Synthesis and characterization of biopolymer incorporated with 45S5 bioglass doped with lithium and magnesium through sol–gel method for biomedical applications

Abstract The development of biocompatible and bioactive materials is essential for the advancement of regenerative medicine. Biocomposites of chitosan incorporated with pure and lithium- and magnesium-doped 45S5 bioglasses were developed by the sol–gel process for biomedical applications. The bioglass was synthesized from tetraethyl orthosilicate (TEOS), triethyl phosphate (TEP), calcium nitrate tetrahydrate, and sodium carbonate, with the addition of lithium and magnesium nitrates at concentrations of 1, 2, 5, and 10% by mass. After gel formation, the samples were dried at 60 °C and heat treated at 700 °C, dispersed in a 1% chitosan solution, freeze-dried, and neutralized. The samples were characterized using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), biodegradation studies, and cytotoxicity tests. The results indicated that higher concentrations of dopants increased mass loss and crystallinity. FTIR analyses revealed that metal ions served as network modifiers, with magnesium also acting as an intermediary, promoting more significant structural reorganizations. Thermal analyses indicated multistage decomposition and greater stability of the polymeric phase in the undoped samples. Lithium doping enhanced hydration and structural stability, while magnesium introduced greater disorder in the glass network, potentially increasing bioactivity. Swelling tests showed greater water absorption in the doped samples, the 10% formulations achieving the highest values, up to 260%. All samples exhibited nearly complete degradation in phosphate buffer solution after 28 days. Cytotoxicity assays demonstrated high cell viability (> 95%) for all compositions, with Li-doped samples showing values up to 101± 5%. The developed biocomposites may represent a promising alternative for tissue engineering applications.