Control of silicon species released from poly(lactic acid)-polysiloxane hybrid membranes

Novel hybrid membranes consisting of poly(L-lactic acid) (PLLA), aminopropyltriethoxysilane (APTES), and calcium carbonates were prepared for bioresorbable guided bone regeneration. A molecular chain of PLLA was bonded at the end of an organic chain in APTES through the amide bond formed between carboxy-groups in PLLA and amino-groups in ATPES. As a result, the hybrid membrane was formed. The PLLA in the membrane was an amorphous phase. By heating the membrane at 100 degrees C for 1 h, the PLLA in the membrane crystallized and some organic chains in APTES and amide bonds decomposed. Moreover, numerous pores of 0.5-1 microm in diameter were newly formed at the surface. When the membranes before and after heat treatment were soaked in simulated body fluid, the amount of silicon species in SBF released from the membrane after heat treatment was higher than that before heat treatment. A test of osteoblast-like cellular proliferation on the membrane showed that the membrane after heat treatment has much higher cell-proliferation ability than that before heat treatment.