High-modulus and antioxidative tea polyphenol-crosslinked decellularized porcine diaphragmatic tendon patch for myocardial infarction repair

Porcine diaphragmatic tendon enables a high-modulus decellularized cardiac patch. • Tea polyphenols raise modulus to 392.6 MPa and strength to 67.8 MPa. • Crosslinking adds antioxidant activity and resistance to collagenase degradation. • GTP5 reduces implant-associated inflammation compared with uncrosslinked dECM. • The patch limits ventricular dilation and remodeling after myocardial infarction. Decellularized tissues have been widely used for tissue repair because of their intrinsic ability to modulate immune and inflammatory responses. However, their insufficient mechanical strength often limits their capacity to provide adequate structural support, thereby compromising synergistic therapeutic outcomes in applications such as myocardial and tendon repair. In this study, we developed a decellularization strategy for high-strength porcine diaphragmatic tendon, which enabled effective removal of cellular components while preserving the dense extracellular matrix structure responsible for its superior mechanical strength. After crosslinking with 5 mg/mL tea polyphenols, the resulting decellularized porcine diaphragmatic patch retained anisotropic characteristics comparable to those of native cardiac tissue and achieved a Young's modulus of 392.6 ± 96.8 MPa and an ultimate tensile strength of 67.8 ± 18.83 MPa. These values were higher than those reported for representative decellularized or acellular cardiac repair scaffolds, including decellularized porcine myocardial slices, small intestinal submucosa-derived extracellular matrix (SIS-derived ECM), decellularized pericardial scaffolds, and commercial cardiovascular patches. This strategy preserved the intrinsic mechanical strength of the diaphragmatic tendon while ensuring efficient DNA removal, enabling effective mechanical support and stress reduction in the infarcted myocardium. In addition, tea polyphenols as the crosslinking agent, conferring antioxidant properties while further enhancing the immunomodulatory and anti-inflammatory effects of the decellularized scaffold. In a rat myocardial infarction model, the tea polyphenol-crosslinked decellularized diaphragmatic tendon mitigated ventricular dilation and delayed adverse remodeling through the synergistic effects of mechanical support, antioxidation, and immunomodulation, highlighting its potential for myocardial repair and other therapeutic applications requiring both high mechanical strength and bioactivity.