Fabrication of MnO₂-Modified Decellularized Tendon Membrane for Enhancing Tendon Repair

Repairing tendon/ligament injuries is a major challenge in sports medicine. It has been reported that tendon injury healing is hindered by massive production of reactive oxygen species (ROS). Manganese oxides nanoparticles are generally non-toxic, can scavenge ROS, promote tissue regeneration, and hold promise for sustainable nanotechnologies. However, the effective and safe integration of MnO₂ nanoparticles on decellularized scaffold mediating tissue repair is still a great challenge. To address these issues, an in situ MnO₂-modified decellularized scaffold is developed to enhance tendon regeneration through improving microenvironment. The decellularized fibrous membrane is designed and prepared using the central tendon of the porcine diaphragm. Then MnO₂ nanozymes are in situ grown on the collagen fibers using tannic acid (TA) as cross-linking agent and reducing agent. The results showed that MnO₂-modified scaffold eliminates excessive accumulation of ROS in cells, protects mitochondrial, and maintains the phenotype of tendon cells in an oxidative stress environment. Notably, it is found that the MnO₂-modified scaffold exhibits good biocompatibility and is able to promote the tendon healing in the rat patellar tendon defect model. Altogether, this study confirmed that this nanozyme-functionalized decellularized extracellular matrix effectively enhanced tendon repair by scavenging ROS, which provides new strategies for enhancing tendon regeneration.