TENSILE MECHANICAL PROPERTIES OF PORCINE SMALL INTESTINAL SUBMUCOSA SCAFFOLDS: EFFECT OF ORIENTATION AND NUMBER OF LAYERS

Abstract

Small intestinal submucosa (SIS) scaffolds have demonstrated excellent results in soft tissue regeneration. The objective of this study was to determine the tensile mechanical properties of dehydrated SIS scaffolds. Maximal load and deformation and ultimate strength were measured in tensile test(ASTM 882). A factorial experimental design (n=5) was used. The effect of number of layers (single(1), single overlapped(1o), two(2), and four(4) layers) and orientation (longitudinal (L), transversal (T) to the intestinal axis) was investigated. Statistical analysis was performed using ANOVA and Tukey test. Maximal load was significantly affected by the number of layers, being significantly higher in group 4L (22.1 ± 9.7N), as compared to 1L (8.4 ± 0.5N), 1oL (13.3 ± 7.0N), and 2L (10.5 ± 3.9N); and in group 4T (13.1 ± 5.9N), as compared to 1T (3.2 ± 1.0N) and 2T (3.1 ± 0.8N). In the four and two layer configurations, maximal load was significantly higher in the L direction, as compared to the T direction. Maximal deformation was not influenced by number of layers nor orientation. Ultimate strength was significantly affected by orientation being significantly higher in the L direction. In conclusion, increase in the allowed maximal load of SIS scaffolds can be obtained by using a 4-layer configuration. Orientation of the native SIS tissue affects both maximal load and ultimate strength of scaffolds. Since mechanical properties of larger scaffolds made by overlapping single-layer scaffolds are similar to those of single layer scaffolds, they can be used in lesions with large area.