Aqueous Zn-iodine batteries(ZIBs)face the formidable challenges towards practical implementation,including metal corrosion and rampant dendrite growth on the Zn anode side,and shuttle effect of polyiodide species from...Aqueous Zn-iodine batteries(ZIBs)face the formidable challenges towards practical implementation,including metal corrosion and rampant dendrite growth on the Zn anode side,and shuttle effect of polyiodide species from the cathode side.These challenges lead to poor cycle stability and severe self-discharge.From the fabrication and cost point of view,it is technologically more viable to deploy electrolyte engineering than electrode protection strategies.More importantly,a synchronous method for modulation of both cathode and anode is pivotal,which has been often neglected in prior studies.In this work,cationic poly(allylamine hydrochloride)(Pah^(+))is adopted as a low-cost dual-function electrolyte additive for ZIBs.We elaborate the synchronous effect by Pah^(+)in stabilizing Zn anode and immobilizing polyiodide anions.The fabricated Zn-iodine coin cell with Pah^(+)(ZnI_(2) loading:25 mg cm^(−2))stably cycles 1000 times at 1 C,and a single-layered 3.4 cm^(2) pouch cell(N/P ratio~1.5)with the same mass loading cycles over 300 times with insignificant capacity decay.展开更多
BACKGROUND：It has been reported that chitosan nerve conduits could support axon elongation and improve relevant function during in vivo nerve regeneration. OBJECTIVE： To investigate in vitro biocompatibility of thre...BACKGROUND：It has been reported that chitosan nerve conduits could support axon elongation and improve relevant function during in vivo nerve regeneration. OBJECTIVE： To investigate in vitro biocompatibility of three novel, chitosan/polycation composite materials for nerve regeneration in cultured mouse Schwann cells and PC12 cells. DESIGN, TIME AND SETTING： The observational, control experiments for nerve tissue engineering were performed at the Department of Biological Sciences and Biotechnology of Tsinghua University from August 2007 to January 2008. MATERIALS： Mouse Schwann cells were isolated from the sciatic nerve of 5–7-day-old BALB/C mice. PC12 cells were purchased from the American Type Culture Collection （ATCC, USA）. Chitosan was purchased from Tsingdao Haisheng Co., China. Poly-L-lysine hydrochloride （PLL）, polyethyleneimine （PEI） poly-L-ornithine hydrobromide （POR）, and S-100 antibody was purchased from Sigma Chemical Co., USA. Cell Counting Kit-8 （CCK-8） was purchased from Dojindo Chemical Co., Japan. METHODS： Three chitosan/polycation composite materials for nerve regeneration （PLL-0.25, PEI-0.25, and POR-0.25） were produced by blending chitosan with 0.25% （w/w） poly-L-lysine, polyethyleneimine, and poly-L-ornithine. Pure chitosan was utilized as the control. After 3 days of culture, the morphology of mouse Schwann and PC12 cells cultured on all substrates was observed with an inverted phase contrast microscope. Mouse Schwann cells were stained by immunofluorescence labeling S-100 protein and nuclei, followed by identification with a confocal laser-scanning microscope. The amount of proliferating mouse Schwann and PC12 cells was determined by CCK-8 after 1, 3, and 5 days in culture. The level of PC12 cell differentiation on all substrates was assessed by measuring neurite length at 1, 3, and 5 days after seeding. MAIN OUTCOME MEASURES： Morphology and amount of proliferation of mouse Schwann cells and PC12 cells cultured on chitosan and three polycation-modified materials, as well as amount of differentiation in PC12 cells on these substrates. RESULTS： （1） Morphology of mouse Schwann cells and PC12 cells on all substrates： after 3 days in culture on three different chitosan/polycation composite substrates, Schwann cells were connected to each other and exhibited greater proliferation, compared to the chitosan control. In particular, on PLL-0.25 and POR-0.25 substrates, some cells congregated and nearly reached confluence. The PC12 cells on chitosan substrate, after 3 days in culture, maintained a round shape; few exhibited a bipolar shape and began to form neurite extensions. However, on PLL-0.25 and POR-0.25 substrates, most PC12 cells displayed a bipolar shape with obvious neurite outgrowth, and almost grew as an adherent, spreading monolayer. （2） Proliferation of mouse Schwann cells and PC12 cells on all substrates： on the first day, Schwann cell proliferation on the three composite substrates was significantly greater than the cells on chitosan control （P 〈 0.01）. After 3 and 5 days in culture, PLL-0.25 and POR-0.25 substrates resulted in greater cell proliferation when compared to pure chitosan （P 〈 0.01）. On the third and fifth day in culture PC12 cell proliferation on PLL-0.25 and POR-0.25 was significantly greater than on chitosan substrate （P 〈 0.01）. （3） Differentiation of PC12 cells on all substrates： at all time points, the average neurite length of cells cultured on composite materials was significantly longer than on chitosan control （P 〈 0.05-0.01）. Cells on PLL-0.25 exhibited the longest average neurite length at days 3 and 5. CONCLUSION： Mouse Schwann cells and PC12 cells exhibit in vitro biocompatibility with poly-L-lysine-and poly-L-ornithine-modified substrates, which indicates that these substrates could serve as suitable substrates for peripheral nerve regeneration.展开更多
F-actins are semi-flexible polyelectrolytes and can be assembled into large polymer-actin complex with polymorphism through electrostatic interaction with polycations. This study investigates the structural phase beha...F-actins are semi-flexible polyelectrolytes and can be assembled into large polymer-actin complex with polymorphism through electrostatic interaction with polycations. This study investigates the structural phase behavior and the growth of polymer-actin complexes in terms of its longitudinal and lateral sizes. Our results show that formation of polymer-actin complexes is cooperative, and morphology and growth of polymer-actin complexes depend on polycation species and concentrations of polycation and salt in a constant actin concentration. We found that the longitudinal growth and lateral growth of polymer-actin complexes are dominated by different factors. This induces the structural polymorphism of polymer-actin complexes. Major factors to influence the polymorphism of polymer-actin complexes in polyelectrolytc system have been discussed. Our results indicate that the semi-flexible polyelectrolyte nature of F-actins is important for controlling the morphology and growth ofactin architectures in cell.展开更多
An improved aerobiological virus sampling method was developed based on adding adsorptive nanoparticles in samplers for concentrating viruses in sampling liquid buffers.The objectives of this research were to select e...An improved aerobiological virus sampling method was developed based on adding adsorptive nanoparticles in samplers for concentrating viruses in sampling liquid buffers.The objectives of this research were to select effective adsorptive materials and optimize sampling parameters for increasing recovery of airborne viruses,such as influenza A virus or respiratory syndrome virus(RSV).Three kinds of polycation nanoparticles were evaluated for direct effects on absorption and desorption of influenza virus hemagglutinin and DNA.Chitosan particles showed good performance in absorption and desorption for both influenza virus hemagglutinin and DNA.A subsequent study evaluated the effects of collection buffer,pH and sampling time on the recovery of aerosolized viruses using a method for making direct comparisons of three treatments.The results demonstrated that various components in air-sampling collection buffer,impinger model,and sampling time,independently influenced the recovery of viruses.It was shown that adsorptive samplers with air disperser had the highest levels of sensitivity and repeatability in virus sampling.Both unspecifically adsorptive chitosan particles and specifically adsorptive particles labeled specific antibody to virus significantly enhanced recovery rate of aerosolized viruses.We succeeded to sample low level different pathogen viruses in outdoor environments with the optimized sampling system.展开更多
Molybdenum trioxide(MoO_(3))can be employed as an excellent host for intercalation due to its 2D lay-ered structure that connected by van der Waals interactions.Herein,a series of polyoxometalate-based MoO_(3) composi...Molybdenum trioxide(MoO_(3))can be employed as an excellent host for intercalation due to its 2D lay-ered structure that connected by van der Waals interactions.Herein,a series of polyoxometalate-based MoO_(3) composites(Al_(13)@MoO_(3))were successfully prepared by interpolating the Keggin-type polycationic AlO_(4)Al_(12)(OH)_(24)H_(2)O_(12)^(7+)(Al_(13))into MoO_(3)gallery.These composites can be applied to rapidly adsorb the anionic dye methyl orange(MO)through strong electrostatic interactions lead to compact and sta-ble gathering in the surrounding of the numerous charged Al_(13).Adsorption behaviors of composites with the different amount of Al_(13) were determined,these results revealed that Al_(13)-3.34%@MoO_(3)exhibited the most remarkable adsorption capacity.More importantly,the composite maintains superior adsorption capacity for five consecutive adsorption/desorption cycles,suggesting that Al_(13)@MoO_(3)can be an efficient and durable adsorbent.展开更多
The continued evolution of bacterial and fungal species poses a significant difficulty for the treatment of disease of microbial origin. Given this situation, the prevention of transmission of such microbial diseases ...The continued evolution of bacterial and fungal species poses a significant difficulty for the treatment of disease of microbial origin. Given this situation, the prevention of transmission of such microbial diseases becomes of increasing importance. Efforts of this laboratory have been directed toward the destruction of microbial species on environmental surfaces as a prophylaxis toward infection, and we herein report on the efficacy of a system that demonstrates activity against both Gram-positive and Gram-negative bacteria, as well as fungi. We report specifically herein on the use of fabric materials so activated for the destruction of these microbial species, useful for a variety of surfaces within hospital and related settings wherein transmission of microbial disease is a major problem, while these approaches are also applicable for a variety of other types of surfaces.展开更多
Although cancer immunotherapy has made great strides in the clinic,it is still hindered by the tumor immunosuppressive microenvironment(TIME).The stimulator of interferon genes(STING)pathway which can modulate TIME ef...Although cancer immunotherapy has made great strides in the clinic,it is still hindered by the tumor immunosuppressive microenvironment(TIME).The stimulator of interferon genes(STING)pathway which can modulate TIME effectively has emerged as a promising therapeutic recently.However,the delivery of most STING agonists,specifically cyclic dinucleotides(CDNs),is performed intratumorally due to their insufficient pharmacological properties,such as weak permeability across cell membranes and vulnerability to nuclease degradation.To expand the clinical applicability of CDNs,a novel pH-sensitive polycationic polymer-modified lipid nanoparticle(LNP-B)system was developed for intravenous delivery of CDNs.LNP-B significantly extended the circulation of CDNs and enhanced the accumulation of CDNs within the tumor,spleen,and tumor-draining lymph nodes compared with free CDNs thereby triggering the STING pathway of dendritic cells and repolarizing pro-tumor macrophages.These events subsequently gave rise to potent anti-tumor immune reactions and substantial inhibition of tumors in CT26 colon cancer-bearing mouse models.In addition,due to the acid-sensitive property of the polycationic polymer,the delivery system of LNP-B was more biocompatible and safer compared with lipid nanoparticles formulated with an indissociable cationic DOTAP(LNP-D).These findings suggest that LNP-B has great potential in the intravenous delivery of CDNs for tumor immunotherapy.展开更多
基金supported by the financial support from the National Research Foundation,Singapore,under its Singapore-China Joint Flagship Project(Clean Energy).
文摘Aqueous Zn-iodine batteries(ZIBs)face the formidable challenges towards practical implementation,including metal corrosion and rampant dendrite growth on the Zn anode side,and shuttle effect of polyiodide species from the cathode side.These challenges lead to poor cycle stability and severe self-discharge.From the fabrication and cost point of view,it is technologically more viable to deploy electrolyte engineering than electrode protection strategies.More importantly,a synchronous method for modulation of both cathode and anode is pivotal,which has been often neglected in prior studies.In this work,cationic poly(allylamine hydrochloride)(Pah^(+))is adopted as a low-cost dual-function electrolyte additive for ZIBs.We elaborate the synchronous effect by Pah^(+)in stabilizing Zn anode and immobilizing polyiodide anions.The fabricated Zn-iodine coin cell with Pah^(+)(ZnI_(2) loading:25 mg cm^(−2))stably cycles 1000 times at 1 C,and a single-layered 3.4 cm^(2) pouch cell(N/P ratio~1.5)with the same mass loading cycles over 300 times with insignificant capacity decay.
基金National Basic Research Program of China, ("973" Program), No. 2005CB623905Tsinghua-Yue-Yuen Medical Science Fund, Beijing Municipal Science & Technology Commission, No. H060920050430the National Natural Science Foundation of China, No. 30670528, 30700848, 30772443
文摘BACKGROUND：It has been reported that chitosan nerve conduits could support axon elongation and improve relevant function during in vivo nerve regeneration. OBJECTIVE： To investigate in vitro biocompatibility of three novel, chitosan/polycation composite materials for nerve regeneration in cultured mouse Schwann cells and PC12 cells. DESIGN, TIME AND SETTING： The observational, control experiments for nerve tissue engineering were performed at the Department of Biological Sciences and Biotechnology of Tsinghua University from August 2007 to January 2008. MATERIALS： Mouse Schwann cells were isolated from the sciatic nerve of 5–7-day-old BALB/C mice. PC12 cells were purchased from the American Type Culture Collection （ATCC, USA）. Chitosan was purchased from Tsingdao Haisheng Co., China. Poly-L-lysine hydrochloride （PLL）, polyethyleneimine （PEI） poly-L-ornithine hydrobromide （POR）, and S-100 antibody was purchased from Sigma Chemical Co., USA. Cell Counting Kit-8 （CCK-8） was purchased from Dojindo Chemical Co., Japan. METHODS： Three chitosan/polycation composite materials for nerve regeneration （PLL-0.25, PEI-0.25, and POR-0.25） were produced by blending chitosan with 0.25% （w/w） poly-L-lysine, polyethyleneimine, and poly-L-ornithine. Pure chitosan was utilized as the control. After 3 days of culture, the morphology of mouse Schwann and PC12 cells cultured on all substrates was observed with an inverted phase contrast microscope. Mouse Schwann cells were stained by immunofluorescence labeling S-100 protein and nuclei, followed by identification with a confocal laser-scanning microscope. The amount of proliferating mouse Schwann and PC12 cells was determined by CCK-8 after 1, 3, and 5 days in culture. The level of PC12 cell differentiation on all substrates was assessed by measuring neurite length at 1, 3, and 5 days after seeding. MAIN OUTCOME MEASURES： Morphology and amount of proliferation of mouse Schwann cells and PC12 cells cultured on chitosan and three polycation-modified materials, as well as amount of differentiation in PC12 cells on these substrates. RESULTS： （1） Morphology of mouse Schwann cells and PC12 cells on all substrates： after 3 days in culture on three different chitosan/polycation composite substrates, Schwann cells were connected to each other and exhibited greater proliferation, compared to the chitosan control. In particular, on PLL-0.25 and POR-0.25 substrates, some cells congregated and nearly reached confluence. The PC12 cells on chitosan substrate, after 3 days in culture, maintained a round shape; few exhibited a bipolar shape and began to form neurite extensions. However, on PLL-0.25 and POR-0.25 substrates, most PC12 cells displayed a bipolar shape with obvious neurite outgrowth, and almost grew as an adherent, spreading monolayer. （2） Proliferation of mouse Schwann cells and PC12 cells on all substrates： on the first day, Schwann cell proliferation on the three composite substrates was significantly greater than the cells on chitosan control （P 〈 0.01）. After 3 and 5 days in culture, PLL-0.25 and POR-0.25 substrates resulted in greater cell proliferation when compared to pure chitosan （P 〈 0.01）. On the third and fifth day in culture PC12 cell proliferation on PLL-0.25 and POR-0.25 was significantly greater than on chitosan substrate （P 〈 0.01）. （3） Differentiation of PC12 cells on all substrates： at all time points, the average neurite length of cells cultured on composite materials was significantly longer than on chitosan control （P 〈 0.05-0.01）. Cells on PLL-0.25 exhibited the longest average neurite length at days 3 and 5. CONCLUSION： Mouse Schwann cells and PC12 cells exhibit in vitro biocompatibility with poly-L-lysine-and poly-L-ornithine-modified substrates, which indicates that these substrates could serve as suitable substrates for peripheral nerve regeneration.
基金This research is financially supported by SORST, JST and the Ministry of Education, Science, Sports, and Culture, Japan (Grant-in-Aid of Creative Scientific Research).
文摘F-actins are semi-flexible polyelectrolytes and can be assembled into large polymer-actin complex with polymorphism through electrostatic interaction with polycations. This study investigates the structural phase behavior and the growth of polymer-actin complexes in terms of its longitudinal and lateral sizes. Our results show that formation of polymer-actin complexes is cooperative, and morphology and growth of polymer-actin complexes depend on polycation species and concentrations of polycation and salt in a constant actin concentration. We found that the longitudinal growth and lateral growth of polymer-actin complexes are dominated by different factors. This induces the structural polymorphism of polymer-actin complexes. Major factors to influence the polymorphism of polymer-actin complexes in polyelectrolytc system have been discussed. Our results indicate that the semi-flexible polyelectrolyte nature of F-actins is important for controlling the morphology and growth ofactin architectures in cell.
文摘An improved aerobiological virus sampling method was developed based on adding adsorptive nanoparticles in samplers for concentrating viruses in sampling liquid buffers.The objectives of this research were to select effective adsorptive materials and optimize sampling parameters for increasing recovery of airborne viruses,such as influenza A virus or respiratory syndrome virus(RSV).Three kinds of polycation nanoparticles were evaluated for direct effects on absorption and desorption of influenza virus hemagglutinin and DNA.Chitosan particles showed good performance in absorption and desorption for both influenza virus hemagglutinin and DNA.A subsequent study evaluated the effects of collection buffer,pH and sampling time on the recovery of aerosolized viruses using a method for making direct comparisons of three treatments.The results demonstrated that various components in air-sampling collection buffer,impinger model,and sampling time,independently influenced the recovery of viruses.It was shown that adsorptive samplers with air disperser had the highest levels of sensitivity and repeatability in virus sampling.Both unspecifically adsorptive chitosan particles and specifically adsorptive particles labeled specific antibody to virus significantly enhanced recovery rate of aerosolized viruses.We succeeded to sample low level different pathogen viruses in outdoor environments with the optimized sampling system.
基金the National Natural Science Foundation of China(Nos.21872021,21671033,22172022 and 22071019).
文摘Molybdenum trioxide(MoO_(3))can be employed as an excellent host for intercalation due to its 2D lay-ered structure that connected by van der Waals interactions.Herein,a series of polyoxometalate-based MoO_(3) composites(Al_(13)@MoO_(3))were successfully prepared by interpolating the Keggin-type polycationic AlO_(4)Al_(12)(OH)_(24)H_(2)O_(12)^(7+)(Al_(13))into MoO_(3)gallery.These composites can be applied to rapidly adsorb the anionic dye methyl orange(MO)through strong electrostatic interactions lead to compact and sta-ble gathering in the surrounding of the numerous charged Al_(13).Adsorption behaviors of composites with the different amount of Al_(13) were determined,these results revealed that Al_(13)-3.34%@MoO_(3)exhibited the most remarkable adsorption capacity.More importantly,the composite maintains superior adsorption capacity for five consecutive adsorption/desorption cycles,suggesting that Al_(13)@MoO_(3)can be an efficient and durable adsorbent.
文摘The continued evolution of bacterial and fungal species poses a significant difficulty for the treatment of disease of microbial origin. Given this situation, the prevention of transmission of such microbial diseases becomes of increasing importance. Efforts of this laboratory have been directed toward the destruction of microbial species on environmental surfaces as a prophylaxis toward infection, and we herein report on the efficacy of a system that demonstrates activity against both Gram-positive and Gram-negative bacteria, as well as fungi. We report specifically herein on the use of fabric materials so activated for the destruction of these microbial species, useful for a variety of surfaces within hospital and related settings wherein transmission of microbial disease is a major problem, while these approaches are also applicable for a variety of other types of surfaces.
基金supported by the National Science Foundation of China(8217070298,81773283)the Guangdong Basic and Applied Basic Research Foundation(2021A1515220011,China).
文摘Although cancer immunotherapy has made great strides in the clinic,it is still hindered by the tumor immunosuppressive microenvironment(TIME).The stimulator of interferon genes(STING)pathway which can modulate TIME effectively has emerged as a promising therapeutic recently.However,the delivery of most STING agonists,specifically cyclic dinucleotides(CDNs),is performed intratumorally due to their insufficient pharmacological properties,such as weak permeability across cell membranes and vulnerability to nuclease degradation.To expand the clinical applicability of CDNs,a novel pH-sensitive polycationic polymer-modified lipid nanoparticle(LNP-B)system was developed for intravenous delivery of CDNs.LNP-B significantly extended the circulation of CDNs and enhanced the accumulation of CDNs within the tumor,spleen,and tumor-draining lymph nodes compared with free CDNs thereby triggering the STING pathway of dendritic cells and repolarizing pro-tumor macrophages.These events subsequently gave rise to potent anti-tumor immune reactions and substantial inhibition of tumors in CT26 colon cancer-bearing mouse models.In addition,due to the acid-sensitive property of the polycationic polymer,the delivery system of LNP-B was more biocompatible and safer compared with lipid nanoparticles formulated with an indissociable cationic DOTAP(LNP-D).These findings suggest that LNP-B has great potential in the intravenous delivery of CDNs for tumor immunotherapy.
