Kubo Hirotsugu, Shimizu Tatsuya, Yamato Masayuki, Fujimoto Tetsuo, Okano Teruo
Institute of Advanced Biomedical Engineering and Science, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, Japan.
Biomaterials. 2007 Aug;28(24):3508-16. doi: 10.1016/j.biomaterials.2007.04.016. Epub 2007 Apr 18.
Regenerative medicine involving injection of isolated cells and transplantation of tissue-engineered myocardial patches, has received significant attention as an alternative method to repair damaged heart muscle. In the present study, as the next generation of myocardial tissue engineering we demonstrate the in vitro fabrication of pulsatile myocardial tubes using cell sheet engineering technologies. Three neonatal rat cardiomyocyte sheets, which were harvested from temperature-responsive culture dishes, were wrapped around fibrin tubes using a novel cell sheet-wrapping device. The tubular constructs demonstrated spontaneous, synchronized pulsation within 3h after cell sheet wrapping. Contractile force measurements showed that the contractile force increased in accordance with both increasing rest length (Starling mechanism) and increasing extracellular Ca(2+) concentration. Furthermore, the tissue-engineered myocardial tubes presented measurable inner pressure changes evoked by tube contraction (0.11+/-0.01mmHg, max 0.15mmHg, n=5). Histological analyses revealed both well-differentiated sarcomeres and diffuse gap junctions within the myocardial tissues that resembled native cardiac muscle. These data indicate that tissue-engineered myocardial tubes have native heart-like structure and function. These new myocardial tissue constructs should be useful for future applications in physiological studies and pharmacological screening, and present a possible core technology for the creation of engineered tissues capable of independent cardiac assistance.
涉及注射分离细胞和移植组织工程心肌补片的再生医学，作为修复受损心肌的替代方法已受到广泛关注。在本研究中，作为下一代心肌组织工程，我们展示了利用细胞片工程技术在体外制造搏动性心肌管。从温度响应培养皿中收获的三张新生大鼠心肌细胞片，使用一种新型的细胞片包裹装置包裹在纤维蛋白管周围。管状构建体在细胞片包裹后3小时内显示出自发、同步的搏动。收缩力测量表明，收缩力随着静息长度的增加（斯塔林机制）和细胞外Ca(2+)浓度的增加而增加。此外，组织工程心肌管呈现出由管收缩引起的可测量的内压变化（0.11±0.01mmHg，最大值0.15mmHg，n = 5）。组织学分析显示心肌组织内既有分化良好的肌节，又有弥漫性的间隙连接，类似于天然心肌。这些数据表明，组织工程心肌管具有类似天然心脏的结构和功能。这些新的心肌组织构建体应有助于未来在生理学研究和药理学筛选中的应用，并为创建能够独立提供心脏辅助的工程组织提供一种可能的核心技术。
