Optimization of the Decellularization Process of Native Porcine Heart Valves to Obtain Cell-free Xenograft Scaffolds and Best Mechanical Properties

Background: Natural tissue-originated scaffolds derived from human or animal sources are known for their high potential for immunogenicity. Decellularized xenografts have low immunogenicity and are expected to be best tolerated by the recipient’s immune system. Less is known about the best decellularization techniques and their remaining characteristics.

Methods: We tried n = 23 different decellularization protocols (DP) on native porcine leaflets (aortic and pulmonary) in a pilot study and isolated and quantified residual DNA of each in the extracellular matrix (ECM). Out of the most efficient DP we further investigated mechanical and hemodynamic properties of the leaflet substitutes. Treated and untreated porcine aortic and pulmonary leaflets were compared.

Results: Treating ECM with Tergitol, a new eco-friendly detergent, avoidance of ionic detergents, lower trypsin concentrations, and a higher concentration of DNase and RNase in our decellularization protocols, so-called new experimental protocol (NEP), we were able to extract nearly all of the DNA content. Aortic (Ao) and pulmonary (PM) substitutes treated with NEP showed lower systolic gradients and higher valve opening areas in comparison to the native, non-treated (NT) ones.

Systolic Gradients: Ao NEP 2.58 ± 0.55 mm Hg versus AoNT4.99 ± 1.92 mm Hg; p < 0.001; PM NEP 2.40 ± 0.51 versus PM NT 3.83 ± 1.18 mm Hg; p < 0.001.

Valve Opening Area: Ao NEP 115.24 ± 37.13 mm² versus AoNT 62.84 ± 18.48 mm²; p < 0.001; PM NEP 104.61 ± 18.1 mm² versus PM NT 92.4 ± 17.92 mm²; p < 0.001.

Conclusion: This study demonstrates a new experimental protocol for untraceable cells and residual DNA, thereby maximally reducing any chance of immunogenicity. The mechanical and biochemical properties of the ECM resemble those of native heart valves. These results will profoundly support the use of tissue-engineered heart valves.

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Artikel online veröffentlicht:
11. Februar 2025