New Fabrication Process of Layered Membranes Based on Poly(Lactic Acid) Fibers for Guided Bone Regeneration

Abstract

A siloxane-containing poly(L-lactic acid) (PLLA)/calcium carbonate (vaterite) hybrid (Si-PVH) shows excellent proliferation of osteoblast-like cells, which may be enhanced by continuously released silicon-species. In the present work a novel membrane for guided bone regeneration (GBR) was developed using Si-PVH. The membrane was composed of bi-layered nonwoven fabrics; the first layer consists of an Si-PVH fabric with large-sized pores for enhancing bone formation, and the second layer consists of a PLLA fabric with small-sized pores for controlling the intrusion of soft tissues and for reinforcing the mechanical strength of the brittle Si-PVH layer. These nonwoven fabrics with high porosities were prepared by an electrospinning method. The PLLA fabric was placed on the Si-PVH one, and then pressed with a stainless steel mesh heated at 150°C, resulting in the preparation of a bi-layered porous membrane with excellent flexibility. The bi-layered membrane was implanted; the Si-PVH fabric was placed in contact with 8 mm in diameter hole drilled in calvaria of 14-week old rabbits and the PLLA fabric was placed in contact with the skin; new bone formation was observed in the Si-PVH layer. The result showed that the PLLA fibers layer interrupted the intrusion of soft tissues and the Si-PVH one induced the bone formation. The bi-layered membrane is expected to be effective in GBR treatment.