Objective To review the current status and problems in the developing scaffolds for the myocardial tissue engineering appl ication. Methods The l iterature concerning the myocardial tissue engineering scaffold in recent years was reviewed extensively and summarized. Results As one of three elements for tissue engineering, a proper scafold is veryimportant for the prol iferation and differentiation of the seeding cells. The naturally derived and synthetic extracellular matrix (ECM) materials aim to closely resemble the in vivo microenvironment by acting as an active component of the developing tissue construct in myocardial tissue engineering. With the advent and continuous refinement of cell removal techniques, a new class of native ECM has emerged with some striking advantages. Conclusion Through using the principle of composite scaffold, computers and other high-technology nano-polymer technology, surface modification of traditional biological materials in myocardial tissue engineering are expected to provide ideal myocardial scaffolds.
ObjectiveTo review the role of stem cell niches in maintaining cardiac stem cells homeostasis, and to foresee its prospects.
MethodsThe literature on cardiac stem cells niches was extensively reviewed. The roles of stem cell niches components, extracellular matrix, and secretory factors in maintaining cardiac stem cell homeostasis were analysed and reviewed.
ResultsLots of experiments reveal that stem cell niches are able to delay the aging of cardiac stem cells, protect from external damage, keep stem properties, and improve the purity and quantity. However, the mechanism is not fully understood.
ConclusionThe stem cell niches have a very bright application prospect in homeostasis, purification, and amplification for the cardiac stem cells, and it needs further study.
Objective To establish an effective model of myocardial infarction in black goat so as to provide a safe, convenient and credible model of myocardial infarction for treatment and research. Methods Sixteen black goats were made chronic myocardial infarction by ligation of far end of left anterior descending coronary artery through incision below xiphoidprocess. Electrocardiogram(ECG) and serum myocardial enzymes were investigated before and after occlusion. Echocardiographic measurements were performed, and left coronary artery angiography was performed with digital subtraction angiography (DSA) before infarction and 6 weeks after infarction. The myocardial ultrastructure were observed. Results All goats survived more than 6 weeks. ECG showed ambulatory change, ST-segment elevated half an hour after occlusion and pathologic Q waves 6 weeks after infarction, CK-MB significantly increased. Echocardiographic indexes showed significant decrease of maximal peak A, percent wall thickening(WHT) and ejecting fraction (EF), increase ofend-systolic volume (ESV), end-diastolic volume (EDV), and dilation of left ventricle. DSA showed block or decrease of perfusion of far end of left anterior descending coronary artery. Conclusion It is safe, convenient and credible to establish model of myocardial infarction by ligation of far end of left anterior descending coronary artery through incision below xiphoidprocess in black goat.
Objective To review the current status and problems in developing cardiac biological pacemaker(CBP) by cell transplantation. Methods The l iterature over the past decade concerning CBP constructed through celltransplantation was reviewed and summarized. Results Experiments in vivo testified that the cell transplantation was feasible for CBP construction, and the transplantation of sinus atrial node cell and stem cell was still the predominant method for constructing CBP. However, such problems as difficult ampl ification of transferred cardio muscle cell, low success rate of CBP construction as well as unstable function of CBP make it lag behind the tremendous cl inical demands. The gene transfection technology might be one of the approaches to resolve these issues. Conclusion As one feasible method for CBP construction, the cell transplantation has a bright future in the cl inical appl ication and is worthy of further study.
摘要: 目的 探討自體骨髓間充質干細胞(MSCs)小腸黏膜下層(SIS)支架復合物移植于陳舊性心肌梗死區域后細胞的存活、支架的降解情況及其對心功能的影響。 方法 將16只黑山羊按隨機數字表法分為兩組，每組8只。實驗組：建立心肌梗死模型，抽取自體骨髓,經體外分離MSCs,進行培養、傳代、BrdU標記、與SIS支架復合，并于心肌梗死6周時將MSCs-SIS復合物補片移植至陳舊性心肌梗死區；對照組：建立心肌梗死模型。于移植后6周行超聲心動圖、HE染色及免疫組織化學檢測。 結果 MSCs-SIS植入心肌梗死區2周時在補片區可見大量炎性細胞浸潤；6周時淋巴細胞浸潤消失，SIS部分降解，移植區見大量移植細胞存活。MSCs-SIS植入體內后6周時，實驗組每搏輸出量(42.81±4.91 ml vs. 37.06±4.75 ml)、射血分數(59.20%±5.41% vs. 44.56%±4.23%)、室壁增厚率（54.51%±8.60% vs. 43.36%±8.91%）、舒張期E峰 (54.85±6.35 cm/s vs. 43.14±4.81 cm/s)顯著高于對照組(Plt;0.05)，左心室收縮期末容積(29.75±5.98 ml vs. 46.25±6.68 ml)、舒張期末容積(72.55±8.13 ml vs. 83.31±8.61 ml)顯著低于對照組(Plt;0.05)。 結論 SIS作為支架移植MSCs有利于移植細胞存活，對陳舊性心肌梗死后心功能有明顯的改善作用。
