Development of bentonite-gelatin nanocomposite hybrid hydrogels for tissue engineering

Clay nanocomposite hydrogels show great potential in tissue engineering applications due to their large layer space, cationic exchange capability, antimicrobial activity and advances in cell attachment and cell proliferation. Bentonite is a natural clay composed of a multi-layered structure with calcium and sodium cations between the tetrahedral and the octahedral layers. This article presents the development of a nanocomposite hydrogel from bentonite nanoparticles and gelatin methacryloyl (GelMA) for tissue engineering applications by investigating its mechanical, morphological and biocompatibility properties. In this research, two chemical treatment methods were studied on bentonite to manipulate it's drying density and its moisture content as an aim to enhance the mechanical stiffness of bentonite. Compression test was used to compare the mechanical properties of calcium and sodium bentonite-GelMA. It is clear that sodium bentonite enhances the mechanical properties of pure GelMA two times, while calcium bentonite showed no effect. The microstructure analysis showed a difference in the pore size when the concentrations of bentonite were varied. The 3D cell encapsulation experiment showed a maintenance of high cell viability over 5 days. The content covered in this paper will be an introduction for bentonite-GelMA nanocomposite hydrogels for further research studies in tissue engineering.