ABSTRACT
BACKGROUND: How to successfully obtain compact endothelium layers on smooth muscle cells is the most crucial part for the tissue-engineered vessels. OBJECTIVE: To explore the effects of different cell implantation concentrations on the construction of the complete biological tissue-engineered blood vessels.METHODS: Different concentrations of porcine vascular smooth muscle cells (5×105, 5×107 cells/L) were implanted on the porcine acellular vascular matrix to culture for 3 days. Then different concentrations of endothelial progenitor cells (5×105, 5×107 cells/L) were implanted on the smooth muscle cell-vascular matrix composite to construct lamellar complete biological tissue-engineered blood vessels.RESULTS AND CONCLUSION: The growth curves of high concentrations of smooth muscle cells on the acellular vascular matrix were similar to that of low concentrations. Moreover, the growth curves of cells implanted in the culture plates were similar to that implanted on the acellular matrix. However, cells in the low concentration groups have relatively low proliferation activity and low coverage rate. The cell coverage rate decreased as follows: high concentrations of endothelial progenitor cells+acellular matrix containing high concentrations of smooth muscle cells > high concentrations of endothelial progenitor cells+acellular matrix containing low concentrations of smooth muscle cells > low concentrations of endothelial progenitor cells+acellular matrix containing high concentrations of smooth muscle cells > low concentrations of endothelial progenitor cells+acellular matrix containing low concentrations of smooth muscle cells. Moreover, high concentrations of endothelial progenitor cells form relatively compact layers on the acellular matrix and show cobble-like growth. These findings indicate that an increase in the cell implantation concentrations is beneficial to the rapid formation of compact cell layers on the material surface.
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Objective To study the curative effect of continuous veno-venous hemodiafiltration(CVVH)in patients with acute renal failure(ARF)after aortic dissection surgery. Methods Fifteen patients with renal dysfunction following aortic dissection surgery underwent CVVH from Feb. 2002 to Dec. 2009 in this study.The clinical data of these patients were collected,such as heart rate(HR),central vein pressure(CVP),mean artery blood pressure(MAP),PaO2,renal function,perioperative manifestations and outcomes. Results Eleven patients survived but 4 died during the course of treatment. There were significant decreases of BUN,Creatinin after CVVH (P ＜ 0. 05)treatment,and the urine volume returned to nomal after CVVH in 6 -40 days. Conclusions CVVH is an effective,convenient and safe treatment for patients with severely ARF following aortic dissection surgery.
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Objective To investigate the synthesis of heat shock protein 70 (HSP70) induced by norepinephrine preconditioning on donor heart and its effects on myocardial cell apoptosis and apoptosis related proteins. Methods 18 Wistar rats were random divided into 2 groups, with 9 in each group. The rats in the control group were intraperitoneally injected with 0.5 ml saline. After 24 hours, hearts were isolated and stored with histidine-tryptophan-ketoglutarate (HTK) solution at 4 ℃ for 3 hours to establish Langendorff isolated heart models, and then isolated hearts were perfused by Langendorff model with Krebs-Hense leit (K-H) solution for 2 hours. The rats in the experimental group received intraperitoneally 3. 1 μmol/kg (0. 53 mg/kg) noradrenaline bitartrate that was dissolved in saline and hearts were isolated and stored after 24 hours. Followed process was the same as that in the control group. Myocardial HSP70, Bcl-2, Bax content, apoptosis index were measured, cell structures were observed under light and electron microscope.Results HSP70 in the experimental group were higher [(17.78 ± 1.82)%] than those in control group [(5.22 ± 1.05)%], and biochemical indicators in texperimental group[(41.88 ± 5.09)%, (22.61 ±3. 49 ) %] were better than those in control group [(31.36 ± 3. 27 ) %, ( 40. 52 ± 4. 1 7) %]. There were alleviated ultrastructure injures in experimental group compared with those in control group. Conclusions This study demonstrated that norepinephrine preconditioning could induce high expression of HSP70 and it could play a very important role during ischemia-reperfusion. It could protect the structure and function of myocytes in isolated rat hearts and inhibited myocardial apoptosis.
ABSTRACT
Vascular graft is an important component of vascular tissue engineering. In the past several decades, the scaffold materials for vascular tissue engineering have developed from simple natural materials to compound of degradable polymer and biological materials. Great progress has been made in material design and procossing. Electrospirming has been introduced to replace the manual processing. However, more work still needs to be done to make the method of design and processing more satisfactory. Main efforts should be put into the studies on improving the mechanical properties and biological functions of the scaffold materials.