Synthesis of PDMS-based porous materials for biomedical applications

Polydimethylsiloxane (PDMS) and tetraethoxysilane (TEOS)-based porous organically modified silicates (ORMOSILs) for biomedical applications were synthesized through a sol-gel process, using sucrose particles as templates. These materials were characterized by Si-29 CP-MAS NMR spectroscopy, thin film X-ray diffraction, and scanning electron microscopy. Their bioactivity was evaluated using a simulated body fluid (SBF) of Kokubo recipe. These materials had a bimodal porous structure with pores of 300-500 mum and 10-50 mum in diameter. NMR showed that the silanol groups of the PDMS chain cross-linked to silica derived from the hydrolysis and condensation of TEOS. The samples containing Ca(II) exhibited apatite deposition on the pore walls within 3 days in SBF.