Synthesis of organic-inorganic hybrids of poly (tetramethylene oxide)-calcium silicate and in vitro evaluation of their bioactivity

Bioactive organic-inorganic hybrids can be used as biomaterials for bone substitution because they exhibit osteoconduction and other functions due to their organic components, such as flexibility and bioabsorbability. In this study, we synthesized uniform organic-inorganic hybrids from triethoxysilane-functionalized poly (tetramethylene oxide) (Si-PTMO), tetraethoxysilane (TEOS) and calcium chloride (CaCl₂) via the sol-gel process. The starting composition of Si-PTMO/TEOS molar had a weight ratio ranging from 20/80 to 90/10. The CaCl₂ concentration was kept constant at a CaCl₂/TEOS molar ratio of 0.15. Uniform and transparent hybrids were obtained with a Si-PTMOJTEOS compositional range from 20/80 to 90/10. The potential bioactivity was evaluated by determining the formation of a bone-like apatite layer in simulated body fluid (SBF). Formation of a bone-like apatite layer was observed on the surface of the organic-inorganic hybrids when they were prepared from starting compositions of Si-PTMO/TEOS with weight ratios ranging from 20/80 to 50/50. An appreciable quantity of the calcium silicate is required to produce bioactive organic-inorganic hybrids.