Application of yak pericardium in anti-calcification heart valves

Objective To explore the feasibility of the application of yak pericardium as anti-calcified heart valve materials in transcatheter aortic valve replacement (TAVR). Cattle pericardium and commercial Sino products were used as controls. Methods Yak and cattle pericardium was decellularized, and then the acellular extent was qualitatively and quantitatively analyzed with hematoxylin-eosin (HE) staining and DNA detection kit respectively. Two cross-linking agents, i.e. glutaraldehyde and genipin, were used to cross-link the acellular pericardium, respectively. After testing the mechanical property, thermodynamic stability and biocompatibility of the pericardium, the cross-linked pericardium was subcutaneously implanted in juvenile Wistar rats. After 2~4 weeks of the implantation, histological staining and tissue calcification analysis were conducted. Results The nuclei of the yak pericardium were almost invisible after decellularized treatment, and the DNA content decreased from (0.90±0.13) μg/mg to (0.09±0.02) μg/mg that was significantly lower than that of Sino product (P 0.05). For the two cross-linked yak pericardium, the hemolysis rate and cell proliferation ratio was similar with that of cattle pericardium (all P>0.05), the tissue regeneration ability of subcutaneous implantations was inferior, and the calcification level was higher than that of cattle pericardium with an no statistically significant difference (all P>0.05). After 4 weeks of the subcutaneously implantation, the calcium content of the glutaraldehyde cross-linked pericardium was 32.62~65.49 μg/mg. Conclusions Yak pericardium has better mechanical properties and thermodynamic stability than cattle pericardium, and the biocompatibility can meet the requirements of transcatheter aortic valve replacement. Key words: Heart valves; Yak pericardium; Acellular matrix; Crosslinking; Anti-calcification