Biomechanical Analysis of Silk as a Tendon or Ligament Replacement.

Advances in silk-based tissue-engineered constructs offer promising opportunities to improve tendon and ligament repair by increasing graft availability and enhancing patient outcomes. The rising demand for tendon and ligament reconstruction highlights the need for biomaterials that address limitations of autografts and allografts, including donor-site morbidity, limited supply, and immune rejection risks. Silk-based scaffolds leverage their tunable biomechanical properties-such as Young's modulus, ultimate tensile strength, and strain to failure-to closely mimic native tendon and ligament function. This review synthesizes current literature on silk-derived grafts, summarizing their mechanical performance, fabrication strategies, and translational potential. Emphasis is placed on spider silk, which demonstrates exceptional tensile strength, elasticity, and biocompatibility, making it a strong candidate for next-generation scaffolds. Remaining challenges include optimizing in vivo degradation rates, enhancing tendon-to-bone (enthesis) integration, developing tunable structural and biochemical features, improving manufacturability, and validating clinical efficacy through standardized testing and robust clinical trials. Additional limitations to the application of silk as a biomaterial scaffold include high production costs, challenges associated with controlled spinning and processing, and the current lack of scalable manufacturing methods. Continued innovation and rigorous preclinical and clinical evaluation will be critical to realizing silk's potential in advancing tendon and ligament repair and improving long-term functional outcomes.