Bioinspired Biodegradable, Porous and Photoactive Cellulosic Scaffold with Antibacterial Properties for Bone Regeneration

Aim and Background: Bone-related diseases are common clinical problems that result in hardly recoverable bone defects. In this study, mild heat-induced osteogenesis is studied by a biodegradable cellulose-based scaffold coated with Bismuth Sulfide nanoparticles (NPs) while its pores are filled with gelatin-hyaluronic acid thermo-responsive hydrogel. Methods: Bismuth Sulfide NPs were prepared using a simple chemical reaction and plant-derived cellulose scaffolds (C-scaffold) were coated with NPs entirely to generate Bi-scaffold. Then the scaffolds were immersed in gelatin-HA hydrogel for 4 hours (Bi-Gel scaffold). Following that, the scaffolds were dried by freeze-drying. Results and discussion: The FE-SEM images of scaffolds demonstrated that the scaffold coated with NPs and impregnated with gel while indicating desirable porosity. The elemental analysis of Bi-scaffold confirms that the scaffold coated with bismuth sulfide sufficiently. The compressive strength of Bi-Gel scaffold is approximately about 17.2 Mpa. The photothermal performance of the Bi-scaffold showed that the temperature increased rapidly to 76°C after NIR laser irradiation at 1.5 W/cm2, which confirm the high photothermal conversion efficiency of the scaffold. The scaffolds showed very potent antibacterial effect against E. coli and S. aureus under NIR irradiation. Conclusion: The Bismuth Sulfide coated cellulosic scaffold has great potential in orthopedic applications due to good NIR-mediated and hydrogel-assisted osteogenic performances and this study provides new insights into the design and fabrication of new-style osteoimplants for bone regeneration.