes were not cytotoxic to osteoblast or fibroblast cells, and did not cause monocyte activation.…”