| Objective:In this study, application of surgical methods on the chinese mini-swine model of acute myocardial infarction by direct injection of mesenchymal stem cells into myocardial infarct area, after feeding animals 3 months, observed the improve of heart function, the survival and transformation of stem cells in myocardial infarcted zone.Method:Miniswine were anesthetized with intramuscular administration of ketamine followed by an intravenous drip of sodium pentobarbital, and bone marrow aspirated from the anterior iliac crest was put into a syringe containing 6000u heparin, and then, was diluted with Dulbecco's PBS. MSCs were isolated from bone marrow with density gradient centrifugation and then resuspended in culture medium. The cells were incubated in a 95% humidified incubator at 37℃and 5%CO2. Medium was replaced every 3 days and adherent cells were retained until about 90% confluence. Before implantation, the cells were labeled with the cross-linkable membrane dye CM-Dil according to the protocol of the supplier. Briefly, 1-2×107 cells were incubated for 5 min at 37℃, and then for an additional 15 min at 4℃. After being washed with PBS, the cells were resuspended in 100μL saline and then kept on ice before transplantation.The ligation of the left anterior descending coronary artery (LAD) was performed on an AMI model. Miniswine was intubated under general anesthesia and positive pressure ventilation was maintained. The heart was fully exposed via a median sternotomy. Then, the LAD was ligated after three intermittent brief preconditioning occlusions. A bonus dose of lignocaine was given intravenously (1mg·kg-1) and then maintained at 1mg·min-1·kg-1 by intravenous dripping. After the successful establishment of the model, the miniswines were randomly divided into four groups (n=6 in each), Model group:The animals only established models of AMI; Saline group:AMI immediately followed by saline injection take the place of MSCs implantation; MSCs group:AMI immediately followed by MSCs implantation. Three months after operation, detection the cardiac function in each group and observation the surviving and transformation of bone marrow-derived mesenchymal stem cell by use Immunofluorescence microscopy. Result:Three months later, the ejection fraction (EF%) was significantly improvement in MSCs group (50.2±5.3 and 58.9±1.5; P<0.01) and the mass defect percentage(%) was decreased (1.95±0.22 and -1.75±0.19; P<0.05) in MSCs group compared with saline group importantly, Immunofluorescence and histochemical results confirm that transplanted MSCs still alive and part of the experiment appears to have differentiated into cardiomyocytes and vascular endothelial cells.Conclusion:Bone marrow-derived mesenchymal stem cell transplantation by injection method into myocardial infarction mothed, the cells could survive 3 months and differentiated into cardiomyocytes and vascular endothelial cells in sight, on the other hand, the same kinds of the opposite sex bone marrow mesenchymal stem cell transplantation can improve cardiac function infarction model. Objective:In recent years, the treatment of ischemic heart disease has made considerable progress; including stem cell transplantation is a promising treatment method. However, due to a lack of adequate blood supply, the low survival rate of transplanted stem cells becomes an important tissue to today's troubled clinician. In this study, application of the new invention of a larger diameter of transmyocardial drilling revascularization and basic fibroblast growth factor release anticoagulant heparin stent combined bone marrow mesenchymal stem cell transplantation for myocardial infarction, Three months after operation, cardiac function was detected functional and to explore the role of the principle of the method.Method:(1) Cultured bone marrow-derived mesenchymal stem cells:extraction mini-pig suckling pig iliac bone marrow, using density gradient centrifugation of bone marrow, cultured in vitro, and tested the phenotype. Before transplantation, the cells were stained by fluorescent dyes (DiI).(2) Established model of acute myocardial infarction, transmyocardial drilling revascularization and basic fibroblast growth factor release anticoagulant heparin stent combined bone marrow mesenchymal stem cell transplantation. Experiments were divided into four groups each of six animals, respectively, the control group, stem cell transplantation group, transmyocardial drilling revascularization and heparin stent implantation group, stem cell transplantation combined with transmyocardial drilling revascularization and heparin stent implantation group.(3) Three months after operation in each group to evaluate cardiac function, using immunohistochemistry to detect the heart infarcted zone infarct size, vascular density and the number of apoptotic cells; RT-PCR method to detect the vascular endothelial growth factor (VEGF, vWF, TGF and IL) expression in infracted region.Results:Three months later, stem cell transplantation combined with stent group compared with other groups:(1) Cardiac left ventricular ejection fraction and myocardial perfusion defects significantly improved (P<0.05).(2) The vessel density was augmented, infarct size and the number of cell apoptosis was reduced (P<0.05).(3) the expression levels of von Willebrand factor (vWF), transforming growth factor-β3 (TGF-β3), vascular endothelial growth factor (VEGF), and interleukin-1beta (IL-1β) were much higher (P<0.05).Conclusions:Transmyocardial drilling revascularization and basic fibroblast growth factor release anticoagulant heparin stent implantation can improve the therapeutic effect of stem cell transplantation in patients with acute myocardial infarction, improving pig model of acute myocardial infarction cardiac function and reduce myocardial infarct size, increasing the regional vascular density of myocardial infarction. This approach provides new ideas for clinical surgical treatment of myocardial infarction... |
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