Tissue engineering in oro-maxillary bone regeneration

To synthesize a polyurethane (PU) foam-like scaffold which could perform both as a resorbable membrane and as a cavity filling material in oro-maxillary bone defects. MATERIALS & METHODS: A PU foam was synthesized via a onepot reaction starting from a pre-polymerized isocyanate and a biocompatible polyester diol, using water as a foaming agent. Different foaming conditions were examined, with the aim of creating a dense/porous functional graded material. The obtained PU was characterized in terms of morphological and mechanical properties. Biocompatibility assessment was performed in combination with bonemarrow- derived human mesenchymal stromal cells (hBMSC). RESULTS: PU showed a highly porous structure, consisting of interconnected round pores with a diameter larger than 200 μm. Degradation test showed a slow degradation (ca. 1% weight loss after 6 weeks). Mechanical properties were strongly dependent upon foaming conditions, and not significantly affected by in vitro degradation process. In vitro biocompatibility assessments combined with hBMSCs proved the materials non cytotoxic, with cell viability values higher than 95% after 24 hours. CONCLUSIONS: This work demonstrates the feasibility of fabricating biphasic dense/porous polyurethane foams by a confined foaming reaction. Results support the potential application of the synthesized materials in the treatment of oro-maxillary bone defects.