ABSTRACT
BACKGROUND:The auditory ossicle chain reconstruction is stil an important method to treat conductive deafness. Although a great variety of materials have been applied, the blood supply of otosteon after the implantation is ignored. Moreover, there is no real bone formed. OBJECTIVE:To observe the angiogenesis of vascular endothelial growth factor and col agen I modifiedβ-tricalcium phosphate porous scaffold which is implanted into the otocyst of guinea pig. METHODS:Total y 60 guinea pigs were randomly divided into experimental group (vascular endothelial growth factor and col agen I modifiedβ-tricalcium phosphate porous scaffold), col agen I control group (col agen I modifiedβ-tricalcium phosphate porous scaffold) and blank control group (β-tricalcium phosphate porous scaffold). The guinea pigs were executed under anesthesia at weeks 1, 2, 3, 4 respectively. The surface of scaffolds was observed by scanning electron microscopy. The angiogenesis of scaffolds were observed by hematoxylin-eosin staining and CD34 immunohistochemistry staining, and then the microvascular density was counted. The osteogenesis of the scaffolds was observed by toluidine blue staining. RESULTS AND CONCLUSION:Endothelial cel proliferation and lumen formation could be observed after 1 week in the experimental group, and the angiogenesis reach the peak after 3 weeks with traffic branches formedbetween micropores. In the other two groups, the lumen formed at 2 weeks but no traffic branches were visible. The sprouting of new blood vessels in the pores were observed more in the experimental group than the other two groups (P<0.05). The adherence and proliferation of cel s could be examined in the surface and pores of the scaffold by scanning electron microscope. After 4 weeks, the osteogenesis could be observed by toluidine blue staining, especial y in the experimental group. These findings suggest that the vascular endothelial growth factor and col agen I modifiedβ-tricalcium phosphate porous scaffold can realize an effective vascularization in the environment of guinea pigs’ middle ear. What’s more, the scaffold also can promote bone formation.
ABSTRACT
BACKGROUND:Mesenchymal stem celltransplantation promoted skin repair in trauma via various regulatory mechanisms and inhibited scar formation. At present, many scholars believed that bioactive factors secreted by mesenchymal stem cells played an important role. OBJECTIVE:To investigate the effects of bone marrow mesenchymal stem cellconditioned medium on the proliferation and col agen synthesis of hypertrophic scar fibroblasts. METHODS:Human bone marrow mesenchymal stem cells and hypertrophic scar fibroblasts were isolated and cultured, and bone marrow mesenchymal stem cellconditioned medium was prepared. Hypertrophic scar fibroblasts were cultured in vitro with 12, 24, and 48 hour-col ected conditioned medium for 24 hours, which was compared with blank control group. The proliferation of cells was determined by CCK-8. Type I and type III col agen expression in hypertrophic scar fibroblasts was detected using real-time PCR. RESULTS AND CONCLUSION:Compared with the blank control group, 24 and 48 hour-col ected conditioned medium significantly inhibited the proliferation of hypertrophic scar fibroblasts (P<0.01), and also suppressed col agen synthesis of hypertrophic scar fibroblasts (P<0.01). Results suggested that bone marrow mesenchymal stem cellconditioned medium inhibited the proliferation and col agen synthesis of hypertrophic scar fibroblasts by secreting anti-fibrotic bioactive factors, which may provide new theoretical supports for celltherapy to reduce cutaneous scarring.
ABSTRACT
BACKGROUND:Experiments have shown that the col agen substrate has the capability of stimulating cartilage generation, but the stimulating role of different types of col agen substrates remains controversial. OBJECTIVE:To investigate the effect of type I and type II col agen on the biological characteristics of human chondrocytes cultured in vitro. METHODS:Human chondrocytes at passage were cultured onto the ordinary culture plates (ordinary plate), type I col agen-coated culture plates (type I plate), and type II col agen-coated culture plates (type II plate). cellgrowth curves were determined by MTT method after cells were cultured for 10 days. By ELISA, PCR, and 1,9-dimethyl methyleneblue technology, type I and type II col agen and glycosaminoglycan contents were quantitatively detected in cartilage cells 28 days after culture. RESULTS AND CONCLUSION:The number of cartilage cells was the highest in type II plate, which was twice of that in type I plate and five times of that in ordinary plate. Cartilage cells in type II plate secreted the least amount of type I col agen, which showed significant differences compared with the ordinary plate (P0.01). Cartilage cells in type II plate secreted the most amount of type II col agen and glycosaminoglycan, showing significant differences compared with the other two plates (P<0.01). The cartilage cells cultured in col agen plates are better than that cultured in ordinary culture plate, type II col agen culture plate is better than type I col agen culture plate in maintaining cellshape, extending the dedifferentiation pattern, and promoting celldifferentiation.