Transplantation of bone marrow-derived endothelial progenitor cells preconditioned with ex vivo 17β-estradiol enhances healing efficacy after acute myocardial infarction / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the therapeutic efficacy of intravenous implanted bone marrow-derived endothelial progenitor cells (BM-EPC) preconditioned with 17β-estradiol in ovariectomized mice model of acute myocardial infarction (AMI).</p><p><b>METHODS</b>BM-EPC were cultured and identified from ovariectomized BALB/C mice tibia and femur. The ovariectomized BALB/C mice models of acute myocardial infarction (AMI) were established, and randomly divided into 17β-estradiol + BM-EPC group (n = 6), BM-EPC group (n = 6) and control group (n = 6). Three days after AMI, BM-EPC pretreated with or without 17β-estradiol was infused via tail vein. The equal volume of saline was infused in control group. Twenty-five days after infusion, left ventricular (LV) function and dimensions, capillary density and ratio of fibrosis area to LV area were measured.</p><p><b>RESULTS</b>LV function and dimensions, capillary density and LV fibrosis were significantly improved in 17β-estradiol + BM-EPC group than in control group [(LVDs: (3.09 ± 0.05) mm vs. (3.27 ± 0.10)mm, P < 0.05; LVDd: (4.18 ± 0.07) mm vs. (4.31 ± 0.05) mm, P < 0.05; FS: (33.0 ± 3.8)% vs. (26.0 ± 3.2)%, P < 0.05; capillary density: (1428 ± 214)/mm² vs. (1070 ± 168)/mm², P < 0.05; ratio of fibrosis: (38.8 ± 4.9)% vs. (49.0 ± 4.6)%, P < 0.05]. However, Above mentioned parameters were similar between BM-EPC group and control group (P > 0.05).</p><p><b>CONCLUSIONS</b>BM-EPC preconditioned with 17β-estradiol can enhance capillary density, decrease LV fibrosis and improve cardiac function in this mice model of AMI.</p>

Experimental study on mechanical properties of decellularized porcine aortic valve and effects of precoating methods of biological scaffold on histocompatibility / 中华外科杂志

<p><b>OBJECTIVE</b>To observe the mechanical properties of decellularized porcine aortic valve, and to explore the effects of precoating methods of biological scaffold on histocompatibility.</p><p><b>METHODS</b>Fresh porcine aortic valves were decellularized using trypsin, TritonX-100 and nuclease. Treated valves were evaluated by light microscopy, scanning electron microscopy (SEM) and mechanical test. Three groups of scaffold were precoated with phosphate buffered saline (PBS), poly-L-lysine (PLL) and fetal bovine serum (FBS) respectively. Myofibroblasts were seeded onto each scaffold. Light and electron microscopic observation was performed and MTT test was used to examine efficiency of cell attachment.</p><p><b>RESULTS</b>HE stain and SEM showed that cells were almost absent in the treated leaflet. The wave-like collagen together with the whole three-dimensional structure was maintained. Compared with normal valves, the Max-load, Max-stress and elastic modulus decreased while the Max-strain increased (P<0.05). The result of MTT test showed more cells were attached on the valves treated with FBS compared to the other two groups. Histological investigations also confirm that the high degree of cell attachment on the valves precoated with FBS (F=129.26, P=0.000).</p><p><b>CONCLUSIONS</b>Enzyme combined with detergent and nucleases can remove cells from porcine aortic valves. Meanwhile the mechanical properties of these valves may be altered. Precoating porcine aortic valve with FBS is an effective method to improve cell attachment, growth and increasing.</p>