Preparation of epoxy–SiO2 hybrid sol–gel material for bone cement

An organic–inorganic hybrid material, epoxy–SiO2, was prepared by incorporating epoxy structure units covalently into a SiO2 glass network via the sol–gel approach. The precursor was obtained by the reaction of diglycidyl ether of bisphenol A (DGEBA) with 3-aminopropyl trimethoxysilane (APTS). The precursor was then hydrolyzed and co-condensated with tetraethyl orthosilicate (TEOS) in tetrahydrofuran (THF) at room temperature to yield epoxy–SiO2 hybrid sol–gel material having a 50 wt % SiO2 content. Thermal properties of the hybrid material were characterized by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The hybrid sol–gel material epoxy–SiO2 was the solid, powder component of bone cement. The liquid component contains bis-phenol-A glycidyl methacrylate (Bis-GMA), triethyleneglycol dimethacrylate (TEGDMA), and methyl methacrylate (MMA) with 25, 55, and 20 vol %, respectively. We discuss the comparison between the new epoxy–SiO2 bone cement and the commercial Simplex® P bone cement. Mechanical properties such as Young's modulus, compressive strength, hardness, and impact strength of the new epoxy–SiO2 bone cement exceeded those of SimplexR P bone cement. The tensile and bending strengths of the new epoxy–SiO2 bone cement were approximately the same as those of Simplex® P bone cement. In order to evaluate the biocompatibility of the new bone cement, an MTT test and optical microscopy were conducted in cell culture. Results indicated that the new epoxy–SiO2 bone cement exhibits very low cytotoxicity compared with Simplex® P bone cement. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 64A: 138–146, 2003