Elastomers are widely used in various fields owing to their excellent tensile properties.Recyclable and self-healing properties are key to extending the service life of elastomers.Accumulating evidence indicates that ...Elastomers are widely used in various fields owing to their excellent tensile properties.Recyclable and self-healing properties are key to extending the service life of elastomers.Accumulating evidence indicates that dynamic covalent chemistry has emerged as a powerful tool for constructing recyclable and self-healing materials.In this work,we demonstrate the preparation of a recyclable and self-healable polydimethylsiloxane(PDMS)elastomer based on the Knoevenagel condensation(KC)reaction.This PDMS elastomer was prepared by the KC reaction catalyzed by 4-dimethylaminopyridine(DMAP).The obtained PDMS elastomer exhibited an elongation at break of 266%,a tensile strength of 0.57 MPa,and a good thermal stability(Td=357℃).In addition,because of the presence of dynamic C=C bonds formed by the KC reaction and low glass transition temperature(Tg=-117℃).This PDMS exhibited good self-healing and recycling properties at room temperature and could be reprocessed by hot pressing.In addition,the PDMS elastomer exhibits good application prospects in the fields of adhesives and flexible electronic devices.展开更多
Aliphatic polyesters and polycarbonates are among the promising sustainable polymers,which exhibit unique degradability and chain-chain interactions owing to their heterofunctionality.However,monocomponent aliphatic p...Aliphatic polyesters and polycarbonates are among the promising sustainable polymers,which exhibit unique degradability and chain-chain interactions owing to their heterofunctionality.However,monocomponent aliphatic polyesters and polycarbonates usually suffer from inferior properties and functionalities.By contrast,precisely modulated block copolymers composed of polyesters and polycarbonates give rise to sustainable materials with tailored performance.An efficient approach to synthesize the block copolymers is the ring-opening(co)polymerization of the heterocycle monomers.Herein,this review presents the heterocycle monomer ring-opening(co)polymerization for the formation of sequence-controlled block polyesters and polycarbonates.Available synthetic strategies,different monomers,monomer combinations and the catalyst systems for the formation of different block polyesters and polycarbonates are summarized.展开更多
Chemical modification of polymers represents a pivotal method for achieving functionalized polymer materials.However,due to the lack of post-functional handle,the chemical modification of polyester materials remains a...Chemical modification of polymers represents a pivotal method for achieving functionalized polymer materials.However,due to the lack of post-functional handle,the chemical modification of polyester materials remains a significant challenge.Ring-opening copolymerization of cyclic anhydride and epoxides is a powerful approach to synthesize polyesters.In this work,we for the first time demonstrate the functionalizability of polyesters synthesized with brominated anhydride monomers.The post-functionalization is amenable to a wide variety of reactive groups and reactions with high yields.With multiple well-established functionalization pathways of brominated polyester materials and optimized the conditions for the modification reactions,a series of functionalized polyester materials can be obtained with high yields,providing new insights for the research about functionalization of polymers.展开更多
It is important to understand the evolution of the matter on the polymer membrane surface.The in situ and real-time monitoring of the membrane surface will not only favor the investigation of selective layer formation...It is important to understand the evolution of the matter on the polymer membrane surface.The in situ and real-time monitoring of the membrane surface will not only favor the investigation of selective layer formation but can also track the fouling process during operation.Herein,an aggregation-induced emission(AIE)-active polymer membrane was prepared by the interfacial polymerization of a cyclodextrin-based glycocluster(CD@Glucose)and a tetraphenylethylene derivative modified with boronic acid groups(TPEDB)on the surface of a polyacrylonitrile(PAN)ultrafiltration membrane.This interfacial polymerization method can be stacked layer-by-layer to regulate the hydrophilicity and pore structure of the membrane.With the increase in the number of polymer layers,the separation and antifouling properties of the membrane gradually improved.Owing to the AIE property of the crosslinking agent TPEDB,the occurrence of interfacial polymerization and the degree of fouling during membrane operation can be monitored by the fluorescence distribution and intensity.With the aggravation of membrane fouling,the fluorescence decreased gradually,but recovered after cleaning.Therefore,this AIE effect can be used for real-time monitoring of interfacial polymerization as well as membrane fouling.展开更多
Immunotherapy offers the promise of a potential cure for cancer,yet achieving the desired therapeutic effect can be challenging due to the immunosuppressive tumor microenvironments(TMEs) present in some tumors.Therefo...Immunotherapy offers the promise of a potential cure for cancer,yet achieving the desired therapeutic effect can be challenging due to the immunosuppressive tumor microenvironments(TMEs) present in some tumors.Therefore,robust immune system activation is crucial to enhance the efficacy of cancer immunotherapy in clinical applications.Bacteria have shown the ability to target the hypoxic TMEs while activating both innate and adaptive immune responses.Engineered bacteria,modified through chemical or biological methods,can be endowed with specific physiological properties,such as diverse surface antigens,metabolites,and improved biocompatibility.These unique characteristics give engineered bacteria distinct advantages in stimulating anti-cancer immune responses.This review explores the potential regulatory mechanisms of engineered bacteria in modulating both innate and adaptive immunity while also forecasting the future development and challenges of using engineered bacteria in clinical cancer immunotherapy.展开更多
Oxidative stress,characterized by the excessive accumulation of reactive oxygen species(ROS),is linked to various pathological conditions,including myocardial infarction,cancer,and neurodegenerative diseases.Addressin...Oxidative stress,characterized by the excessive accumulation of reactive oxygen species(ROS),is linked to various pathological conditions,including myocardial infarction,cancer,and neurodegenerative diseases.Addressing ROS-induced cell damage has become a critical focus of biomedical research.In this study,a thermo-sensitive poly(amino acid)hydrogel,composed of poly(ethylene glycol)-block-poly(l-methionine),was prepared for cytoprotection through ROS scavenging.The sol-to-gel transition mechanism of the hydrogel was elucidated,and its potent antioxidant properties and cell protective effects were validated using hydrogen peroxide(H_(2)O_(2))-induced oxidative stress and oxygen-glucose deprivation(OGD)models.The hydrogel significantly mitigated H_(2)O_(2)-induced damage in L929 cells,doubling their survival rate.Additionally,it scavenged approximately 35.8%of the ROS during OGD,reducing mitochondrial oxidative damage and resulting in a 29.4%decrease in apoptotic cell number.These findings underscore the potential biomedical applications of thermo-sensitive poly(amino acid)hydrogels,particularly in treating oxidative stress-related cell damage.展开更多
Glioblastoma(GBM)is a highly infiltrative brain tumor.The treatment of GBM is challenging due to the existence of blood brain barrier,its highly invasive nature,and its heterogeneity.Given the limitations of conventio...Glioblastoma(GBM)is a highly infiltrative brain tumor.The treatment of GBM is challenging due to the existence of blood brain barrier,its highly invasive nature,and its heterogeneity.Given the limitations of conventional therapies,this Perspective explores the development trajectory of implantable devices,highlighting the advantages of current models.With the progression in research,these implantable devices certainly hold promising potential for GBM therapy.展开更多
It is well known that cationic polymers have excellent antimicrobial capacity accompanied with high biotoxicity,to reduce biotoxicity needs to decrease the number of cationic groups on polymers,which will influence an...It is well known that cationic polymers have excellent antimicrobial capacity accompanied with high biotoxicity,to reduce biotoxicity needs to decrease the number of cationic groups on polymers,which will influence antimicrobial activity.It is necessary to design a cationic polymer mimic natural antimicrobial peptide with excellent antibacterial activity and low toxicity to solve the above dilemma.Here,we designed and prepared a series of cationic poly(β-amino ester)s(PBAEs)with different cationic contents,and introducing hydrophobic alkyl chain to adjust the balance between antimicrobial activity and biotoxicity to obtain an ideal antimicrobial polymer.The optimum one of synthesized PBAE(hydrophilic cationic monomer:hydrophobic monomer=5:5)was screened by testing cytotoxicity and minimum inhibitory concentration(MIC),which can effectively kill S.aureus and E.coli with PBAE concentration of15μg/m L by a spread plate bacteriostatic method and dead and alive staining test.The way of PBAE killing bacterial was destroying the membrane like natural antimicrobial peptide observed by scanning electron microscopy(SEM).In addition,PBAE did not exhibit hemolysis and cytotoxicity.In particular,from the result of animal tests,the PBAE was able to promote healing of infected wounds from removing mature S.aureus and E.coli on the surface of infected wound.As a result,our work offers a viable approach for designing antimicrobial materials,highlighting the significant potential of PBAE polymers in the field of biomedical materials.展开更多
Tumor blockade therapy inhibits tumor progression by cutting off essential supplies of nutrients,oxygen,and biomolecules from the surrounding microenvironments.Inspired by natural processes,tumor biomineralization has...Tumor blockade therapy inhibits tumor progression by cutting off essential supplies of nutrients,oxygen,and biomolecules from the surrounding microenvironments.Inspired by natural processes,tumor biomineralization has evolved due to its biocompatibility,self-reinforcing capability,and penetrationindependent mechanism.However,the selective induction of tumor biomineralization using synthetic tools presents a significant challenge.Herein,a metabolic glycoengineering-assistant tumor biomineralization strategy was developed.Specifically,the azido group(N_(3))was introduced onto the cytomembrane by incubating tumor cells with glycose analog Ac4ManNAz.In addition,a bisphosphonate-containing polymer,dibenzocyclooctyne-poly(ethylene glycol)-alendronate(DBCO-PEG-ALN,DBPA)was synthesized,which attached to the tumor cell surface via"click chemistry"reaction between DBCO and N_(3).Subsequently,the bisphosphonate group on the cell surface chelated with positively charged ions in the microenvironments,triggering a consecutive process of biomineralization.This physical barrier significantly reduced tumor cell viability and mobility in a calcium ion concentration-dependent manner,suggesting its potential as an effective anti-tumor strategy for in vivo applications.展开更多
Chirality is pervasive and plays a crucial role in biological processes.Although amino acids possess inherent chirality,the stereochemical influence of this property on the regulation of immune cells remains insuffici...Chirality is pervasive and plays a crucial role in biological processes.Although amino acids possess inherent chirality,the stereochemical influence of this property on the regulation of immune cells remains insufficiently explored.To address this,the unimolecular chiral poly(amino acid)s were synthesized to evaluate their immunostimulatory effects and anti-cancer potential.Among the candidates,G0-P_(D)-Lys_(50)emerged as the most effective adjuvant through in vitro screening.When complexed with antigen ovalbumin(OVA)to form chiral nanovaccines,G0-P_(L)-Lys_(50)-OVA and G0-P_(D)-Lys_(50)-OVA exhibited similar morphology,particle size,and zeta potential.Despite these comparable physicochemical properties,G0-P_(D)Lys_(50)-OVA induced significantly stronger activation of dendritic cells(DCs).Specifically,it resulted in 1.38-and 1.34-fold increases in CD11c^(+)CD80^(+)DCs and CD11c^(+)SIINFEKL-H-2Kb^(+)DCs in lymph nodes,respectively.In the LLC-OVA cancer model,G0-P_(D)-Lys_(50)-OVA reduced tumor volume by 50%compared to its enantiomer.These results establish a unique approach to designing chiral nanovaccines and provide a foundational strategy for developing broadly applicable immunotherapies.展开更多
Poly(lactic acid)(PLA)is a biodegradable and eco-friendly polymer that is increasingly being incorporated into various applications in contemporary society.However,the limited stability of PLA-based products remains a...Poly(lactic acid)(PLA)is a biodegradable and eco-friendly polymer that is increasingly being incorporated into various applications in contemporary society.However,the limited stability of PLA-based products remains a significant challenge for their broader use in various applications.In this study,poly(L-lactic acid)(PLLA)/poly(D-lactic acid)(PDLA)melt-blown nonwovens were prepared by melt spinning.The structure,thermal properties,thermal stability,biodegradability and crystalline morphology of the melt-blown nonwovens were investigated.DSC and WAXD confirmed the formation of stereocomplex(SC)crystallites in the PLLA matrix.The storage modulus(G′),loss modulus(G″),and complex viscosity(∣η^(*)∣)of the PLLA/PDLA blend increased with an increase in SC crystallite content.The thermal degradation temperatures of PLLA/PDLA melt-blown nonwovens increased with the incorporation of SC crystallites,and the maximum rate of decomposition increased to 385.5℃,thus enhancing the thermal stability.Compared with neat PLLA melt-blown nonwovens,the hydrophobicity of PLLA/PDLA melt-blown nonwovens was improved,and WCA increased to 139.7°.The SC crystallites were more resistant to degradation by proteinase K compared to neat PLLA.However,the degradation rate of PLLA/PDLA melt-blown nonwovens remained at a high level.This work provides an effective strategy to obtain high-performance PLLA melt-blown nonwovens.展开更多
The oxygen evolution reaction(OER)is regarded as the bottleneck of electrolytic water splitting.Thus,developing robust earth-abundant electrocatalysts for efficient OER has received a great deal of attention and it is...The oxygen evolution reaction(OER)is regarded as the bottleneck of electrolytic water splitting.Thus,developing robust earth-abundant electrocatalysts for efficient OER has received a great deal of attention and it is an ongoing scientific challenge.Herein,hierarchical hollow nanorods assembled with ultrathin mesoporous cobalt silicate hydroxide nanosheets(denoted as CoSi)were successfully fabricated,using the silica nanotube derived from halloysite as a sacrificial template,via a simple hydrothermal method.The resulting cobalt silicate hydroxide nanosheets stack with thicknesses∼10 nm,as confirmed by transmis-sion electron microscopy.The elaborated nanoarchitecture possesses a high specific surface area(SSA)al-lowing good exposure to the cobalt active centers exhibiting superior catalytic activity vs analogs synthe-sized using sodium silicate.Among all as-prepared CoSi samples,those synthesized at 150℃(CoSi-150)exhibited the minimum overpotential of∼347 mV at a current density of 10 mA cm^(-2).In addition,CoSi-150 also exhibited superior performance against typical cobalt-based catalysts,and its surface hydroxyl groups were beneficial for the enhancement of OER performance.Furthermore,the CoSi-150 showed ex-cellent durability and stability after the 105 s chronopotentiometry test in 1 M KOH.This design concept provides a new strategy for the low-cost preparation of high-quality cobalt water splitting electrocata-lysts.展开更多
Antibacterial ceramic was prepared by doping enamel slurry with composite phosphate inorganic antibacterial materials containing rare earth (inorganic antibacterial additives), and then the mechanisms for activating w...Antibacterial ceramic was prepared by doping enamel slurry with composite phosphate inorganic antibacterial materials containing rare earth (inorganic antibacterial additives), and then the mechanisms for activating water and improving seed germinative property were tested by nuclear magnetic resonance (NMR) and the method of testing oxygen dissolved in activated water. Results show that the half peak width of (()^(17)O-NMR) for tap water activated by the antibacterial ceramic drops from 115.36 to 99.15 Hz, and oxygen concentrations of activated water increase by 20%, germinate rate of horsebean and earthnut seeds increases by 12.5% and 7.5%, respectively. Therefore antibacterial ceramic doped enamel slurry with inorganic antibacterial additives containing rare earth can reduce the volume of clusters of water molecules, improve activation of tap water, and promote plant seeds germinate.展开更多
Lithium iron phosphate （LiFePO4） doped with magnesium was hydrothermally synthesized from commercial LiOH, FeSO4, H3PO4 and MgSO4 with glucose as carbon precursor in aqueous solution. The samples were characterized ...Lithium iron phosphate （LiFePO4） doped with magnesium was hydrothermally synthesized from commercial LiOH, FeSO4, H3PO4 and MgSO4 with glucose as carbon precursor in aqueous solution. The samples were characterized by X-ray powder diffraction, scanning electron microscopy and constant charge-discharge cycling. The results show that the synthesized powders have been in situ coated with carbon precursor produced from caramel reaction of glucose. At ambient temperature （28±2℃）, the electrochemical performances of LiFePO4 prepared exhibit the high discharge capacity of 135 mAh g^-1 at 5C and good capacity retention of 98% over 90 cycles. The excellent electrochemical performances should be correlated with the intimate contact between carbon and LiFePO4 primary and secondary particles, resulting from the in situ formation of carbon precursor/carbon, leading to the increase in conductivity of LiFePO4.展开更多
A kind of new long life aluminum air batteries with open configuration was developed, using aluminum alloy doped with Ga, In, Sn, Bi, Pb and Mn as anode, NaCl solution as electrolyte and air electrode as cathode. The ...A kind of new long life aluminum air batteries with open configuration was developed, using aluminum alloy doped with Ga, In, Sn, Bi, Pb and Mn as anode, NaCl solution as electrolyte and air electrode as cathode. The polarization curves of aluminum electrode and air electrode were tested. And the cell′s performance was tested to calculate the utilization of aluminum electrode and the energy density. It is shown that, in the 3.5% NaCl solution, the cell can discharge at 0.29 A for 140 h with the working voltage keeping over 1.1 V. The utilization ratio of aluminum anode is over 44%, and the life of battery is longer than 2400 h.展开更多
The surface acidity of synthetic amorphous AI hydroxide was determined by acid/base titration with several complementary methods including solution analyses of the reacted solutions and XRD characterization of the rea...The surface acidity of synthetic amorphous AI hydroxide was determined by acid/base titration with several complementary methods including solution analyses of the reacted solutions and XRD characterization of the reacted solids. The synthetic specimen was characterized to be the amorphous material showing four broad peaks in XRD pattern. XRD analyses of reacted solids after the titration experiments showed that amorphous AI hydroxide rapidly transformed to crystalline bayerite at the alkaline condition （pH〉10）. The solution analyses after and during the titration Ksp=^aAl^3＋/aH^＋^3 ,was 10^10.3. The amount of consumption of added acid or base during the titration experiment was attributed to both the protonation/deprotonation of dissolved AI species and surface hydroxyl group. The surface acidity constants, surface hydroxyl density and specific surface area were estimated by FITEQL 4.0.展开更多
Poly（propylene carbonate） （PPC） was blended with polylactide （PLA） and poly（1,2-propylene glycol adipate） （PPA） using a twin screw extruder. Then the PPC/PLA/PPA films were prepared using the blown film tech...Poly（propylene carbonate） （PPC） was blended with polylactide （PLA） and poly（1,2-propylene glycol adipate） （PPA） using a twin screw extruder. Then the PPC/PLA/PPA films were prepared using the blown film technique. DMA results showed that PPA could act as a plasticizer and improve the miscibility between PPC and PLA. Crystal morphology displayed that blending PLA with the amorphous PPC led to a decrease of the spherulite size of PLA. The results of mechanical tests indicated that PPC-rich films showed high elongation at break and PLA-rich films showed high tear strength and good optical properties. The content of PPC and PLA significantly affected the physical properties of the films. With increasing PPC content, the melt strengths of the PPC/PLA/PPA films were enhanced. These findings contributed to the biodegradable materials application for designing and manufacturing polymer packaging.展开更多
Rare earth mineral composite materials were prepared using rare earths and natural far-infrared mineral materials . The influences of rare earth additive content and heat treatment temperature on the far infrared radi...Rare earth mineral composite materials were prepared using rare earths and natural far-infrared mineral materials . The influences of rare earth additive content and heat treatment temperature on the far infrared radiance were studied. The results show that the far infrared radiance of rare earth mineral composite materials is 0.93 when the rare earth additive content is 6% and heat treatment temperature is 750℃.展开更多
A biodegradable blend foaming material of poly(butylene adipate-co-terephthalate)(PBAT)/poly(propylene carbonate)(PPC)was successfully prepared by chemical foaming agent and screw extrusion method.First,PBAT was modif...A biodegradable blend foaming material of poly(butylene adipate-co-terephthalate)(PBAT)/poly(propylene carbonate)(PPC)was successfully prepared by chemical foaming agent and screw extrusion method.First,PBAT was modified by bis(tert-butyl dioxy isopropyl)benzene(BIBP)for chain extension,and then the extended PBAT(E-PBAT)was foamed with PPC using a twin(single)screw extruder.By analyzing the properties of the blends,we found that Young’s modulus increased from 58.8 MPa of E-PBAT to 244.7 MPa of E-PBAT/PPC 50/50.The viscosity of the polymer has a critical influence on the formation of cells.Compared with neat PBAT(N-PBAT),the viscosity of E-PBAT increased by 3396 Pa·s and E-PBAT/PPC 50/50 increased by 8836 Pa·s.Meanwhile,the dynamic mechanical analysis(DMA)results showed that the storage modulus(E’)at room temperature increased from 538 MPa to 1650 MPa.The various phase morphologies(“sea-island”,“quasi-co-continuous”and“cocontinuous”)and crystallinity of the blends affected the spread velocity of gas and further affected the foaming morphology in E-PBAT/PPC foam.Therefore,through the analysis of phase morphology and foaming mechanism,we concluded that the E-PBAT/PPC 70/30 component has both excellent strength and the best foaming performance.展开更多
The novel composite films containing clustered TiO2 particles and fine tourmaline particles on the surface of copper webs were prepared by the sol-gel method. The microstructures of the composite films were investigat...The novel composite films containing clustered TiO2 particles and fine tourmaline particles on the surface of copper webs were prepared by the sol-gel method. The microstructures of the composite films were investigated by scanning electron microscopy (SEM), and the photocatalytic activity of the films was evaluated by photocatalytic degradation of methyl orange, respectively. The results indicate that tourmaline particles can obviously influence the microstructures of TiO2 films and enhance the photocatalytic activity due to their spontaneous permanent polarity and high radiotechnology of far infrared. During preparing the composite films, the clustered TiO2 particles with lots of nano-sized ladder layers can grow on the surface of fine tourmaline particles, the thickness of ladder layer is 10 nm, and the average diameter of nano-sized TiO2 particles is 15 nm.展开更多
基金supported by the National Natural Science Foundation of China(Nos.51973025 and 52222307)Jilin Science and Technology Bureau(Nos.20220204107YY and 20230204086YY)+1 种基金Changchun Science and Technology Bureau(No.21ZGY06)Jilin Province Development and Reform Commission(No.2023C028-4).
文摘Elastomers are widely used in various fields owing to their excellent tensile properties.Recyclable and self-healing properties are key to extending the service life of elastomers.Accumulating evidence indicates that dynamic covalent chemistry has emerged as a powerful tool for constructing recyclable and self-healing materials.In this work,we demonstrate the preparation of a recyclable and self-healable polydimethylsiloxane(PDMS)elastomer based on the Knoevenagel condensation(KC)reaction.This PDMS elastomer was prepared by the KC reaction catalyzed by 4-dimethylaminopyridine(DMAP).The obtained PDMS elastomer exhibited an elongation at break of 266%,a tensile strength of 0.57 MPa,and a good thermal stability(Td=357℃).In addition,because of the presence of dynamic C=C bonds formed by the KC reaction and low glass transition temperature(Tg=-117℃).This PDMS exhibited good self-healing and recycling properties at room temperature and could be reprocessed by hot pressing.In addition,the PDMS elastomer exhibits good application prospects in the fields of adhesives and flexible electronic devices.
基金supported by the National Natural Science Foundation of China,Fund for Distinguished Young Scholars(No.52325301)CAS Project for Young Scientists in Basic Research(YSBR-094)the National Natural Science Foundation of China,Basic Science Center Program(No.51988102).
文摘Aliphatic polyesters and polycarbonates are among the promising sustainable polymers,which exhibit unique degradability and chain-chain interactions owing to their heterofunctionality.However,monocomponent aliphatic polyesters and polycarbonates usually suffer from inferior properties and functionalities.By contrast,precisely modulated block copolymers composed of polyesters and polycarbonates give rise to sustainable materials with tailored performance.An efficient approach to synthesize the block copolymers is the ring-opening(co)polymerization of the heterocycle monomers.Herein,this review presents the heterocycle monomer ring-opening(co)polymerization for the formation of sequence-controlled block polyesters and polycarbonates.Available synthetic strategies,different monomers,monomer combinations and the catalyst systems for the formation of different block polyesters and polycarbonates are summarized.
基金financially supported by the National Key R&D Program of China(No.2021YFA1501700)the Science and Technology Development Plan of Jilin Province(Nos.20230101042JC and 20210201059GX)+1 种基金the National Natural Science Foundation of China,Basic Science Center Program(No.51988102)the National Natural Science Foundation of China(Nos.52203017 and 52073272)。
文摘Chemical modification of polymers represents a pivotal method for achieving functionalized polymer materials.However,due to the lack of post-functional handle,the chemical modification of polyester materials remains a significant challenge.Ring-opening copolymerization of cyclic anhydride and epoxides is a powerful approach to synthesize polyesters.In this work,we for the first time demonstrate the functionalizability of polyesters synthesized with brominated anhydride monomers.The post-functionalization is amenable to a wide variety of reactive groups and reactions with high yields.With multiple well-established functionalization pathways of brominated polyester materials and optimized the conditions for the modification reactions,a series of functionalized polyester materials can be obtained with high yields,providing new insights for the research about functionalization of polymers.
基金supported by the Fundamental Research Funds for Central Universities(No.30922010811).
文摘It is important to understand the evolution of the matter on the polymer membrane surface.The in situ and real-time monitoring of the membrane surface will not only favor the investigation of selective layer formation but can also track the fouling process during operation.Herein,an aggregation-induced emission(AIE)-active polymer membrane was prepared by the interfacial polymerization of a cyclodextrin-based glycocluster(CD@Glucose)and a tetraphenylethylene derivative modified with boronic acid groups(TPEDB)on the surface of a polyacrylonitrile(PAN)ultrafiltration membrane.This interfacial polymerization method can be stacked layer-by-layer to regulate the hydrophilicity and pore structure of the membrane.With the increase in the number of polymer layers,the separation and antifouling properties of the membrane gradually improved.Owing to the AIE property of the crosslinking agent TPEDB,the occurrence of interfacial polymerization and the degree of fouling during membrane operation can be monitored by the fluorescence distribution and intensity.With the aggravation of membrane fouling,the fluorescence decreased gradually,but recovered after cleaning.Therefore,this AIE effect can be used for real-time monitoring of interfacial polymerization as well as membrane fouling.
基金supported by the Science and Technology Research Project of Jilin Education Bureau(No.JJKH20230804KJ)。
文摘Immunotherapy offers the promise of a potential cure for cancer,yet achieving the desired therapeutic effect can be challenging due to the immunosuppressive tumor microenvironments(TMEs) present in some tumors.Therefore,robust immune system activation is crucial to enhance the efficacy of cancer immunotherapy in clinical applications.Bacteria have shown the ability to target the hypoxic TMEs while activating both innate and adaptive immune responses.Engineered bacteria,modified through chemical or biological methods,can be endowed with specific physiological properties,such as diverse surface antigens,metabolites,and improved biocompatibility.These unique characteristics give engineered bacteria distinct advantages in stimulating anti-cancer immune responses.This review explores the potential regulatory mechanisms of engineered bacteria in modulating both innate and adaptive immunity while also forecasting the future development and challenges of using engineered bacteria in clinical cancer immunotherapy.
基金financially supported by the National Key R&D Program of China(No.2022YFB3808000)the National Natural Science Foundation of China(No.U21A2099)+2 种基金the Science and Technology Development Program of Jilin Province(No.20240101002JJ)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.Y2023066)the Plan for Enhancing Health Science and Technology Capacity in Jilin Province(No.2020J041).
文摘Oxidative stress,characterized by the excessive accumulation of reactive oxygen species(ROS),is linked to various pathological conditions,including myocardial infarction,cancer,and neurodegenerative diseases.Addressing ROS-induced cell damage has become a critical focus of biomedical research.In this study,a thermo-sensitive poly(amino acid)hydrogel,composed of poly(ethylene glycol)-block-poly(l-methionine),was prepared for cytoprotection through ROS scavenging.The sol-to-gel transition mechanism of the hydrogel was elucidated,and its potent antioxidant properties and cell protective effects were validated using hydrogen peroxide(H_(2)O_(2))-induced oxidative stress and oxygen-glucose deprivation(OGD)models.The hydrogel significantly mitigated H_(2)O_(2)-induced damage in L929 cells,doubling their survival rate.Additionally,it scavenged approximately 35.8%of the ROS during OGD,reducing mitochondrial oxidative damage and resulting in a 29.4%decrease in apoptotic cell number.These findings underscore the potential biomedical applications of thermo-sensitive poly(amino acid)hydrogels,particularly in treating oxidative stress-related cell damage.
基金financially supported by the National Natural Science Foundation of China(U23A20591 and 52273158).
文摘Glioblastoma(GBM)is a highly infiltrative brain tumor.The treatment of GBM is challenging due to the existence of blood brain barrier,its highly invasive nature,and its heterogeneity.Given the limitations of conventional therapies,this Perspective explores the development trajectory of implantable devices,highlighting the advantages of current models.With the progression in research,these implantable devices certainly hold promising potential for GBM therapy.
基金financially supported by the Natural Science Foundation of Jilin Province Science and Technology Department(No.20230101221JC)the National Natural Science Foundation of China(Nos.52173115,52073278,52203189)the Research Foundation for Advanced Talents of Xiamen University of Technology(Nos.5010423019,YKJ22052R)。
文摘It is well known that cationic polymers have excellent antimicrobial capacity accompanied with high biotoxicity,to reduce biotoxicity needs to decrease the number of cationic groups on polymers,which will influence antimicrobial activity.It is necessary to design a cationic polymer mimic natural antimicrobial peptide with excellent antibacterial activity and low toxicity to solve the above dilemma.Here,we designed and prepared a series of cationic poly(β-amino ester)s(PBAEs)with different cationic contents,and introducing hydrophobic alkyl chain to adjust the balance between antimicrobial activity and biotoxicity to obtain an ideal antimicrobial polymer.The optimum one of synthesized PBAE(hydrophilic cationic monomer:hydrophobic monomer=5:5)was screened by testing cytotoxicity and minimum inhibitory concentration(MIC),which can effectively kill S.aureus and E.coli with PBAE concentration of15μg/m L by a spread plate bacteriostatic method and dead and alive staining test.The way of PBAE killing bacterial was destroying the membrane like natural antimicrobial peptide observed by scanning electron microscopy(SEM).In addition,PBAE did not exhibit hemolysis and cytotoxicity.In particular,from the result of animal tests,the PBAE was able to promote healing of infected wounds from removing mature S.aureus and E.coli on the surface of infected wound.As a result,our work offers a viable approach for designing antimicrobial materials,highlighting the significant potential of PBAE polymers in the field of biomedical materials.
基金supported by the National Natural Science Foundation of China(Nos.U23A20591 and 52273158)the Science and Technology Development Program of Jilin Province(Nos.20240101002JJ and 20210504001GH).
文摘Tumor blockade therapy inhibits tumor progression by cutting off essential supplies of nutrients,oxygen,and biomolecules from the surrounding microenvironments.Inspired by natural processes,tumor biomineralization has evolved due to its biocompatibility,self-reinforcing capability,and penetrationindependent mechanism.However,the selective induction of tumor biomineralization using synthetic tools presents a significant challenge.Herein,a metabolic glycoengineering-assistant tumor biomineralization strategy was developed.Specifically,the azido group(N_(3))was introduced onto the cytomembrane by incubating tumor cells with glycose analog Ac4ManNAz.In addition,a bisphosphonate-containing polymer,dibenzocyclooctyne-poly(ethylene glycol)-alendronate(DBCO-PEG-ALN,DBPA)was synthesized,which attached to the tumor cell surface via"click chemistry"reaction between DBCO and N_(3).Subsequently,the bisphosphonate group on the cell surface chelated with positively charged ions in the microenvironments,triggering a consecutive process of biomineralization.This physical barrier significantly reduced tumor cell viability and mobility in a calcium ion concentration-dependent manner,suggesting its potential as an effective anti-tumor strategy for in vivo applications.
基金financially supported by the National Natural Science Foundation of China(Nos.U23A20591,82472144,52273158,52273159,and W2421115)the Science and Technology Department Project of Jilin Province(No.20220204018YY)+3 种基金the Industrial Technology Research and Development Project of Jilin Province(No.2023C040-8)the Health Research Talent Special Project of Jilin Province(Nos.2023SCZ70 and 2024SCZ46)the Youth Innovation Promotion Association of Chinese Academy of Sciences(No.Y2023066)the Bethune Project of Jilin University(No.2023B01)。
文摘Chirality is pervasive and plays a crucial role in biological processes.Although amino acids possess inherent chirality,the stereochemical influence of this property on the regulation of immune cells remains insufficiently explored.To address this,the unimolecular chiral poly(amino acid)s were synthesized to evaluate their immunostimulatory effects and anti-cancer potential.Among the candidates,G0-P_(D)-Lys_(50)emerged as the most effective adjuvant through in vitro screening.When complexed with antigen ovalbumin(OVA)to form chiral nanovaccines,G0-P_(L)-Lys_(50)-OVA and G0-P_(D)-Lys_(50)-OVA exhibited similar morphology,particle size,and zeta potential.Despite these comparable physicochemical properties,G0-P_(D)Lys_(50)-OVA induced significantly stronger activation of dendritic cells(DCs).Specifically,it resulted in 1.38-and 1.34-fold increases in CD11c^(+)CD80^(+)DCs and CD11c^(+)SIINFEKL-H-2Kb^(+)DCs in lymph nodes,respectively.In the LLC-OVA cancer model,G0-P_(D)-Lys_(50)-OVA reduced tumor volume by 50%compared to its enantiomer.These results establish a unique approach to designing chiral nanovaccines and provide a foundational strategy for developing broadly applicable immunotherapies.
基金financially supported by the fund of the Science and Technology Development Plan Project of Jilin Province of China(No.20240304161SF)the Science and Technology Development Plan Project of Jilin Province of China(No.20220203019SF)+1 种基金the Science and Technology Bureau of Changchun City of China(Nos.23SH11,23SH08)the Chinese Science Academy(Changchun Branch)(No.2024SYHZ0038).
文摘Poly(lactic acid)(PLA)is a biodegradable and eco-friendly polymer that is increasingly being incorporated into various applications in contemporary society.However,the limited stability of PLA-based products remains a significant challenge for their broader use in various applications.In this study,poly(L-lactic acid)(PLLA)/poly(D-lactic acid)(PDLA)melt-blown nonwovens were prepared by melt spinning.The structure,thermal properties,thermal stability,biodegradability and crystalline morphology of the melt-blown nonwovens were investigated.DSC and WAXD confirmed the formation of stereocomplex(SC)crystallites in the PLLA matrix.The storage modulus(G′),loss modulus(G″),and complex viscosity(∣η^(*)∣)of the PLLA/PDLA blend increased with an increase in SC crystallite content.The thermal degradation temperatures of PLLA/PDLA melt-blown nonwovens increased with the incorporation of SC crystallites,and the maximum rate of decomposition increased to 385.5℃,thus enhancing the thermal stability.Compared with neat PLLA melt-blown nonwovens,the hydrophobicity of PLLA/PDLA melt-blown nonwovens was improved,and WCA increased to 139.7°.The SC crystallites were more resistant to degradation by proteinase K compared to neat PLLA.However,the degradation rate of PLLA/PDLA melt-blown nonwovens remained at a high level.This work provides an effective strategy to obtain high-performance PLLA melt-blown nonwovens.
基金supported by the Central Government Guiding Local Science and Technology Development Fund Projects(No.236Z4108G)China Scholarship Council,the National Natu-ral Science Foundation of China(No.51874115)+2 种基金the Open Project of State Key Laboratory of Environment-friendly Energy Materials(No.22kfhg09)the Open Project of Key Laboratory of Solid Waste Treatment and Resource Recycle of Ministry of Education(No.22kfgk01)the Youth Talent Support Program of Hebei Province,the Giant Plan Innovation Team Project of Hebei Province,and the Excellent Young Scientist Foundation of Hebei province,China(No.E2018202241).
文摘The oxygen evolution reaction(OER)is regarded as the bottleneck of electrolytic water splitting.Thus,developing robust earth-abundant electrocatalysts for efficient OER has received a great deal of attention and it is an ongoing scientific challenge.Herein,hierarchical hollow nanorods assembled with ultrathin mesoporous cobalt silicate hydroxide nanosheets(denoted as CoSi)were successfully fabricated,using the silica nanotube derived from halloysite as a sacrificial template,via a simple hydrothermal method.The resulting cobalt silicate hydroxide nanosheets stack with thicknesses∼10 nm,as confirmed by transmis-sion electron microscopy.The elaborated nanoarchitecture possesses a high specific surface area(SSA)al-lowing good exposure to the cobalt active centers exhibiting superior catalytic activity vs analogs synthe-sized using sodium silicate.Among all as-prepared CoSi samples,those synthesized at 150℃(CoSi-150)exhibited the minimum overpotential of∼347 mV at a current density of 10 mA cm^(-2).In addition,CoSi-150 also exhibited superior performance against typical cobalt-based catalysts,and its surface hydroxyl groups were beneficial for the enhancement of OER performance.Furthermore,the CoSi-150 showed ex-cellent durability and stability after the 105 s chronopotentiometry test in 1 M KOH.This design concept provides a new strategy for the low-cost preparation of high-quality cobalt water splitting electrocata-lysts.
文摘Antibacterial ceramic was prepared by doping enamel slurry with composite phosphate inorganic antibacterial materials containing rare earth (inorganic antibacterial additives), and then the mechanisms for activating water and improving seed germinative property were tested by nuclear magnetic resonance (NMR) and the method of testing oxygen dissolved in activated water. Results show that the half peak width of (()^(17)O-NMR) for tap water activated by the antibacterial ceramic drops from 115.36 to 99.15 Hz, and oxygen concentrations of activated water increase by 20%, germinate rate of horsebean and earthnut seeds increases by 12.5% and 7.5%, respectively. Therefore antibacterial ceramic doped enamel slurry with inorganic antibacterial additives containing rare earth can reduce the volume of clusters of water molecules, improve activation of tap water, and promote plant seeds germinate.
文摘Lithium iron phosphate （LiFePO4） doped with magnesium was hydrothermally synthesized from commercial LiOH, FeSO4, H3PO4 and MgSO4 with glucose as carbon precursor in aqueous solution. The samples were characterized by X-ray powder diffraction, scanning electron microscopy and constant charge-discharge cycling. The results show that the synthesized powders have been in situ coated with carbon precursor produced from caramel reaction of glucose. At ambient temperature （28±2℃）, the electrochemical performances of LiFePO4 prepared exhibit the high discharge capacity of 135 mAh g^-1 at 5C and good capacity retention of 98% over 90 cycles. The excellent electrochemical performances should be correlated with the intimate contact between carbon and LiFePO4 primary and secondary particles, resulting from the in situ formation of carbon precursor/carbon, leading to the increase in conductivity of LiFePO4.
基金This work was financially supported by the Doctor Foundation of Hebei Province (045472226D-1).
文摘A kind of new long life aluminum air batteries with open configuration was developed, using aluminum alloy doped with Ga, In, Sn, Bi, Pb and Mn as anode, NaCl solution as electrolyte and air electrode as cathode. The polarization curves of aluminum electrode and air electrode were tested. And the cell′s performance was tested to calculate the utilization of aluminum electrode and the energy density. It is shown that, in the 3.5% NaCl solution, the cell can discharge at 0.29 A for 140 h with the working voltage keeping over 1.1 V. The utilization ratio of aluminum anode is over 44%, and the life of battery is longer than 2400 h.
文摘The surface acidity of synthetic amorphous AI hydroxide was determined by acid/base titration with several complementary methods including solution analyses of the reacted solutions and XRD characterization of the reacted solids. The synthetic specimen was characterized to be the amorphous material showing four broad peaks in XRD pattern. XRD analyses of reacted solids after the titration experiments showed that amorphous AI hydroxide rapidly transformed to crystalline bayerite at the alkaline condition （pH〉10）. The solution analyses after and during the titration Ksp=^aAl^3＋/aH^＋^3 ,was 10^10.3. The amount of consumption of added acid or base during the titration experiment was attributed to both the protonation/deprotonation of dissolved AI species and surface hydroxyl group. The surface acidity constants, surface hydroxyl density and specific surface area were estimated by FITEQL 4.0.
基金financially supported by the fund of Science&Technology Bureau of Jilin Province of China(No.20130305028NY)Chinese Science Academy(Changchun Branch)(No.2014SYHZ0019)+1 种基金the National High Technology Research and Development Program of China(863 Program)(No.2012AA062904)the National Natural Science Foundation of China(No.51021003)
文摘Poly（propylene carbonate） （PPC） was blended with polylactide （PLA） and poly（1,2-propylene glycol adipate） （PPA） using a twin screw extruder. Then the PPC/PLA/PPA films were prepared using the blown film technique. DMA results showed that PPA could act as a plasticizer and improve the miscibility between PPC and PLA. Crystal morphology displayed that blending PLA with the amorphous PPC led to a decrease of the spherulite size of PLA. The results of mechanical tests indicated that PPC-rich films showed high elongation at break and PLA-rich films showed high tear strength and good optical properties. The content of PPC and PLA significantly affected the physical properties of the films. With increasing PPC content, the melt strengths of the PPC/PLA/PPA films were enhanced. These findings contributed to the biodegradable materials application for designing and manufacturing polymer packaging.
基金Project supported by the Key Technologies R & D Programme of Tianjin (06YFGZGX02400)
文摘Rare earth mineral composite materials were prepared using rare earths and natural far-infrared mineral materials . The influences of rare earth additive content and heat treatment temperature on the far infrared radiance were studied. The results show that the far infrared radiance of rare earth mineral composite materials is 0.93 when the rare earth additive content is 6% and heat treatment temperature is 750℃.
基金financially supported by the National Key Research and Development Program of China(No.2016YFC0501402)Science and Technology Services Network Program of Chinese Science Academy(STS Project)(No.KFJSTS-ZDTP-082)Chinese Academy of Sciences(Changchun Branch)(Nos.2020SYHZ0002 and No.2020SYHZ0047)。
文摘A biodegradable blend foaming material of poly(butylene adipate-co-terephthalate)(PBAT)/poly(propylene carbonate)(PPC)was successfully prepared by chemical foaming agent and screw extrusion method.First,PBAT was modified by bis(tert-butyl dioxy isopropyl)benzene(BIBP)for chain extension,and then the extended PBAT(E-PBAT)was foamed with PPC using a twin(single)screw extruder.By analyzing the properties of the blends,we found that Young’s modulus increased from 58.8 MPa of E-PBAT to 244.7 MPa of E-PBAT/PPC 50/50.The viscosity of the polymer has a critical influence on the formation of cells.Compared with neat PBAT(N-PBAT),the viscosity of E-PBAT increased by 3396 Pa·s and E-PBAT/PPC 50/50 increased by 8836 Pa·s.Meanwhile,the dynamic mechanical analysis(DMA)results showed that the storage modulus(E’)at room temperature increased from 538 MPa to 1650 MPa.The various phase morphologies(“sea-island”,“quasi-co-continuous”and“cocontinuous”)and crystallinity of the blends affected the spread velocity of gas and further affected the foaming morphology in E-PBAT/PPC foam.Therefore,through the analysis of phase morphology and foaming mechanism,we concluded that the E-PBAT/PPC 70/30 component has both excellent strength and the best foaming performance.
基金Project(E2004000033) supported by the Natural Science Foundation of Hebei Province, China
文摘The novel composite films containing clustered TiO2 particles and fine tourmaline particles on the surface of copper webs were prepared by the sol-gel method. The microstructures of the composite films were investigated by scanning electron microscopy (SEM), and the photocatalytic activity of the films was evaluated by photocatalytic degradation of methyl orange, respectively. The results indicate that tourmaline particles can obviously influence the microstructures of TiO2 films and enhance the photocatalytic activity due to their spontaneous permanent polarity and high radiotechnology of far infrared. During preparing the composite films, the clustered TiO2 particles with lots of nano-sized ladder layers can grow on the surface of fine tourmaline particles, the thickness of ladder layer is 10 nm, and the average diameter of nano-sized TiO2 particles is 15 nm.
