Optimized bioactive glass/PLA nanocomposites for bone tissue engineering: balancing mechanical strength and biodegradability
Razie Moradi, Majid Vaseghi, Majid Sohrabian, Hamid Reza Vanaei
Abstract
Bioactive glass (BG)/polylactic acid (PLA) nanocomposites have gained significant attention for bone repair applications due to their mechanical and biological properties. In this study, sol-gel-derived bioactive glass nanoparticles (nBG) with a mean diameter of 53.38 nm were surface-modified with (3-Aminopropyl) triethoxysilane (APTES) to ensure uniform dispersion within the PLA matrix. Composite materials containing 0, 2, 8, and 16 wt% of surface-modified bioactive glass nanoparticles (m-nBG) were synthesized using a solvent-evaporation method. The composites’ mechanical properties (tensile and flexural), degradation rate, hydrophilicity, and cellular responses were evaluated. The addition of 2 wt% m-nBG significantly improved the mechanical performance, achieving a tensile strength of 37.14 MPa and a flexural strength of 72.2 MPa. However, increasing the filler content beyond this threshold resulted in agglomeration, leading to a reduction in mechanical strength, though the tensile modulus continued to rise with higher nanoparticle loading. Biodegradation tests showed that m-nBG fillers accelerated the degradation process, with higher filler concentrations further promoting matrix degradation and increasing water absorption. The 2 wt% m-nBG nanocomposite exhibited optimal cell viability, proliferation, and attachment, highlighting its potential for bone tissue engineering applications. These findings suggest that a balanced nanoparticle content enhances both mechanical integrity and biological activity in PLA-based composites.