Microbubble-Assisted Bioresorbable Biphasic Scaffolds Reinforced with TiO2 Nanosheets for Oral and Maxillofacial Bone Repair: In Vitro Evaluation

Abstract This study presents the development of bioresorbable biphasic scaffolds incorporating titanium dioxide (TiO2) nanostructures, specifically nanoparticles (TNPs) and nanosheets (TNSs), into a poly(vinyl alcohol) (PVA) and silk fibroin (SF) polymeric matrix using a bubbling technique followed by freeze-drying. Both TNPs and TNSs were synthesized via a hydrothermal method. The resulting scaffolds featured two distinct layers: a porous sponge-like structure and a dense film, designed to mimic the architecture of natural bone and soft tissue interfaces in oral and maxillofacial regions. Structural characterization confirmed the successful integration of TiO2 nanostructures within the scaffold matrix. X-ray diffraction showed that both TNPs and TNSs exhibited a pure anatase phase. Compared to TNPs, the nanosheet form offered significantly improved molecular mobility and dispersion within the matrix. Additionally, TNSs-incorporated scaffolds exhibited favorable porosity, compressive strength, swelling behavior, and degradation rate. In vitro studies demonstrated enhanced proliferation of both osteoblasts and fibroblasts, particularly in the TNSs scaffolds. The anatase-phase TiO2 contributed to improved cell-material interactions and scaffold performance without significant cytotoxicity. These findings suggest that TNSs-based scaffolds hold strong potential as functional biomaterials for oral and maxillofacial tissue repair, including alveolar cleft and mandibular ridge reconstruction.