Hidrogel de quitosana contendo nanomaterial polimérico e cerâmico aplicado ao reparo ósseo

Abstract

Bone tissue has an intrinsic self-regeneration capacity; however, extensive injuries or conditions such as aging may require alternative therapies to conventional surgeries. Chitosan (QTS)-based hydrogels are promising for bone repair due to their biocompatibility, biodegradability, and similarity to the extracellular matrix, although they exhibit mechanical limitations. The association of QTS with cellulose nanofibers (NFC), which provide structural reinforcement, and barium titanate nanoparticles (NPTB), which possess piezoelectric properties, emerges as a strategy to overcome such constraints. This study aimed to develop and characterize QTS-based hydrogels combined with NFC and NPTB, evaluating their cytocompatibility, in vitro osteogenic bioactivity using SHED cells, and in vivo performance in bone repair. Four experimental groups were synthesized (QTS, QTS/NFC, QTS/NPTB, and QTS/NFC/NPTB), with QTS defined as the 3D control. The hydrogels were subjected to physicochemical analyses (SEM, FTIR, Raman, degradation, and wettability), cytotoxicity and osteogenesis assays (MTT, Alamar Blue, and ALP), as well as in vivo tests using a Swiss mouse calvaria model. The results showed that the incorporation of nanomaterials led to a porous microstructure, hydrophilic profile (contact angles <90°), and progressive degradation over 21 days. In vitro, groups containing nanomaterials exhibited higher cell viability (measured by MTT and Alamar Blue assays) and increased alkaline phosphatase (ALP) activity compared to the control (QTS). In vivo, the QTS/NFC/NPTB composite promoted faster epithelialization (average of 9 days) and greater bone tissue formation/mineralized matrix volume, whereas the presence of NPTB, alone or combined, was associated with a lower degradation rate and higher initial inflammatory response. Future three-dimensional quantitative analyses and staining assays will be essential to verify the potential mineralization capacity and consequent applicability of this material in bone tissue engineering.