Porcine heart bioengineering with a novel selective decellularization protocol for immune tolerance induction: preliminary results

The critical shortage of donor hearts and the limitations of current mechanical circulatory support devices highlight the need for alternative strategies to address advanced heart failure. Although cardiac xenotransplantation and whole-heart bioengineering have gained interest, several issues still have to be addressed. In the attempt of reducing xenograft immunogenicity and optimizing compatibility, selective endothelial decellularization of the coronary vessels has therefore emerged as a promising approach, aiming to remove donor endothelial cells while preserving myocardial architecture and enabling subsequent repopulation with recipient-derived endothelial cells. However, this technique has never been applied to an intact porcine heart. This proof-of-concept study aimed to develop an ex-vivo model for selective decellularization of the coronary vasculature in whole porcine hearts. Four hearts were perfused via cannulation of the aortic root using a controlled circuit, applying variable concentrations of sodium dodecyl sulfate (SDS) or trypsin as decellularizing agents, followed by rinsing with different washing solutions: saline, distilled water, or hypothermic Buckberg cardioplegia. Histological and immunofluorescence analyses were performed on samples of the coronary arteries and ventricular myocardium to assess endothelial cell removal and tissue preservation. Across all experiments, SDS perfusion achieved the most effective qualitative and quantitative endothelial decellularization of large-caliber coronary arteries, while maintaining the integrity of the internal elastic lamina, extracellular matrix, and myocardial structure. The hypothermic cardioplegic washout protocol demonstrated the highest efficacy, with marked loss of endothelial nuclei and decreased expression of CD31, with no evidence of myocardial cell depletion nor damage to the surrounding tissues. These findings provide preliminary evidence that selective endothelial decellularization of whole porcine heart coronary arteries is feasible using SDS under controlled hypothermic conditions. This model may represent an essential step toward generating immunologically compatible xenogeneic hearts through subsequent autologous endothelial repopulation. Further studies are required to standardize the protocol, evaluate the effects on the microvascular compartment, and explore effective recellularization strategies.