Objective To observe the impact of collagen patches using 1-ethyl-3- （3-dimethylaminopropyl) carbod-iimide hydrochloride chemistry （EDC） to conjugate vascular endothelial growth factor （VEGF） ＋ basic fibroblast growth factor （bFGF） or VEGF alone on the survival rate of transplanted human bone morrow mesenchymal stem cells （hBM-MSCs）in vitro and in vivo. Methods Collagen patches which were activated by EDC were used as the control group，and EDC activated collagen patches that were conjugated with VEGF or VEGF ＋ bFGF were used as the experiment groups（VEGF group and VEGF ＋ bFGF group）. hBM-MSCs （0.5×106/patch） were used as seeding cells to construct engineered heart tissue （EHT）. MTT assay was performed to assess in vitro proliferation of hBM-MSCs on 3 different collagen patches. Ventricular aneurysm model after myocardial infarction was created by left anterior descending artery （LAD） ligation in male SD rats，and EHT which were constructed with 3 different patches were used for ventricular plasty. Four weeks later，immunofluorescence staining was used to examine arteriole density （anti-α-SMA staining） and transplanted cell survival （anti-h-mitochondria staining）. Results （1） hMSCs proliferation in VEGF group and VEGF ＋ bFGF group was significantly better than that in the control group on the 2nd and 4th day after cell transplantation （P＜0.05）； （2） Four weeks afterEHT implantation，immunofluorescence staining for α-SMA revealed that arteriole density of VEGF group and VEGF ＋ bFGF group was significantly higher than that of the control group （P＜0.05）； （3） Immunofluorescence staining forh-mitochondria showed that survival rates of transplanted hBM-MSCs of VEGF group and VEGF ＋ bFGF group were significantly higher than that of the control group （P＜0.05）； （4） There was a significantly positive correlation between survival rate of hBM-MSCs and arteriole density （r 2=0.99，P=0.02）. Conclusion VEGF or VEGF ＋ bFGF conjugated collagen patch can significantly improve hBM-MSCs proliferation in vitro and enhance survival rate of transplanted hBM-MSCs by accelerating revascularization of EHT in vivo.
ObjectiveTo investigate the feasibility of animal model of the reconstruction of right ventricular outflow tract in rats.MethodsA total of 15 female Sprague-Dawley (SD) rats underwent right ventricular outflow tract reconstruction surgery. Before the operation, the collagen scaffolds were treated with g 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride chemistry (EDC), and seeded with human bone marrow stem cells (h-MSCs). Three days after the surgery, 3 rats were randomly sacrificed to evaluate the transmural resection of right ventricular outflow tract. One or 3 months later, other 3 rats at each timepoint were sacrificed, stained with Masson’s Trichrome to observe the degradation of scaffold. Furthermore, 4 weeks after the surgery, 4 rats were sacrificed and the hearts were sliced. Anti-human mitochondria staining was used to identify the survival of seeding cells.ResultsThe transmural resection of right ventricular outflow tract was feasible in rats at an acceptable mortality (13.3%). After EDC treatment, the degradation rate of collagen scaffold was extended greatly. The seeding cells were detected by anti-mitochandria immunofluorescent staining in all patches 4 weeks after the operation.ConclusionRat model of right ventricular outflow tract reconstruction could be a stable, reliable and economical screening model for engineered heart tissue research.