Clinical and Histological Evaluation of Porcine Urinary Bladder Matrix and Artificial Dermis in the Treatment of Tendon/Bone Exposed Wounds.

Abstract

Full-thickness skin defects involving tendon or bone exposure present significant clinical challenges owing to inadequate vascularity, which renders spontaneous wound healing unlikely. Conventional treatments using autologous flap transplantation may incur donor-site morbidity. Dermal substitutes are employed to enhance wound bed construction and improve skin graft survival by promoting vascularization and extracellular matrix (ECM) deposition. However, currently available substitutes are predominantly composed of purified bovine- or porcine-derived type I collagen and lack the bioactive components. Urinary bladder matrix (UBM), a naturally derived scaffold, contains a rich repertoire of ECM constituents that effectively promote the healing process, offering a potential novel approach for dermal regeneration. Nevertheless, human histological evidence on UBM in tendon/bone-exposed wounds remains limited. In this study, we compared the efficacy of UBM wound matrix (ExceFil Biological Wound Matrix, ZhuoRuan Medical Technology) with that of artificial dermal substitute (Pelnac, GUNZE Medical Division) in treating extremity wounds with tendon/bone exposure in a series of six clinical cases. Clinically, both products successfully promoted wound vascularization and graft survival. Histological analysis revealed that the UBM group exhibited superior regenerative features, including enhanced fibroblast migration, collagen deposition, neovascularization, and immunomodulatory properties, with a higher rate of M2 macrophage polarization at 15 ± 2 days post-implantation. Furthermore, RNA sequencing demonstrated that the UBM matrix significantly upregulated pathways related to cytokine-cytokine receptor interaction and chemokine signaling, both of which modulate immune and regenerative processes within the wound microenvironment. These findings suggest that UBM biological matrix represents a promising dermal substitute for promoting regenerative healing in tendon/bone-exposed wounds.