Lignocellulose shows significantly potential in sustainable conversion to high-quality fuel and valueadded chemicals with the demands for realizing the rapid cycle of carbon resources and helping to reach carbon neutr...Lignocellulose shows significantly potential in sustainable conversion to high-quality fuel and valueadded chemicals with the demands for realizing the rapid cycle of carbon resources and helping to reach carbon neutrality in nature.Selective tailoring of α-O-4,β-O-4,etc.linkages in lignin has always been viewed as "death blow" for its depolymerization.Herein,novel sodium lignosulfonate(SL) modified Fe_(3)O_(4)/TiO_(2)(SL-Fe_(3)O_(4)/TiO_(2)) spherical particles have been developed and used as catalysts for selectively photocatalytic oxidative cleavage of organosolv lignin.As expected,80% selective conversion of lignin in C2-C4 esters has been achieved,while C-O bonds in lignin model compounds can be effectively cleaved.Other than normal hydroxyl radical-mediated photocatalytic depolymerization of lignin over TiO_(2)-based materials,in this contribution,mechanism studies indicate that photogenerated holes and superoxide anion radicals are main active species,which trigger the cleavage of α/β-O-4 bond,and the isotopelabeling study confirms the crucial factor of C_β-H dehydrogenation in cleavage of β-O-4 bonds.展开更多
Whitefly-transmitted begomoviruses are economically important plant pathogens that cause severe problems in many crop plants,such as tomato,papaya,cotton,and tobacco.Tomato yellow leaf curl virus(TYLCV)is a typical mo...Whitefly-transmitted begomoviruses are economically important plant pathogens that cause severe problems in many crop plants,such as tomato,papaya,cotton,and tobacco.Tomato yellow leaf curl virus(TYLCV)is a typical monopartite begomovirus that has been extensively studied,but methods that can efficiently control begomoviruses are still scarce.In this study,we combined artificial microRNA(amiRNA)-mediated silencing technology and clay nanosheetmediated delivery by spraying and developed a method for efficiently preventing TYLCV infection in tomato plants.We designed three amiRNAs that target different regions of TYLCV to silence virus-produced transcripts.Three plant expression vectors expressing pre-amiRNAs were constructed,and recombinant plasmid DNAs(pDNAs)were loaded onto nontoxic and degradable layered double hydroxide(LDH)clay nanosheets.LDH nanosheets containing multiple pDNAs were sprayed onto plant leaves.We found that the designed amiRNAs were significantly accumulated in leaves 7 days after spraying,while the pDNAs were sustainably detected for 35 days after the spray,suggesting that the LDH nanosheets released pDNAs in a sustained manner,protected pDNAs from degradation and efficiently delivered pDNAs into plant cells.Importantly,when the LDH nanosheets coated with pDNAs were sprayed onto plants infected by TYLCV,both the disease severity and TYLCV viral concentration in sprayed plants were significantly decreased during the 35 days,while the levels of H_(2)O_(2) were significantly increased in those plants.Taken together,these results indicate that LDH nanosheets loaded with pDNAs expressing amiRNAs can be a sustainable and promising tool for begomovirus control.展开更多
Ionic liquids(ILs) have attracted increasing attention since last few decades due to their high molecular design abilities and wide applications in different fields.In this study,four novel fluorescent isoquinolino [2...Ionic liquids(ILs) have attracted increasing attention since last few decades due to their high molecular design abilities and wide applications in different fields.In this study,four novel fluorescent isoquinolino [2,1-a]quinoxalin-5-ium ILs were designed and synthesized via a two-step process including a simple dual Schiff’s base formation and a subsequent [RhCp*Cl_(2)]_(2)-catalyzed oxidative C-H activation/annulation reaction.The as-synthesized ILs were extensively characterized using FT-IR,~1 H-NMR,^(13)C-NMR,^(19)F-NMR,HSQC-NMR,HMBC-NMR and HR-MS.Their photophysical properties were determined by steady-state fluorescence spectroscopy.The results demonstrate that all these ILs showed dual or triple emissions,large stokes shift(90 nm) and mechanochromic behaviors.Basing on solvatochromism and titration experiments,it is thought that the emission bands of the ILs are raised from their local excited states,charge transfer states or excited state proton transfer of cations,while the substitute effect of these quinoxaline derived ILs on their stokes shifts is negligible.展开更多
As one of the three major components of woody biomass,lignin is a kind of natural organic polymer and the only abundant natural renewable resource with aromatic nucleus.Chemical catalysis induced depolymerization is a...As one of the three major components of woody biomass,lignin is a kind of natural organic polymer and the only abundant natural renewable resource with aromatic nucleus.Chemical catalysis induced depolymerization is an important and effective approach for lignin utilization.In particular,photocatalysis and electrocatalysis show great potential in accurately activating C-O/C-C bonds,which is a critical point of selective cleavage of lignin.In this contribution,we focus on radical and(photo)electron transfer induced reaction mechanisms of the photo(electro)catalytic depolymerization of lignin.Primarily,the general situation of Carbon-centered radicals and active oxygen species mediated lignin conversion has been discussed.Then the mechanisms for(photo)electron transfer mediated lignin depolymerization have been summarized.At the end of this review,the challenges and opportunities of photo(electro)catalysis in the applications of lignin valorization have been forecasted.展开更多
Setting time as the fourth dimension,4D printing allows us to construct dynamic structures that can change their shape,property,or functionality over time under stimuli,leading to a wave of innovations in various fiel...Setting time as the fourth dimension,4D printing allows us to construct dynamic structures that can change their shape,property,or functionality over time under stimuli,leading to a wave of innovations in various fields.Recently,4D printing of smart biomaterials,biological components,and living cells into dynamic living 3D constructs with 4D effects has led to an exciting field of 4D bioprinting.4D bioprinting has gained increasing attention and is being applied to create programmed and dynamic cell-laden constructs such as bone,cartilage,and vasculature.This review presents an overview on 4D bioprinting for engineering dynamic tissues and organs,followed by a discussion on the approaches,bioprinting technologies,smart biomaterials and smart design,bioink requirements,and applications.While much progress has been achieved,4D bioprinting as a complex process is facing challenges that need to be addressed by transdisciplinary strategies to unleash the full potential of this advanced biofabrication technology.Finally,we present future perspectives on the rapidly evolving field of 4D bioprinting,in view of its potential,increasingly important roles in the development of advanced dynamic tissues for basic research,pharmaceutics,and regenerative medicine.展开更多
Eucalyptus chemithermomechanical pulp(CTMP)was modified with the white-rot fungus 19-6 in a stationary culture condition.Different factors that influence the effect of white-rot fungus treatment,including additional n...Eucalyptus chemithermomechanical pulp(CTMP)was modified with the white-rot fungus 19-6 in a stationary culture condition.Different factors that influence the effect of white-rot fungus treatment,including additional nutrition,pH value,temperature,treatment time and oxygen input were investigated.The results show that the energy consumption of post refining of CTMP treated by white-rot fungus 19-6 was lower than that of untreated pulp and the strength properties also obviously improved.At a freeness level of about 330 mL,compared to the untreated pulp,the tensile index,tear index and internal bonding strength increased by 21.3%,27.4% and 33.1%,respectively.Unfortunately,the treatment with white-rot fungus substantially decreased all optical properties except for opacity,which was essentially unchanged.Brightness and light scatter-ing coefficient were reduced to as much as 25%and 21%compared to the untreated pulps.However,after a tow-stage“Na_(2)S_(2)O_(4)-H_(2)O_(2)”bleaching,the final brightness can reach 70.3%ISO,which is similar to that of the untreated CTMP.展开更多
Carbon-enriched lignocelluloses are regarded as the perfect alternative for nonrenewable fossil fuel, and have a great potential to alleviate the increasing energy crisis and climate change. However, the tightly coval...Carbon-enriched lignocelluloses are regarded as the perfect alternative for nonrenewable fossil fuel, and have a great potential to alleviate the increasing energy crisis and climate change. However, the tightly covalent structure and strong intra and in- ter-molecular hydrogen bonding in lignoceUulose make it high recalcitrance to transformation due to the poor solubility in wa- ter or common organic solvents. Dissolution and transformation of lignocellulose and its constituents in ionic liquids have therefore attracted much attention recently due to the tunable physical-chemical properties. Here, ionic liquids with excellent dissolving capability for biomass and its ingredients were examined. The technologies for lignocellulose biorefining in the presence of ionic liquid solvents or catalysts were also summarized. Some pertinent suggestions for the future catalytic conver- sion and unitization of this sustained carbon-rich resource are proposed.展开更多
Soft hydrogels are excellent candidate materials for repairing various tissue defects,yet the mechanical strength,anti-swelling properties,and biocompatibility of many soft hydrogels need to be improved.Herein,inspire...Soft hydrogels are excellent candidate materials for repairing various tissue defects,yet the mechanical strength,anti-swelling properties,and biocompatibility of many soft hydrogels need to be improved.Herein,inspired by the nanostructure of collagen fibrils,we developed a strategy toward achieving a soft but tough,anti-swelling nanofibrillar hydrogel by combining the self-assembly and chemical crosslinking of nanoparticles.Specifically,the collagen fibril-like injectable hydrogel was subtly designed and fabricated by self-assembling methylacrylyl hydroxypropyl chitosan(HM)with laponite(LAP)to form nanoparticles,followed by the inter-nanoparticle bonding through photo-crosslinking.The assembly mechanism of nanoparticles was elucidated by both experimental and simulation techniques.Due to the unique structure of the crosslinked nanoparticles,the nanocomposite hydrogels exhibited low stiffness(G’<2 kPa),high compressive strength(709 kPa),and anti-swelling(swelling ratio of 1.07 in PBS)properties.Additionally,by harnessing the photo-crosslinking ability of the nanoparticles,the nanocomposite hydrogels were processed as microgels,which can be three-dimensionally(3D)printed into complex shapes.Furthermore,we demonstrated that these nanocomposite hydrogels are highly biocompatible,biodegradability,and can effectively promote fibroblast migration and accelerate blood vessel formation during wound healing.This work presents a promising approach to develop biomimetic,nanofibrillar soft hydrogels for regenerative medicine applications.展开更多
With high biocompatibility and degradability,polysaccharide-based hydrogels are favorable healthcare materials.However,in many biomedical applications,these materials are inconvenient to handle with fixed morphology,u...With high biocompatibility and degradability,polysaccharide-based hydrogels are favorable healthcare materials.However,in many biomedical applications,these materials are inconvenient to handle with fixed morphology,unable to closely match the wounds,and easy to detach due to insufficient adhesion.Inspired by the superior wet adhesive properties of marine mussels,researchers have used mussel-inspired chemistry to create mussel-mimetic injectable polysaccharide-based hydrogels that are simple to operate,controllable in shape,and highly adhesive,and have significantly extended their applications such as tissue adhesives,delivery vehicles,tissue engineering scaffolds,and wearable sensors.However,there are few comprehensive reviews on polysaccharide-based hydrogels with both mussel-mimetic adhesion and injectability,and few critical analyses of these hydrogels'preparation methods and applications.This review fills this gap and systematically summarizes the preparation strategies for novel mussel-mimetic injectable polysaccharide-based hydrogels,including modifying polysaccharides with catechol-or pyrogallol-containing small molecules and leveraging different interactions between catechol-/pyrogallol-modified polysaccharides and other substances to form crosslinked hydrogels.Furthermore,recent biomedical applications of injectable catechol-/pyrogallol-modified polysaccharide-based hydrogels are discussed,and their future challenges and research trends are proposed.展开更多
The application of porous carbon microspheres derived from pure biomass in supercapacitors is restricted due to their limited reactive groups.MXene owns a combination of redox Faradic surface with good metallic conduc...The application of porous carbon microspheres derived from pure biomass in supercapacitors is restricted due to their limited reactive groups.MXene owns a combination of redox Faradic surface with good metallic conductivity and hydrophilicity,which assists to obtain high pseudocapaci-tance and energy density.Herein,Ti_(3)C_(2)T_(x)MXene was introduced to chitosan-based porous carbon microsphere(CPCM)to fabricated sandwich-like structure(CPCM/MXene)through electrostatic interaction.The Ti_(3)C_(2)T_(x)protected the spherical structure of CPCM.Meanwhile,CPCM hindered the reaggregation of Ti_(3)C_(2)T_(x)by inserting in the Ti_(3)C_(2)T_(x)layers,promoting the electrolyte migra-tion kinetics.The synergistic effect endowed CPCM/MXene high specific capacitance of 362 F/g at current density of 0.5 A/g and acceptable cycling stability with 93.87%capacitance retention at a high current density of 10 A/g after 10,000 cycles.Furthermore,CPCM/MXene displayed a high energy density of 27.8 W/(h•kg)at 500.0 W/kg of power density.These satisfactory perfor-mances prove that combining Ti_(3)C_(2)T_(x)MXene nanosheets with porous carbon microspheres is a considering method to construct a new generation electrode material of supercapacitor.展开更多
The sunlight is the largest single available source of clean and renewable energy to ensure human society＇s sustainable devel- opment. Owing to their low production cost and high energy conversion efficiency, dye-sen...The sunlight is the largest single available source of clean and renewable energy to ensure human society＇s sustainable devel- opment. Owing to their low production cost and high energy conversion efficiency, dye-sensitized solar cells （DSSCs） have been regarded as good alternatives to conventional photovoltaic devices. Herein, a series of composite electrolytes based on poly（ethylene oxide） （PEO） and the binary ionic liquids 1-propyl-3-methy-imidazolium iodide （[PMIm]I） and l-ethyl-3- methylimidazolium thiocyanate （[EMIm][SCN]） were prepared and then applied to fabricate six DSSCs. The composite elec- trolytes were characterized by fourier transform infrared spectroscopy （FTIS）, X-ray diffraction （XRD）, and electrochemical impedance spectra （EIS）. It was shown that the addition of binary ionic liquids would reduce the degree of crystallinity of PEO thus improving the ionic conductivities of the electrolytes by about 2 orders of magnitude. Investigation on the photovoltaic performances of these DSSCs showed that the fill factor （FF） could reach up to 0.67 and energy conversion efficiency （η） could reach up to 4.04% under AM 1.5 full sunlight （100 mW/cm^2）.展开更多
The comparison of pentachlorophenol(PCP)degradation was conducted under micro-aeration and anaerobic condition with three series of batch experiment,results of which indicated that during micro-aeration condition co-i...The comparison of pentachlorophenol(PCP)degradation was conducted under micro-aeration and anaerobic condition with three series of batch experiment,results of which indicated that during micro-aeration condition co-immobilized of anaerobic granular sludge and isolated aerobic bacterial species could enhance the efficiency of PCP reduction through the synergism of aerobes and anaerobes reductive dechlorination and exchange of metabolites within the co-immobilized granular sludge.While during anaerobic condition,there was no great difference in the three series.The specific activities experiment further confirmed that strict anaerobes were not affected over the presence of micro aeration environment.Microorganism community construc-tion of co-immobilized anaerobic granular sludge and the mixed isolated aerobic community was also deduced.By the efficient cooperation of aerobes and anaerobes,the high efficiency removal rate of PCP was implemented.展开更多
基金the financial support of the Natural Science Foundation of China (21736003, 22178130 and 22005106)the Natural Science Foundation of Guangdong Province, China (2020A0505100008)the Science and Technology Program of Guangzhou (202206010024)。
文摘Lignocellulose shows significantly potential in sustainable conversion to high-quality fuel and valueadded chemicals with the demands for realizing the rapid cycle of carbon resources and helping to reach carbon neutrality in nature.Selective tailoring of α-O-4,β-O-4,etc.linkages in lignin has always been viewed as "death blow" for its depolymerization.Herein,novel sodium lignosulfonate(SL) modified Fe_(3)O_(4)/TiO_(2)(SL-Fe_(3)O_(4)/TiO_(2)) spherical particles have been developed and used as catalysts for selectively photocatalytic oxidative cleavage of organosolv lignin.As expected,80% selective conversion of lignin in C2-C4 esters has been achieved,while C-O bonds in lignin model compounds can be effectively cleaved.Other than normal hydroxyl radical-mediated photocatalytic depolymerization of lignin over TiO_(2)-based materials,in this contribution,mechanism studies indicate that photogenerated holes and superoxide anion radicals are main active species,which trigger the cleavage of α/β-O-4 bond,and the isotopelabeling study confirms the crucial factor of C_β-H dehydrogenation in cleavage of β-O-4 bonds.
基金funded by the National Natural Science Foundation of China(31801707)the Key Projects of Science and Technology Research in Henan Province(182102110470)+3 种基金the Plant Protection of Key Discipline Project of Henan province(107020219001/005)the National Key Research and Development Program of China(2016YFD0300203-3)First-Class Postdoctoral Research Grant in Henan Province(001701038)the Science-Technology Foundation for High Level Talent of Henan Institute of Science and Technology(2015028).
文摘Whitefly-transmitted begomoviruses are economically important plant pathogens that cause severe problems in many crop plants,such as tomato,papaya,cotton,and tobacco.Tomato yellow leaf curl virus(TYLCV)is a typical monopartite begomovirus that has been extensively studied,but methods that can efficiently control begomoviruses are still scarce.In this study,we combined artificial microRNA(amiRNA)-mediated silencing technology and clay nanosheetmediated delivery by spraying and developed a method for efficiently preventing TYLCV infection in tomato plants.We designed three amiRNAs that target different regions of TYLCV to silence virus-produced transcripts.Three plant expression vectors expressing pre-amiRNAs were constructed,and recombinant plasmid DNAs(pDNAs)were loaded onto nontoxic and degradable layered double hydroxide(LDH)clay nanosheets.LDH nanosheets containing multiple pDNAs were sprayed onto plant leaves.We found that the designed amiRNAs were significantly accumulated in leaves 7 days after spraying,while the pDNAs were sustainably detected for 35 days after the spray,suggesting that the LDH nanosheets released pDNAs in a sustained manner,protected pDNAs from degradation and efficiently delivered pDNAs into plant cells.Importantly,when the LDH nanosheets coated with pDNAs were sprayed onto plants infected by TYLCV,both the disease severity and TYLCV viral concentration in sprayed plants were significantly decreased during the 35 days,while the levels of H_(2)O_(2) were significantly increased in those plants.Taken together,these results indicate that LDH nanosheets loaded with pDNAs expressing amiRNAs can be a sustainable and promising tool for begomovirus control.
基金the financial support of the Natural Science Foundation of Guangdong Province (Grant No. 2020A0505100008)the Science and Technology Program of Guangzhou, China (202206010024)。
文摘Ionic liquids(ILs) have attracted increasing attention since last few decades due to their high molecular design abilities and wide applications in different fields.In this study,four novel fluorescent isoquinolino [2,1-a]quinoxalin-5-ium ILs were designed and synthesized via a two-step process including a simple dual Schiff’s base formation and a subsequent [RhCp*Cl_(2)]_(2)-catalyzed oxidative C-H activation/annulation reaction.The as-synthesized ILs were extensively characterized using FT-IR,~1 H-NMR,^(13)C-NMR,^(19)F-NMR,HSQC-NMR,HMBC-NMR and HR-MS.Their photophysical properties were determined by steady-state fluorescence spectroscopy.The results demonstrate that all these ILs showed dual or triple emissions,large stokes shift(90 nm) and mechanochromic behaviors.Basing on solvatochromism and titration experiments,it is thought that the emission bands of the ILs are raised from their local excited states,charge transfer states or excited state proton transfer of cations,while the substitute effect of these quinoxaline derived ILs on their stokes shifts is negligible.
基金financial support of the National Natural Science Foundation of China,China(Grant No.21736003,21975082)the Guangdong Basic and Applied Basic Research Foundation(Grant Number:2019A1515011472)the Science and Technology Program of Guangzhou(Grant Number:202102080479)。
文摘As one of the three major components of woody biomass,lignin is a kind of natural organic polymer and the only abundant natural renewable resource with aromatic nucleus.Chemical catalysis induced depolymerization is an important and effective approach for lignin utilization.In particular,photocatalysis and electrocatalysis show great potential in accurately activating C-O/C-C bonds,which is a critical point of selective cleavage of lignin.In this contribution,we focus on radical and(photo)electron transfer induced reaction mechanisms of the photo(electro)catalytic depolymerization of lignin.Primarily,the general situation of Carbon-centered radicals and active oxygen species mediated lignin conversion has been discussed.Then the mechanisms for(photo)electron transfer mediated lignin depolymerization have been summarized.At the end of this review,the challenges and opportunities of photo(electro)catalysis in the applications of lignin valorization have been forecasted.
基金support from CUHK’s Vice-Chancellor Early Career Professorship Scheme and CUHK Research Committee (via Direct Grant for Research 2022/2023,4055182)supported by the Lee Quo Wei and Lee Yik Hoi Lun Professorship in Tissue Engineering and Regenerative Medicine of CUHK+2 种基金supported by the Center for Neuromusculoskeletal Restorative Medicine (to RST,ZAL,GL,and PSY),under the Health@InnoHK program launched by the Innovation and Technology Commission,the Government of the Hong Kong SAR of the People’s Republic of China,the National Natural Science Foundation of China (to ZAL,82302753)the Research Grants Council of Hong Kong SAR of the People’s Republic of China (to ZAL,24203523)support from the Shenzhen Science and Technology Project (JCYJ20210324102815040).
文摘Setting time as the fourth dimension,4D printing allows us to construct dynamic structures that can change their shape,property,or functionality over time under stimuli,leading to a wave of innovations in various fields.Recently,4D printing of smart biomaterials,biological components,and living cells into dynamic living 3D constructs with 4D effects has led to an exciting field of 4D bioprinting.4D bioprinting has gained increasing attention and is being applied to create programmed and dynamic cell-laden constructs such as bone,cartilage,and vasculature.This review presents an overview on 4D bioprinting for engineering dynamic tissues and organs,followed by a discussion on the approaches,bioprinting technologies,smart biomaterials and smart design,bioink requirements,and applications.While much progress has been achieved,4D bioprinting as a complex process is facing challenges that need to be addressed by transdisciplinary strategies to unleash the full potential of this advanced biofabrication technology.Finally,we present future perspectives on the rapidly evolving field of 4D bioprinting,in view of its potential,increasingly important roles in the development of advanced dynamic tissues for basic research,pharmaceutics,and regenerative medicine.
基金This work was supported by the National Basic Research Program of China(No 2006 CB 708614).
文摘Eucalyptus chemithermomechanical pulp(CTMP)was modified with the white-rot fungus 19-6 in a stationary culture condition.Different factors that influence the effect of white-rot fungus treatment,including additional nutrition,pH value,temperature,treatment time and oxygen input were investigated.The results show that the energy consumption of post refining of CTMP treated by white-rot fungus 19-6 was lower than that of untreated pulp and the strength properties also obviously improved.At a freeness level of about 330 mL,compared to the untreated pulp,the tensile index,tear index and internal bonding strength increased by 21.3%,27.4% and 33.1%,respectively.Unfortunately,the treatment with white-rot fungus substantially decreased all optical properties except for opacity,which was essentially unchanged.Brightness and light scatter-ing coefficient were reduced to as much as 25%and 21%compared to the untreated pulps.However,after a tow-stage“Na_(2)S_(2)O_(4)-H_(2)O_(2)”bleaching,the final brightness can reach 70.3%ISO,which is similar to that of the untreated CTMP.
基金financial support of the National Natural Science Foundation of China (20876055, 21076085)the Natural Science Foundation of Guangdong Province (S2011020001472)the Fundamental Research Funds for the Central Universities, SCUT
文摘Carbon-enriched lignocelluloses are regarded as the perfect alternative for nonrenewable fossil fuel, and have a great potential to alleviate the increasing energy crisis and climate change. However, the tightly covalent structure and strong intra and in- ter-molecular hydrogen bonding in lignoceUulose make it high recalcitrance to transformation due to the poor solubility in wa- ter or common organic solvents. Dissolution and transformation of lignocellulose and its constituents in ionic liquids have therefore attracted much attention recently due to the tunable physical-chemical properties. Here, ionic liquids with excellent dissolving capability for biomass and its ingredients were examined. The technologies for lignocellulose biorefining in the presence of ionic liquid solvents or catalysts were also summarized. Some pertinent suggestions for the future catalytic conver- sion and unitization of this sustained carbon-rich resource are proposed.
基金financially supported in part by the Guangdong Basic and Applied Basic Research Foundation(Nos.2020B1515120038 and 2021A1515012154)the Fundamental Research Funds for the Central Universities(No.2022ZYGXZR105)+3 种基金the National Natural Science Foundation of China(Nos.82072470 and 81871809)the State Key Laboratory of Pulp and Paper Engineering(No.2022C02)supported by the High-performance Computing Platform of Guangxi Universitysupport from the Vice-Chancellor Early Career Professorship Scheme of The Chinese University of Hong Kong.
文摘Soft hydrogels are excellent candidate materials for repairing various tissue defects,yet the mechanical strength,anti-swelling properties,and biocompatibility of many soft hydrogels need to be improved.Herein,inspired by the nanostructure of collagen fibrils,we developed a strategy toward achieving a soft but tough,anti-swelling nanofibrillar hydrogel by combining the self-assembly and chemical crosslinking of nanoparticles.Specifically,the collagen fibril-like injectable hydrogel was subtly designed and fabricated by self-assembling methylacrylyl hydroxypropyl chitosan(HM)with laponite(LAP)to form nanoparticles,followed by the inter-nanoparticle bonding through photo-crosslinking.The assembly mechanism of nanoparticles was elucidated by both experimental and simulation techniques.Due to the unique structure of the crosslinked nanoparticles,the nanocomposite hydrogels exhibited low stiffness(G’<2 kPa),high compressive strength(709 kPa),and anti-swelling(swelling ratio of 1.07 in PBS)properties.Additionally,by harnessing the photo-crosslinking ability of the nanoparticles,the nanocomposite hydrogels were processed as microgels,which can be three-dimensionally(3D)printed into complex shapes.Furthermore,we demonstrated that these nanocomposite hydrogels are highly biocompatible,biodegradability,and can effectively promote fibroblast migration and accelerate blood vessel formation during wound healing.This work presents a promising approach to develop biomimetic,nanofibrillar soft hydrogels for regenerative medicine applications.
基金This work was supported by the Guangdong Basic and Applied Basic Research Foundation(No.2020B1515120038)the Fundamental Research Funds for the Central Universities(No.2022ZYGXZR105)+4 种基金Science and Technology Planning Project of Guangzhou City(No.2023B03J1332)ZAL acknowledges the support from CUHK's Vice‐Chancellor Early Career Professorship Scheme,CUHK Research Committee(via Direct Grant for Research 2022/2023,4055182)the National Natural Science Foundation of China(82302753)the Research Grants Council of Hong Kong SAR of the People's Republic of China(24203523)the Center for Neuromusculoskeletal Restorative Medicine(CNRM)under the Health@InnoHK program launched by the Innovation and Technology Commission,the Government of the Hong Kong SAR of the People's Republic of China.
文摘With high biocompatibility and degradability,polysaccharide-based hydrogels are favorable healthcare materials.However,in many biomedical applications,these materials are inconvenient to handle with fixed morphology,unable to closely match the wounds,and easy to detach due to insufficient adhesion.Inspired by the superior wet adhesive properties of marine mussels,researchers have used mussel-inspired chemistry to create mussel-mimetic injectable polysaccharide-based hydrogels that are simple to operate,controllable in shape,and highly adhesive,and have significantly extended their applications such as tissue adhesives,delivery vehicles,tissue engineering scaffolds,and wearable sensors.However,there are few comprehensive reviews on polysaccharide-based hydrogels with both mussel-mimetic adhesion and injectability,and few critical analyses of these hydrogels'preparation methods and applications.This review fills this gap and systematically summarizes the preparation strategies for novel mussel-mimetic injectable polysaccharide-based hydrogels,including modifying polysaccharides with catechol-or pyrogallol-containing small molecules and leveraging different interactions between catechol-/pyrogallol-modified polysaccharides and other substances to form crosslinked hydrogels.Furthermore,recent biomedical applications of injectable catechol-/pyrogallol-modified polysaccharide-based hydrogels are discussed,and their future challenges and research trends are proposed.
基金supported by National Natural Science Foundation of China(No.22078119)Fundamental Re-search Funds for the Central Universities(No.2020ZYGXZR066)+1 种基金Guangdong Basic and Applied Basic Research Foundation(No.2020B1515120038 and No.2020A1515110004)China Postdoctoral Science Foundation(No.2020M682716).
文摘The application of porous carbon microspheres derived from pure biomass in supercapacitors is restricted due to their limited reactive groups.MXene owns a combination of redox Faradic surface with good metallic conductivity and hydrophilicity,which assists to obtain high pseudocapaci-tance and energy density.Herein,Ti_(3)C_(2)T_(x)MXene was introduced to chitosan-based porous carbon microsphere(CPCM)to fabricated sandwich-like structure(CPCM/MXene)through electrostatic interaction.The Ti_(3)C_(2)T_(x)protected the spherical structure of CPCM.Meanwhile,CPCM hindered the reaggregation of Ti_(3)C_(2)T_(x)by inserting in the Ti_(3)C_(2)T_(x)layers,promoting the electrolyte migra-tion kinetics.The synergistic effect endowed CPCM/MXene high specific capacitance of 362 F/g at current density of 0.5 A/g and acceptable cycling stability with 93.87%capacitance retention at a high current density of 10 A/g after 10,000 cycles.Furthermore,CPCM/MXene displayed a high energy density of 27.8 W/(h•kg)at 500.0 W/kg of power density.These satisfactory perfor-mances prove that combining Ti_(3)C_(2)T_(x)MXene nanosheets with porous carbon microspheres is a considering method to construct a new generation electrode material of supercapacitor.
基金the financial support of the National Natural Science Foundation of China (21006035, 21076085)Science and Technology Key Project of Guangdong Province (2006A10702004,S2011020001472)the Fundamental Research Funds for the Central Universities, South China University of Technology
文摘The sunlight is the largest single available source of clean and renewable energy to ensure human society＇s sustainable devel- opment. Owing to their low production cost and high energy conversion efficiency, dye-sensitized solar cells （DSSCs） have been regarded as good alternatives to conventional photovoltaic devices. Herein, a series of composite electrolytes based on poly（ethylene oxide） （PEO） and the binary ionic liquids 1-propyl-3-methy-imidazolium iodide （[PMIm]I） and l-ethyl-3- methylimidazolium thiocyanate （[EMIm][SCN]） were prepared and then applied to fabricate six DSSCs. The composite elec- trolytes were characterized by fourier transform infrared spectroscopy （FTIS）, X-ray diffraction （XRD）, and electrochemical impedance spectra （EIS）. It was shown that the addition of binary ionic liquids would reduce the degree of crystallinity of PEO thus improving the ionic conductivities of the electrolytes by about 2 orders of magnitude. Investigation on the photovoltaic performances of these DSSCs showed that the fill factor （FF） could reach up to 0.67 and energy conversion efficiency （η） could reach up to 4.04% under AM 1.5 full sunlight （100 mW/cm^2）.
基金This research was funded by the National Natural Science Foundation of China(Grant No.20676045)State Key Laboratory of Pulp and Paper Engineering,South China University of Technology(200552).
文摘The comparison of pentachlorophenol(PCP)degradation was conducted under micro-aeration and anaerobic condition with three series of batch experiment,results of which indicated that during micro-aeration condition co-immobilized of anaerobic granular sludge and isolated aerobic bacterial species could enhance the efficiency of PCP reduction through the synergism of aerobes and anaerobes reductive dechlorination and exchange of metabolites within the co-immobilized granular sludge.While during anaerobic condition,there was no great difference in the three series.The specific activities experiment further confirmed that strict anaerobes were not affected over the presence of micro aeration environment.Microorganism community construc-tion of co-immobilized anaerobic granular sludge and the mixed isolated aerobic community was also deduced.By the efficient cooperation of aerobes and anaerobes,the high efficiency removal rate of PCP was implemented.
