Optimized Bio-Based Polyurethane Structure for Enhanced Durability and Biocompatibility in Artificial Ligaments.

In the field of sports medicine, especially in high-intensity sports such as football, basketball, and skiing, ligament injuries are extremely common. However, current artificial ligaments face multiple critical limitations, including suboptimal biocompatibility, limited host tissue integration, insufficient mechanical durability to withstand physiological stresses, and inadequate durability during long-term cyclic loading. To address these challenges, 1-(2-Hydroxyphenyl)-3-phenyl-2-propenone (HCC), which shared structural similarity with naturally occurring chalcones, is employed as the raw material for the chain extender, combined with HMDI and polycaprolactone diol (PCL diol), to synthesize a novel polyurethane (HCMPU). The results showed that the maximum stress of HCMPU-3 reached 42.1 MPa, with an elongation at break of up to 710%. It also demonstrated outstanding durability, maintaining structural integrity without significant degradation after 5000 loading cycles. Additionally, during the initial implantation period, its stability in an enzymatic environment can provide strong support to the human body before new tissue regeneration, making it a promising candidate for an ideal artificial ligament. Moreover, the favorable biocompatibility of HCMPUs is demonstrated through cytotoxicity testing and rat pathological staining sections. Therefore, this work demonstrated the potential of HCMPU to overcome key limitations in current artificial ligaments and advance the development of next-generation materials for ligament repair.