Improving the bioactivity of bioglass/ (PMMA-co-MPMA) organic/inorganic hybrid

Binary system of CaO-SiO₂ glasses enables the apatite formation in simulated body fluid (SBF). However, the presence of phosphate content in SiO₂-CaO-P₂O₅ glasses leads to the formation of orthophosphate nanocrystalline nuclei, which facilitates the generation of carbonate hydroxyapatite; this compound is more compatible with natural bone. The brittle and less flexible properties of bioactive glasses are the major obstacle for their application as bone implant. The hybridization of essential constituents of bioactive glasses and glass-ceramics with polymers such as PMMA can improve their poor mechanical properties. The aim of this study was to improve the bioactivity of nanocomposites fabricated from poly(methyl metacrylate) (PMMA) and bioglass for bone implant applications. Bioglass compounds with various phosphate contents were used for the preparation of PMMA/bioglass hybrid matrices. Since the lack of adhesion between the two phases impedes the homogenous composite formation, a silane coupling agent such as 3-(trimethoxysilyl)propyl methacrylates (MPMA) was incorporated into the polymer structure. The effect of addition of MPMA on the molecular structure of composite was investigated. Furthermore, the presence of MPMA in the system improved the homogeneity of sample. Increasing phosphate content in the inorganic segment of hybrid up to 10 mol% resulted in the formation of apatite layer on the surface; hence the hybrid was bioactive and suitable candidate for bone tissue engineering.