Esponja mineralizada de colágeno /quitosana com hidroxiapatita co-substituída com estrôncio e magnésio: síntese, caracterização e citotoxicidade

Abstract

Biomaterials engineering aims to develop materials with superior biological and mechanical properties to promote tissue regeneration and integration with the host tissue. The combination of bioactive components favors synergistic effects that enhance bone regeneration. In addition, the modulation of physicochemical properties, such as porosity, biodegradability, and controlled ion release, is essential to stimulate the cellular response and optimize the bone repair process. The objective of this study was to synthesize, physicochemically characterize, and evaluate the in vitro cytotoxicity of a mineralized collagen–chitosan sponge containing hydroxyapatite cosubstituted with strontium (5%) and magnesium (5%). The material was obtained by precipitation of the inorganic phase, followed by polymer incorporation and lyophilization. Four groups were synthesized: pure hydroxyapatite, co-substituted hydroxyapatite, collagen–chitosan sponge, and polymeric sponge with co-substituted hydroxyapatite. The samples were characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy with energy-dispersive spectroscopy (SEM/EDS), swelling, and pH measurement. Cytocompatibility was assessed through the MTT cell viability assay. The results indicated increased thermal stability, the presence of a crystalline structure consistent with hydroxyapatite, a hydrophilic surface, and absence of cytotoxicity, with cell viability above 90% in all groups. Taken together, the findings suggest that the developed composite has potential for application as a scaffold in bone regeneration therapies.