OBJECTIVE: To prepare the compound biodegradable matrices, polyglycolic acid (PGA), polylactic acid (PLA) mesh and poly-beta-hydroxybutyrate(PHB) which precoated with collagen, and to observe the growth and differentiation of bovine vascular endothelial cells on these scaffolds. METHODS: By enzymatic digestion methods, bovine vascular endothelial cell (VEC) were isolated from calf thoracic aorta, then cultured and purified. PGA, PLA, PHB meshes were dipped into cross-linked type I collagen solution, dried under vacuum frozen condition. VEC were seeded into these scaffolds. The growth of VEC on scaffolds was analyzed by MTT method. RESULTS: The collagen, PGA/collagen, PLA/collagen scaffolds were elasticity and tenacity. VEC grew better on collagen, PGA/collagen, and PLA/collagen membranes than on the PHB/collagen one. CONCLUSION: The PGA/collagen scaffold has elasticity, plasticity and tenacity. VEC grow best on it. It is an ideal scaffold for tissue engineered vessel reconstruction for it integrating both advantages of biomaterials and degradable materials.
Bone tissue regeneration and blood vessel formation are inseparable. How to realize the vascularization of bone repair scaffolds is an urgent problem in bone tissue engineering. The growth and development, mineralization maturity, reconstruction and remodeling, and tissue regeneration of bone are all based on forming an excellent vascularization network. In recent years, more and more researchers have used hydrogels to carry different cells, cytokines, metal ions and small molecules for in vitro vascularization and application in bone regeneration. Based on this background, this article reviews the hydrogel-based vascularization strategies in bone tissue engineering.
Objective To examine the effect of zinc finger protein A20 on regeneration of small-for-sized liver allograft, graft rejection and recipient rat survival time. Methods Small-for-sized liver transplantation with 30% partial liver allograft was performed by using a b-rejection combination rat model of DA (RT1a) to Lewis (RT1l) rats. The rats were grouped into rAdEasy-A20 treatment group （A20 group）, the control empty Ad vector rAdEasy treatment group (rAdEasy group) and PS control treatment group (PS group). Ex vivo gene transfer in donor liver graft was performed through portal vein infusion. Animals were assessed for survival days, expression of A20 in liver graft, liver graft regeneration, hepatocyte apoptosis, graft rejection, NF-κB activation and ICAM-1 mRNA expression in liver graft sinusoidal endothelial cells (LSECs), number of liver graft infiltrating mononuclear cells (LIMCs) and the subproportion of NK/NKT cells, and serum IFN-γ level. Results Survival day of A20 group rats was prominently longer than that of PS group rats and rAdEasy group rats (P=0.001 8), whereas survival day of rAdEasy group rats was remarkably shorter than that of PS group rats (P=0.001 8). Regeneration of the small-for-sized liver allograft was markedly augmented by A20, BrdU labelling index of hepatocyte on postoperative day 4 was significantly increased in the A20 group compared with the PS group and rAdEasy group (P＜0.01). Hepatocyte apoptosis on postoperative day 4 was significantly inhibited by A20 (P＜0.01). On postoperative day 4, histologic examination revealed a mild rejection in the A20 group but a more severe rejection in the PS and rAdEasy groups. NF-κB activity and ICAM-1 mRNA expression in LSECs on postoperative day 1 were notably suppressed by A20 overexpression. Flow cytometry analysis showed a marked downregulation of LIMCs number by A20, including more prominent decrease in the subproportion of NK/NKT cells on postoperative day 1 and 4, respectively (P＜0.05). Serum IFN-γ level on postoperative day 4 was also significantly suppressed by A20 overexpression (P＜0.05). Conclusion These data suggest that A20 could effectively promote small-for-sized liver allograft regeneration, suppresses rejection and prolong survival days of recipient rats. These effects of A20 could be related to an inhibition of LSECs activation, suppression of infiltration of LIMCs and the subpopulations such as NK cells and NKT cells into liver graft, and inhibition of hepatocyte apoptosis.
Objective To study the biological behavior of osteoblast and vascular endothelial cell culture. Methods The osteoblasts and vascular endothelial cells were obtained from calvarial bone and renal cortox of 2-week rabbits respectively. The experiment were divided into group A (osteoblasts), group B (vascular endothelial cells) and group C(co-cultured osteoblasts and vascular endothelial cells). The cells were identified with cytoimmunochemical staining. The cellular biological behavior and compatibilitywere observed under inverted phase contrast microscope and with histological staining. The cells viability and alkaline phosphatase(ALP) activity were measured. Results The cytoimmunochemical staining showed that the cultured cells were osteoblasts and vascular endothelial cells .The cellular compatibility of osteoblasts and vascular endothelial cells was good. The ALP activity was higher in group C than in group A and group B(P＜0.01), and it was higher in group A than in group B(P＜0.05). In group C, the cellproliferation were increased slowly early, but fast later. Conclusion Thecellular compatibility of osteoblasts and vascular endothelial cells were good. The vascular endothelial cells can significantly increased the osteoblast viability and ALP activity,and the combined cultured cells have greater proliferation ability.
Objective To investigate the role of vascular endothelial growth factor-C (VEGF-C) and its receptors in the formation of lymphatic vessels and lymphatic metastasis in gastric cancer. Methods By the domestic and overseas literatures review, the expressions of VEGF-C and its receptors in gastric cancer, their role in tumor lymphatic metastasis and prospect in treatment of gastric cancer were summarized.Results There was a significant correlation between VEGF-C and its receptors and the formation of lymphatic vessels and lymphatic metastasis in gastric cancer. VEGF-C high expression might be an early event in lymphatic metastasis and could be considered as an independent predictive factor of lymphaticmicrometastasis. By inhibition of gastric cancer cell from secrete VEGF-C or blockage of the interaction of VEGF-C with VEGFR3, it was possible to inhibit tumor angiogenesis and the invasion and distant spread of cancer cells, thereby decreased mortality and improve survival. ConclusionVEGF-C and its receptors may promote the formation of lymphatic vessels and lymphatic metastasis in gastric cancer. It may be an effective way to gastric cancer for the treatments against VEGF-C and its receptors.
Abstract In order to investigate the mechanism ofregeneration of lymphatic vessel, the regulatory control of various cell factors on the new born bovine lymphatic endothelial cell (NBLEC) was observed. The cell factors used for investigation were bFGF, TGFα, EGF, TNFα and IL-1α. The results showed that bFGF, TGFα and EGF could stimulate NBLEC proliferation and DNA synthesis in dosage-dependent pattern. Combined use of either two factorsdid not increase the effect, and bFGF could increase cell migration and improve the activity of tissue plasminogen activator (t-PA). TNFα and IL-α inhibited NBLEC regeneration and DNA synthesis but TNFα improved the activity of t-PA. It could be concluded that growth factor and inflammatory factor had differentrole on regeneration of NBLEC, such as cell proliferation, migration and t-PA activity. bFGF was the main factor which improved the regenerationof lymphatic endothelial cell.
Objective To study whether the porcine endothelial cells (PECs) lines transfected by HLA-G1 can alter the lysis mediated by human peripheral blood mononuclear cell (PBMC) and natural killer cell 92(NK-92). Methods By use of liposomes pack, the pcDNA3.0 eukaryotic expression vector carrying HLA-G1 was transfected into PECs. Using indirect immunofluorescence and RT-PCR assays, the HLA-G1 expression in PECs was detected. The alteration of the lysis mediated by PBMC and NK-92 was detected by51Cr-release assays. Results HLA-G1 expression could be detected in PECs after transfection of HLA-G1 at the levels of protein andRNA. It also could be found that the survival rate of transfected PECs was muchhigher than that of non-transfected PECs, when both of them faced the lysismediated by human PBMC and NK-92.After transfecting the expression of HLA-G1 could be found in the transfected PECs and the lysis mediated by PBMC and NK-92 to PECs decreased obviously (Plt;0.05). Conclusion The PECs- transfected by HLAG1 can decrease the NK lysis, so that it may provide us a new thought to inhibit the xeno-cell-rejection.
Objective To analyze the expressions of galectin-3， human bone marrow endothelial cell-1 （HBME-1），cytokeratin （CK）19， and RET in benign and malignant thyroid tumor and to discuss their clinical significances. Methods The clinicopathologic and immunohistochemical staining data of 131 patients with benign and malignant thyroid tumor were analyzed retrospectively， including 45 patients with malignant thyroid tumor， 86 patients with benign thyroidtumor. The expressions of galectin-3， HBME-1， CK19， and RET in the benign and malignant thyroid tumor were detectedby immunohistochemical staining. Results The positive expression rates of the galectin-3， HBME-1， CK19， and RET in the malignant thyroid tumor were 97.8% （44/45）， 88.9% （40/45）， 100% （45/45）， and 71.1% （32/45）， respectively，which in the benign thyroid tumor were 9.3% （8/86）， 12.8% （11/86）， 37.2% （32/86）， and 8.1% （7/86）， respectively， the differences were statistically significant （P＜0.05）. The diagnostic sensitivity， specificity， and accordance rates were 97.8 %， 90.7%， and 93.1% for the galectin-3， respectively；88.9%， 87.2%， and 87.8% for the HBME-1， respec-tively；100%， 62.8%， and 75.6% for the CK19， respectively；71.1%， 91.9%， and 84.7% for the RET， respectively. Conclusions The expression levels of galectin-3， HBME-1， CK19， and RET in malignant thyroid tumor are significantly higher than those in benign thyroid tumor. Galectin-3， HBME-1， CK19， and RET can be important factors for identifying the benign and malignant tumor and their biological behaviors. Galectin-3 has a high reference value in the diagnosis of thyroid carcinoma.
OBJECTIVE: To explore the possibility of improving the performance of tissue engineering valve by means of preendothelialization with cultured human umbilical vein endothelial cell(hUVEC) and to develop a new xenogenic bioprosthesis valve material. METHODS: The porcine aortic valves treated by use of glutaraldehyde(GA), epoxychloropropane(EC), L-glutamic acid(L-GA) and cellular extraction(CE) respectively were divided into four groups; group 1(GA), group 2(EC), group 3(EC + L-GA), and group 4(EC + L-GA + CE). The cultured hUVECs were seeded onto the treated porcine aortic valve, then that stuff were examined by means of EC VIII factor staining, living cells counting and microscopy. RESULTS: The cultured hUVEC could adhere to culturing bottle wall an hour later, and propagated to two passages after seven days. The cells increased with serial passage at a 7-day interval. But the hUVEC grew slowly when seeded onto the treated valve material except group 4. The cells in group 4 covered the surface of valve completely seven days later, which could also be seen in group 3 but not completely. There was no cell growing in group 1, and only fewer in group 2. The living cell in groups 3 and 4 were significantly more than in groups 1 and 2 on the 3rd, 7th and 14th days (P lt; 0.01), meanwhile, the number of cells in group 4 were also significantly more than that in group 3 (P lt; 0.05). The covering area of cultured cell on the valve material in groups 3 and 4 was significantly larger than that in groups 1 and 2. The covering area of cell in group 4 was over 95%, and higher than that in group 3(60%-70%). The hUVEC of group 4 arranged in pattern of three dimension. So it could resist rising of foreign power from the cardiac cavity of high pressure and flowing volume. There was no cell on the leaflet surface in group 1, and only a few pinch of cells could be seen in group 2. CONCLUSION: The porcine aortic valve can be used to be an ideal xenogeneic valve scaffold; the scaffold of porcine aortic valve should be treated by use of epoxy-chloropropane, L-glutamic acid and cellular extraction, so that a best growing environment to the hUVEC would be given; the cultured hUVECs used to be source of seed living cell had a boundless prospects; the growing velocity of cultured hUVEC was controllable, which facilitated clinical application; and the endothelial cells of xenogeneic valve material which grew compactly onto the scaffold can resist rising of foreign power from the cardiac cavity itself.
Abstract: Objective To study the expression of E-selectin on vascular endothelial cells of nude mice liver induced by esophageal carcinoma cells, in order to find out the function of E-selectin in the metastasis of esophageal carcinoma into the liver. Methods Twelve Balb/c nude mice aged from 6 to 8 weeks with their weight ranged between 20 and 25 grams were selected in our research. The mice were equally distributed into the experimental group and the control group(n=6). EC9706 cell solution (5×10.6/0.02 ml) were injected beneath the splenic capsule of the mice in the experimental group. One hour later, spleen was removed. For the mice in the control group, after laparotomy, phosphate buffer without EC 9706 was injected beneath the splenic capsule and spleen was also removed one hour after the injection. Eight hour later, we resected the liver of the nude mice, and expression of E-selectin on vascular endothelial cells of the liver was detected with reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC). Results In the experimental group, 8 hours after injection of EC9706 cells (5×10.6), the results of RT-PCR showed expression of E-selectin mRNA in the liver, and IHC showed a positive protein expression of E-selectin in the cytosol and membrane of hepatic sinus vessels.However, no E-selectin mRNA expression was found in the control group and IHC showed a negative protein expression of E-selectin. Conclusion Human esophageal carcinoma cell line EC9706 can induce balb/c mice liver vascular endothelial cell E-selectin expression, which shows that EC9706 may stay in the liver and form etastatic focus.