Herein, we report the cartilage tissue engineering application of nanographene oxide (NGO)-reinforced gelatin hydrogel fabricated by utilizing a microplasma-assisted cross-linking method. NGO sheets with surface functionalities were introduced to enhance the mechanical and biomedical properties of gelatin-based hydrogels. Highly energetic reactive radicals were generated from the nonthermal plasma (NTP), which is used to facilitate the cross-linking and polymerization during the polymeric hydrogel fabrication. The NTP treatment substantially reinforced a small amount (1 wt %) of NGO into the gelatin hydrogel. Systematic material characterization thus shows that the fabricated hydrogel possessed unique properties such as moderate surface roughness and adhesiveness, suitable pores sizes, temperature-dependent viscoelasticity, and controllable degradability. In vitro studies demonstrated that the as-fabricated hydrogel exhibited excellent cell-material interactions with SW 1353 cells, bone marrow-derived mesenchymal stem cells, and a rat chondrocyte cell line, thereby exhibiting appropriate cytocompatibility for cartilage tissue engineering applications. Furthermore, an in vivo study indicated that the formation of a healthy hyaline cartilage after the microfracture was enhanced by the fabricated hydrogel implant, offering a potential biocompatible platform for microfracture-based cartilage reconstructive surgery.
Keywords: cartilage defect; graphene oxide; hydrogel; microfracture; microplasma.