Biomechanical tensile behavior of human Wharton's jelly

Wharton's jelly (WJ) is a mucous connective tissue of the umbilical cord. It shows high healing capabilities, mainly attributed to the chemical composition and to the presence of stem cells, growth factors and peptides. Although WJ biological properties are well documented in vitro and in vivo, there is still a lack of mechanical data on this tissue, which is paramount for its use as a biomaterial for medical applications. In this study, mechanical responses of ten WJ samples within close physiological conditions were registered undergoing quasi static cyclic tensile tests followed by a load up to failure. This protocol aimed on one hand to provide biomechanical data to feed predictive numerical models and on the other hand increase WJ knowledge in view of its potential use in biomedical field. In spite of the WJ harvest, the resulting viscous nonlinear elastic response obtained is fully in tune with the literature confirming the database quality. A side of the knowledge improvement on WJ mechanical response, this paper provides accurate data that will enhance predictive simulation work such as finite element analysis. The mechanical step-through brought by the analytical nonlinear characterization over cyclic and ultimate loads is to predict WJ behavior. Actually, principal component analysis highlighted its quality while pointing out indicators, such as failure or hydration criteria, as well as models' limitations.