Objective To develop a new method for a tissue engineered vascular graft by combining endothelial cells and an acelluarized allogenic matrix. Methods Acellularized matrix tubes were obtained by a 0.1% trypsin and 0 02% EDTA solution for 24 hours and 1% Triton X 100 for 176 hours, respectively. Endothelial cells were isolated from alloaorta and expanded in vitro. Finally, the inner surface of acellularized matrix was reseeded with endothelial cells. Acellularity and reseeding were analysed by light microscopy and scanning electron microscopy. Results The acellularization procedure resulted in an almost complete removal of the original cells and the loose three-dimensional (3D) matrix. The acellular matrix could be reseeded with expanded endothelial cells in vitro, and endothelial cells had the potential of spread and proliferation. Conclusion Acellular matrix produces by Tritoon X-100 and trypsin possesses satisfactory biocompatibility for allogenic endothelial cell. Vascular grafts can be generated in vitro by a combination of endothelial cells and allogenic acelluarized matrix.
Objective To explore a new method of treating early avascular necrosis of femoral head (AVNFH). Methods Sixty-nine New Zealand adult rabbitswith a mean weight of 2.8 kg after AVNFH presenting were randomly divided into three groups. In group A, deproteinized bone(DPB) combined with the recombinant plasmid pcDNA3.1/vascular endothelial growth factor 165(VEGF165) was implanted in the drilled channel of the necrotic femoral head. In group B, only DPB was implanted. In group C, channel was drilled without DPB or plasmid implanted. Femoral head specimens were obtained 3 days, 1, 2, 4, 8 and 16 weeks after operation. The expression of VEGF165 was examined by RT-PCR, Western blot and immunohistochemical techniques. X-ray testedbone formation generally. Angiogenesis and repair of the femoral head were observed by histological and histomorphometric analysis. Results In group A, the expressions of VEGF165 mRNA and protein were detected 3 days postoperatively, reached apex 1 week and lasted more than 3 weeks after implantation. The ratios of IOD of collagen type Ⅰ were 0.29±0.11, 0.55±0.13 and 0.67±0.10 IOD/μm2 respectively at 2, 4 and 8 weeks postoperatively and the ratios of IOD of new capillary vessels were 0.33±0.10and 0.57±0.16 IOD/μm2 respectively at 2, 4 weeks postoperatively in group A, showing statistically significant difference (Plt;0.01) when compared with groups B and D. X-ray test indicated much bone callus formed early. Conclusion Transfection of the VEGF165 gene can enhance local angiogenesis at early stage andDPBVEGF165 compound can improve bone formation. Deproteinized bone combined with VEGF165 gene provides a potential method for therapy of osteonecrosis.
【摘要】 目的 通过比较两种原代人脐静脉内皮细胞的分离培养方法并对细胞特异性抗原进行鉴定,探索提高原代内皮细胞体外培养存活率及纯化率的方法。 方法 采用一次性无菌注射器向人脐静脉灌注消化液,消化液的浓度和消化时间分别025%(质量体积比)胰蛋白酶,10 min和01%(质量体积比)胶原酶Ⅱ,15 min。通过在倒置显微镜下观察细胞的形态特点和用免疫荧光染色的方法对细胞进行鉴定,比较两种消化方法的优劣。 结果 01%胶原酶Ⅱ,15 min的消化方法较025%胰蛋白酶,10 min对原代人脐静脉内皮细胞有更好的分离效果,活细胞数量多且细胞纯度较高。免疫荧光染色结果表明细胞内有Ⅷ因子相关抗原表达。结论 胶原酶Ⅱ可以有效分离脐静脉内皮细胞,最佳消化条件是01%胶原酶Ⅱ,37℃,15 min。【Abstract】 Objective To explore the optimal method for primary culture of human umbilical vein endothelial cells (HUVECs). Methods HUVECs were prepared from human umbilical cords by 01% collagenase Ⅱ digestion for 15 minutes and 025 trypsinase digestion for 10 minutes,respectively. HUVECs were observed under inverted microscope and identified by immunofluorescence.The two methods of digestion were compared. Results More HUVECs were harvested through the method of 01% collagenase Ⅱ for 15 minutes,which expressed Ⅷ related antigen. Conclusion The method of 0.1% collagenase Ⅱ digestion for 15 minutes is a better choice to isolate HUVECs.
In order to study the effect of vascular endothelial cell growth factor (VEGF) on the survival of skin flap 30 SD rats were used. A randomized flap measuring 7.5 cm x 3.0 cm was created on the back of each SD rat. The treatment group (n = 10) received VEGF 40 ng/flap by subcutaneous injection with microinjector during and 24 hours after operation. The control groups received heparin 16 U/flap (n = 10) or normal saline 800 microliters/flap (n = 10). After operation, on the 3rd and 11th day, the survival rate of the skin flaps and the dermovascular density of each flap were investigated by histological and histo-morphometrical examination. The results showed that there was no significant difference in the survival rate between the treatment group and the controls on the 3rd day after operation, while on the 11th day, there was a significant difference between them, and the survival rate was much higher in the treatment group. Besides, dermovascular density was much more increased in the treatment group than that in the controls, especially in the distal 1/3 of the flap (P lt; 0.02). The conclusion was that VEGF could .
Objective Glucocorticoid is the main cause of non-traumatic avascular necrosis of femoral head. To explore the changes of reactive oxygen species (ROS) in the bone microvascular endothel ial cells treated with glucocorticoid so as to investigate the pathogenesis of steroid-induced avascular necrosis of femoral head. Methods The cancellous bone of femoral head was harvested from voluntary donators undergoing total hip arthroplasty, and then the bone microvascular endothel ial cells were isolated by enzyme digestion. The cells at passage 3 were cocultured with different concentrations of hydrocortisone (0, 0.03, 0.10, 0.30, and 1.00 mg/mL) for 24 hours. MTT assay was used for the inhibitory rate of cell prol iferation, flow cytometry for apoptosis rate, and fluorescence probe for the production of ROS and xanthine oxidase (XOD). Results At 2-3 days primary culture, the cells were spindle and arranged l ike cobbles and they reached confluence after 1 week. The inhibitory rates of cell prol iferation in 0.03, 0.10, 0.30, and 1.00 mg/mL groups were 20.22% ± 2.97%, 22.94% ± 4.52%, 43.98% ± 3.35%, and 78.29% ± 3.85%, respectively; and 2 high-concentration groups (0.30 and 1.00 mg/mL groups) were significantly higher (P lt; 0.05) than 2 low-concentration groups (0.03 and 0.10 mg/mL groups). The apoptosis rates in 0, 0.03, 0.10, 0.30, and 1.00 mg/mL groups were 0.10% ± 0.01%, 0.23% ± 0.02%, 1.83% ± 0.04%, 6.34% ± 0.11%, and 15.33% ± 0.53%, respectively; 2 high-concentration groups (0.30 and 1.00 mg/mL groups) were significantly higher (P lt; 0.05) than 0 mg/mL group. In 0, 0.30, and 1.00 mg/ mL groups, the ROS levels were 57.35 ± 7.11, 120.47 ± 15.68, and 166.15 ± 11.57, respectively, and the XOD levels were 0.017 9 ± 0.000 9, 0.028 3 ± 0.001 7, and 0.067 7 ± 0.004 1, respectively; there were significant differences in the levels of ROS and XOD among 3 groups (P lt; 0.05). Conclusion Increasing of ROS production in bone microvascular endothel ial cells can be induced by high concentration glucocorticoid, and it can result in cell injury
Objective To investigate the effect of surface propertyof different polyether-ester block copolymers［poly(ethylene glycol-terephthalate)/poly(butylene terephthalate), PEGT/PBT］ on the growth of smooth muscle cells (SMCs) and endothelial cells(ECs). Methods Three kinds of copolymers were synthesized, which were 1000-T20 (group A), 1000PEGT70/PBT30 (group B) and 600PEGT70/PBT30 (group C). The water-uptake and contact angle of three polyether-ester membranes were determined. The canine aorta smooth muscle cells and external jugular vein endothelial cells were primarily harvested, subcultured, and then identified. The proliferation of SMCs and ECs on the different polyether-ester membranes were investigated. Results The water-uptake of three copolymers arranged as the sequence of group C＜group A＜group B, and contact angle as the sequence of group C＞group A＞group B, indicating group B being more hydrophilic. However, smooth musclecells andendothelial cells grew poorly on the membrane of group B after low density seeding, but proliferated well on the membranes of group A and group C. Conclusion In contrast with more hydrophilic 1000PEGT70/PBT30, moderately hydrophilic 1000-T20 and 600PEGT70/PBT30 has better compatibility with vascular cells. The above results indicate that the vascular cells can grow well on moderately hydrophilic PEGT/PBT and that PEGT/PBT can be used in vascular tissue engineering.
ObjectiveTo investigate whether exosomes derived from miR-27a-overexpressing human umbilical vein endothelial cells (HUVECs)—exo (miR-27a) can promote bone regeneration and improve glucocorticoids (GC) induced osteonecrosis of femoral head (ONFH) (GC-ONFH).MethodsThe exo (miR-27a) were intended to be constructed and identified by transmission electron microscopy, nanoparticle tracking analysis, Western blot, and real-time fluorescent quantitative PCR (qRT-PCR). qRT-PCR was used to evaluate the effect of exo (miR-27a) in delivering miR-27a to osteoblasts (MC3T3-E1 cells). Alkaline phosphatase staining, alizarin red staining, and qRT-PCR were used to evaluate its effect on MC3T3-E1 cells osteogenesis. Dual-luciferase reporter (DLRTM) assay was used to verify whether miR-27a targeting Dickkopf WNT signaling pathway inhibitor 2 (DKK2) was a potential mechanism, and the mechanism was further verified by qRT-PCR, Western blot, and alizarin red staining in MC3T3-E1 cells. Finally, the protective effect of exo (miR-27a) on ONFH was verified by the GC-ONFH model in Sprague Dawley (SD) rats.ResultsTransmission electron microscopy, nanoparticle tracking analysis, Western blot, and qRT-PCR detection showed that exo (miR-27a) was successfully constructed. exo (miR-27a) could effectively deliver miR-27a to MC3T3-E1 cells and enhance their osteogenic capacity. The detection of DLRTM showed that miR-27a promoted bone formation by directly targeting DDK2. Micro-CT and HE staining results of animal experiments showed that tail vein injection of exo (miR-27a) improved the osteonecrosis of SD rat GC-ONFH model.Conclusionexo (miR-27a) can promote bone regeneration and protect against GC-ONFH to some extent.