【摘要】：心肌梗死是由于心血管局部堵塞導(dǎo)致心肌局部供血不足而引發(fā)的心肌壞死，由于心肌組織的再生潛能極其有限，而且用于心臟移植的供體器官嚴(yán)重缺乏，心肌梗死和相關(guān)的心血管疾病是全世界最首要的死亡原因。目前對心肌梗死的治療手段包括再灌注心肌、緩解疼痛、抗心律失常、抗休克、并發(fā)癥治療等，尤其是介入治療技術(shù)的突飛猛進(jìn)使很多急性心肌梗死患者避免了死亡，但臨床治療對心肌梗死后的心力衰竭仍力不從心，原因是心梗誘發(fā)的心室重構(gòu)過程中心肌細(xì)胞的缺失和細(xì)胞外基質(zhì)降解，心室壁變薄，室壁的力學(xué)性能下降，導(dǎo)致心功能降低，甚至心力衰竭的發(fā)生，因此研究用于心肌梗死治療的新策略具有重要意義。大量研究表明，利用組織工程的方法將由生物材料與心肌細(xì)胞研制的組織工程心肌或活細(xì)胞移植或注射到受影響的心肌組織中，對于改善受損心肌的功能具有重要意義，為心肌梗死的治療開辟了新的途徑。然而這種治療方案目前仍然處于動物實驗的嘗試階段。本研究針對心梗誘發(fā)的心室重構(gòu)過程中心肌細(xì)胞的缺失和細(xì)胞外基質(zhì)的降解，以海藻酸鈉水凝膠為基本材料，，分別設(shè)計體外心肌組織工程構(gòu)建3D類心肌組織和注射水凝膠的原位心肌組織工程的方案對心肌梗死的損傷進(jìn)行修復(fù)治療，取得了較好的結(jié)果，為心肌梗死的治療開辟了新的途徑。 海藻酸鈉是一種多糖類的高分子材料，因其有良好的生物相容性和抗凝血性，故在組織工程和心肌組織工程中具有廣泛的應(yīng)用，尤其作為支架材料在骨組織、心肌組織中應(yīng)用較多。鑒于心肌梗死的病理過程中心肌細(xì)胞的缺失和常規(guī)三維支架材料難以在體外構(gòu)建高密度的類心肌組織的難點，本研究采用微囊化技術(shù)在體外構(gòu)建結(jié)構(gòu)致密的三維類心肌組織。首先利用不同比例的膠原研制海藻酸鈉/膠原復(fù)合微囊，該復(fù)合微囊的細(xì)胞相容性得到顯著改善，適于原代大鼠心肌細(xì)胞的貼附和增殖。二維培養(yǎng)的心肌細(xì)胞通常增殖能力較弱，而且容易失去心肌細(xì)胞特征，而包覆于該微囊內(nèi)的心肌細(xì)胞能夠持續(xù)處于增殖狀態(tài)，且無需傳代，并維持典型心肌細(xì)胞的特征。因此，該復(fù)合微囊技術(shù)具有維持乳鼠心肌細(xì)胞持續(xù)增殖的獨特優(yōu)勢。利用該復(fù)合微囊對大鼠乳鼠原代心肌細(xì)胞進(jìn)行三維培養(yǎng)，可以持續(xù)培養(yǎng)長達(dá)3個月時間，在微囊內(nèi)形成了高細(xì)胞密度、有持續(xù)搏動功能的三維類心肌組織。為了進(jìn)一步驗證該類心肌組織在體內(nèi)的活性，將該類心肌組織植入大鼠心肌梗死的模型，6w后檢測大鼠的心功能證實，該三維類心肌組織能夠顯著改善心臟的射血分?jǐn)?shù)和梗死部位的血管再生。 心肌梗死引發(fā)的心肌細(xì)胞外基質(zhì)的缺失是導(dǎo)致心功能降低的一個關(guān)鍵問題，可注射凝膠的局部注射能改善心肌梗死區(qū)的力學(xué)性能，減少心衰的發(fā)生。由于目前多用鈣離子交聯(lián)的海藻酸鈉水凝膠，雖然有功能改善，但是鈣離子交聯(lián)的水凝膠存在著力學(xué)性能差，體內(nèi)不易降解，細(xì)胞親和力差等不足。本文采用將海藻酸鈉進(jìn)行部分氧化，得到具有活性的醛基，進(jìn)而與明膠分子中的游離氨基發(fā)生反應(yīng)形成共價交聯(lián)的水凝膠。將化學(xué)交聯(lián)的可注射的海藻酸鈉水凝膠與離子交聯(lián)的水凝膠進(jìn)行了系統(tǒng)的對比研究，共價交聯(lián)的凝膠系統(tǒng)的力學(xué)性能、降解性能和細(xì)胞親和力明顯優(yōu)于鈣離子交聯(lián)的水凝膠，從而總體上提高了心肌功能的恢復(fù)，該凝膠力學(xué)性能達(dá)到106Pa，凝固時間可調(diào)控于30-40min，孔隙率達(dá)到70%�；瘜W(xué)交聯(lián)的凝膠在體外、體內(nèi)降解率加快，植入大鼠心肌梗死模型后，心功能恢復(fù)增強(qiáng)。組織學(xué)研究表明，化學(xué)交聯(lián)的可注射凝膠在體內(nèi)增加左心室室壁厚度，促進(jìn)血管再生，并能抑制基質(zhì)金屬蛋白酶的活性。 總之，本論文針對心肌梗死的病理過程中心肌細(xì)胞損傷和細(xì)胞外基質(zhì)損傷兩個基本問題進(jìn)行了研究。針對心肌細(xì)胞的損傷設(shè)計了海藻酸鈉水凝膠三維微囊化技術(shù)成功構(gòu)建了具有持續(xù)搏動功能的類心肌組織，而針對細(xì)胞外基質(zhì)流失設(shè)計了化學(xué)交聯(lián)的可注射凝膠，并應(yīng)用于大鼠心肌梗死模型，實驗證實：三維類心肌組織和可注射凝膠均能改善梗死區(qū)的心肌功能，為心肌梗死的治療提供了新的途徑。
文內(nèi)圖片：
圖片說明：心肌梗死的發(fā)病機(jī)制[20]
[Abstract]:The myocardial infarction is the myocardial necrosis caused by the partial blood supply of the myocardium due to the partial blockage of the cardiovascular system, because the regeneration potential of the myocardial tissue is extremely limited, and the donor organ for the heart transplantation is severely deficient, Myocardial infarction and related cardiovascular diseases are the leading cause of death in the world. At present, the treatment of myocardial infarction includes the reperfusion of the myocardium, the alleviation of pain, the anti-arrhythmia, the anti-shock, the complication treatment, and the like, in particular the rapid development of the interventional treatment technology to avoid the death of many patients with acute myocardial infarction, but the heart failure of the heart failure after the myocardial infarction is still in the clinical treatment, the reason is that the loss of the myocardial cells and the degradation of the extracellular matrix during the ventricular remodeling induced by the myocardial infarction, the thinning of the ventricular wall, the mechanical property of the chamber wall are reduced, the heart function is reduced, and even the occurrence of the heart failure is caused, Therefore, it is of great significance to study the new strategy for the treatment of myocardial infarction. A large number of studies have shown that the method of tissue engineering is to transplant or inject tissue engineering myocardium or living cells developed by biological materials and myocardial cells into the affected myocardial tissue, which is of great significance for improving the function of the damaged myocardium, and opens up a new way for the treatment of myocardial infarction. However, such a treatment regimen is still at the experimental stage of the animal experiment. In this study, the loss of cardiac myocyte and the degradation of extracellular matrix in the process of ventricular remodeling induced by myocardial infarction were studied, and the sodium alginate hydrogel was used as the base material. The in-situ myocardial tissue engineering of the in vitro myocardial tissue engineering and the in situ myocardial tissue engineering of the injection hydrogel were designed to repair the myocardial infarction, and a good result was obtained, which opened up a new way for the treatment of myocardial infarction. Sodium alginate is a kind of high molecular material of polysaccharide, because it has good biocompatibility and anticoagulant effect, it has wide application in tissue engineering and myocardial tissue engineering, especially as scaffold material in bone tissue and myocardial tissue. In view of the lack of myocardial cells in the pathological process of myocardial infarction and the difficulty of the conventional three-dimensional scaffold materials in the construction of high-density myocardial tissue in vitro, this study uses the microencapsulation technology to construct a compact three-dimensional myocardial group in vitro The preparation method comprises the following steps of: firstly, developing a sodium alginate/ collagen composite microcapsule by using a different proportion of collagen, the cell compatibility of the composite microcapsule is remarkably improved, and the preparation method is suitable for the attachment and the increase of the cardiac muscle of the primary rat The two-dimensional cultured cardiomyocytes usually have weak proliferation ability and can easily lose the characteristics of the cardiac muscle cells, and the myocardial cells coated in the micro-capsules can be continuously in the proliferation state without passage, and the special cardiac muscle cells are maintained. Therefore, the composite micro-capsule technology has the unique advantages of maintaining the continuous proliferation of the neonatal rat cardiac muscle cells. a three-dimensional cardiac muscle group with high cell density and continuous beating function is formed in the microcapsule by the three-dimensional culture of the primary myocardial cells of the rat mammary rat by using the composite microcapsule, in order to further verify the activity of the myocardial tissue in the body, the myocardial tissue is implanted into the model of the rat myocardial infarction, the heart function of the rat is detected after 6w, and the three-dimensional myocardial tissue can obviously improve the ejection fraction of the heart and the blood vessel of the infarction site, The deletion of the extracellular matrix of the myocardial cells induced by myocardial infarction is a key problem in the reduction of cardiac function. The local injection of the injectable gel can improve the mechanical properties of the myocardial infarction area and reduce the heart failure. The calcium ion cross-linked hydrogel has poor mechanical property, is not easy to degrade in the body, and the cell affinity is poor due to the fact that the present multi-purpose calcium ion cross-linked sodium alginate hydrogel In this paper, the sodium alginate is partially oxidized to obtain the active aldehyde group, and then the covalent cross-linking is formed with the free amino group in the gelatin molecule. The mechanical properties, degradation performance and cell affinity of the covalently cross-linked gel system were better than that of calcium ion cross-linking. The hydrogel can improve the recovery of the myocardial function as a whole, the mechanical property of the gel reaches 106 Pa, the setting time can be controlled at 30-40 min, and the porosity is achieved. 70%. The chemical cross-linked gel is in vitro, the in vivo degradation rate is accelerated, and after the myocardial infarction model of the rat is implanted, the heart function is improved. The histological study shows that the chemical cross-linked injectable gel increases the wall thickness of the left ventricle in the body, promotes the regeneration of the blood vessel, and can inhibit the matrix metalloproteinases. In conclusion, this paper deals with two basic problems of myocardial cell injury and extracellular matrix injury in the pathological process of myocardial infarction In this paper, the three-dimensional microencapsulation of sodium alginate hydrogel was designed to successfully construct a type of myocardial tissue with the function of continuous pulsatility, and a chemical cross-linked injectable gel was designed for the loss of extracellular matrix and applied to the model of myocardial infarction in rats. The experimental results show that both the three-dimensional myocardial tissue and the injectable gel can improve the myocardial function of the infarct zone and provide the treatment for myocardial infarction.
【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2013
【分類號】：R542.22;R318.08

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 陳紅霞,高英茂,邴魯軍;急性大鼠心肌梗死實驗?zāi)Ｐ偷闹苽鋄J];中國組織化學(xué)與細(xì)胞化學(xué)雜志;2005年01期

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