From Bench to Operating Room: A Comparative Study of Tensile and Puncture Tests in Self-Assembled Constructs with Clinical Feedback.

Urethral reconstruction is required for a variety of congenital and acquired conditions. Current grafting techniques rely on autologous tissues such as buccal mucosa, which are often limited by donor-site morbidity. Biomaterials could be an alternative. However, they may present immunological risks and inconsistent surgical outcomes. The tissue-engineering self-assembly approach, which uses autologous patient cells to generate tissue constructs without exogenous biomaterials, offers a promising alternative by improving graft integration. Such natural tissue-engineered constructs exhibit promising histological similarity to native urethral tissue and hold potential for clinical application. However, graft selection for surgery remains subjective, lacking standardized mechanical criteria to ensure consistent quality. Previous efforts to quantify graft properties through uniaxial tensile testing have proven informative but require cutting the tissue into standardized specimens and are therefore not readily suited to routine quality-control workflows. To address this, we investigated puncture testing as a simpler practical alternative that does not require tissue cutting and assessed its correlation with tensile testing and surgeon-based evaluation. Self-assembled dermal and urethral constructs were evaluated using uniaxial tensile and puncture tests, and results were correlated with the surgeon's qualitative assessments during graft handling. Our findings reveal a strong linear relationship between two mechanical testing techniques. Puncture testing also showed a strong relationship with surgeon-based qualitative assessments of graft handling. This study highlights the potential of puncture testing as a practical mechanical assessment tool for characterizing graft mechanical behavior in the context of surgical handling, and offers a pathway toward the development of standardized, objective quality control protocols for tissue-engineered urethral grafts prior to implantation.