The most frequent cause of death of patients with osteosarcoma is the metastasis of tumour cells. In spite of successful control of the primary tumour, the mortality of the patients due to metastatic spread is more th...The most frequent cause of death of patients with osteosarcoma is the metastasis of tumour cells. In spite of successful control of the primary tumour, the mortality of the patients due to metastatic spread is more than 30% within 5 years. 1 Recent studies about osteosarcoma metastatic mechanism are based on osteosarcoma matrilineal cell lines. 2 For further studies of metastatic mechanism of osteosarcoma the establishment of a better metastatic experimental model of osteosarcoma is needed. We isolated and established two cell sublines, with high and low metastatic potentials, respectively, derived from human osteosarcoma MG-63 cell line by cloning in vitro and transplantation in vivo , then analysed and identified their biological characteristics.展开更多
Dental implantation is an effective standard treatment modality to restore missing teeth and maxillofacial defects. However, in diabetics there is an increased risk for implant failure due to impaired peri-implant oss...Dental implantation is an effective standard treatment modality to restore missing teeth and maxillofacial defects. However, in diabetics there is an increased risk for implant failure due to impaired peri-implant osseous healing. Early topical insulin treat- ment was recently shown to normalize diabetic bone healing by rectifying impairments in osteoblastic activities. In this study, insulin/poly(lactic-co-glycolic acid) (PLGA) microspheres were prepared by a double-emulsion solvent evaporation method. Microspheres were then incorporated in fibrin gel to develop a local drug delivery system for diabetic patients requiring im- plant treatment. In vitro release of insulin from fibrin gel loaded with these microspheres was assessed, and sustained prolonged insulin release over 21 days ascertained. To assess the bioactivity of released insulin and determine whether slow release might improve impaired diabetic bone formation, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), alkaline phosphatase (ALP) activity, mineralized nodule formation, and ELISA (enzyme-linked immunosorbent assay) assays were performed. The insulin released from the drug delivery system stimulated cell growth in previously inhibited cells, and ameliorated the impaired bone-forming ability of human MG-63 cells under high glucose conditions. Fibrin gel loaded with insulin/PLGA microspheres shows potential for improving peri-implant bone formation in diabetic patients.展开更多
OBJECTIVE: To determine whether algal oligosaccharide affects the levels of parathyroid hormone 1-84(PTH1-84) and vascular endothelial growth factor(VEGF).METHODS: An osteoporosis rat model was established via bilater...OBJECTIVE: To determine whether algal oligosaccharide affects the levels of parathyroid hormone 1-84(PTH1-84) and vascular endothelial growth factor(VEGF).METHODS: An osteoporosis rat model was established via bilateral ovariectomy. The model rats were fed algal oligosaccharides(molecular weights:600-1, 200 Da) for 4 months. Bone mineral density(BMD) was then measured. MG-63 human osteoblastic cells were treated with algal oligosaccharides. The expression of PTH1-84 and VEGF was then examined. Oligosaccharide-treated cells were transfected with PTH1-84 short hairpin RNA(sh RNA), VEGF sh RNA, and PTH1-84-VEGF small interfering RNA(si RNA). The growth rates were then compared between transfected and non-transfected cells.RESULTS: Algal oligosaccharides increased the BMD of the osteoporosis rat model compared with untreated controls(P < 0.05). When MG-63 cells were treated with algal oligosaccharides, the growth rate increased by 25% compared with the control group at day 3(P < 0.05). In addition, the expression of PTH84 and VEGF was enhanced. Con-versely, when the cells were transfected with PTH84 sh RNA, VEGF sh RNA, or PTH1-84-VEGF si RNA, the growth rate was decreased by 17%, 35% and 70%, respectively, compared with controls at day 3(P < 0.05).CONCLUSION: Algal oligosaccharides ameliorate osteoporosis via up-regulation of PTH1-84 and VEGF. Algal oligosaccharides should be developed as a potential drug for osteoporosis treatment.展开更多
基金Theprojectwassupportedbythe973ProjectofChina (No 2002CB513107)
文摘The most frequent cause of death of patients with osteosarcoma is the metastasis of tumour cells. In spite of successful control of the primary tumour, the mortality of the patients due to metastatic spread is more than 30% within 5 years. 1 Recent studies about osteosarcoma metastatic mechanism are based on osteosarcoma matrilineal cell lines. 2 For further studies of metastatic mechanism of osteosarcoma the establishment of a better metastatic experimental model of osteosarcoma is needed. We isolated and established two cell sublines, with high and low metastatic potentials, respectively, derived from human osteosarcoma MG-63 cell line by cloning in vitro and transplantation in vivo , then analysed and identified their biological characteristics.
文摘Dental implantation is an effective standard treatment modality to restore missing teeth and maxillofacial defects. However, in diabetics there is an increased risk for implant failure due to impaired peri-implant osseous healing. Early topical insulin treat- ment was recently shown to normalize diabetic bone healing by rectifying impairments in osteoblastic activities. In this study, insulin/poly(lactic-co-glycolic acid) (PLGA) microspheres were prepared by a double-emulsion solvent evaporation method. Microspheres were then incorporated in fibrin gel to develop a local drug delivery system for diabetic patients requiring im- plant treatment. In vitro release of insulin from fibrin gel loaded with these microspheres was assessed, and sustained prolonged insulin release over 21 days ascertained. To assess the bioactivity of released insulin and determine whether slow release might improve impaired diabetic bone formation, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), alkaline phosphatase (ALP) activity, mineralized nodule formation, and ELISA (enzyme-linked immunosorbent assay) assays were performed. The insulin released from the drug delivery system stimulated cell growth in previously inhibited cells, and ameliorated the impaired bone-forming ability of human MG-63 cells under high glucose conditions. Fibrin gel loaded with insulin/PLGA microspheres shows potential for improving peri-implant bone formation in diabetic patients.
文摘OBJECTIVE: To determine whether algal oligosaccharide affects the levels of parathyroid hormone 1-84(PTH1-84) and vascular endothelial growth factor(VEGF).METHODS: An osteoporosis rat model was established via bilateral ovariectomy. The model rats were fed algal oligosaccharides(molecular weights:600-1, 200 Da) for 4 months. Bone mineral density(BMD) was then measured. MG-63 human osteoblastic cells were treated with algal oligosaccharides. The expression of PTH1-84 and VEGF was then examined. Oligosaccharide-treated cells were transfected with PTH1-84 short hairpin RNA(sh RNA), VEGF sh RNA, and PTH1-84-VEGF small interfering RNA(si RNA). The growth rates were then compared between transfected and non-transfected cells.RESULTS: Algal oligosaccharides increased the BMD of the osteoporosis rat model compared with untreated controls(P < 0.05). When MG-63 cells were treated with algal oligosaccharides, the growth rate increased by 25% compared with the control group at day 3(P < 0.05). In addition, the expression of PTH84 and VEGF was enhanced. Con-versely, when the cells were transfected with PTH84 sh RNA, VEGF sh RNA, or PTH1-84-VEGF si RNA, the growth rate was decreased by 17%, 35% and 70%, respectively, compared with controls at day 3(P < 0.05).CONCLUSION: Algal oligosaccharides ameliorate osteoporosis via up-regulation of PTH1-84 and VEGF. Algal oligosaccharides should be developed as a potential drug for osteoporosis treatment.
