Polylactide bioabsorbable polymers for guided tissue regeneration

Objective: Guided tissue regeneration is a procedure to improve tissue repair, which creates an optimal environment for the intrinsic growth ability of tissues. Methods: A prerequisite for guided tissue regeneration is the availability of materials with suitable physicochemical and bio-compatibility properties for the preparation of the devices. We investigated bone and peripheral nerve guided tissue regeneration, making two conduits from poly[L-lactide-co-6-caprolactone] (PLLC - peripheral nerve) and with poly [DL-lactide] (PDLLA - bone) with different features. After the polymer synthesis and chemical characterization, the conduits were evaluated in vivo in rat sciatic nerve gaps and in rabbit radius defects, Results: The results demonstrated good biocompatibility of both polymeric conduits, A good axonal regeneration and the restoration of the nerve trunk continuity, similar to that observed with autologous grafts has been obtained with PLLC conduits, that slowly degrade in about 6 months, PDLLA conduits protected the bone defect against the invasion of surrounding soft tissues; an effective bone growth bridging the defect was observed in their lumen. Conclusion: These results confirm the versatility of polylactides as biomaterials and will encourage further investigations on hard and soft tissues.