Objective To review research progress of corneal tissueengineering.Methods The recent articles on corneal tissue engineering focus on source and selection of corneal cells, the effects of growth factors on culture of corneal cells in vitro. The preparation and selection of three-dimensional biomaterial scaffolds and their b and weak points were discussed. Results The corneal tissue engineering cells come from normal human corneal cells. The embryo corneal cell was excellent. Several kinds of growth factors play important roles in culture, growth and proliferation of corneal cell, and incroporated into matrix.Growth factors including basic fibroblast growth factor, keratinocyte growth factor, transforming growth factor β1 and epidermal growth factor was favor to corneal cell. Collagen, chitosan and glycosaninoglycans were chosen as biomaterial scaffolds. Conclusion Human tissue engineering cornea can be reconstructed and transplanted. It has good tissue compatibility and can be used as human corneal equivalents.
Objective To observe the expression of p53, bcl-2 genes, vascular endothelial cell growth factor（VEGF）, basic fibroblast growth factor（bFGF）, insulin-like growth factor-I （IGF-I）, and the receptors of these factors of retinal vascular endothelial cells (VECs) of 1- to 20-week diabetic rats, and the relationship between the expressions and cell cycle arrest.Methods Retinal sections of diabetic rats induced by alloxan were immunohistochemically stained and observed by light microscopy (LM) and electron microscopy (EM). Dot blotting and Western blotting were used to determine the expression of mRNA, proteins of p53 and bcl-2. Results Under LM, immunohistochemical positive expression of p53 and bcl-2 were found on the vessels of ganglion cell layer and inner nuclear layer of retinae of 8- to 20-week diabetic rats; under EM, these substances were observed depositing in VECs. The retinal VECs also expressed VEGF, bFGF, IGF-I and their receptors. There was no positive expression of other cell types in these retinae, all cell types of retinae in control group, or all cells of retinae of diabetic rats with the course of disease of 1 to 6 weeks. The result of dot blotting revealed that retinal tissue of 20-week diabetic rat expressed p53 and bcl-2 mRNA, and the result of Western blotting revealed that they also expressed p53 and bcl-2 proteins. But retinal tissues of control group did not. Positive expression of bax was not found in the retinae in control group or 1- to 20-week diabetic rats. Conclusion p53, bcl-2 may introduce cell cycle arrest of VECs of retinae in 8- to 20-week diabetic rats. High glucose might stimulate the expression of VEGF, bFGF, IGF-I and their receptors, and the growth factors may keep VECs surviving by self-secretion. (Chin J Ocul Fundus Dis，2003，19：29-33)
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.
OBJECTIVE: To determine the influence of basic fibroblast growth factor (bFGF) on endothelial cell (EC) proliferation in vitro and its possible mechanisms, and to examine the effect of both TNP-470 and dexamethasone (Dex) on the EC proliferation induced by bFGF. METHODS: Human umbilical vein endothelial cells were cultured and the proliferation of EC was quantified by a colorimetric assay using MTT reagent. The expression of nuclear factor-kappa B (NF-kappa B) and ki-67 was detected with SABC immunohistochemical method. RESULTS: bFGF stimulated the EC proliferation and enhanced the expression of NF-kappa B and ki-67 in nucleus; TNP-470 and Dex suppressed EC proliferation induced by bFGF, and reduced the expression of NF-kappa B and ki-67 in nucleus. CONCLUSION: The above results indicate that the possible mechanisms of EC proliferation stimulated by bFGF come from that bFGF can activate NF-kappa B to promote the synthesis of DNA and EC mitosis. TNP-470 and Dex inhibited EC proliferation stimulated by bFGF by inhibiting NF-kappa B.
Objective To evaluate the effect of vascular endothelial growth factor (VEGF) on tumor angiogenesis, and its usage in tumor therapy.Methods The recent literatures about VEGF and angiogenesis were reviewed and analyzed. The advances of VEGF study were summarized. The effects of anti-angiogenesis in tumor biological therapy were introduced.Results Angiogenesis had been identified as an important factor for promoting tumor growth. VEGF was a basic and pivotal factor in tumor angiogenesis. The anti-angiogenesis treatments aimed at VEGF, including the applications of VEGF inhibitor and gene therapy of adenovirus medium, had got great progress. Conclusion VEGF is a leading factor of tumor angiogenesis, the anti-angiogenesis therapy aimed at VEGF has probably provided a new chance to malignant tumor treatment.
Objective To investigate the effect of Fujiguning Ointment and epidermal growth factor (EGF) on the wounds with bone exposed. Methods Forty-five rabbits were made the models of a 2 cm×5 cm wound on theback with exposure of 4 spinl process and vertebral lamina of thoracic vertebrae, and divided into 3 groupsaccording to different methods of therapy: Group A(Fujiguning OintmentEGF), Group B(Fujiguning Ointment) and Group C(normal saline). During experimental period of 60 days, the healing of wounds was observed and immunohistochemistry and in situ hybridization were employed to detect the expression of EGF/EGFR and EGF/EGFRmRNA in the granulation tissues. From February 2002 to May 2003, 23 cases of wounds with bone exposure werelocally treated with Fujiguning Ointment and EGF. First, Fujiguning Ointmentwas used to cover the wounds. After the granulation grew and covered the exposed bone, EGF was used to infiltrate the wound until the wound healed. Results The healing time of wounds with bone exposure was shorterin group A(30 days) than those in group B (45 dyas) and group C (60 dyas), showing statistically significant difference (Plt;0.01). EGF/EGFR increased significantly, the expression of EGF and EGF mRNA reached the peak at the 15th day, the expression of EGFR and EGFR mRNA reached the peak during the 15th and the 22nd days in the Fujiguning OintmentEGF group and Fujiguning Ointment group in comparison with normal saline group. Twentythree cases of wounds were cured and the average healing time was 51 days. Conclusion Fujiguning Ointment and EGF can promote the healing of the wounds with bone exposure.
OBJECTIVE To investigate the effects of basic fibroblast growth factor(bFGF) on repairing transected sciatic nerves in rats. METHODS The animal models of the transected sciatic nerve of 40 SD rats were established, which divided into 4 groups: normal saline (NS) group, nerve growth factor (NGF) group, bFGF group and normal control group. The epineurium of the transected sciatic nerve was sutured under microscope, then bFGF or NGF was dropped into local sites and injected intramuscularly once a day for 30 days after operation. Functional repair for the transected sciatic nerves was studied by nerve conductive velocity (NCV) and sciatic nerve function index (SFI). RESULTS As a criterion, the level of the normal control group was regarded as zero, SFI of NS group, NGF group and bFGF group were -114.30 +/- 10.34, -70.50 +/- 11.01, -50.45 +/- 7.82 respectively at 1 month after operation, and they were -54.96 +/- 16.46, -35.21 +/- 10.80, -27.53 +/- 11.23 respectively in 3 months after operation. NCV of bFGF group was significantly faster than NS group and NGF group. CONCLUSION bFGF can significantly promote the functional repair of injured peripheral nerve, and its effects are better than NGF.