Physiological function and transplantation of scaffold-free and vascularized human cardiac muscle tissue
Physiological function and transplantation of scaffold-free and vascularized human cardiac muscle tissue
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DOI：
10.1073/pnas.0908381106
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发表时间：
2009-09-29
影响因子：
11.1
通讯作者：
Murry, C. E.
中科院分区：
文献类型：
--
作者：
Stevens, K. R.;Kreutziger, K. L.;Murry, C. E.
由于支架材料的不良影响、组织核心的坏死以及因缺血损伤而导致的移植后存活率低，人类心肌组织工程在心脏修复方面的成功受到限制。在这里，我们报道了无支架预血运人体心脏组织的发展，这种组织在体内移植后存活下来，并与宿主冠状动脉循环结合。利用激活素A和骨形态发生蛋白-4将人胚胎干细胞(HESCs)分化为心肌细胞，然后将其悬浮在旋转的轨道振荡器上，制成人心脏组织贴片。贴片培养基优化显著提高了贴片中心心肌细胞的存活率。这些补片只由丰富的心肌细胞组成，在体内植入后没有存活下来形成重要的移植物。为了验证移植后的缺血损伤将通过加速血管生成来减轻的假设，我们从心肌细胞、内皮细胞(包括人脐静脉和hESC来源的内皮细胞)和成纤维细胞中创造了“第二代”、无血运的、完全的人类补片。在功能上，与只由心肌细胞组成的补片相比，带血管的补片主动收缩，可以电起搏，并且表现出更类似于心肌的被动力学。与仅由心肌细胞组成的补片相比，植入这些补片的细胞移植物大10倍。此外，预制的人微血管与宿主大鼠冠状动脉循环吻合，并将血液输送到移植物。因此，血管和基质成分的加入提高了工程化人心肌的体外性能，并显著提高了移植后的存活能力。这些研究表明，在设计用于再生治疗的人体组织时，包括血管和基质元素的重要性。
Success of human myocardial tissue engineering for cardiac repair has been limited by adverse effects of scaffold materials, necrosis at the tissue core, and poor survival after transplantation due to ischemic injury. Here, we report the development of scaffold-free prevascularized human heart tissue that survives in vivo transplantation and integrates with the host coronary circulation. Human embryonic stem cells (hESCs) were differentiated to cardiomyocytes by using activin A and BMP-4 and then placed into suspension on a rotating orbital shaker to create human cardiac tissue patches. Optimization of patch culture medium significantly increased cardiomyocyte viability in patch centers. These patches, composed only of enriched cardiomyocytes, did not survive to form significant grafts after implantation in vivo. To test the hypothesis that ischemic injury after transplantation would be attenuated by accelerated angiogenesis, we created "second-generation,'' prevascularized, and entirely human patches from cardiomyocytes, endothelial cells (both human umbilical vein and hESC-derived endothelial cells), and fibroblasts. Functionally, vascularized patches actively contracted, could be electrically paced, and exhibited passive mechanics more similar to myocardium than patches comprising only cardiomyocytes. Implantation of these patches resulted in 10-fold larger cell grafts compared with patches composed only of cardiomyocytes. Moreover, the preformed human microvessels anastomosed with the rat host coronary circulation and delivered blood to the grafts. Thus, inclusion of vascular and stromal elements enhanced the in vitro performance of engineered human myocardium and markedly improved viability after transplantation. These studies demonstrate the importance of including vascular and stromal elements when designing human tissues for regenerative therapies.