Accurate tumor targeting,deep penetration and superb retention are still the main pursuit of developing excellent nanomedicine.To achieve these requirements,a stepwise stimuli-responsive strategy was developed through...Accurate tumor targeting,deep penetration and superb retention are still the main pursuit of developing excellent nanomedicine.To achieve these requirements,a stepwise stimuli-responsive strategy was developed through co-administration tumor penetration peptide iRGD with shape-transformable and GSH-responsive SN38-dimer(d-SN38)-loaded nanoparticles(d-SN38@NPs/iRGD).Upon intravenous injection,d-SN38@NPs with high drug loading efficiency(33.92±1.33%)could effectively accumulate and penetrate into the deep region of tumor sites with the assistance of iRGD.The gathered nanoparticles simultaneously transformed into nanofibers upon 650 nm laser irradiation at tumor sites so as to promote their retention in the tumor and burst release of reactive oxygen species for photodynamic therapy.The loaded d-SN38 with disulfide bond responded to the high level of GSH in tumor cytoplasm,which consequently resulted in SN38 release and excellent chemo-photodynamic effect on tumor.In vitro,coadministering iRGD with d-SN38@NPs+laser showed higher cellular uptake,apoptosis ratio and multicellular spheroid penetration.In vivo,d-SN38@NPs/iRGD+laser displayed advanced penetration and accumulation in tumor,leading to 60.89%of tumor suppression in 4 T1 tumor-bearing mouse model with a favorable toxicity profile.Our new strategy combining iRGD with structural transformable nanoparticles greatly improves tumor targeting,penetrating and retention,and empowers anticancer efficacy.展开更多
Objective:To investigate the interacting effects of co-administration of methanol leaf extract of Catharanthus roseus（C.roseus） on the hypoglycemic activity of metformin as well as glibenclamide using experimental r...Objective:To investigate the interacting effects of co-administration of methanol leaf extract of Catharanthus roseus（C.roseus） on the hypoglycemic activity of metformin as well as glibenclamide using experimental rats.Methods:Phytochemical analysis as well as acute toxicity and lethality(LD<sub>50</sub>) test were carried out on its methanol leaf extract.The alloxan model for experimental induction of diabetes in rats was employed.Six groups comprising five rats each were used.GroupsⅡ,ⅢandⅣreceived 250 mg/kg of extract,100 mg/kg of metformin and 1 mg/kg of glibenclamide respectively,while V and VI were administered metformin-extract and glibenclamide-extract combinations respectively at doses as above.Group I served as negative control and received only distilled water.All administration was done once daily for seven days. Fasting blood glucose was determined at 2,12,24,72 and 168 h using a glucometer.One-way ANOVA with post-hoc tests was used to assess for significant difference due to administration of drug alone and with co-administration of drug and extract.Results:The LD<sub>50</sub> was 2 121.32 mg/kg. The phytochemical studies indicated the presence of saponins,tannins,alkaloids,phlotatannins, flavonoids,triterpenoids,reducing sugars,anthraquinones and glycosides.All medicaments significantly reduced blood glucose levels when compared with control alone（P【0.05） with the highest percentage reduction in blood glucose（64.86%） exhibited by metformin-extract combination.Conclusions:The leaf extract of C.roseus significandy increases the hypoglycemic effect of metformin.展开更多
基金the financial support from National Natural Science Foundation of China(Nos.8196113800982071915)+3 种基金Research Funds of Sichuan Science and Technology Department(No.19YYJC2250,China)111 Project(No.B18035,China)Fundamental Research Funds for the Central UniversitiesNatural Science Foundation of Heilongjiang Province of China(No.YQ2019H004)
文摘Accurate tumor targeting,deep penetration and superb retention are still the main pursuit of developing excellent nanomedicine.To achieve these requirements,a stepwise stimuli-responsive strategy was developed through co-administration tumor penetration peptide iRGD with shape-transformable and GSH-responsive SN38-dimer(d-SN38)-loaded nanoparticles(d-SN38@NPs/iRGD).Upon intravenous injection,d-SN38@NPs with high drug loading efficiency(33.92±1.33%)could effectively accumulate and penetrate into the deep region of tumor sites with the assistance of iRGD.The gathered nanoparticles simultaneously transformed into nanofibers upon 650 nm laser irradiation at tumor sites so as to promote their retention in the tumor and burst release of reactive oxygen species for photodynamic therapy.The loaded d-SN38 with disulfide bond responded to the high level of GSH in tumor cytoplasm,which consequently resulted in SN38 release and excellent chemo-photodynamic effect on tumor.In vitro,coadministering iRGD with d-SN38@NPs+laser showed higher cellular uptake,apoptosis ratio and multicellular spheroid penetration.In vivo,d-SN38@NPs/iRGD+laser displayed advanced penetration and accumulation in tumor,leading to 60.89%of tumor suppression in 4 T1 tumor-bearing mouse model with a favorable toxicity profile.Our new strategy combining iRGD with structural transformable nanoparticles greatly improves tumor targeting,penetrating and retention,and empowers anticancer efficacy.
文摘Objective:To investigate the interacting effects of co-administration of methanol leaf extract of Catharanthus roseus（C.roseus） on the hypoglycemic activity of metformin as well as glibenclamide using experimental rats.Methods:Phytochemical analysis as well as acute toxicity and lethality(LD<sub>50</sub>) test were carried out on its methanol leaf extract.The alloxan model for experimental induction of diabetes in rats was employed.Six groups comprising five rats each were used.GroupsⅡ,ⅢandⅣreceived 250 mg/kg of extract,100 mg/kg of metformin and 1 mg/kg of glibenclamide respectively,while V and VI were administered metformin-extract and glibenclamide-extract combinations respectively at doses as above.Group I served as negative control and received only distilled water.All administration was done once daily for seven days. Fasting blood glucose was determined at 2,12,24,72 and 168 h using a glucometer.One-way ANOVA with post-hoc tests was used to assess for significant difference due to administration of drug alone and with co-administration of drug and extract.Results:The LD<sub>50</sub> was 2 121.32 mg/kg. The phytochemical studies indicated the presence of saponins,tannins,alkaloids,phlotatannins, flavonoids,triterpenoids,reducing sugars,anthraquinones and glycosides.All medicaments significantly reduced blood glucose levels when compared with control alone（P【0.05） with the highest percentage reduction in blood glucose（64.86%） exhibited by metformin-extract combination.Conclusions:The leaf extract of C.roseus significandy increases the hypoglycemic effect of metformin.
