Masuda Noriyasu, Sekine Hidekazu, Niinami Hiroshi, Shimizu Tatsuya
Department of Cardiovascular Surgery, Tokyo Women's Medical University, Tokyo, Japan.
Institute of Advanced Biomedical Engineering and Science, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan.
Heart Vessels. 2020 Jun;35(6):859-867. doi: 10.1007/s00380-019-01550-7. Epub 2020 Jan 2.
Implantable organ-like grafts made using tissue engineering techniques could potentially be used as circulatory assist devices in people with heart failure. The aims of this study were to engineer implantable, thick cardiac tubes by the stepwise transplantation of cardiac cell sheets onto intestinal mesentery and confirm that these cardiac tubes exhibited pulsatile activity and generated an internal pressure. Cell sheets were created by culturing neonatal rat cardiac cells on temperature-responsive dishes. After harvesting, three cell sheets were stacked, and the triple-layered cell sheet was rolled around a section of endotracheal tube. The resulting construct was cultured to generate a cardiac tube. In the single-step group (n = 6), a cardiac tube was implanted onto the intestinal mesentery of a rat. In the double-step group (n = 6), a cardiac tube was implanted onto the intestinal mesentery of a rat, and another new cardiac tube was inserted into the original cardiac tube one day later. The pulsations and internal pressures of the implanted cardiac tubes were evaluated 1, 2 and 4 weeks after transplantation. Histology and immunohistochemistry were used to confirm whether vasculature was present in the cardiac tubes at 4 weeks after transplantation. We found that the cardiac tubes developed spontaneous pulsations from 1 week after transplantation. The average internal pressures of the cardiac tubes at 4 weeks after transplantation were 1.8 ± 1.0 mmHg in the single-step group and 2.5 ± 0.3 mmHg in the double-step group. The cardiac tubes in the double-step group contracted in response to electrical stimulation at 4 weeks after transplantation. Histological and immunohistochemical analyses revealed engraftment of the transplanted cardiac cell sheets and neovascularization of the cardiac tubes in both groups. Our findings demonstrate that it is feasible to generate functional cardiac tubes using the mesentery as a vascular bed. Further development of this technique will include the creation of a thicker tube, transplantation of the tube into major vessels and evaluation of the function of the tube under physiological conditions.
利用组织工程技术制造的可植入类器官移植物，有可能用作心力衰竭患者的循环辅助装置。本研究的目的是通过将心肌细胞片逐步移植到肠系膜上，构建可植入的厚心脏管，并证实这些心脏管具有搏动活性并能产生内压。通过在温度响应培养皿上培养新生大鼠心肌细胞来制备细胞片。收获后，将三张细胞片堆叠起来，然后将三层细胞片围绕一段气管导管卷绕。将所得构建体进行培养以生成心脏管。在单步组（n = 6）中，将一根心脏管植入大鼠的肠系膜。在双步组（n = 6）中，将一根心脏管植入大鼠的肠系膜，一天后再将另一根新的心脏管插入原来的心脏管。在移植后1、2和4周评估植入心脏管的搏动和内压。在移植后4周，使用组织学和免疫组织化学方法确认心脏管中是否存在血管。我们发现心脏管在移植后1周开始出现自发搏动。移植后4周，单步组心脏管的平均内压为1.8±1.0 mmHg，双步组为2.5±0.3 mmHg。双步组的心脏管在移植后4周对电刺激有收缩反应。组织学和免疫组织化学分析显示，两组移植的心肌细胞片均已植入，心脏管均有新生血管形成。我们的研究结果表明，以系膜作为血管床来生成功能性心脏管是可行的。该技术的进一步发展将包括制造更厚的管子、将管子移植到大血管中以及评估管子在生理条件下的功能。
