Biotube/Biosheet as a collagen-based scaffold for vaginal reconstruction: evaluation in a rat model

Biotube/Biosheet, collagenous tissue membranes generated by in-body tissue architecture, have been used as scaffolds in various tissue engineering applications. However, their use in vaginal reconstruction has not been reported. This study aimed to evaluate the biocompatibility and potential utility of Biotube/Biosheet as scaffolds for vaginal reconstruction in a rat model. A cylindrical mold was implanted subcutaneously on the backs of rats to generate Biotube/Biosheet. Two models were established: a partial defect of the posterior vaginal wall and a complete circumferential implantation. In each model, trimmed Biotube/Biosheet was sutured into place. Rats were euthanized 4 to 14 days after surgery for macroscopic and histological evaluation. An epithelial extension from the residual vagina along the luminal surface of the Biotube/Biosheet was observed and eventually reached the vaginal orifice, resulting in complete mucosal coverage. The Biotube/Biosheet was gradually infiltrated and replaced by granulation tissue, and muscular tissue extended toward the vaginal orifice. No neutrophil or lymphocyte infiltration suggestive of acute rejection was detected. Biotube/Biosheet shows promise as a scaffold for vaginal reconstruction. Long-term follow-up studies are needed to determine whether it is fully replaced by normal vaginal tissue and whether the reconstructed vagina can support pregnancy and childbirth.