The accelerated blood clearance(ABC) phenomenon which is induced by repeated injection of poly(ethylene glycol)(PEG)-coated colloidal carriers gives clinical challenge to the promising drug delivery system. It is nece...The accelerated blood clearance(ABC) phenomenon which is induced by repeated injection of poly(ethylene glycol)(PEG)-coated colloidal carriers gives clinical challenge to the promising drug delivery system. It is necessary to decrease this unexpected immunological response.A novel 4-arm poly(ethylene glycol-5000)4-cholesteryl methyl amide(4-arm PEG5000-CHMA)has been synthesized. The structure of 4-arm PEG5000-CHMA was confirmed by IR and 1H-NMR spectrum. The pharmacokinetics of the tocopheryl nicotinate(TN)-loaded nanoemulsions modified with 4-arm PEG5000-CHMA or/and 1, 2-distearoyl-Sn-glycero-3-phosphoethanolamine-n-[methoxy(poly-ethyleneglycol)-2000](mPEG2000-DSPE) have been studied. Furthermore, the ABC phenomenon has been detailed investigated in rats by TN-loaded nanoemulsions modified with 4-arm PEG5000-CHMA and mPEG2000-DSPE(CPNE). The plasma levels of TN and anti-PEG IgM antibody were determined by HPLC and ELISA, respectively.The circulation time of the CPNEs were comparable to the mPEG2000-DSPE coated nanoemulsions. Moreover, the ABC phenomenon can be decreased by CPNEs. This study designs a method to decrease the ABC phenomenon and develops a clinical promising nanoemulsion for therapeutic or imaging purpose.展开更多
Interfacial solar evaporation holds great promise to address the freshwater shortage.However,most interfacial solar evaporators are always filled with water throughout the evaporation process,thus bringing unavoidable...Interfacial solar evaporation holds great promise to address the freshwater shortage.However,most interfacial solar evaporators are always filled with water throughout the evaporation process,thus bringing unavoidable heat loss.Herein,we propose a novel interfacial evaporation structure based on the micro–nano water film,which demonstrates significantly improved evaporation performance,as experimentally verified by polypyrrole-and polydopamine-coated polydimethylsiloxane sponge.The 2D evaporator based on the as-prepared sponge realizes an enhanced evaporation rate of 2.18 kg m^(−2)h^(−1)under 1 sun by fine-tuning the interfacial micro–nano water film.Then,a homemade device with an enhanced condensation function is engineered for outdoor clean water production.Throughout a continuous test for 40 days,this device demonstrates a high water production rate(WPR)of 15.9–19.4 kg kW^(−1)h^(−1)m^(−2).Based on the outdoor outcomes,we further establish a multi-objective model to assess the global WPR.It is predicted that a 1 m^(2)device can produce at most 7.8 kg of clean water per day,which could meet the daily drinking water needs of 3 people.Finally,this technology could greatly alleviate the current water and energy crisis through further large-scale applications.展开更多
Fusarium crown rot(FCR) is a soilborne disease causing severe yield losses in many wheat-growing areas of the world. Diseased plants show browning and necrosis of roots and stems causing white heads at maturity. Littl...Fusarium crown rot(FCR) is a soilborne disease causing severe yield losses in many wheat-growing areas of the world. Diseased plants show browning and necrosis of roots and stems causing white heads at maturity. Little is known about the molecular processes employed by wheat roots to respond to the disease. We characterized morphological, transcriptional and hormonal changes in wheat seedling roots following challenge with Fusarium pseudograminearum(Fp), the main pathogen of FCR. The pathogen inhibited root development to various extents depending on plants' resistance level. Many genes responsive to FCR infection in wheat roots were enriched in plant hormone pathways. The contents of compounds involved in biosynthesis and metabolism of jasmonic acid, salicylic acid, cytokinin and auxin were drastically changed in roots at five days post-inoculation. Presoaking seeds in methyl jasmonate for 24 h promoted FCR resistance, whereas presoaking with cytokinin 6-benzylaminopurine made plants more susceptible. Overexpression of TaOPR3, a gene involved in jasmonic acid biosynthesis, enhanced plant resistance as well as root and shoot growth during infection.展开更多
Researchers reported that intravenously injected PEGylated colloidal drug carriers lose their long-circulating characteristic and accumulated extensively in liver when they are administrated twice in the same animal w...Researchers reported that intravenously injected PEGylated colloidal drug carriers lose their long-circulating characteristic and accumulated extensively in liver when they are administrated twice in the same animal with certain intervals. This phenomenon was referred to as the 'accelerated blood clearance(ABC) phenomenon'. Some former studies had found that complement-mediated phagocytosis, activated by antigen–antibody complex, was responsible for inducing the phenomenon. According to the theory, we have used cobra venom factor to deplete complement in vivo and to investigate the effect of complement inhibition on the ABC phenomenon. Rats were administered by injection of cobra venom factor solution to build up the model of complement exhaustion/inhibition, and the effect of the inhibition of complement on ABC phenomenon was carried out. It seemed that inhibition of complement didn’t affect the pharmacokinetic of the first infection. By contrast, in rats of which complement had been depleted, the second dose of PEGylated nanoemulsions showed enhanced circulation time compared with normal rats in a complement inhibition-independent manner, but the ABC phenomenon was not completely eliminated. It indicated that complement inhibition could certainly weaken the accelerated clearance;meanwhile, there were other factors causing the ABC effect.These findings provide novel insights into the attenuating of ABC phenomenon and lay foundation for further study of immune mechanism.展开更多
For investigating the accelerated blood clearance(ABC) phenomenon of polyglycerin modified nanoemulsions upon cross administration with polyethylene glycol(PEG) covered nanoemulsion, we used the 1,2-distea-royl-sn-gly...For investigating the accelerated blood clearance(ABC) phenomenon of polyglycerin modified nanoemulsions upon cross administration with polyethylene glycol(PEG) covered nanoemulsion, we used the 1,2-distea-royl-sn-glycero-3-phosphoethanolamine-npolyglycerine-610 and the 1,2-distearoyl-n-glycero-3-phosphoethanolamine-n-[methoxy(polyethylene glycol)-2000] as modify materials, the dialkylcarbocyanines as fluorescence indicator. Exhausted macrophages rat model was established and new material containing polycarboxyl structure was synthesized. The microplate reader and the in vivo optical imaging system were applied to measure the concentration of nanoemulsions in tissues.The results show that the first dose of polyglycerin modified nanoemulsion can induce the ABC phenomenon of the second dose of PEGylated nanoemulsion. With the increase in the amount of the surface polyglycerin, the extent of the ABC phenomenon decreases. Liver accumulation has positive relationship with the ABC phenomenon. Furthermore, kupffer cells in liver can get more immune information from polyhydroxy structure than polycarboxyl group in the modify compound. The results of our work imply that the polycarboxyl structure has advantages to eliminate the ABC phenomenon.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 81072602, Grant No. 81373334)
文摘The accelerated blood clearance(ABC) phenomenon which is induced by repeated injection of poly(ethylene glycol)(PEG)-coated colloidal carriers gives clinical challenge to the promising drug delivery system. It is necessary to decrease this unexpected immunological response.A novel 4-arm poly(ethylene glycol-5000)4-cholesteryl methyl amide(4-arm PEG5000-CHMA)has been synthesized. The structure of 4-arm PEG5000-CHMA was confirmed by IR and 1H-NMR spectrum. The pharmacokinetics of the tocopheryl nicotinate(TN)-loaded nanoemulsions modified with 4-arm PEG5000-CHMA or/and 1, 2-distearoyl-Sn-glycero-3-phosphoethanolamine-n-[methoxy(poly-ethyleneglycol)-2000](mPEG2000-DSPE) have been studied. Furthermore, the ABC phenomenon has been detailed investigated in rats by TN-loaded nanoemulsions modified with 4-arm PEG5000-CHMA and mPEG2000-DSPE(CPNE). The plasma levels of TN and anti-PEG IgM antibody were determined by HPLC and ELISA, respectively.The circulation time of the CPNEs were comparable to the mPEG2000-DSPE coated nanoemulsions. Moreover, the ABC phenomenon can be decreased by CPNEs. This study designs a method to decrease the ABC phenomenon and develops a clinical promising nanoemulsion for therapeutic or imaging purpose.
基金supported by the National Natural Science Foundation of China(No.52070162)the National Key Research and Development Program of China(2018YFA0901300).
文摘Interfacial solar evaporation holds great promise to address the freshwater shortage.However,most interfacial solar evaporators are always filled with water throughout the evaporation process,thus bringing unavoidable heat loss.Herein,we propose a novel interfacial evaporation structure based on the micro–nano water film,which demonstrates significantly improved evaporation performance,as experimentally verified by polypyrrole-and polydopamine-coated polydimethylsiloxane sponge.The 2D evaporator based on the as-prepared sponge realizes an enhanced evaporation rate of 2.18 kg m^(−2)h^(−1)under 1 sun by fine-tuning the interfacial micro–nano water film.Then,a homemade device with an enhanced condensation function is engineered for outdoor clean water production.Throughout a continuous test for 40 days,this device demonstrates a high water production rate(WPR)of 15.9–19.4 kg kW^(−1)h^(−1)m^(−2).Based on the outdoor outcomes,we further establish a multi-objective model to assess the global WPR.It is predicted that a 1 m^(2)device can produce at most 7.8 kg of clean water per day,which could meet the daily drinking water needs of 3 people.Finally,this technology could greatly alleviate the current water and energy crisis through further large-scale applications.
基金supported by the State Key Laboratory of North China Crop Improvement and RegulationNational Key Research and Development Program of China (2018YFD0300501)National Natural Science Foundation of China (31872865)。
文摘Fusarium crown rot(FCR) is a soilborne disease causing severe yield losses in many wheat-growing areas of the world. Diseased plants show browning and necrosis of roots and stems causing white heads at maturity. Little is known about the molecular processes employed by wheat roots to respond to the disease. We characterized morphological, transcriptional and hormonal changes in wheat seedling roots following challenge with Fusarium pseudograminearum(Fp), the main pathogen of FCR. The pathogen inhibited root development to various extents depending on plants' resistance level. Many genes responsive to FCR infection in wheat roots were enriched in plant hormone pathways. The contents of compounds involved in biosynthesis and metabolism of jasmonic acid, salicylic acid, cytokinin and auxin were drastically changed in roots at five days post-inoculation. Presoaking seeds in methyl jasmonate for 24 h promoted FCR resistance, whereas presoaking with cytokinin 6-benzylaminopurine made plants more susceptible. Overexpression of TaOPR3, a gene involved in jasmonic acid biosynthesis, enhanced plant resistance as well as root and shoot growth during infection.
基金supported by the National Natural Science Foundation of China(Grant No.81373334)
文摘Researchers reported that intravenously injected PEGylated colloidal drug carriers lose their long-circulating characteristic and accumulated extensively in liver when they are administrated twice in the same animal with certain intervals. This phenomenon was referred to as the 'accelerated blood clearance(ABC) phenomenon'. Some former studies had found that complement-mediated phagocytosis, activated by antigen–antibody complex, was responsible for inducing the phenomenon. According to the theory, we have used cobra venom factor to deplete complement in vivo and to investigate the effect of complement inhibition on the ABC phenomenon. Rats were administered by injection of cobra venom factor solution to build up the model of complement exhaustion/inhibition, and the effect of the inhibition of complement on ABC phenomenon was carried out. It seemed that inhibition of complement didn’t affect the pharmacokinetic of the first infection. By contrast, in rats of which complement had been depleted, the second dose of PEGylated nanoemulsions showed enhanced circulation time compared with normal rats in a complement inhibition-independent manner, but the ABC phenomenon was not completely eliminated. It indicated that complement inhibition could certainly weaken the accelerated clearance;meanwhile, there were other factors causing the ABC effect.These findings provide novel insights into the attenuating of ABC phenomenon and lay foundation for further study of immune mechanism.
基金supported by the National Natural Science Foundation of China (Grant Nos.81072602,81373334)
文摘For investigating the accelerated blood clearance(ABC) phenomenon of polyglycerin modified nanoemulsions upon cross administration with polyethylene glycol(PEG) covered nanoemulsion, we used the 1,2-distea-royl-sn-glycero-3-phosphoethanolamine-npolyglycerine-610 and the 1,2-distearoyl-n-glycero-3-phosphoethanolamine-n-[methoxy(polyethylene glycol)-2000] as modify materials, the dialkylcarbocyanines as fluorescence indicator. Exhausted macrophages rat model was established and new material containing polycarboxyl structure was synthesized. The microplate reader and the in vivo optical imaging system were applied to measure the concentration of nanoemulsions in tissues.The results show that the first dose of polyglycerin modified nanoemulsion can induce the ABC phenomenon of the second dose of PEGylated nanoemulsion. With the increase in the amount of the surface polyglycerin, the extent of the ABC phenomenon decreases. Liver accumulation has positive relationship with the ABC phenomenon. Furthermore, kupffer cells in liver can get more immune information from polyhydroxy structure than polycarboxyl group in the modify compound. The results of our work imply that the polycarboxyl structure has advantages to eliminate the ABC phenomenon.