Objective To study the effect of vascular endothelial cell growth factor (VEGF) on repair of bone defect with cortical bone allograft. Methods Forty five New Zealand white rabbits, weighted 2.5-3.0 kg, were made bone defect model of 1.5 cm in length in the bilateral radii and then were randomly divided into 3groups. The defect was repaired with only cortical bone allograft in the control group, with the cortical bone allograft and local injection of human recombinantVEGF in the experimental group, and with the cortical bone allograft and abdominal injection of VEGF PAb3 in the antagonist group. Roentgenography, immunohistochemical staining and tetracycline labelling were carried out to evaluate the reparative results 1, 3, 5, 8 and 16 weeks after operation. Results Immunohistochemical staining results showed that a great deal of blood vessels formed in the experimental group, and the number of blood vessels increased gradually with the time and reached the highest value at the 8th week. Tetracyclinelabelling showed the same result.The best results in callus formation, ossification rate and count of microvascular density were shown in the experimental group, while those in the control group were significantly better than those in the antagonist group (Plt;0.05),but there was no significant difference between the experimental group and the control group at the 8th week and the 16th week (Pgt;0.05). Conclusion VEGF can accelerates the bone formation and angiogenesis in the bone allografts, thus it can promote the repair of bone defects.
Objective To investigate effects of the basic fibroblast growth factor (bFGF) and fibronection (FN) on the osteoblast adhesion on the bio-derived bone. Methods The third generation of the osteoblast was treated with bFGF 0.1, 1, 10, and 100 ng/ml, respectively, and then was seeded in the bioderived bone, which had been modified with FN 0.1, 1, 10, and 100 μg/ml, or Polylysine, respectively. The cell adhesion was measured by the MTT assay. The cell density and the cell appearance were observed by the scanning electron microscope. The abovementioned procedures were repeated by an application of the GRGDS peptide. Results Both FN and bFGF could enhance the osteoblast adhesion efficiency on the bioderived bone (Plt;0.05). However, the osteoblast adhesion efficiency could be significantly strengthened bya combined use of FN and bFGF. FN and bFGF had a significant synergistic effectin statistics (Plt;0.01), but Polylysine and bFGF had no such synergistic effect (P＞0.05). The combined use of FN and bFGF had a better effect on the cell density and the cell appearance than either of them when observed with the scanning electron microscope. Adhesion efficiency generated by the combined use of FN and bFGF was significantly blocked by the application of the GRGDS peptide. Conclusion The combined use of FN and bFGF has a significant synergistic effect on the osteoblast adhesion efficiency on the bioderived bone. This effect is probably mediated by the RGD-integrin α5β1 pathway.
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 To evaluate the effect of composite (bFGF/PDPB) of basic fibroblast growth factor（bFGF） and partially deproteinized bone (PDPB) on the repair of femoral head defect. Methods Forty-eight femoral heads with defect derived from 24 New Zealand rabbits were divided into 3 groups at random, which were implanted with bFGF/PDPB(group A), PDPB(group B) and nothing(group C) respectively.The rabbits were sacrificed at 2,4,and8 weeks after operation, and then the femoral heads were obtained. The specimens injected with Chinese ink were created. Then X-ray examination, histopathological and morphological examination of blood vessel, and image analysis were made. Results The bone defects healed completely 8 weeks after operation in group A. The implants in the repaired tissue were not substituted completely in group B. The bone defects did not heal completely in group C. Two weeks after operation, affluent newly formed vessels were seen in repaired areas in groupA. No significant difference between group A and group B was observed 8 weeks after operation. In group C, newly formed vessels were scarce 2, 4, and 8 weeks after operation. There were 3 sides rated excellent, 2 good and 1 fair in group A; 1 excellent, 2 good, 2 fair and 1 poor in group B; and 1 fair and 5 poor in group C according to the X-ray evaluation 8 weeks after operation. Eight weeks after operation, the volume fraction of bone trabecula in repaired tissue was higher in group A than that in group B (Plt;0.05), and the fraction in group C was thelowest among the 3 groups (Plt;0.05). Conclusion The composite ofbFGF and PDPB can effectively promote the repair of femoral head defect of rabbit.
Objective To construct a mammalian expression vector ofbasic fibroblast growth factor (bFGF) and to investigate the expression of bFGFin vitro and in vivo. Methods A mammalian expression vector pcDNA3.1/myc-His(-)C-bFGF was constructed with gene cloning technique. The mammalian expression system was prepared and purified. The expression of bFGF cDNAin cultured transfected cells was examined by RT-PCR and cell immunohistochemistry. The recombinant plasmids, pcDNA3.1/myc-His(-)C-bFGF and pCD2-VEGF121, were transferred into rabbit cervical muscle by direct injection of plasmid following electric pulses in vivo. The transferred gene expression and the biological effect were measured by use of histochemistry and immunohistochemistry analysis. Results The eukaryon expression system pcDNA3.1/myc-His(-)C-bFGF could express the target protein bFGF in vitro. The recombinant plasmids, pcDNA3.1/myc-His(-)C-bFGF and pCD2-VEGF121 were transferred into muscles flap in vivo successfully. The active proteins bFGF and VEGF121were expressed at high levels. Blood vessels increased significantly in the muscles, and blood circulation was improved by local angiogenesis. Conclusion Theeukaryon expression vector of bFGF is constructed and can be expressed successfully in vitro and in vivo. That is a primary preparation for the research on tissue transplantation and tissue engineering with bFGF gene therapy.
Abstract To observe the effect of fibroblast growth factor (FGF) on wound healing, 50 mice were divided into 5 groups. On the back of every mouse, 2 wounds were made by operative cuts, one for experiment and the other for control. The wounds of the experimental group were covered with 0.5ml FGF solution (contented FGF 300 μg/ml, heparin 100 μg/ml), whereas the wounds of the control group were covered with 0.5ml 0.9% NaCl solution. All of the wounds were dressed by sterilized gauze, and received the same treatment once a day. After 1,3,5,7,10 days, the mice in every group were sacrificed and the tissues of the wounds were collected and prepared for microscopic examination. The results showed that the capillaries and fibroblasts in the experimental group were markedly increased and reached the peak 2～3 days earlier than those in the control group. It was suggested that FGF promoted the formation of granulation tissue and the wound healing.
OBJECTIVE This paper aims to explore the new method of continuous delivery of epidermal growth factor to wounds by transfected fibroblasts to promote wound repair. METHODS It was constructed a novel chimeric expression plasmid in which the biologically active portion of the human epidermal growth factor (EGF) gene was fused in-frame to the human granulocyte colony-stimulating factor signal sequence. RESULTS Clonally selected human fibroblasts transfected with this construct could secrete biologically active EGF. After the transplantation of irradiated gene-transfected fibroblasts suspended in fibrin glue to murine full-thickness wounds, EGF could be demonstrated for at least seven days in the wounds, slowly decreasing from initially 470 ng/L to 140 ng/L in 7 days. No EGF was found in the wound at 14 days. CONCLUSION A single application of irradiated EGF gene transfected fibroblasts to wounds can continuously deliver the transgene in vivo and can be used to administer drugs to the wound bed during the crucial first seven days of wound-healing.
OBJECTIVE To observe the effect of recombinant human epidermal growth factor (rhEGF) on healing of chronic ulcer wound. METHODS From January 1999 to January 2001, twenty-six patients with chronic wounds were adopted in this study. Among them, there were 17 males and 9 females, aged from 12 to 61 years. The area of the chronic wound varied from 3 cm x 3 cm to 5 cm x 8 cm and the disease course was 7 to 16 days. These patients were treated with rhEGF in the way of sprinkling locally (400 U/10 cm2). Another 26 patients with chronic wounds were adopted as the control group and were treated with 0.9% saline in the same way. The healing time of wounds and the local and systemic reactions of patients were observed. RESULTS The healing time of chronic wounds was shorter obviously to about 7 days with rhEGF than that of the control group and there was significant difference between the two groups(P lt; 0.01). CONCLUSION rhEGF can obviously promote the healing of chronic ulcer wound.
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.