枝化状聚乙二醇交联去细胞瓣复合材料抗钙化性能研究

Anti-calcification ability of branched polyethylene glycol cross-linked decellularized valve

目的探讨枝化状聚乙二醇（PEG）交联去细胞瓣复合材料的皮下抗钙化性能。方法N-丁二酸-S-乙酰基巯基乙二醇酯（SATA）巯基化修饰去细胞瓣，以相对分子质量为20×10^3的枝化状丙烯酰化PEG交联获得复合材料（PEG组）。以戊二醛固定天然瓣（GA-NAV组）和戊二醛固定去细胞瓣（GA-DAV组）为对照。取3组瓣膜样本各18枚，植入新西兰白兔背部皮下，分别于2、4、8周取出行VonKossa染色观察钙沉积，原子吸收光谱法测定其钙含量。结果GA-NAV组钙化发生快且进展迅速，2、4、8周的钙含量依次为（22．39±1．79）、（93．05±6．08）、（174．97±8．34）μg／mg，GA-DAV组钙化程度较轻，钙含量分别为（5．57±2．11）、（31．15±5．16）、（72．54±6．50）μg／mg，而PEG组未见明显钙化发生，对应钙含量仅为（0．46±0．07）、（1．68±0．10）、（2．92±0．25）μg／mg，相同时间点组间差异有统计学意义（P〈0．05）。结论相对分子质量为20×10^3的枝化状丙烯酰化PEG交联去细胞瓣复合材料具有良好的抗钙化性能。

Objective To assess the anti-calcification ability of branched polyethylene glycol diac- rylate （PEG-DA） cross-linked porcine decellularized aortic valves （DAVs） in rabbit subcutaneous model. Methods PEG-DA with a weight of 20 kD was used to cross-link the DAVs which have been modified by SATA. Fresh native aortic valves （NAVs） and DAVs were fixed by 0. 625% glutaraldehyde buffer saline （GA） as control groups. Eighteen samples of each group were implanted subcutaneously in rabbits. Six samples of each group were taken out for calcium staining and quantitative analysis at 2nd, 4th and 8th week, respectively. Results Calcium staining showed that severe calcification appeared in GA-NAV group, and the calcium contents at 2nd, 4th and 8th week were （22. 39 ± 1.79）, （93.05 ±6. 08） and （174. 97 ± 8.34） μg/mg respectively. Mild calcification occurred in GA-DAV group, and the calcium contents at 2nd, 4th and 8th week were （5.57 ± 2. 11 ）, （31.15 ± 5.16 ） , and （72. 54 ± 6. 50） μg/mg respectively. No obvious calcification was observed in PEG group, and the calcium contents in PEG group at 2nd, 4th and 8th week were （0.46 ±0. 07） , （ 1.68 ±0. 10） and （2. 92 ±0. 25） μg/mg, respectively. There was significant difference between two groups at the same time points （ P 〈 0. 05 ）. Conclusion PEG cross-linking can remarkably inhabit the calcification of the DAVs in rabbit subcutaneous model.