Magnetic particle labeling of bone marrow-derived mononuclear cells and magnetic resonance imaging after autologous transplantation / 中国组织工程研究

ABSTRACT

BACKGROUND:Among many transplanted cells,adult autologous bone barrow-derived mononuclear cells have beenused in clinical practice because they are easy to be obtained,without immunological rejection and ethical disputationand other advantages.How to distinguish donor cells from receptors and observe the survival of donor cells following stem cell transplantation still trouble people.OBJECTIVE: superparamagnetic iron oxide (SPIO)particles-labeled bone marrow-derived mononuclear cells from minipigs were used to observe the feasibility of in vivo tracking with magnetic resonance imaging(MRI).DESIGN:A controlled observation experiment.SETTING:Institute of Cardiovascular Disease,Zhongda Hospital Affiliated to Southeast University.MATERIALS:This experiment was carried out in the Institute of Cardiovascular Disease,Zhongda Hospital Affiliated to Southeast University between April 2006 and August 2006.Healthy Chinese minipigs,aged 3 to 4 months,weighing from 20 to 30 kg,were provided by the Experimental Animal Center of Southeast University[SYXK(Su)2002-0012].METHODS: Autologous bone marrow-derived mononuclear cells of minipigs were isolated and cultured. Bone marrow-derived mononuclear cells in the suspension were traced with SPIO particles.Ferrum in the cells were shown by Prussian blue staining, and cell viability was evaluated by trypan blue exclusion method. Eleven minipigs used for preparation of model of myocardial infarction were divided into experimental group(n=9)and control group(n=2).By means of percutaneous left or right cervical artery or femoral artery puncturation, 1.5 to 2.0 mm balloon was used to occlude 1/3 left anterior descending branch,304 to 405 kPa,60 minutes later,ischemic preconditioning was conducted 3 tO 4 times before operation. When pig models of myocardial infarction were successful that was proved by surface electrocardiogram,bone marrow-derived mononuclear cells were percutaneously injected into coronary artery.Coronary arteriography was performed through femoral artery acupuncture at 24 hours after establishing infarction models.Suspension of bone marrow-derived mononuclear cells was perfused into coronary artery with OTW catheter.Then,the injector and OTW catheter for containing cells were rinsed with normal saline containing heparin and infused with the residual cells within 10 minutes.Non-labeled cells were perfused in 2 minipigs of control group by the same method.Postoperatively, bone marrow-derived mononuclear cells were traced by magnetic resonance and compared with Prussian blue-stained myocardial tissue sections.RESULTS: Seven minipigs of experimental group and one minipig of control group were Involved in the final analysis.One of each group was used for preparation of model of myocardial Infarction.One minipig of experimental group died from anesthetic accident before magnetic resonance.①Bone marrow-derived mononuclear cells all were nearly labeled by SPIO particles. Bone marrow-derived mononuclear cells could further proliferate in culture medium containing Fe2O3-PLL without obvious changes of cellular shape. ②T2+WI showed that 5 of 8 models of myocardial infarction presented fuzzy low-echo signal region in peripheral myocardial infarction after transplantation of labeled cells and the low-echo signal disappeared 4 weeks Iater. Ex vivo T2+WI sequence showed there was a dot-distributed low-echo signal region in the peripheral infarction region.③It was found in histological examination that 5 models(cell number over 106) had Prussian blue-positive cells,which distributed the same as those in magnetic resonance signal reducing region.CONCLUSION:SPIO particles-labeled bone marrow-derived mononuclear cells are safe and effective;T2+ WI is sensitive to tracing SPIO particles-labeled bone marrow-derived mononuclear cells;Magnetic resonance can in vivo trace SPIO particles-labeled stem cells transplanted through coronary artery,magnetic resonance signal change is related with the number of stem cells and division growth.