Histological Comparison of Buccal and Lingual Mucosa Grafts for Urethroplasty: Do They Share Tissue Structures and Vascular Supply?

Advances in 3D bioprinting for urethral tissue reconstruction

Urethral conditions affect children and adults, increasing the risk of urinary tract infections, voiding and sexual dysfunction, and renal failure. Current tissue replacements differ from healthy urethral tissues in structural and mechanical characteristics, causing high risk of postoperative complications. 3D bioprinting can overcome these limitations through the creation of complex, layered architectures using materials with location-specific biomechanical properties. This review highlights prior research and describes the potential for these emerging technologies to address ongoing challenges in urethral tissue engineering, including biomechanical and structural mismatch, lack of individualized repair solutions, and inadequate wound healing and vascularization. In the future, the integration of 3D bioprinting technology with advanced biomaterials, computational modeling, and 3D imaging could transform personalized urethral surgical procedures.

Off-the-shelf acellular fetal skin scaffold as a novel alternative to buccal mucosa graft: the development and characterization of human tissue-engineered fetal matrix in rabbit model of hypospadiasis

AIM

In this study, we aimed to develop a novel alternative to buccal mucosal graft from the acellular human fetal skin to manage hypospadias in a rabbit model. We optimized the decellularization protocol to develop and characterize the human tissue-engineered fetal dermal matrix as an "off-the-shelf" natural biomaterial.

MATERIAL AND METHODS

Human fetal skin was obtained at 16-19 weeks gestational age with respect to a signed informed consent from parents under the university ethical committee approval. The dissected full-thickness fetal skin tissues were placed into SDS and Triton X-100 in different dosages to achieve the optimum decellularization protocol. Histopathology of the acellular fetal matrix was assessed by Hematoxylin & Eosin (H&E) and DAPI staining to confirm the removal of all cell materials, Masson's trichrome staining for collagen evaluation, DNA quantification for confirmation of DNA content, and scanning electron microscopy (SEM) for evaluation of scaffold microstructure. Immunohistochemistry (IHC) staining was used to detect specific dermal markers, namely vimentin, type I collagen, cytokeratin (CK)19. The prepared dermal scaffolds were then grafted on the 8 rabbit models of hypospadias. The rabbits underwent evaluations at 1, 2, 3, and 6 months postoperatively.

RESULTS

H&E, Masson's trichrome, DAPI staining, and SEM confirmed the significant removal of cells; meanwhile, the ECM was completely preserved. At the time of biopsy, after 2, 4, and 6 months, no evidence of inflammation, fibrosis, necrosis, or rejection was observed. The grafted dermal scaffolds appeared histologically and anatomically normal. It was observed that the scaffolds were recellularized by circulating CD 34 + bone marrow stem cells (BMSCs) inside the body, implicating the body as a natural bioreactor.

CONCLUSION

The application of acellular fetal skin (AFS) is a safe and feasible method that can decrease surgical time in a complex hypospadias reconstruction. Moreover, AFS demonstrated excellent angiogenesis characteristics and migration of the stem cells to the scaffold observed during the course of treatment. Novel natural AFS scaffold without cell seeding is an excellent alternative to buccal mucosal graft; hence, it can overcome the limitations concerning the graft size and prevent the creation of wounds in oral mucosal tissue.