Uniaxial tensile tests and Digital Image Correlation analysis for the mechanical characterization of human Fascia Lata under different decellularization treatments

Fascia Lata (FL) is frequently employed as a graft source in reconstructive surgery. To minimize unwanted responses from the host immune system, several decellularization treatments have been proposed. Effective treatments should aim at avoiding the deterioration of the physical and mechanical properties of the implanted tissue. In this work, we carried out a mechanical characterization of FL specimens from human dead donors, both in their native-physiological condition and upon decellularization with three commonly used detergents, t-octyl-phenoxypolyethoxyethanol (Triton X-100), sodium dodecyl sulfate (SDS), and tri-n-butyl phosphate (TnBP). Uniaxial tensile tests were used to characterize the elastic stiffness and ultimate stresses of the tissue, and Digital Image Correlation (DIC) was applied to monitor the strain evolutions and meso-mechanical deformation responses. None of the investigated decellularization protocols was found to lead to a significant deterioration of the FL mechanical properties, suggesting the applicability of these chemical treatments for graft preparation and usage in the clinical practice. The application of DIC also allowed us to get a first estimate of the FL Poisson ratio as well as to draw the attention on the inhomogeneity of strain distributions, suggesting that the use of average engineering strains can lead to an oversimplification of the actual deformation field.