Chitosan was modified by conjugating coupling with linolenic acid through the 1-ethyl-3-（3-dimethylami- nopropyyl） carbodiimide （EDC）-mediated reaction. The degree of substitution 1.8% （ i.e. 1.8 linolenic acid g...Chitosan was modified by conjugating coupling with linolenic acid through the 1-ethyl-3-（3-dimethylami- nopropyyl） carbodiimide （EDC）-mediated reaction. The degree of substitution 1.8% （ i.e. 1.8 linolenic acid group per 100 anhydroglucose units） was measured by ^1H NMR. The critical aggregation concentration （CAC） of the self-aggregate of hydrophobically modified chitosan was determined by measuring the fluorescence intensity of the pyrene as a fluorescent probe. The CAC value in phosphate-buffered saline （PBS） solution （pH 7.4） was 5 × 10^-2 mg mL^-1. The average particle size of selfaggregates of hydrophobically modified chitosan in PBS solution （pH7.4） was 210.8 nm with a unimodal size distribution ranging from 100 to 500 nm. Transmission electron microscopy （TEM） study showed that the formation of near spherical shape nanoparticles has enough structural integrity. The loading ability of hydrophibically modified chitosan （LA-chitosan） was investigated by using bovine serum albumin （BSA） as the model. The loading capacity of self-aggregated nanoparticles increases （ 19.85 % ± 0.04 % to 37.57 % ± 0.25 % ） with the concentration of BSA （0.1-0.5 mg mL^-1 ）.展开更多
AIM: Although polysaccharides from Phellinus mushrooms are a well-known material with anti-tumor properties, there is no information about the effect of polysaccharides from Phellinus gilvus (PG) on tumor. The modulat...AIM: Although polysaccharides from Phellinus mushrooms are a well-known material with anti-tumor properties, there is no information about the effect of polysaccharides from Phellinus gilvus (PG) on tumor. The modulating effect of polysaccharides isolated from PG on the benzo(a)pyrene (BaP)-induced forestomach carcinogenesis in ICR female mice was investigated in this study.METHODS: A forestomach carcinogenesis model was established in 40 ICR female mice receiving oral administration of BaP for 4 wk. The mice were randomly assigned to 4 groups (10 each). The mice in each group were treated with sterile water or PG for 4 and 8 wk (SW4,PGW4, SW8, and PGW8 groups). Eight or 12 wk after the first dose of BaP, forestomachs were removed for histopathological and RT-PCR analysis.RESULTS: In histopathological changes and RT-PCR analysis, sterile water-treated mice showed significant hyperplasia of the gastric mucosa with a significantly increased expression of mutant p53 mRNA compared to mice treated with PG for 8 wk.CONCLUSION: Polysaccharides isolated from PG may inhibit BaP-induced forestomach carcinogenesis in mice bydown-regulating mutant p53 expression.展开更多
Thanks to the pure blue emitting, high planarity, electron rich and ease of chemical modification, pyrene has been thoroughly investigated for applications in organic electronics such as organic light emitting diodes(...Thanks to the pure blue emitting, high planarity, electron rich and ease of chemical modification, pyrene has been thoroughly investigated for applications in organic electronics such as organic light emitting diodes(OLEDs), organic field effect transistors(OFETs), and organic solar cells(OSCs). Especially, great progresses have been made of pyrene-based organic semiconductors for OFETs in past decades. Due to the difference of molecular structure, pyrene-based organic semiconductors are divided into three categories, pyrene as terminal group, pyrene as center core and fused pyrene derivatives. This minireview gives a brief introduction of the structure-property relationship and application in OFETs about most of pyrene-based semiconducting materials since 2006,illustrating that pyrene is a good building block to construct semiconductors with superior transport property for OFETs. Finally, we provide a summary concerning the methodology to improve the transport property of the pyrene-based semiconducting materials as well as an outlook.展开更多
基金National Natural Science Foundation of China(30370344)Korea Science and Engineering Foundation(19992-220-009-4)supported this study
文摘Chitosan was modified by conjugating coupling with linolenic acid through the 1-ethyl-3-（3-dimethylami- nopropyyl） carbodiimide （EDC）-mediated reaction. The degree of substitution 1.8% （ i.e. 1.8 linolenic acid group per 100 anhydroglucose units） was measured by ^1H NMR. The critical aggregation concentration （CAC） of the self-aggregate of hydrophobically modified chitosan was determined by measuring the fluorescence intensity of the pyrene as a fluorescent probe. The CAC value in phosphate-buffered saline （PBS） solution （pH 7.4） was 5 × 10^-2 mg mL^-1. The average particle size of selfaggregates of hydrophobically modified chitosan in PBS solution （pH7.4） was 210.8 nm with a unimodal size distribution ranging from 100 to 500 nm. Transmission electron microscopy （TEM） study showed that the formation of near spherical shape nanoparticles has enough structural integrity. The loading ability of hydrophibically modified chitosan （LA-chitosan） was investigated by using bovine serum albumin （BSA） as the model. The loading capacity of self-aggregated nanoparticles increases （ 19.85 % ± 0.04 % to 37.57 % ± 0.25 % ） with the concentration of BSA （0.1-0.5 mg mL^-1 ）.
基金Supported by grant R08-2003-000-10120-0 from the Basic Research Program of the Korea Science & Engineering Foundation
文摘AIM: Although polysaccharides from Phellinus mushrooms are a well-known material with anti-tumor properties, there is no information about the effect of polysaccharides from Phellinus gilvus (PG) on tumor. The modulating effect of polysaccharides isolated from PG on the benzo(a)pyrene (BaP)-induced forestomach carcinogenesis in ICR female mice was investigated in this study.METHODS: A forestomach carcinogenesis model was established in 40 ICR female mice receiving oral administration of BaP for 4 wk. The mice were randomly assigned to 4 groups (10 each). The mice in each group were treated with sterile water or PG for 4 and 8 wk (SW4,PGW4, SW8, and PGW8 groups). Eight or 12 wk after the first dose of BaP, forestomachs were removed for histopathological and RT-PCR analysis.RESULTS: In histopathological changes and RT-PCR analysis, sterile water-treated mice showed significant hyperplasia of the gastric mucosa with a significantly increased expression of mutant p53 mRNA compared to mice treated with PG for 8 wk.CONCLUSION: Polysaccharides isolated from PG may inhibit BaP-induced forestomach carcinogenesis in mice bydown-regulating mutant p53 expression.
基金supported by the National Natural Science Foundation of China(21325416)
文摘Thanks to the pure blue emitting, high planarity, electron rich and ease of chemical modification, pyrene has been thoroughly investigated for applications in organic electronics such as organic light emitting diodes(OLEDs), organic field effect transistors(OFETs), and organic solar cells(OSCs). Especially, great progresses have been made of pyrene-based organic semiconductors for OFETs in past decades. Due to the difference of molecular structure, pyrene-based organic semiconductors are divided into three categories, pyrene as terminal group, pyrene as center core and fused pyrene derivatives. This minireview gives a brief introduction of the structure-property relationship and application in OFETs about most of pyrene-based semiconducting materials since 2006,illustrating that pyrene is a good building block to construct semiconductors with superior transport property for OFETs. Finally, we provide a summary concerning the methodology to improve the transport property of the pyrene-based semiconducting materials as well as an outlook.
