A TISSUE-ENGINEERED CONDUIT FOR PERIPHERAL-NERVE REPAIR

Background: Peripheral nerve repair using autograft material has sever al shortcomings, including donor site morbidity, inadequate return of function, and aberrant regeneration. Recently, peripheral nerve resear ch has focused on the generation of synthetic nerve guidance conduits that might overcome these phenomena to improve regeneration. In our la boratory, we use the unique chemical and physical properties of synthe tic polymers in conjunction with the biological properties of Schwann cells to create a superior prosthesis for the repair of multiply branc hed peripheral nerves, such as the facial nerve. Objectives: To create a polymeric facial nerve analog approximating the fascicular architec ture of the extratemporal facial nerve, to introduce a population of S chwann cells into the analog, and to implant the prosthesis into an an imal model for assessment of regeneration. Results: Tubes of poly-L-la ctic acid (molecular weight, 100000) or polylactic-co-glycolic acid co polymer were formed using a dip-molding technique. They were created c ontaining 1, 2, 4, or 5 sublumina, or ''fascicular analogs.'' Populati ons of Schwann cells were isolated, expanded in culture, and plated on to these polymer films, where they demonstrated excellent adherence to the polymer surfaces. Regeneration was demonstrated through several c onstructs. Conclusions: A tubular nerve guidance conduit possessing th e macroarchitecture of a polyfascicular peripheral nerve was created. The establishment of resident Schwann cells onto poly-L-lactic acid an d polylactic-co-glycolic acid surfaces was demonstrated, and the feasi bility of in vivo regeneration through the conduit was shown. It is hy pothesized that these tissue-engineered devices, composed of widely us ed biocompatible, biodegradable polymer materials and adherent Schwann cells, will be useful in promoting both more robust and more precisel y directed peripheral nerve regeneration.