Zimmermann Wolfram-Hubertus, Didié Michael, Wasmeier Gerald H, Nixdorff Uwe, Hess Andreas, Melnychenko Ivan, Boy Oliver, Neuhuber Winfried L, Weyand Michael, Eschenhagen Thomas
Institute of Experimental and Clinical Pharmacology and Toxicology, Nuremberg, Germany.
Circulation. 2002 Sep 24;106(12 Suppl 1):I151-7.
Cell grafting has emerged as a novel approach to treat heart diseases refractory to conventional therapy. We hypothesize that survival and functional and electrical integration of grafts may be improved by engineering cardiac tissue constructs in vitro before grafting.
Engineered heart tissue (EHT) was reconstituted by mixing cardiac myocytes from neonatal Fischer 344 rats with liquid collagen type I, matrigel, and serum-containing culture medium. EHTs were designed in circular shape (inner/outer diameter: 8/10 mm; thickness: 1 mm) to fit around the circumference of hearts from syngenic rats. After 12 days in culture and before implantation on uninjured hearts, contractile function of EHT was measured under isometric conditions. Baseline twitch tension amounted to 0.34+/-0.03 mN (n=33) and was stimulated by Ca(2+) and isoprenaline to 200+/-12 and 185+/-10% of baseline values, respectively. Despite utilization of a syngenic model immunosuppression (mg/kg BW: azathioprine 2, cyclosporine A 5, methylprednisolone 2) was necessary for EHT survival in vivo. Echocardiography conducted 7, 14, and 28 days after implantation demonstrated no change in left ventricular function compared with pre-OP values (n=9). Fourteen days after implantation, EHTs were heavily vascularized and retained a well organized heart muscle structure as indicated by immunolabeling of actinin, connexin 43, and cadherins. Ultrastructural analysis demonstrated that implanted EHTs surpassed the degree of differentiation reached before implantation. Contractile function of EHT grafts was preserved in vivo.
EHTs can be employed for tissue grafting approaches and might serve as graft material to repair diseased myocardium.
细胞移植已成为治疗传统疗法难以治愈的心脏病的一种新方法。我们假设，在移植前体外构建心脏组织工程结构可能会提高移植细胞的存活率、功能及电整合能力。
将新生Fischer 344大鼠的心肌细胞与I型液态胶原蛋白、基质胶和含血清培养基混合，重构工程化心脏组织（EHT）。EHT设计为圆形（内径/外径：8/10毫米；厚度：1毫米），以适应同基因大鼠心脏的周长。培养12天后，在植入未受损心脏之前，在等长条件下测量EHT的收缩功能。基线抽搐张力为0.34±0.03毫牛顿（n = 33），分别用Ca(2+)和异丙肾上腺素刺激后达到基线值的200±12%和185±10%。尽管使用了同基因模型，但为使EHT在体内存活，仍需进行免疫抑制（毫克/千克体重：硫唑嘌呤2、环孢素A 5、甲基强的松龙2）。植入后7、14和28天进行的超声心动图检查显示，与术前值相比，左心室功能无变化（n = 9）。植入后14天，EHT血管化严重，并保留了组织结构良好的心肌结构，这通过肌动蛋白、连接蛋白43和钙黏着蛋白的免疫标记得以证实。超微结构分析表明，植入的EHT超过了植入前达到的分化程度。EHT移植物的收缩功能在体内得以保留。
EHT可用于组织移植方法，可能作为移植材料修复病变心肌。
