Preparation and Heat-Setting of Warp-Knitted Silk Patches for Soft Tissue Repairs

Currently, synthetic materials for soft tissue repair are non-biodegradable and rigid, while biodegradable natural polymer materials exhibit low mechanical strength. This study focuses on creating biodegradable silk patches with superior mechanical properties using warp knitting. Four kinds of silk patches were made, degummed, and their structural parameters and mechanical properties were evaluated. An orthogonal experiment was conducted to investigate the effects of heat-setting temperature and time on the patches' mechanical properties. The results show that the #D patch, with its moderate thickness and density, large and concentrated pores, high strength, and low elongation, closely resembles natural soft tissue. After heat setting at 120°C for 3 min, the mechanical properties significantly enhanced (up to 17.1%). The patch exhibited a longitudinal tensile strength of 276.81 N, transverse tensile strength of 330.73 N, burst strength of 1566.5 N, longitudinal tear strength of 307.33 N, transverse tear strength of 124.66 N, longitudinal suture pullout strength of 53.28 N, and transverse suture pullout strength of 73.89 N. This method of using warp knitting and digital weaving technology allows for the preparation of silk patches suitable for soft tissue repair, with high strength, stability, and porosity, making them ideal for tendon and rotator cuff repairs.