P50 | OPTIMIZATION OF A RAPID AND EFFICIENT DECELLULARIZATION PROTOCOL FOR COMPOSITE VASCULARIZED FACIAL GRAFT FABRICATION

A. Menini¹, A. M. Sacco¹, V. Romano¹, D. Nurzynska², G. Ricci³, S. La Padula¹, F. Schonauer¹, C. Castaldo¹, F. Di Meglio¹ | ¹Department of Public Health, University of Naples «Federico II», Naples, Italy; ²Department of Medicine, Surgery and Dentistry, University of Salerno, Baronissi, Italy; ³Department of Experimental Medicine, University of Campania «Luigi Vanvitelli», Naples, Italy

Reconstruction of complex facial defects remains a significant challenge in reconstructive surgery. Current solutions, including autografts, allografts, and synthetic implants, are complicated by incomplete aesthetic, morphological, and functional recovery, lifelong immunosuppression, and limited graft survival. Decellularized cadaveric facial grafts, obtained by removing cellular components while preserving the composition and architecture of the extracellular matrix (ECM) and the vascular network, offer a promising alternative. The aim of the present study was to develop a protocol for the complete decellularization of composite facial grafts. To this end, full-thickness rat faces, including both ears, were obtained with vascular pedicles formed by the external carotid artery (ECA) and the external jugular vein (EJV), from animals sacrificed following other experimental procedures (n=4). The specimens were decellularized using a combination of SDS, Triton and antibiotics, under constant agitation. After seven days of decellularization, the blanching of the facial grafts became evident while the overall macroscopic architecture remained unchanged. Samples were then collected from each specimen and processed for histological or molecular analysis. The absence of nuclei in histological slides stained with hematoxylin and eosin and a residual dsDNA content of 12.13±2.94 ng/mg of dry tissue demonstrated the efficacy of decellularization. Furthermore, staining with Sirius Red, Masson and Mallory, immunostaining for fibronectin, laminin and tenascin, and specific quantitative assays for GAGs, collagen or elastin, demonstrated the preservation of the ECM structure and composition after decellularization. Finally, the uniform distribution of the Patent Blue V dye upon antegrade injection through the ECA and retrograde injection through the EJV demonstrated the patency of the vascular network. Overall, our results support the efficacy of the proposed decellularization protocol in producing a well-preserved, completely acellular, and vascularized facial graft in an experimental model of whole face composite graft.