Constructing a heparin-modified penile decellularized scaffold to improve re-endothelialization in organizational reconstruction

Background: Due to the unique anatomy and complex function of the penis, the reconstruction of penile defect is fraught with great challenges. The current standard methods are limited by numerous complications and insufficient donor sites. While functional vascularized penile tissue engineering offers a novel way to ackiress this problem, revascularization remains the primary concern. Methods: In this study, a penile scaffold with associated modifications was constructed. The performance of decellularized penile scaffolds (DPSs) was improved by conjugation with heparin (HEP) and reseeding with human umbilical vein endothelial cells (HUVECs). There were three groups according to the modifications, including native DPSs, HEP-DPSs, HEP- HUVECs-DPSs. After perfusing with 1% Triton X-100/0.1% ammonium hydroxide solution, the cellular components were removed. Subsequently, the covalent binding of heparin in the DPSs was performed with 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide/N-hydroxysuccinimide, followed by reseeding with HUVECs. Scaffolds were implanted into the backs of rats and the implanted tissues were harvested at 1, 2, 3, and 4 weeks. Then hematoxylin and eosin (H&E) staining and immunofluorescence assays were performed to assess the degree of angiogenesis. Results: The native DPSs retained the extracellular matrix and heparinized modification. The H&E results indicated that more HUVECs covered the inner surface of tubular structures in the HEP-DPSs group compared to the native DPSs group. The number of vessels in the HEP-HUVECs-DPSs was significantly increased compared to the control scaffolds at all time points. Conclusions: These results suggested that, compared to the native DPS, heparin-conjugated scaffolds provided a superior environment for the growth of HUVECs and the modified methods provided a perspective for overcoming the obstacles in tissue engineering of transplantable penile tissues and the establishment of a functional vasculature.