Optimized consolidation process at a near-room temperature of nano-hydroxyapatite and sodium silicate glass composites for bone healing applications

Abstract

ABSTRACT Hydroxyapatite nanoparticles (nHap) with chemical and structural characteristics similar to the bone mineral are widely used for orthopaedic applications. However, conventional sintering methods applied to consolidate nHap alter significantly their properties. Recently, a near-room temperature process was developed to consolidate nHap using a sodium silicate solution (SS) as a mineral binder to produce highly reactive composites. In this work, a central composite design is employed to determine the best parameters to elaborate nHap/SSG with optimized mechanical properties. The studied factors were the molar ratio of SS (n), liquid-to-solid ratio (Ls) and drying temperature (T°C). A maximum compressive strength of 24.01 MPa was achieved when composites were formulated using SS with a ratio of 1, Ls of 0.4 cm3/g and drying temperatures below 50 °C. In vitro biocompatibility of bone cells (MG-63) revealed that the optimized composite enhanced cellular proliferation and differentiation which make them a promising candidate for bone regeneration.