Improving Mechanical Properties of Vitrified Umbilical Arteries with Magnetic Warming

The damage caused by thermal stress during rewarming vitrified biosamples is one of the major obstacles for clinical purposes. Magnetic warming is a highly effective approach to overcome this hurdle and can achieve rapid and spatially homogeneous heating. The current research investigates the effects of magnetic warming on the histological and biomechanical properties of the vitrified umbilical arteries (UAs) through experiments and simulation. The results of experiments show that, for the case of magnetic warming comparing with the conventional water bath, magnetic warming presents better preservation of extracellular matrix (ECM), collagen fibers, elastic fibers, and muscle fibers of the umbilical artery. There is no significant difference between magnetothermal and fresh UAs (p > 0.05) in the elastic modulus and the ultimate stress. The theoretical results reveal that the maximum temperature difference T-max inside the biosample is 1.117 +/- 0.649 degrees C, and the maximum thermal stress sigma(max) is 0.026 +/- 0.016 MPa. However, for the case of conventional water bath, T-max is 32.342 +/- 0.967 degrees C and sigma(max) is 1.453 +/- 0.047 MPa. Moreover, we have arrived at the same conclusion by simulation as theoretical calculation have. Therefore, magnetic warming can effectively reduce the thermal stress damage of biological samples during the warming period due to more uniform and rapid warming. These results confirm that magnetothermal can significantly improve the mechanical properties of large size cryopreserved tissues or organs such as UAs.