Radiopaque organic-inorganic hybrids based on poly(D,L)-lactide

Hybrid organic-inorganic nanocomposites were prepared starting from α,ω-triethoxysilane-terminated poly(D,L)-lactic acid to be used as potential radiopaque biocompatible coatings for medical devices. The synthesis of the organic phase precursors of given chain length was achieved via anionic polymerization of (D,L)-lactide using a bi-functional initiator and subsequent triethoxysilane functionalization of end groups. PDLLA-based ceramers were then synthesized by the sol-gel process at room temperature (RT) in the presence of different amounts of tetraethoxysilane. The RT-synthesised hybrids were then cured (at 80°C or 130°C) and their thermal and viscoelastic properties were investigated. All obtained hybrids were optically transparent, due to the nanometric dimension of the silica particles, and yielded clearly contrasted radiographic images.