This study was designed to determine the total phenolic content of 50 herbs and to examine their antioxidant potential. In the sample preparation, 60% ethanol was chosen as the extraction solvent for the subsequent ex...This study was designed to determine the total phenolic content of 50 herbs and to examine their antioxidant potential. In the sample preparation, 60% ethanol was chosen as the extraction solvent for the subsequent experiments. Folin-Cicolteau phenol reagent and a colorimetric method were used to determine the total phenolic content of the selected herbs. The result showed that total phenolic content of those herbs ranged from 2 to 185 mg/g. In antioxidant assay, the ferric reducing/antioxidant power (FRAP) values ranged from 2 to 134 mg GAE/g;the IC50 values of DPPH?·, ·OH and ?scavenging were in the range of 0.06 - 5.50 mg/mL, 0.017 - 0.636 mg/mL and 0.050 - 0.681 mg/mL respectively. Flos caryophylli was the exceptant in the ?scavenging assay because there was no linear relation between the concentration and the scavenging percentage. Compared to gallic acid, ascorbic acid and butylated hydroxytoluene (BHT) in antioxidant assay as positive control, the most potential antioxidant herbs were Cacumen platycladi, Radix et Rhizoma rhei, Rhizoma rhodiolae crenulatae, and Rhizoma sanguisorbae with considerable content of phenolics. Especially, a positive and significant correlation was found between the total phenolic content and FRAP value or DPPH· scavenging percentage.展开更多
A light-switchable transgene system called LightOn gene expression system could regulate gene expression with a high on/off ratio under blue light,and have great potential for spatiotemporally controllable gene expres...A light-switchable transgene system called LightOn gene expression system could regulate gene expression with a high on/off ratio under blue light,and have great potential for spatiotemporally controllable gene expression.We developed a nanoparticle drug delivery system(NDDS)to achieve tumor microenvironment-responsive and targeted delivery of diphtheria toxin A(DTA)fragment-encoded plasmids to tumor sites.The expression of DTA was induced by exposure to blue light.Nanoparticles composed of polyethylenimine and vitamin E succinate linked by a disulfide bond,and PEGylated hyaluronic acid modified with RGD peptide,accumulated in tumor tissues and were actively internalized into 4 T1 cells via dual targeting to CD44 andαvβ3 receptors.The LightOn gene expression system was able to control target protein expression through regulation of the intensity or duration of blue light exposure.In vitro studies showed that lisht-induced DTA expression reduced 4 T1 cell viability and induced apoptosis.Furthermore,the LightOn gene expression system enabled spatiotemporal control of the expression of DTA in a mouse 4 T1 tumor xenogratt model,which resulted in excellent antitumor effects,reduced tumor angiogenesis,and no systemic toxicity.The combination of the LightOn gene expression system and NDDS may be an effective strategy for treatment of breast cancer.展开更多
Developing reliable and facile approaches for alkaline phosphatase(ALP)sensing is important due to its role as a clinical biomarker for many diseases.In this study,we proposed a new and convenient colorimetric assay b...Developing reliable and facile approaches for alkaline phosphatase(ALP)sensing is important due to its role as a clinical biomarker for many diseases.In this study,we proposed a new and convenient colorimetric assay based on the pyrophosphate(PPi)-mediated oxidase-mimicking activity switching of nanosized MnFe_(2)O_(4) for the detection of ALP.The synthesized MnFe_(2)O_(4) exhibited high oxidase-like activity to catalyze the oxidation of colorless 3,3′,5,5′-tetramethylbenzidine(TMB)to its blue product TMBox in the presence of dissolved O2,leading to a color reaction rapidly and remarkably;PPi could significantly inhibit the activity of the MnFe_(2)O_(4) nanozyme via the strong interaction between PPi and the Fe(III)species in MnFe_(2)O_(4),resulting in the suppression of the TMB color reaction;when ALP was added,it hydrolyzed the PPi substrate to phosphate(Pi)that had no obvious effect on the MnFe_(2)O_(4) activity,and such that the TMB color reaction catalyzed by the nanozyme could be observed again.With the above principle,linear colorimetric determination of ALP in the scope of 0.6-55 U L−1 was achieved,giving the limit of detection down to 0.27 U L−1.Besides,the developed assay could provide selective response toward ALP against other co-existing biological species.Furthermore,reliable detection of ALP in human serum samples was verified by our assay,revealing its great promise as an effective and facile tool for ALP monitoring in clinical practice.展开更多
文摘This study was designed to determine the total phenolic content of 50 herbs and to examine their antioxidant potential. In the sample preparation, 60% ethanol was chosen as the extraction solvent for the subsequent experiments. Folin-Cicolteau phenol reagent and a colorimetric method were used to determine the total phenolic content of the selected herbs. The result showed that total phenolic content of those herbs ranged from 2 to 185 mg/g. In antioxidant assay, the ferric reducing/antioxidant power (FRAP) values ranged from 2 to 134 mg GAE/g;the IC50 values of DPPH?·, ·OH and ?scavenging were in the range of 0.06 - 5.50 mg/mL, 0.017 - 0.636 mg/mL and 0.050 - 0.681 mg/mL respectively. Flos caryophylli was the exceptant in the ?scavenging assay because there was no linear relation between the concentration and the scavenging percentage. Compared to gallic acid, ascorbic acid and butylated hydroxytoluene (BHT) in antioxidant assay as positive control, the most potential antioxidant herbs were Cacumen platycladi, Radix et Rhizoma rhei, Rhizoma rhodiolae crenulatae, and Rhizoma sanguisorbae with considerable content of phenolics. Especially, a positive and significant correlation was found between the total phenolic content and FRAP value or DPPH· scavenging percentage.
基金supportedby Shanghai Municipal Natural Science Foundation(No.17ZR1406600,China)Science and Technology Commission of Shanghai Municipality(No.10DZ2220500,China)+1 种基金The Shanghai Committee of Science and Technology(Grant No.11DZ2260600,China)National Natural Science Foundation of China(Grant No.81973700)
文摘A light-switchable transgene system called LightOn gene expression system could regulate gene expression with a high on/off ratio under blue light,and have great potential for spatiotemporally controllable gene expression.We developed a nanoparticle drug delivery system(NDDS)to achieve tumor microenvironment-responsive and targeted delivery of diphtheria toxin A(DTA)fragment-encoded plasmids to tumor sites.The expression of DTA was induced by exposure to blue light.Nanoparticles composed of polyethylenimine and vitamin E succinate linked by a disulfide bond,and PEGylated hyaluronic acid modified with RGD peptide,accumulated in tumor tissues and were actively internalized into 4 T1 cells via dual targeting to CD44 andαvβ3 receptors.The LightOn gene expression system was able to control target protein expression through regulation of the intensity or duration of blue light exposure.In vitro studies showed that lisht-induced DTA expression reduced 4 T1 cell viability and induced apoptosis.Furthermore,the LightOn gene expression system enabled spatiotemporal control of the expression of DTA in a mouse 4 T1 tumor xenogratt model,which resulted in excellent antitumor effects,reduced tumor angiogenesis,and no systemic toxicity.The combination of the LightOn gene expression system and NDDS may be an effective strategy for treatment of breast cancer.
基金This study was supported by the National Natural Science Foundation of China(21605061 and 31601549)the Natural Science Foundation of Jiangsu Province(BK20160489)+1 种基金the Open Fund from the Shanghai Key Laboratory of Functional Materials Chemistry(SKLFMC201601)the Cultivation Project for Excellent Young Teachers in Jiangsu University.
文摘Developing reliable and facile approaches for alkaline phosphatase(ALP)sensing is important due to its role as a clinical biomarker for many diseases.In this study,we proposed a new and convenient colorimetric assay based on the pyrophosphate(PPi)-mediated oxidase-mimicking activity switching of nanosized MnFe_(2)O_(4) for the detection of ALP.The synthesized MnFe_(2)O_(4) exhibited high oxidase-like activity to catalyze the oxidation of colorless 3,3′,5,5′-tetramethylbenzidine(TMB)to its blue product TMBox in the presence of dissolved O2,leading to a color reaction rapidly and remarkably;PPi could significantly inhibit the activity of the MnFe_(2)O_(4) nanozyme via the strong interaction between PPi and the Fe(III)species in MnFe_(2)O_(4),resulting in the suppression of the TMB color reaction;when ALP was added,it hydrolyzed the PPi substrate to phosphate(Pi)that had no obvious effect on the MnFe_(2)O_(4) activity,and such that the TMB color reaction catalyzed by the nanozyme could be observed again.With the above principle,linear colorimetric determination of ALP in the scope of 0.6-55 U L−1 was achieved,giving the limit of detection down to 0.27 U L−1.Besides,the developed assay could provide selective response toward ALP against other co-existing biological species.Furthermore,reliable detection of ALP in human serum samples was verified by our assay,revealing its great promise as an effective and facile tool for ALP monitoring in clinical practice.
