Mechanical properties of native and decellularized aortic wall after long-term storage in biocide solutions

Abstract

Objective: to determine the optimal method for long-term wet storage of donor material (50 days after collection), with maximum ability to preserve the original mechanical characteristics.Materials and methods. Porcine aortic wall fragments were used as objects of study. Half of the original material underwent detergent-based decellularization. The entire material (native and processed) was placed for 50 days in biocidal solutions: complex alcohol solution; ethanol and glycerol mixture; antibiotics mixture. Then the tests for mechanical strength of native and decellularized samples were carried out by the method of uniaxial longitudinal and circumferential stress.Results. Storage of native material in all media resulted in a significant increase in tensile strength. In the «complex alcohol solution», «ethanol and glycerol mixture», and «antibiotic mixture» group, tensile strength increased by 1.38-, 1.72- and 1.62-fold compared to the native control in circumferential tension. Also, in the «complex alcohol solution» group, the decellularized material was 1.57-fold stronger than the native in circumferential tension. In the «antibiotic mixture» group, the decellularized material was 1.33-fold less strong than the native in longitudinal tension. According to elongation to rupture data, significantly greater plasticity was noted in the «ethanol-glycerol» storage group for the decellularized aortic wall compared to the control group (1.5-fold). Young’s modulus did not reliably differ from those of control in all experimental groups regardless of the stress direction. Notably, decellularized specimens clearly tended to be stiffer under circumferential stress.Conclusion. Detergent-based decellularization of the porcine aortic wall and subsequent storage of these samples in our chosen experimental solutions for 50 days does not significantly affect the elastic properties of the material. Our proposed treatment methods partially increase the stiffness of the material after storage in alcohol-containing solutions.

Keywords

• young’s modulus
• tensile strength
• xenografts
• bioprosthetics