Laboratory for Cardiovascular Tissue Engineering, Department of Cardiac Surgery, Ludwig - Maximilian University Munich, Germany.
Laboratory for Cardiovascular Tissue Engineering, Department of Cardiac Surgery, Ludwig - Maximilian University Munich, Germany.
J Mech Behav Biomed Mater. 2021 Jun;118:104432. doi: 10.1016/j.jmbbm.2021.104432. Epub 2021 Mar 11.
Bovine pericardium - native, fixed as well as decellularized - is one of the most common implant materials in modern cardiovascular surgery. Although used in everyday procedures, there are no recommendations in regard to which part of the pericardium to prefer. It was the aim of this study, to identify areas of the pericardium with consistent properties and high durability.
Fresh bovine pericardia were collected from a local slaughterhouse. The native pericardia were analyzed at 140 spots in regard to thickness and fiber orientation. Based on these results, five promising areas were selected for further evaluation. The pericardia were decellularized with detergents (0.5% sodiumdesoxycholate/0.5% sodiumdodecylsulfate) and subsequently incubated in DNAse. The two investigation groups native und DC consisted of 20 samples each. The efficiency of the decellularization was evaluated by DNA quantification, as well as DAPI and H&E staining. Biomechanical properties were determined using uniaxial tensile tests. To evaluate the microstructure, scanning electron microscopy, Picrosirius Red- and Movat's Pentachrome staining were utilized. To assess the long-term durability, patches were tested in a high-cycle system for a duration equaling the stress of three months in-vivo. Commercially available, fixed pericardium patches served as control group.
Only a limited part of the pericardium showed a homogenous and usable thickness. The decellularization removed all cell nuclei, proven by negative DAPI and H&E staining, and also significantly reduced the DNA amount by 84%. The mechanical testing revealed that two investigated areas had an inconsistent tensile strength. Microscopical observations showed that the integrity of the extracellular matrix did not suffer by the decellularization procedure. During the long-term testing, most of the pericardia slowly lost tautness, though none of them got measurably damaged. Especially one area showed no decline of tensile strength after durability testing at all. Decellularized patches and fixed patches achieved comparable results in mechanical testing and microscopical evaluation after the durability testing.
We could clearly document significant, location-based differences within single pericardia. Only one area showed consistent properties and a high durability. We highly recommend taking this into account for future implant material selections.
牛心包 - 天然的、固定的和去细胞的 - 是现代心血管外科学中最常用的植入材料之一。尽管在日常手术中使用，但对于应该选择心包的哪个部位，目前尚无建议。本研究的目的是确定具有一致特性和高耐久性的心包区域。
从当地屠宰场收集新鲜牛心包。对 140 个部位的天然心包进行厚度和纤维方向分析。基于这些结果，选择了五个有前途的区域进行进一步评估。使用去污剂（0.5%脱氧胆酸钠/0.5%十二烷基硫酸钠）对心包进行去细胞处理，然后在 DNAse 中孵育。天然和去细胞（DC）两组各包含 20 个样本。通过 DNA 定量、DAPI 和 H&E 染色评估去细胞效率。通过单轴拉伸试验测定生物力学性能。为了评估微观结构，使用扫描电子显微镜、Picrosirius Red 和 Movat 的 Pentachrome 染色。为了评估长期耐久性，将补丁在高循环系统中进行测试，持续时间等于体内三个月的应力。商业上可用的固定心包补丁作为对照组。
只有心包的有限部分显示出均匀且可用的厚度。去细胞处理去除了所有的细胞核，通过阴性 DAPI 和 H&E 染色证明，并且还显著降低了 84%的 DNA 含量。力学测试表明，两个研究区域的拉伸强度不一致。显微镜观察显示，细胞外基质的完整性没有因去细胞处理而受损。在长期测试中，大多数心包逐渐失去紧绷度，但没有一个心包明显受损。特别是一个区域在耐久性测试后，拉伸强度根本没有下降。去细胞化补丁和固定补丁在耐久性测试后的机械测试和显微镜评估中均取得了可比的结果。
我们可以清楚地记录到单个心包内存在显著的、基于位置的差异。只有一个区域具有一致的特性和高耐久性。我们强烈建议在未来的植入材料选择中考虑这一点。
