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
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
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
Vanadium flow batteries(VFBs)have drawn considerable attention as an emerging technology for largescale energy storage systems(ESSs).One of the pivotal challenges is the availability of eligible ion exchange membranes...Vanadium flow batteries(VFBs)have drawn considerable attention as an emerging technology for largescale energy storage systems(ESSs).One of the pivotal challenges is the availability of eligible ion exchange membranes(ICMs)that provide high ion selectivity,proton conductivity,and stability under rigorous condition.Herein,a‘side-chain-type’strategy has been employed to fabricate highly stable phenolphthalein-based cardo poly(arylene ether ketone)s(PAEKs)membrane with low area resistance(0.058Ωcm^(2)),in which flexible alkyl spacers effectively alleviated inductive withdrawing effect from terminal ion exchange groups thus enabling a stable backbone.The assembled VFBs based on PAEKs bearing pendent alkyl chain terminated with quaternary ammonium(Q-PPhEK)demonstrated an energy efficiency above 80%over 700 cycles at 160 mA/cm^(2).Such a remarkable results revealed that the side-chain-type strategy contributed to enhancing the ICMs stability in strong oxidizing environment,meanwhile,more interesting backbones would be woken with this design engaging in stable ICMs for VFBs.展开更多
Neurological injury caused by ischemic stroke is a major cause of permanent disability and death. The currently available neuroprotective drugs fail to achieve desired therapeutic efficacy mainly due to short circulat...Neurological injury caused by ischemic stroke is a major cause of permanent disability and death. The currently available neuroprotective drugs fail to achieve desired therapeutic efficacy mainly due to short circulation half-life and poor blood−brain barrier (BBB) permeability. For that, an edaravone-loaded pH/glutathione (pH/GSH) dual-responsive poly(amino acid) nanogel (NG/EDA) was developed to improve the neuroprotection of EDA. The nanogel was triggered by acidic and EDA-induced high-level GSH microenvironments, which enabled the selective and sustained release of EDA at the site of ischemic injury. NG/EDA exhibited a uniform sub-spherical morphology with a mean hydrodynamic diameter of 112.3 ± 8.2 nm. NG/EDA efficiently accumulated at the cerebral ischemic injury site of permanent middle cerebral artery occlusion (pMCAO) mice, showing an efficient BBB crossing feature. Notably, NG/EDA with 50 µM EDA significantly increased neuron survival (29.3%) following oxygen and glucose deprivation by inhibiting ferroptosis. In addition, administering NG/EDA for 7 d significantly reduced infarct volume to 22.2% ± 7.2% and decreased neurobehavioral scores from 9.0 ± 0.6 to 2.0 ± 0.8. Such a pH/GSH dual-responsive nanoplatform might provide a unique and promising modality for neuroprotection in ischemic stroke and other central nervous system diseases.展开更多
The synthesis of degradable polymers with easy-to-break in-chain carbon-oxygen bonds has attracted much attention.This minireview introduces the synthesis of a variety of degradable polymers from the(co)polymerization...The synthesis of degradable polymers with easy-to-break in-chain carbon-oxygen bonds has attracted much attention.This minireview introduces the synthesis of a variety of degradable polymers from the(co)polymerizations of several typical oxygenated monomers such as epoxides,cyclic carbonates,cyclic esters,carbon dioxide(CO_(2)),carbonyl sulfide(COS),and cyclic anhydrides.We highlight the catalysts and mechanisms for these(co)polymerizations.The ring-opening copolymerization of five-membered carbonate with cyclic anhydride or COS has been introduced.We also highlight the synthesis of block copolymers and cyclic copolymers with well-defined sequences by the method of growing center switching.We hope that these new polymerization systems can provide new ideas for the development of degradable low-carbon polymers in the future.展开更多
Biomass electrooxidation has garnered much attention in recent years,owing to its potential to circumvent greenhouse gas emissions.Substituting the sluggish water oxidation with biomass oxidizable species such as lign...Biomass electrooxidation has garnered much attention in recent years,owing to its potential to circumvent greenhouse gas emissions.Substituting the sluggish water oxidation with biomass oxidizable species such as lignin at anode is thermodynamically more favorable,enabling energy efficient hydrogen production and concomitant fine chemicals.The present study shows the organosolv lignin electrooxidation in an additively manufactured 3D printed reactor(3DPR)consisting of platinized nickel foam(PtNF)as anode and cathode and compared with commercial hardware electrolyzer(CHE).The electrolysis of organosolv lignin in 3DPR outperformed CHE by achieving 1.23 times higher current at an applied voltage range from 0 to 2.2 V with a membrane(Nafion 115)interposed between anode and cathode under a continuous flow of lignin feed at the anode.The chronoamperometry study reveals a mixture of diverse aromatic compounds,including vanillic acid,syringic acid,3,5-dimethoxy-4-hydroxyacetophenone,2-hydroxyacetophenone,4-ethycathecol,and 2,6-dimethoxyphenol in anolyte,and sinapic acid and vanillin acetate in catholyte.Thus,realizing renewable biomass electrolysis in the 3DPR is an intriguing strategy for the co-production of hydrogen and fine aromatic chemicals.展开更多
It is of great interest to make a degradable material widely tailorable to replace petroleum-derived products among diverse applications.Here,we report the construction of a new multi-purpose degradable material for t...It is of great interest to make a degradable material widely tailorable to replace petroleum-derived products among diverse applications.Here,we report the construction of a new multi-purpose degradable material for the first time via a simple ternary copolymerization system comprisingε-caprolactone(ε-CL),cyclohexane oxide(CHO)and CO_(2).Under low pressure of 1 bar∼5 bar,the ring-opening polymerization(ROP)ofε-CL and ring-opening copolymerization(ROCOP)of CO_(2) and CHO can simultaneously proceed.The carbonate units are randomly distributed on the polymer chain.These random terpolymers have controllable molar mass(10-106 kDa)and compositions(4-33 mol%CO_(2)).And the obtained materials show large-span tunability from tough plastic to elastomer and even adhesive.展开更多
A series of transparent crosslinked colorless polyimide(CPI)films are prepared from 3,3',4,4'-biphenyltetracarboxylic dianhydride(BPDA),2,2'-bis(trifluoro-methyl)benzidine(TFMB),and 4,4'-oxydianiline(O...A series of transparent crosslinked colorless polyimide(CPI)films are prepared from 3,3',4,4'-biphenyltetracarboxylic dianhydride(BPDA),2,2'-bis(trifluoro-methyl)benzidine(TFMB),and 4,4'-oxydianiline(ODA)by thermal imidization,incorporating varying contents of 2,2'-(1,3-phenylene)bis(2-oxazoline)(1,3-PBO)as the crosslinking agent.Following the incorporation of the crosslinking structure,the CPI films show good optical transparency(approximately 85%winthin visible light range),enhanced glass transition temperature(from 325℃to 341℃),and improved thermal stability,and tensile strength.Notably,compared with the pristine uncrosslinked CPI,these crosslinked CPI films significantly increase in elongation at break(from 5.4%to 44.2%).Furthermore,the new approach ensures that crosslinked CPIs improve heat resistance and mechanical properties,while avoiding the embrittlement of materials.This study also offeres straightforward preparation methods for optically transparent crosslinked polyimides without additional processing steps.All these results make this approach can effectively improve the competitive performance of the CPI films for potential applications in microelectronic and optoelectronic fields.展开更多
Owing to its high production volume and wide range of application s,polyethylene has gained a great deal of attention,but its low surface energy and non-polar nature have limited its application in some important fiel...Owing to its high production volume and wide range of application s,polyethylene has gained a great deal of attention,but its low surface energy and non-polar nature have limited its application in some important fields.In this study,ethylene/11-iodo-1-undecene copolymers were prepared and used as the intermediates to afford a series of imidazolium-based ionomers bearing methanesulfonate(CH_(3)SO_(3)^(-)),trifluoromethanesulfonate(CF_(3)SO_(3)^(-)),or bis(trifluoromethane)sulfonimide(Tf_(2)N^(-))counteranions.The tensile test results showed that the stress-at-break(7.8-25.6 MPa)and the elongation-at-break(445%-847%)of the ionomers could be adjusted by changing the counterion species and the ionic group contents.Most importantly,the ionomers exhibited marvelous antibacterial activities against Staphylococcus aureus(S.aureus)and Escherichia coli(E.coli).The ionomers bearing Tf_(2)N^(-)exhibited antibacterial activities>99%against both S.aureus and E.coli when ionic content reached 9.1%.The imidazolium-based ionomers prepared in this work demonstrated excellent comprehensive properties,especially highefficient and broad-spectrum antibacterial ability,exhibiting the potential fo r the application as the antibacterial materials in packaging,medical,and other fields.展开更多
A new strategy for the metal-free coordination–insertion ring-opening polymerization of tetrahydrofuran by the central metalloid Boron has been first identified.Bis(pentafluorophenyl)(phenoxy)borane was used as a cat...A new strategy for the metal-free coordination–insertion ring-opening polymerization of tetrahydrofuran by the central metalloid Boron has been first identified.Bis(pentafluorophenyl)(phenoxy)borane was used as a catalyst for the polymerization reaction system.And polytetrahydrofuran with high molecular weight and narrow molecular weight distribution could be obtained.The proposed mechanism was studied by MALDI-TOF,ESI-MS and O-18 isotope labeling analyses as a metal-free coordination insertion mechanism.展开更多
The early diagnosis of cancer is vital for effective treatment and improved prognosis. Tumor biomarkers, which can be used for the early diagnosis, treatment, and prognostic evaluation of cancer, have emerged as a top...The early diagnosis of cancer is vital for effective treatment and improved prognosis. Tumor biomarkers, which can be used for the early diagnosis, treatment, and prognostic evaluation of cancer, have emerged as a topic of intense research interest in recent years. Nucleic acid, as a type of tumor biomarker, contains vital genetic information, which is of great significance for the occurrence and development of cancer. Currently, living cell nucleic acid probes, which enable the in situ imaging and dynamic monitoring of nucleic acids, have become a rapidly developing field. This review focuses on living cell nucleic acid probes that can be used for the early diagnosis of tumors. We describe the fundamental design of the probe in terms of three units and focus on the roles of different nanomaterials in probe delivery.展开更多
Stroke is the second leading cause of death and the primary cause of permanent disability worldwide.Ischemic stroke(IS)accounts for 87%of all strokes globally and is characterized by the occlusion of cerebral vasculat...Stroke is the second leading cause of death and the primary cause of permanent disability worldwide.Ischemic stroke(IS)accounts for 87%of all strokes globally and is characterized by the occlusion of cerebral vasculature due to embolic presence.Clinical treatments for IS include enzymatic thrombolysis,mechanical thrombectomy,and neuroprotection.However,these approaches have obvious limitations.First,early vascular recanalization leads to secondary cascade injuries and a high risk of hemorrhagic transformation,resulting in poor clinical outcomes for patients with IS.In addition,neuroprotective agents often fail to achieve satisfactory clinical efficacy due to inadequate drug concentrations and off-target effects[1].Targeted stimuli-responsive nanoformulations for thrombolysis and neuroprotection have been developed to address these limitations in current clinical treatments.These nanoformulations are based on IS-specific thrombus-associated receptors and the pathological microenvironments,showing great promise in treating IS(Figure A).展开更多
Polyester and polyether are two key oxygenated polymers, and completely alternative sequence of poly(ester-alt-ether) could efficiently combine the advantages(including flexibility, degradability, etc.) of both segmen...Polyester and polyether are two key oxygenated polymers, and completely alternative sequence of poly(ester-alt-ether) could efficiently combine the advantages(including flexibility, degradability, etc.) of both segments. Currently, despite their copolymers could be synthesized from one-pot mixture of cyclic esters and epoxides, perfectly alternative microstructure is very challenging to realize and typically restricted to certain monomer pairs. Moving forward, synthesizing poly(ester-alt-ether) from commercially available and largescale monomers would be a significant advance. For example, successfully commercialized poly(glycolic acid)(PGA), which is not easily soluble in polymers due to its high crystallinity and is brittle and difficult to control the degradation cycle, would encounter a new paradigm if engineered into poly(ester-altether). In this work, starting from the design of monomer with hybrid structures, we successfully synthesized a series of 1,4-dioxan-2-one containing different substituents based on glycolide(GA) and epoxides using commercially available Salen-Cr(III) and PPNCl catalytic systems.The new monomers underwent ring-opening polymerization(ROP) to form a series of poly(ester-alt-ether) with perfectly alternating glycolic acid and propylene glycol repeat units under catalytic system of thiourea/base. The poly(ester-alt-ether) have significantly lower glass-transition temperature than PGA. Additionally, the poly(ester-alt-ether) can be chemically recovered to monomer using Sn(Oct)2 or 1,8-diazabicyclo[5.4.0]undecane-7-ene(DBU) as a catalyst in solution, thus establishing a closed-loop life cycle. From monomers derived from GA and epoxides, this work furnishes a novel strategy for the synthesis of poly(ester-alt-ether) with chemical recyclability.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 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the financial support of the National Natural Science Foundation of China(Nos.22075276,U19A2016,U22B6012)CAS Strategic Leading Science&Technology Program(A)(No.XDA21070000)+2 种基金Dalian High Level Talent Innovation Support Program(No.2020RD05)the Development of Scientic and Technological Project of the Jilin Province(No.20210101126JC)International Partnership Program of Chinese Academy of Sciences(No.121421KYSB20210028)。
文摘Vanadium flow batteries(VFBs)have drawn considerable attention as an emerging technology for largescale energy storage systems(ESSs).One of the pivotal challenges is the availability of eligible ion exchange membranes(ICMs)that provide high ion selectivity,proton conductivity,and stability under rigorous condition.Herein,a‘side-chain-type’strategy has been employed to fabricate highly stable phenolphthalein-based cardo poly(arylene ether ketone)s(PAEKs)membrane with low area resistance(0.058Ωcm^(2)),in which flexible alkyl spacers effectively alleviated inductive withdrawing effect from terminal ion exchange groups thus enabling a stable backbone.The assembled VFBs based on PAEKs bearing pendent alkyl chain terminated with quaternary ammonium(Q-PPhEK)demonstrated an energy efficiency above 80%over 700 cycles at 160 mA/cm^(2).Such a remarkable results revealed that the side-chain-type strategy contributed to enhancing the ICMs stability in strong oxidizing environment,meanwhile,more interesting backbones would be woken with this design engaging in stable ICMs for VFBs.
基金supported by the National Natural Science Foundation of China(Grant No.U23A20591,52203201,52173149,and 81971174)the Youth Talents Promotion Project of Jilin Province(Grant No.202019)+1 种基金the Science and Technology Development Program of Jilin Province(Grant No.20210101114JC)Research Cooperation Platform Project of Sino-Japanese Friendship Hospital of Jilin University and Basic Medical School of Jilin University(Grant No.KYXZ2022JC04).
文摘Neurological injury caused by ischemic stroke is a major cause of permanent disability and death. The currently available neuroprotective drugs fail to achieve desired therapeutic efficacy mainly due to short circulation half-life and poor blood−brain barrier (BBB) permeability. For that, an edaravone-loaded pH/glutathione (pH/GSH) dual-responsive poly(amino acid) nanogel (NG/EDA) was developed to improve the neuroprotection of EDA. The nanogel was triggered by acidic and EDA-induced high-level GSH microenvironments, which enabled the selective and sustained release of EDA at the site of ischemic injury. NG/EDA exhibited a uniform sub-spherical morphology with a mean hydrodynamic diameter of 112.3 ± 8.2 nm. NG/EDA efficiently accumulated at the cerebral ischemic injury site of permanent middle cerebral artery occlusion (pMCAO) mice, showing an efficient BBB crossing feature. Notably, NG/EDA with 50 µM EDA significantly increased neuron survival (29.3%) following oxygen and glucose deprivation by inhibiting ferroptosis. In addition, administering NG/EDA for 7 d significantly reduced infarct volume to 22.2% ± 7.2% and decreased neurobehavioral scores from 9.0 ± 0.6 to 2.0 ± 0.8. Such a pH/GSH dual-responsive nanoplatform might provide a unique and promising modality for neuroprotection in ischemic stroke and other central nervous system diseases.
基金the National Science Foundation of China(Nos.52203129,51973190)Zhejiang Provincial Department of Science and Technology(No.2020R52006).
文摘The synthesis of degradable polymers with easy-to-break in-chain carbon-oxygen bonds has attracted much attention.This minireview introduces the synthesis of a variety of degradable polymers from the(co)polymerizations of several typical oxygenated monomers such as epoxides,cyclic carbonates,cyclic esters,carbon dioxide(CO_(2)),carbonyl sulfide(COS),and cyclic anhydrides.We highlight the catalysts and mechanisms for these(co)polymerizations.The ring-opening copolymerization of five-membered carbonate with cyclic anhydride or COS has been introduced.We also highlight the synthesis of block copolymers and cyclic copolymers with well-defined sequences by the method of growing center switching.We hope that these new polymerization systems can provide new ideas for the development of degradable low-carbon polymers in the future.
基金This project received financial support from Natural Sciences and Engineering Research Council of Canada via a Discovery Grant(2022-00058)Canada Research Chair Fund(3266004)+1 种基金The Fonds de recherche du Quebec-Nature et technologies FRQNT(NCR-327419)We would also like to thank Intlvac Thin Film team for the support.
文摘Biomass electrooxidation has garnered much attention in recent years,owing to its potential to circumvent greenhouse gas emissions.Substituting the sluggish water oxidation with biomass oxidizable species such as lignin at anode is thermodynamically more favorable,enabling energy efficient hydrogen production and concomitant fine chemicals.The present study shows the organosolv lignin electrooxidation in an additively manufactured 3D printed reactor(3DPR)consisting of platinized nickel foam(PtNF)as anode and cathode and compared with commercial hardware electrolyzer(CHE).The electrolysis of organosolv lignin in 3DPR outperformed CHE by achieving 1.23 times higher current at an applied voltage range from 0 to 2.2 V with a membrane(Nafion 115)interposed between anode and cathode under a continuous flow of lignin feed at the anode.The chronoamperometry study reveals a mixture of diverse aromatic compounds,including vanillic acid,syringic acid,3,5-dimethoxy-4-hydroxyacetophenone,2-hydroxyacetophenone,4-ethycathecol,and 2,6-dimethoxyphenol in anolyte,and sinapic acid and vanillin acetate in catholyte.Thus,realizing renewable biomass electrolysis in the 3DPR is an intriguing strategy for the co-production of hydrogen and fine aromatic chemicals.
基金funded by the National Key R&D Program of China(No.2021YFA1501700)the Science and Technology Development Plan of Jilin Province(Nos.20230101042JC,20210201059GX)+2 种基金the National Natural Science Foundation of China,Basic Science Center Program(No.51988102)the National Natural Science Foundation of China(Nos.52203017,52073272 and 22293062)Bureau of International Cooperation Chinese Academy of Sciences(No.029GJHZ2023017MI).
文摘It is of great interest to make a degradable material widely tailorable to replace petroleum-derived products among diverse applications.Here,we report the construction of a new multi-purpose degradable material for the first time via a simple ternary copolymerization system comprisingε-caprolactone(ε-CL),cyclohexane oxide(CHO)and CO_(2).Under low pressure of 1 bar∼5 bar,the ring-opening polymerization(ROP)ofε-CL and ring-opening copolymerization(ROCOP)of CO_(2) and CHO can simultaneously proceed.The carbonate units are randomly distributed on the polymer chain.These random terpolymers have controllable molar mass(10-106 kDa)and compositions(4-33 mol%CO_(2)).And the obtained materials show large-span tunability from tough plastic to elastomer and even adhesive.
文摘A series of transparent crosslinked colorless polyimide(CPI)films are prepared from 3,3',4,4'-biphenyltetracarboxylic dianhydride(BPDA),2,2'-bis(trifluoro-methyl)benzidine(TFMB),and 4,4'-oxydianiline(ODA)by thermal imidization,incorporating varying contents of 2,2'-(1,3-phenylene)bis(2-oxazoline)(1,3-PBO)as the crosslinking agent.Following the incorporation of the crosslinking structure,the CPI films show good optical transparency(approximately 85%winthin visible light range),enhanced glass transition temperature(from 325℃to 341℃),and improved thermal stability,and tensile strength.Notably,compared with the pristine uncrosslinked CPI,these crosslinked CPI films significantly increase in elongation at break(from 5.4%to 44.2%).Furthermore,the new approach ensures that crosslinked CPIs improve heat resistance and mechanical properties,while avoiding the embrittlement of materials.This study also offeres straightforward preparation methods for optically transparent crosslinked polyimides without additional processing steps.All these results make this approach can effectively improve the competitive performance of the CPI films for potential applications in microelectronic and optoelectronic fields.
基金financially supported by the National Natural Science Foundation of China(No.52130307)。
文摘Owing to its high production volume and wide range of application s,polyethylene has gained a great deal of attention,but its low surface energy and non-polar nature have limited its application in some important fields.In this study,ethylene/11-iodo-1-undecene copolymers were prepared and used as the intermediates to afford a series of imidazolium-based ionomers bearing methanesulfonate(CH_(3)SO_(3)^(-)),trifluoromethanesulfonate(CF_(3)SO_(3)^(-)),or bis(trifluoromethane)sulfonimide(Tf_(2)N^(-))counteranions.The tensile test results showed that the stress-at-break(7.8-25.6 MPa)and the elongation-at-break(445%-847%)of the ionomers could be adjusted by changing the counterion species and the ionic group contents.Most importantly,the ionomers exhibited marvelous antibacterial activities against Staphylococcus aureus(S.aureus)and Escherichia coli(E.coli).The ionomers bearing Tf_(2)N^(-)exhibited antibacterial activities>99%against both S.aureus and E.coli when ionic content reached 9.1%.The imidazolium-based ionomers prepared in this work demonstrated excellent comprehensive properties,especially highefficient and broad-spectrum antibacterial ability,exhibiting the potential fo r the application as the antibacterial materials in packaging,medical,and other fields.
基金funded by the National Key R&D Program of China(No.2021YFA1501700)the Science and Technology Development Plan of Jilin Province(Nos.20230101042JC,20210201059GX)+2 种基金the National Natural Science Foundation of China,Basic Science Center Program(No.51988102)the National Natural Science Foundation of China(Nos.52203017,52073272 and 22293062)Bureau of International Cooperation Chinese Academy of Sciences(No.029GJHZ2023017MI)。
文摘A new strategy for the metal-free coordination–insertion ring-opening polymerization of tetrahydrofuran by the central metalloid Boron has been first identified.Bis(pentafluorophenyl)(phenoxy)borane was used as a catalyst for the polymerization reaction system.And polytetrahydrofuran with high molecular weight and narrow molecular weight distribution could be obtained.The proposed mechanism was studied by MALDI-TOF,ESI-MS and O-18 isotope labeling analyses as a metal-free coordination insertion mechanism.
基金supported by the National Natural Science Foundation of China (52373161,51973217)Jilin Province Science and Technology Development Program (20200201330JC, 20200201075JC, JJKH20201029KJ)The First Hospital of Jilin University Cross Disciplinary Program (2022YYGFZJC002)。
文摘The early diagnosis of cancer is vital for effective treatment and improved prognosis. Tumor biomarkers, which can be used for the early diagnosis, treatment, and prognostic evaluation of cancer, have emerged as a topic of intense research interest in recent years. Nucleic acid, as a type of tumor biomarker, contains vital genetic information, which is of great significance for the occurrence and development of cancer. Currently, living cell nucleic acid probes, which enable the in situ imaging and dynamic monitoring of nucleic acids, have become a rapidly developing field. This review focuses on living cell nucleic acid probes that can be used for the early diagnosis of tumors. We describe the fundamental design of the probe in terms of three units and focus on the roles of different nanomaterials in probe delivery.
文摘Stroke is the second leading cause of death and the primary cause of permanent disability worldwide.Ischemic stroke(IS)accounts for 87%of all strokes globally and is characterized by the occlusion of cerebral vasculature due to embolic presence.Clinical treatments for IS include enzymatic thrombolysis,mechanical thrombectomy,and neuroprotection.However,these approaches have obvious limitations.First,early vascular recanalization leads to secondary cascade injuries and a high risk of hemorrhagic transformation,resulting in poor clinical outcomes for patients with IS.In addition,neuroprotective agents often fail to achieve satisfactory clinical efficacy due to inadequate drug concentrations and off-target effects[1].Targeted stimuli-responsive nanoformulations for thrombolysis and neuroprotection have been developed to address these limitations in current clinical treatments.These nanoformulations are based on IS-specific thrombus-associated receptors and the pathological microenvironments,showing great promise in treating IS(Figure A).
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)+2 种基金the National Natural Science Foundation of ChinaBasic Science Center Program (No.51988102)the National Natural Science Foundation of China (Nos. 52203017 and 52073272)。
文摘Polyester and polyether are two key oxygenated polymers, and completely alternative sequence of poly(ester-alt-ether) could efficiently combine the advantages(including flexibility, degradability, etc.) of both segments. Currently, despite their copolymers could be synthesized from one-pot mixture of cyclic esters and epoxides, perfectly alternative microstructure is very challenging to realize and typically restricted to certain monomer pairs. Moving forward, synthesizing poly(ester-alt-ether) from commercially available and largescale monomers would be a significant advance. For example, successfully commercialized poly(glycolic acid)(PGA), which is not easily soluble in polymers due to its high crystallinity and is brittle and difficult to control the degradation cycle, would encounter a new paradigm if engineered into poly(ester-altether). In this work, starting from the design of monomer with hybrid structures, we successfully synthesized a series of 1,4-dioxan-2-one containing different substituents based on glycolide(GA) and epoxides using commercially available Salen-Cr(III) and PPNCl catalytic systems.The new monomers underwent ring-opening polymerization(ROP) to form a series of poly(ester-alt-ether) with perfectly alternating glycolic acid and propylene glycol repeat units under catalytic system of thiourea/base. The poly(ester-alt-ether) have significantly lower glass-transition temperature than PGA. Additionally, the poly(ester-alt-ether) can be chemically recovered to monomer using Sn(Oct)2 or 1,8-diazabicyclo[5.4.0]undecane-7-ene(DBU) as a catalyst in solution, thus establishing a closed-loop life cycle. From monomers derived from GA and epoxides, this work furnishes a novel strategy for the synthesis of poly(ester-alt-ether) with chemical recyclability.
