A simple in vivo bioassay suitable for the routine quality control testing of a new erythropoiesis stimulating protein was developed.Subcutaneous administration of the new erythropoiesis stimulating protein to Balb/c ...A simple in vivo bioassay suitable for the routine quality control testing of a new erythropoiesis stimulating protein was developed.Subcutaneous administration of the new erythropoiesis stimulating protein to Balb/c mice in a single dose resulted in a dose-dependent increase in the number of circulating reticulocytes.Within the erythropoiesis stimulating protein dose range of 3.125 to 200 ng per mouse,there is a strong linear relationship between the dose and reticulocyte counts in the treated mice.This linear relationship allows us to determine the biological potency of the testing erythropoiesis stimulating protein preparation relative to a reference standard using parallel line assay.Accuracy,precision,dose variation and blood collection time of this method were analyzed in order to choose doses in the linear range that are suitable for setting up a useful,precise,and economical bioassay.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
文摘A simple in vivo bioassay suitable for the routine quality control testing of a new erythropoiesis stimulating protein was developed.Subcutaneous administration of the new erythropoiesis stimulating protein to Balb/c mice in a single dose resulted in a dose-dependent increase in the number of circulating reticulocytes.Within the erythropoiesis stimulating protein dose range of 3.125 to 200 ng per mouse,there is a strong linear relationship between the dose and reticulocyte counts in the treated mice.This linear relationship allows us to determine the biological potency of the testing erythropoiesis stimulating protein preparation relative to a reference standard using parallel line assay.Accuracy,precision,dose variation and blood collection time of this method were analyzed in order to choose doses in the linear range that are suitable for setting up a useful,precise,and economical bioassay.
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.
