Biomimetic surgical mesh to replace fascia with tunable force-displacement

Abstract

Here we mimic the mechanical properties of native fascia to design surgical mesh for fascia replacement. Despite the widespread acceptance of synthetic materials as tissue scaffolds for pelvic floor disorders, mechanical property mismatch between mesh and adjacent native tissue drives fibrosis and erosion, leading the FDA to remove several surgical meshes from the market. However, autologous tissue does not induce either fibrosis or adjacent tissue erosion, suggesting the potential for biomimetic surgical mesh. In this study, we determined the design rules for mesh that mimics native fascia by mathematically modeling multi-component polymer networks, composed of elastin-like and collagen-like fibers, using a spring-network model. To validate the model, we measured the stress-strain curves of native bovine and nonhuman primate (Macaca mulatta) abdominal fascia in both toe and linear regions. We find that the stiffer collagen-like fibers must remain limp until the elastin-like fibers extend to the initial length of spanning collagen-like fibers under uniaxial tension. Comparing model results to experiment determines the product of fiber volume fraction and elastic modulus, a critical design parameter. Dual fiber mesh with mechanical properties that mimic fascia are feasible. These results have broad application to a wide range of soft tissue replacements including ~200,000 surgeries/year for pelvic floor disorders, because standard-of-care mesh contain only stiffer polymers that behave more like collagen than native tissue.