As the global exploration and development of oil and gas resources advances into deep formations,the harsh conditions of high temperature and high salinity present significant challenges for drilling fluids.In order t...As the global exploration and development of oil and gas resources advances into deep formations,the harsh conditions of high temperature and high salinity present significant challenges for drilling fluids.In order to address the technical difficulties associated with the failure of filtrate loss reducers under high-temperature and high-salinity conditions.In this study,a hydrophobic zwitterionic filtrate loss reducer(PDA)was synthesized based on N,N-dimethylacrylamide(DMAA),2-acrylamido-2-methylpropane sulfonic acid(AMPS),diallyl dimethyl ammonium chloride(DMDAAC),styrene(ST)and a specialty vinyl monomer(A1).When the concentration of PDA was 3%,the FLAPI of PDA-WBDF was 9.8 mL and the FLHTHP(180℃,3.5 MPa)was 37.8 mL after aging at 240℃for 16 h.In the saturated NaCl environment,the FLAPI of PDA-SWBDF was 4.0 mL and the FLHTHP(180℃,3.5 MPa)was 32.0 mL after aging at 220℃ for 16 h.Under high-temperature and high-salinity conditions,the combined effect of anti-polyelectrolyte and hydrophobic association allowed PDA to adsorb on the bentonite surface tightly.The sulfonic acid groups of PDA increased the negative electronegativity and the hydration film thickness on bentonite surface,which enhanced the colloidal stability,maintained the flattened lamellar structure of bentonite and formed an appropriate particle size distribution,resulting in the formation of dense mud cakes and reducing the filtration loss effectively.展开更多
The objective of this study was to predict,screen,synthesize,and investigate cocrystals of poorly soluble flavonoids that are commonly found in dietary supplements with bipolar compound picolinic acid(PA).To improve t...The objective of this study was to predict,screen,synthesize,and investigate cocrystals of poorly soluble flavonoids that are commonly found in dietary supplements with bipolar compound picolinic acid(PA).To improve the efficiency and success rate of experimental screening,two virtual tools based on hydrogen bond propensity(HBP)and modified molecular electrostatic potential(MEP)maps were used.The prediction accuracy of HBP and MEP is 58.82%and 94.11%,respectively,presenting that the MEP model is very powerful in the discovery of pharmaceutical cocrystals.Among the 12 successfully obtained cocrystals,4 single crystals of PA with luteolin(LUT),genistein(GEN),taxifolin(TAX),dihydromyricetin(DHM)were obtained for the first time.Charged-assisted O-H…O and N-H…O hydrogen bonds appear as main hydrogen bonding synthons,and PA adopts a zwitterionic form after cocrystallization.GEN-PA,TAX-PA,and DHM-PA showed higher DPPH'radical-scavenging capacities;LUT-PA and DHM-PA showed higher ABTS^(+)radical-scavenging capacities;GEN-PA and DHM-PA possessed better protective effects on H9c2 cells from hypoxic injury caused by CoCl_(2)than corresponding pure flavonoids.展开更多
Flexible strain sensors have received tremendous attention because of their potential applications as wearable sensing devices.However, the integration of key functions into a single sensor, such as high stretchabilit...Flexible strain sensors have received tremendous attention because of their potential applications as wearable sensing devices.However, the integration of key functions into a single sensor, such as high stretchability, low hysteresis, self-adhesion, andexcellent antifreezing performance, remains an unmet challenge. In this respect, zwitterionic hydrogels have emerged asideal material candidates for breaking through the above dilemma. The mechanical properties of most reported zwitterionichydrogels, however, are relatively poor, significantly restricting their use under load-bearing conditions. Traditional improve-ment approaches often involve complex preparation processes, making large-scale production challenging. Additionally,zwitterionic hydrogels prepared with chemical crosslinkers are typically fragile and prone to irreversible deformation underlarge strains, resulting in the slow recovery of structure and function. To fundamentally enhance the mechanical properties ofpure zwitterionic hydrogels, the most effective approach is the regulation of the chemical structure of zwitterionic monomersthrough a targeted design strategy. This study employed a novel zwitterionic monomer carboxybetaine urethane acrylate(CBUTA), which contained one urethane group and one carboxybetaine group on its side chain. Through the direct polym-erization of ultrahigh concentration monomer solutions without adding any chemical crosslinker, we successfully developedpure zwitterionic supramolecular hydrogels with significantly enhanced mechanical properties, self-adhesive behavior, andantifreezing performance. Most importantly, the resultant zwitterionic hydrogels exhibited high tensile strength and tough-ness and displayed ultralow hysteresis under strain conditions up to 1100%. This outstanding performance was attributedto the unique liquid–liquid phase separation phenomenon induced by the ultrahigh concentration of CBUTA monomers inan aqueous solution, as well as the enhanced polymer chain entanglement and the strong hydrogen bonds between urethanegroups on the side chains. The potential application of hydrogels in strain sensors and high-performance triboelectric nano-generators was further explored. Overall, this work provides a promising strategy for developing pure zwitterionic hydrogelsfor flexible strain sensors and self-powered electronic devices.展开更多
Zwitterionic polymers are polymers containing a pair of oppositely charged groups in their repeating units,which facilitate the formation of a hydration layer on the surface through ionic solvation.This strong hydrati...Zwitterionic polymers are polymers containing a pair of oppositely charged groups in their repeating units,which facilitate the formation of a hydration layer on the surface through ionic solvation.This strong hydration results in the remarkable properties of zwitterionic polymer hydrogels,including antifouling,lubricating,and anti-freezing capabilities.Owing to these properties,zwitterionic polymer hydrogels have attracted notable attention in biomedical and engineering fields.However,the superhydrophilicity of zwitterionic polymer hydrogels renders them brittle and weak,considerably limiting their use in load-bearing applications.Thus,there is an urgent need to improve the mechanical properties of zwitterionic hydrogels.In this work,we systematically review mechanical enhancement strategies for zwitterionic polymer hydrogels.We cover strate-gies applicable to hybrid and pure high-strength zwitterionic polymer hydrogels.Additionally,we discuss the advantages and limitations of various strength enhancement strategies.展开更多
Zwitterionic materials with covalently tethered cations and anions have great potential as electrolyte additives for aqueous Znion batteries(AZIBs)owing to their appealing intrinsic characteristics and merits.However,...Zwitterionic materials with covalently tethered cations and anions have great potential as electrolyte additives for aqueous Znion batteries(AZIBs)owing to their appealing intrinsic characteristics and merits.However,the impact of cationic and anionic moieties within zwitterions on enhancing the performance of AZIBs remains poorly understood.Herein,three zwitterions,namely carboxybetaine methacrylate(CBMA),sulfobetaine methacrylate(SBMA),and 2-methacryloyloxyethyl phosphorylcholine(MPC),were selected as additives to investigate their different action mechanisms in AZIBs.All three zwitterions have the same quaternary ammonium as the positively charged group,but having different negatively charged segments,i.e.,carboxylate,sulfonate,and phosphate for CBMA,SBMA,and MPC,respectively.By systematical electrochemical analysis,these zwitterions all contribute to enhanced cycling life of Zn anode,with MPC having the most pronounced effect,which can be attributed to the synergistic effect of positively quaternary ammonium group and unique negatively phosphate groups.As a result,the Zn//Zn cell with MPC as additive in ZnSO_(4)electrolyte exhibits an ultralong lifespan over 5000 h.This work proposes new insights to the future development of multifunctional zwitterionic additives for remarkably stable AZIBs.展开更多
Zwitterions(ZIs)are considered as an ideal,novel ionic conductive medium due to their high dipole moment and good solubility of lithium salts.However,the strong interactions between ZIs and Li^(+)severely hinder Li^(+...Zwitterions(ZIs)are considered as an ideal,novel ionic conductive medium due to their high dipole moment and good solubility of lithium salts.However,the strong interactions between ZIs and Li^(+)severely hinder Li^(+)migration.Herein,a quasi-solid electrolyte(MSQSE-2Na)was fabricated by adding sodium bis(fluorosulfonyl)imide(NaFSI)to sulfobetaine methacrylate(SBMA,a ZI)based polymerization system.Na^(+)occupies the–SO_(3)^(-)site in SBMA prior to Li^(+),which weakens the self-crosslinking of SBMA and frees the Li^(+)bound to the polymer segments.Thus,the polymer conformation of MSQSE-2Na changes to a relaxed,homogeneous"sea-island"type.Meanwhile,Na^(+),due to its electron-withdrawing effect,decreases the electron cloud density of the polymer segments,building a weakly coordinated environment in MSQSE-2Na.Consequently,MSQSE-2Na exhibits excellent ionic conductivity of 7.38×10^(-4)S cm^(-1)and a high Li^(+)transference number of 0.632 at 25℃.The(-)Li|MSQSE-2Na|Li(+)cells exhibit super stability,sustaining operation for over 6182h.The(-)Li|MSQSE-2Na|LiFePO_(4)(+)cells demonstrate outstanding charge/discharge reversibility with a Coulombic efficiency exceeding 99.9%over 270 cycles(≈4500 h),with a capacity retention of 70.0%.This work proposes a new design concept for regulating the polymer conformation and charge characteristics through competitive coordination,thereby advancing the application of ZI-based polymer electrolytes in lithium metal batteries.展开更多
Emulsification is one of the important mechanisms of surfactant flooding. To improve oil recovery for low permeability reservoirs, a highly efficient emulsification oil flooding system consisting of anionic surfactant...Emulsification is one of the important mechanisms of surfactant flooding. To improve oil recovery for low permeability reservoirs, a highly efficient emulsification oil flooding system consisting of anionic surfactant sodium alkyl glucosyl hydroxypropyl sulfonate(APGSHS) and zwitterionic surfactant octadecyl betaine(BS-18) is proposed. The performance of APGSHS/BS-18 mixed surfactant system was evaluated in terms of interfacial tension, emulsification capability, emulsion size and distribution, wettability alteration, temperature-resistance and salt-resistance. The emulsification speed was used to evaluate the emulsification ability of surfactant systems, and the results show that mixed surfactant systems can completely emulsify the crude oil into emulsions droplets even under low energy conditions. Meanwhile,the system exhibits good temperature and salt resistance. Finally, the best oil recovery of 25.45% is achieved for low permeability core by the mixed surfactant system with a total concentration of 0.3 wt%while the molar ratio of APGSHS:BS-18 is 4:6. The current study indicates that the anionic/zwitterionic mixed surfactant system can improve the oil flooding efficiency and is potential candidate for application in low permeability reservoirs.展开更多
Nanoscale drug delivery systems(nDDS)have been employed widely in enhancing the therapeutic efficacy of drugs against diseases with reduced side effects.Although several nDDS have been successfully approved for clinic...Nanoscale drug delivery systems(nDDS)have been employed widely in enhancing the therapeutic efficacy of drugs against diseases with reduced side effects.Although several nDDS have been successfully approved for clinical use up to now,biological barriers between the administration site and the target site hinder the wider clinical adoption of nDDS in disease treatment.Polyethylene glycol(PEG)-modification(or PEGylation)has been regarded as the gold standard for stabilising nDDS in complex biological environment.However,the accelerated blood clearance(ABC)of PEGylated nDDS after repeated injections becomes great challenges for their clinical applications.Zwitterionic polymer,a novel family of antifouling materials,have evolved as an alternative to PEG due to their super-hydrophilicity and biocompatibility.Zwitterionic nDDS could avoid the generation of ABC phenomenon and exhibit longer blood circulation time than the PEGylated analogues.More impressively,zwitterionic nDDS have recently been shown to overcome multiple biological barriers such as nonspecific organ distribution,pressure gradients,impermeable cell membranes and lysosomal degradation without the need of any complex chemical modifications.The realization of overcoming multiple biological barriers by zwitterionic nDDS may simplify the current overly complex design of nDDS,which could facilitate their better clinical translation.Herein,we summarise the recent progress of zwitterionic nDDS at overcoming various biological barriers and analyse their underlyingmechanisms.Finally,prospects and challenges are introduced to guide the rational design of zwitterionic nDDS for disease treatment.展开更多
The innovation in polymer design to rival conventional polyethylene glycol(PEG)is an important approach to achieving a more sustainable society.Here,cyclic PEG-like polycarbonates having high molecular weight(4.4–49....The innovation in polymer design to rival conventional polyethylene glycol(PEG)is an important approach to achieving a more sustainable society.Here,cyclic PEG-like polycarbonates having high molecular weight(4.4–49.5 kg/mol)were enabled through zwitterionic ring-opening polymerization(ZROP)of macrocyclic carbonates(MCs)mediated by N-heterocyclic carbene(NHC).The thermodynamic behavior of polymerization depends on the ring size of monomers.During this process,the ZROP of 11-membered MC was driven by the change of enthalpy(ΔH_(p))which differed from the ZROP of 14-membered MC driven by the entropic change(ΔS_(p)).Cyclic polycarbonates depicted improved thermostability(T_(d5%)≥204℃)and higher glass transition temperatures(T_(g)>–40℃)in comparison to their linear analogues(T_(d5%)≤185℃,T_(g)~–50℃).In addition,the mechanism of ZROP of MC was addressed through computational study.A distinct mechanism of polymerization distinguishable from the well-known NHC-mediated ZROP of cyclic esters was revealed,where the zwitterion from nucleophilic addition to MC,i.e.tetrahedral intermediate,cannot be ring-opened probably due to the delocalization of negative charge on the carbonate group,but serves as an active center for the polymerization.In comparison to PEG,the attained polymer demonstrated comparable hydrophilic and biocompatible properties,as revealed by the results of contact angle and in vitro cytotoxicity studies,suggesting that cyclic polycarbonate hold the promise as the alternative of PEG.展开更多
Bacterial cellulose(BC)was innovatively combined with zwitterionic copolymer acrylamide and sulfobetaine methacrylic acid ester[P(AM-co-SBMA)]to build a dual-network porous structure gel polymer electrolytes(GPEs)with...Bacterial cellulose(BC)was innovatively combined with zwitterionic copolymer acrylamide and sulfobetaine methacrylic acid ester[P(AM-co-SBMA)]to build a dual-network porous structure gel polymer electrolytes(GPEs)with high ionic conductivity.The dual network structure BC/P(AM-co-SBMA)gels were formed by a simple one-step polymerization method.The results show that ionic conductivity of BC/P(AM-co-SBMA)GPEs at the room temperature are 3.2×10^(-2) S/cm@1 M H_(2)SO_(4),4.5×10^(-2) S/cm@4 M KOH,and 3.6×10^(-2) S/cm@1 M NaCl,respectively.Using active carbon(AC)as the electrodes,BC/P(AM-co-SBMA)GPEs as both separator and electrolyte matrix,and 4 M KOH as the electrolyte,a symmetric solid supercapacitors(SSC)(AC-GPE-KOH)was assembled and testified.The specific capacitance of AC electrode is 173 F/g and remains 95.0%of the initial value after 5000 cycles and 86.2%after 10,000 cycles.展开更多
Enzyme immobilization has attracted great attention for improving the performance of enzymes in industrial applications.This work was designed to create a new support for Candida rugosa lipase(CRL)immobilization.A por...Enzyme immobilization has attracted great attention for improving the performance of enzymes in industrial applications.This work was designed to create a new support for Candida rugosa lipase(CRL)immobilization.A porous poly(vinyl acetate–divinyl benzene)microsphere coated by a zwitterionic polymer,poly(maleic anhydride-alt-1-octadecene)and N,N-dimethylethylenediamine derivative,was developed for CRL immobilization via hydrophobic binding.The catalytic activity,reaction kinetics,stabilities and reusability of the immobilized CRL were investigated.It demonstrated the success of the zwitterionic polymer coating and subsequent CRL immobilization on the porous microsphere.The immobilized lipase(p2-MS-CRL)reached27.6 mg·g^-1 dry carrier and displayed a specific activity 1.5 times higher than free CRL.The increase of Vmax and decrease of Kmwere also observed,indicating the improvement of catalytic activity and enzyme-substrate affinity of the immobilized lipase.Besides,p2-MS-CRL exhibited significantly enhanced thermal stability and pH tolerance.The improved performance was considered due to the interfacial activation regulated by the hydrophobic interaction and stabilization effect arisen by the zwitterionic polymer coating.This study has thus proved the advantages of the zwitterionic polymer-coated porous carrier for lipase immobilization and its potential for further development in various enzyme immobilizations.展开更多
Our previous work proved that the thermal stability of Candida rugosa lipase(CRL)immobilized on zwitterionic polymer(poly(carboxybetaine methacrylate))grafted silica nanoparticle(SNP)was much higher than that on poly(...Our previous work proved that the thermal stability of Candida rugosa lipase(CRL)immobilized on zwitterionic polymer(poly(carboxybetaine methacrylate))grafted silica nanoparticle(SNP)was much higher than that on poly(glycidyl methecrylate)(pGMA)grafted SNP,while the latter showed significantly increased activity.Inspired by the research,we have herein proposed to synthesize copolymers of zwitterionic sulfobetaine methacrylate(SBMA)and GMA for CRL immobilization.The copolymers were grafted onto SNP surface at three GMA/SBMA(G/S)molar ratios(G100/S0,G50/S50,G10/S90),followed by the covalent coupling of CRL to the surface copolymers.The immobilized CRLs on the corresponding supports were denoted as p(G100-S0)-CRL,p(G50-S50)-CRL and p(G10-S90)-CRL.The enzyme loading increased with the increase of GMA content in the copolymer,while the activity varied with the grafted copolymer composition.Kinetic study proved the improvement of enzyme-substrate affinity after immobilization.In comparison to p(G100-S0)-CRL,p(G50-S50)-CRL and p(G10-S90)-CRL presented remarkably enhanced thermal stability and pH tolerance,and p(G10-S90)-CRL showed the highest stability.These results suggest that the copolymer design is promising for development as a versatile platform for enzyme immobilization.展开更多
Nanocarriers play an important role in drug delivery for disease treatment.However,nanocarriers face a series of physiological barriers after administration such as blood clearance,nonspecific tissue/cell localization...Nanocarriers play an important role in drug delivery for disease treatment.However,nanocarriers face a series of physiological barriers after administration such as blood clearance,nonspecific tissue/cell localization,poor cellular uptake,and endosome trapping.These physiological barriers seriously reduce the accumulation of drugs in target action site,which results in poor therapeutic efficiency.Although polyethylene glycol(PEG)can increase the blood circulation time of nanocarriers,its application is limited due to the“PEG dilemma”.Zwitterionic polymers have been emerging as an appealing alternative to PEG owing to their excellent performance in resisting nonspecific protein adsorption.Importantly,the diverse structures bring functional versatility to zwitterionic polymers beyond nonfouling.This review focuses on the structures and characters of zwitterionic polymers,and will discuss and summarize the application of zwitterionic polymers for drug delivery.We will highlight the strategies of zwitterionic polymers to address the physiological barriers during drug delivery.Finally,we will give some suggestions that can be utilized for the development of zwitterionic polymers for drug delivery.This review will also provide an outlook for this field.Our aim is to provide a comprehensive and systemic review on the application of zwitterionic polymers for drug delivery and promote the development of zwitterionic polymers.展开更多
N,N-dimethyl-N-methacryloyloxyethyl-N-carboxyethyl ammonium(DMMCA)was graft-copolymerized onto thesurface of segmented poly(ether urethane)(SPEU)and PE film.The carboxybetaine structure on SPEU and PE filmsurfaces was...N,N-dimethyl-N-methacryloyloxyethyl-N-carboxyethyl ammonium(DMMCA)was graft-copolymerized onto thesurface of segmented poly(ether urethane)(SPEU)and PE film.The carboxybetaine structure on SPEU and PE filmsurfaces was confirmed by ATR-FTIR,XPS and water contact angle measurements.Through the experiments with plateletadhesion and protein adhesion assay in vitro,the two materials studied,including poly-DMMCA gel,all show excellentnonthrombogenicity.This confirms once again that the zwitterionic molecular structure on the surfaces of materials isessential for improving their nonthrombogenicity and biocompatibility.展开更多
Enormous demands on the separation of oil/water(O/W)emulsions in various industries,such as petrochemical,food and pharmaceutical industries,are looking for high performance and energy-efficient separation methods.Cer...Enormous demands on the separation of oil/water(O/W)emulsions in various industries,such as petrochemical,food and pharmaceutical industries,are looking for high performance and energy-efficient separation methods.Ceramic membranes have been used to deal with O/W emulsions,for its outstanding characteristics of easy-operation,high-flux,and long-term stability.However,membrane fouling is still a challenge in the industrial application of ceramic membranes.Herein,antifouling ceramic membranes were fabricated by grafting zwitterions on the membrane surface via an environment-friendly two-step grafting method,which improves the antifouling property and permeability.Successful grafting of such zwitterion on the ceramic surface was assessed by the combination of FTIR and XPS characterization.More importantly,the hydration can be formed by electrostatic interactions layer on the modified membrane,which was confirmed by TGA characterization.The antifouling performance of prepared zwitterionic ceramic membranes in the separation of O/W emulsions was systematically tested.The results suggested that zwitterion can significantly improve the flux of ceramic ultrafiltration membrane,and can also improve antifouling property dramatically by reducing the irreversible fouling in the separation of O/W emulsions.Therefore,zwitterionic ceramic membranes hold promising potentials as an antifouling,highly efficient and green method in the practical purification of the O/W emulsions.展开更多
Five new zwitterionic surfactants with long chain alkyl betaine structure incorporated with hydroxylpropyl group have been synthesized. Their structures were identified by elemental analysis, IR (HNMR)-H-1, and (CNMR)...Five new zwitterionic surfactants with long chain alkyl betaine structure incorporated with hydroxylpropyl group have been synthesized. Their structures were identified by elemental analysis, IR (HNMR)-H-1, and (CNMR)-C-13. Surface tension experiments showed that these surfactants have higher surface activity than those without hydroxypropyl group. The values of CMC and gamma(CMC) of these surfactants have been determined.展开更多
Enzyme-polymer conjugates are complex molecules with great practical significance.This work was designed to develop a novel enzyme-polymer conjugate by covalently coupling a zwitterionic polymer with side dimethyl cha...Enzyme-polymer conjugates are complex molecules with great practical significance.This work was designed to develop a novel enzyme-polymer conjugate by covalently coupling a zwitterionic polymer with side dimethyl chains(pID)to Candida rugosa lipase(CRL)via the reaction between the anhydrides of polymer chains with the amino groups of the enzyme.The resulting two CRL-pID conjugates with different pID grafting densities were investigated in term of the catalytic activity,stability and structural changes.In comparison with native CRL,both the CRL conjugates displayed 2.2 times higher activity than the native enzyme,and showed an increase in the maximum reaction rate(V_(max))and a decrease in the Michaelis constant(K_(m)),thus resulting in about three-fold increases in the catalytic efficiency(k_(cat)/K_(m)).These are mainly attributed to the activation of lipase by the hydrophobic alky side chains.Moreover,the thermostability and pH tolerance of the lipase conjugates were significantly enhanced due to the stabilizing effect of the zwitterion moieties.For instance,a five-fold increase of the enzyme half-life at 50℃ for the high-pID conjugated CRL was observed.Spectroscopic studies reveal that the pID conjugation protected the enzyme in the changes in its microenvironment and conformation,well correlating with enhanced activity and stability of lipase conjugates.The findings indicate that enzyme conjugation to the zwitterionic polymer is promising for improving enzyme performance and deserves further development.展开更多
Developing an effective and durable antibacterial surface is important for surgical tools and biomedical implants.In this work,a zwitterionic copolymer containing catechol groups as biomimetic anchoring segments was c...Developing an effective and durable antibacterial surface is important for surgical tools and biomedical implants.In this work,a zwitterionic copolymer containing catechol groups as biomimetic anchoring segments was coated onto 316 L stainless steel via drop-casting.Energy-dispersive X-ray spectroscopy(EDS)and water contact angle(WCA)measurements indicated that the coatings made of the copolymers containing zwitterionic and dopamine segments at the molar ratios of 8:2 and 6:4 exhibited stronger stability and mechanical durability than the one at 9:1 after inducing tape-peeling and ultrasonication damage.The mechanically durable nanocoatings exhibited excellent antibacterial performance against Staphylococcus aureus and Escherichia coli in a period of 3 days.The nanocoatings with zwitterionic and dopamine segments at the molar ratio of 8:2 were further evaluated and demonstrated durable antibacterial performance after tape-peeling and ultrasonication treatments.展开更多
Antifouling ability and blood compatibility are critically important in the development of medical metallic implants for clinical applications.Here,we report the zwitterionic-phosphonate block polymer as a new type of...Antifouling ability and blood compatibility are critically important in the development of medical metallic implants for clinical applications.Here,we report the zwitterionic-phosphonate block polymer as a new type of high-efficiency antifouling coating for metallic substrates.Six block polymers(pSBMA-b-pDEMMP)with different segment lengths(nSBMA:nDEMMP=10:25,40:25,100:25,75:5,75:40,75:100)were prepared and anchored on titanium alloy(TC4)substrates.1H nuclear magnetic resonance(NMR)results clearly showed the precise preparation of the block polymers.XPS analysis and water contact angle measurement indicated the successful construction of the block polymer on TC4 substrates.The relationship between the antifouling performance of the polymer coating and the length of pDEMMP and pSBMA segments in the block polymer was established.Results showed that the polymer containing the pSBMA segment above 40 repeat units could significantly inhibit protein adsorption,platelet adhesion,bacterial adhesion and cell adhesion,while the pDEMMP segment above 5 repeat units is able to generate stable zwitterionic polymer coating on TC4 substrates.This ease of production and high-efficiency antifouling modification strategy elucidated here may find broad application for biomedical implants and devices in clinical applications.展开更多
In this work, a kind of preparation method of zwitterionic ion chromatography （ZIC） stationary phase modified with phosphorylcholine （PC） was obtained by hydrolyzing after bonding phosphorylcholine dichloride to d...In this work, a kind of preparation method of zwitterionic ion chromatography （ZIC） stationary phase modified with phosphorylcholine （PC） was obtained by hydrolyzing after bonding phosphorylcholine dichloride to diol-silica to better explore the characteristics of the PC groups as ZIC stationary phase ligand in simultaneous separation of acidic proteins and basic proteins. The results showed that tv^o kinds of acidic proteins and three kinds of basic proteins can be separated completely, meanwhile, hen egg white was separated and purified and three kinds of egg white components ovalbumin, G2 ovoglobulin and ovotransfemin proteins were separated completely by one single step on PC-ZIC column, the purity of all proteins reached above 95%. PC-ZIC stationary phase was successfully improved with better separation capacity and selectivity than previously reported in this paper.展开更多
基金supported by State Key Laboratory of Deep Oil and Gas(No.SKLDOG2024-ZYRC-03)supported by the Excellent Young Scientists Fund of the National Natural Science Foundation of China(No.52322401)the National Natural Science Foundation of China(52288101).
文摘As the global exploration and development of oil and gas resources advances into deep formations,the harsh conditions of high temperature and high salinity present significant challenges for drilling fluids.In order to address the technical difficulties associated with the failure of filtrate loss reducers under high-temperature and high-salinity conditions.In this study,a hydrophobic zwitterionic filtrate loss reducer(PDA)was synthesized based on N,N-dimethylacrylamide(DMAA),2-acrylamido-2-methylpropane sulfonic acid(AMPS),diallyl dimethyl ammonium chloride(DMDAAC),styrene(ST)and a specialty vinyl monomer(A1).When the concentration of PDA was 3%,the FLAPI of PDA-WBDF was 9.8 mL and the FLHTHP(180℃,3.5 MPa)was 37.8 mL after aging at 240℃for 16 h.In the saturated NaCl environment,the FLAPI of PDA-SWBDF was 4.0 mL and the FLHTHP(180℃,3.5 MPa)was 32.0 mL after aging at 220℃ for 16 h.Under high-temperature and high-salinity conditions,the combined effect of anti-polyelectrolyte and hydrophobic association allowed PDA to adsorb on the bentonite surface tightly.The sulfonic acid groups of PDA increased the negative electronegativity and the hydration film thickness on bentonite surface,which enhanced the colloidal stability,maintained the flattened lamellar structure of bentonite and formed an appropriate particle size distribution,resulting in the formation of dense mud cakes and reducing the filtration loss effectively.
基金supported by the Beijing Natural Science Foundation(No.7222261)CAMS Innovation Fund for Medical Sciences(No.2022-I2M-1-015)。
文摘The objective of this study was to predict,screen,synthesize,and investigate cocrystals of poorly soluble flavonoids that are commonly found in dietary supplements with bipolar compound picolinic acid(PA).To improve the efficiency and success rate of experimental screening,two virtual tools based on hydrogen bond propensity(HBP)and modified molecular electrostatic potential(MEP)maps were used.The prediction accuracy of HBP and MEP is 58.82%and 94.11%,respectively,presenting that the MEP model is very powerful in the discovery of pharmaceutical cocrystals.Among the 12 successfully obtained cocrystals,4 single crystals of PA with luteolin(LUT),genistein(GEN),taxifolin(TAX),dihydromyricetin(DHM)were obtained for the first time.Charged-assisted O-H…O and N-H…O hydrogen bonds appear as main hydrogen bonding synthons,and PA adopts a zwitterionic form after cocrystallization.GEN-PA,TAX-PA,and DHM-PA showed higher DPPH'radical-scavenging capacities;LUT-PA and DHM-PA showed higher ABTS^(+)radical-scavenging capacities;GEN-PA and DHM-PA possessed better protective effects on H9c2 cells from hypoxic injury caused by CoCl_(2)than corresponding pure flavonoids.
基金supported by the National Natural Science Foundation of China(Nos.T2222013 and 52073203)Tianjin Natural Science Foundation(No.22JCQNJC01040)the State Key Laboratory of Molecular Engineering of Polymers(Fudan University)(No.K2024-19).
文摘Flexible strain sensors have received tremendous attention because of their potential applications as wearable sensing devices.However, the integration of key functions into a single sensor, such as high stretchability, low hysteresis, self-adhesion, andexcellent antifreezing performance, remains an unmet challenge. In this respect, zwitterionic hydrogels have emerged asideal material candidates for breaking through the above dilemma. The mechanical properties of most reported zwitterionichydrogels, however, are relatively poor, significantly restricting their use under load-bearing conditions. Traditional improve-ment approaches often involve complex preparation processes, making large-scale production challenging. Additionally,zwitterionic hydrogels prepared with chemical crosslinkers are typically fragile and prone to irreversible deformation underlarge strains, resulting in the slow recovery of structure and function. To fundamentally enhance the mechanical properties ofpure zwitterionic hydrogels, the most effective approach is the regulation of the chemical structure of zwitterionic monomersthrough a targeted design strategy. This study employed a novel zwitterionic monomer carboxybetaine urethane acrylate(CBUTA), which contained one urethane group and one carboxybetaine group on its side chain. Through the direct polym-erization of ultrahigh concentration monomer solutions without adding any chemical crosslinker, we successfully developedpure zwitterionic supramolecular hydrogels with significantly enhanced mechanical properties, self-adhesive behavior, andantifreezing performance. Most importantly, the resultant zwitterionic hydrogels exhibited high tensile strength and tough-ness and displayed ultralow hysteresis under strain conditions up to 1100%. This outstanding performance was attributedto the unique liquid–liquid phase separation phenomenon induced by the ultrahigh concentration of CBUTA monomers inan aqueous solution, as well as the enhanced polymer chain entanglement and the strong hydrogen bonds between urethanegroups on the side chains. The potential application of hydrogels in strain sensors and high-performance triboelectric nano-generators was further explored. Overall, this work provides a promising strategy for developing pure zwitterionic hydrogelsfor flexible strain sensors and self-powered electronic devices.
基金supported by the National Natural Science Foundation of China(Nos.T2222013,52233008 and 52073203).
文摘Zwitterionic polymers are polymers containing a pair of oppositely charged groups in their repeating units,which facilitate the formation of a hydration layer on the surface through ionic solvation.This strong hydration results in the remarkable properties of zwitterionic polymer hydrogels,including antifouling,lubricating,and anti-freezing capabilities.Owing to these properties,zwitterionic polymer hydrogels have attracted notable attention in biomedical and engineering fields.However,the superhydrophilicity of zwitterionic polymer hydrogels renders them brittle and weak,considerably limiting their use in load-bearing applications.Thus,there is an urgent need to improve the mechanical properties of zwitterionic hydrogels.In this work,we systematically review mechanical enhancement strategies for zwitterionic polymer hydrogels.We cover strate-gies applicable to hybrid and pure high-strength zwitterionic polymer hydrogels.Additionally,we discuss the advantages and limitations of various strength enhancement strategies.
基金supported by the Australian Research Council(LP220100036)the National Key Research and Development Program(2022YFB2502104 and 2022YFA1602700)+3 种基金the Key Research and Development Program of Jiangsu Provincial Department of Science and Technology of China(BE2022332)the Jiangsu Carbon Peak Carbon Neutralization Science and Technology Innovation Special Fund(BE2022605)the Australian Research Council for his Discovery Early Career Researcher Award fellowship(DE230101105)the China Scholarship Council(CSC,grant no.202306190185)for funding a scholarship。
文摘Zwitterionic materials with covalently tethered cations and anions have great potential as electrolyte additives for aqueous Znion batteries(AZIBs)owing to their appealing intrinsic characteristics and merits.However,the impact of cationic and anionic moieties within zwitterions on enhancing the performance of AZIBs remains poorly understood.Herein,three zwitterions,namely carboxybetaine methacrylate(CBMA),sulfobetaine methacrylate(SBMA),and 2-methacryloyloxyethyl phosphorylcholine(MPC),were selected as additives to investigate their different action mechanisms in AZIBs.All three zwitterions have the same quaternary ammonium as the positively charged group,but having different negatively charged segments,i.e.,carboxylate,sulfonate,and phosphate for CBMA,SBMA,and MPC,respectively.By systematical electrochemical analysis,these zwitterions all contribute to enhanced cycling life of Zn anode,with MPC having the most pronounced effect,which can be attributed to the synergistic effect of positively quaternary ammonium group and unique negatively phosphate groups.As a result,the Zn//Zn cell with MPC as additive in ZnSO_(4)electrolyte exhibits an ultralong lifespan over 5000 h.This work proposes new insights to the future development of multifunctional zwitterionic additives for remarkably stable AZIBs.
基金supported by the National Natural Science Foundation of China(22078228)。
文摘Zwitterions(ZIs)are considered as an ideal,novel ionic conductive medium due to their high dipole moment and good solubility of lithium salts.However,the strong interactions between ZIs and Li^(+)severely hinder Li^(+)migration.Herein,a quasi-solid electrolyte(MSQSE-2Na)was fabricated by adding sodium bis(fluorosulfonyl)imide(NaFSI)to sulfobetaine methacrylate(SBMA,a ZI)based polymerization system.Na^(+)occupies the–SO_(3)^(-)site in SBMA prior to Li^(+),which weakens the self-crosslinking of SBMA and frees the Li^(+)bound to the polymer segments.Thus,the polymer conformation of MSQSE-2Na changes to a relaxed,homogeneous"sea-island"type.Meanwhile,Na^(+),due to its electron-withdrawing effect,decreases the electron cloud density of the polymer segments,building a weakly coordinated environment in MSQSE-2Na.Consequently,MSQSE-2Na exhibits excellent ionic conductivity of 7.38×10^(-4)S cm^(-1)and a high Li^(+)transference number of 0.632 at 25℃.The(-)Li|MSQSE-2Na|Li(+)cells exhibit super stability,sustaining operation for over 6182h.The(-)Li|MSQSE-2Na|LiFePO_(4)(+)cells demonstrate outstanding charge/discharge reversibility with a Coulombic efficiency exceeding 99.9%over 270 cycles(≈4500 h),with a capacity retention of 70.0%.This work proposes a new design concept for regulating the polymer conformation and charge characteristics through competitive coordination,thereby advancing the application of ZI-based polymer electrolytes in lithium metal batteries.
基金financially supported by National Natural Science Foundation of China(No.22302229)Beijing Municipal Excellent Talent Training Funds Youth Advanced Individual Project(No.2018000020124G163)。
文摘Emulsification is one of the important mechanisms of surfactant flooding. To improve oil recovery for low permeability reservoirs, a highly efficient emulsification oil flooding system consisting of anionic surfactant sodium alkyl glucosyl hydroxypropyl sulfonate(APGSHS) and zwitterionic surfactant octadecyl betaine(BS-18) is proposed. The performance of APGSHS/BS-18 mixed surfactant system was evaluated in terms of interfacial tension, emulsification capability, emulsion size and distribution, wettability alteration, temperature-resistance and salt-resistance. The emulsification speed was used to evaluate the emulsification ability of surfactant systems, and the results show that mixed surfactant systems can completely emulsify the crude oil into emulsions droplets even under low energy conditions. Meanwhile,the system exhibits good temperature and salt resistance. Finally, the best oil recovery of 25.45% is achieved for low permeability core by the mixed surfactant system with a total concentration of 0.3 wt%while the molar ratio of APGSHS:BS-18 is 4:6. The current study indicates that the anionic/zwitterionic mixed surfactant system can improve the oil flooding efficiency and is potential candidate for application in low permeability reservoirs.
基金financially supported by the National Natural Science Foundation of China(grant no.8217070298)Guangdong Basic and Applied Basic Research Foundation(grant no.2020A1515110770,2021A1515220011,2022A1515010335).
文摘Nanoscale drug delivery systems(nDDS)have been employed widely in enhancing the therapeutic efficacy of drugs against diseases with reduced side effects.Although several nDDS have been successfully approved for clinical use up to now,biological barriers between the administration site and the target site hinder the wider clinical adoption of nDDS in disease treatment.Polyethylene glycol(PEG)-modification(or PEGylation)has been regarded as the gold standard for stabilising nDDS in complex biological environment.However,the accelerated blood clearance(ABC)of PEGylated nDDS after repeated injections becomes great challenges for their clinical applications.Zwitterionic polymer,a novel family of antifouling materials,have evolved as an alternative to PEG due to their super-hydrophilicity and biocompatibility.Zwitterionic nDDS could avoid the generation of ABC phenomenon and exhibit longer blood circulation time than the PEGylated analogues.More impressively,zwitterionic nDDS have recently been shown to overcome multiple biological barriers such as nonspecific organ distribution,pressure gradients,impermeable cell membranes and lysosomal degradation without the need of any complex chemical modifications.The realization of overcoming multiple biological barriers by zwitterionic nDDS may simplify the current overly complex design of nDDS,which could facilitate their better clinical translation.Herein,we summarise the recent progress of zwitterionic nDDS at overcoming various biological barriers and analyse their underlyingmechanisms.Finally,prospects and challenges are introduced to guide the rational design of zwitterionic nDDS for disease treatment.
基金the China Postdoc Council(OCPC)for the financial support of Postdoctoral International Exchange Program(No.YJ20210095)the financial support from the National Natural Science Foundation of China(No.22078150)+3 种基金National Key R&D Program of China(No.2021YFC2101904)the Jiangsu National Synergetic Innovation Center for Advanced Materials(SICAM)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),the Jiangsu Synergetic Innovation Center for Advanced Bio-Manufacture(No.XTB2201)the Top-Notch Academic Programs Project of Jiangsu Higher Education Institutions(TAPP)。
文摘The innovation in polymer design to rival conventional polyethylene glycol(PEG)is an important approach to achieving a more sustainable society.Here,cyclic PEG-like polycarbonates having high molecular weight(4.4–49.5 kg/mol)were enabled through zwitterionic ring-opening polymerization(ZROP)of macrocyclic carbonates(MCs)mediated by N-heterocyclic carbene(NHC).The thermodynamic behavior of polymerization depends on the ring size of monomers.During this process,the ZROP of 11-membered MC was driven by the change of enthalpy(ΔH_(p))which differed from the ZROP of 14-membered MC driven by the entropic change(ΔS_(p)).Cyclic polycarbonates depicted improved thermostability(T_(d5%)≥204℃)and higher glass transition temperatures(T_(g)>–40℃)in comparison to their linear analogues(T_(d5%)≤185℃,T_(g)~–50℃).In addition,the mechanism of ZROP of MC was addressed through computational study.A distinct mechanism of polymerization distinguishable from the well-known NHC-mediated ZROP of cyclic esters was revealed,where the zwitterion from nucleophilic addition to MC,i.e.tetrahedral intermediate,cannot be ring-opened probably due to the delocalization of negative charge on the carbonate group,but serves as an active center for the polymerization.In comparison to PEG,the attained polymer demonstrated comparable hydrophilic and biocompatible properties,as revealed by the results of contact angle and in vitro cytotoxicity studies,suggesting that cyclic polycarbonate hold the promise as the alternative of PEG.
基金Funded by National Natural Science Foundation of China(No.51472166)。
文摘Bacterial cellulose(BC)was innovatively combined with zwitterionic copolymer acrylamide and sulfobetaine methacrylic acid ester[P(AM-co-SBMA)]to build a dual-network porous structure gel polymer electrolytes(GPEs)with high ionic conductivity.The dual network structure BC/P(AM-co-SBMA)gels were formed by a simple one-step polymerization method.The results show that ionic conductivity of BC/P(AM-co-SBMA)GPEs at the room temperature are 3.2×10^(-2) S/cm@1 M H_(2)SO_(4),4.5×10^(-2) S/cm@4 M KOH,and 3.6×10^(-2) S/cm@1 M NaCl,respectively.Using active carbon(AC)as the electrodes,BC/P(AM-co-SBMA)GPEs as both separator and electrolyte matrix,and 4 M KOH as the electrolyte,a symmetric solid supercapacitors(SSC)(AC-GPE-KOH)was assembled and testified.The specific capacitance of AC electrode is 173 F/g and remains 95.0%of the initial value after 5000 cycles and 86.2%after 10,000 cycles.
基金Supported by the National Natural Science Foundation of China(21621004,21878222).
文摘Enzyme immobilization has attracted great attention for improving the performance of enzymes in industrial applications.This work was designed to create a new support for Candida rugosa lipase(CRL)immobilization.A porous poly(vinyl acetate–divinyl benzene)microsphere coated by a zwitterionic polymer,poly(maleic anhydride-alt-1-octadecene)and N,N-dimethylethylenediamine derivative,was developed for CRL immobilization via hydrophobic binding.The catalytic activity,reaction kinetics,stabilities and reusability of the immobilized CRL were investigated.It demonstrated the success of the zwitterionic polymer coating and subsequent CRL immobilization on the porous microsphere.The immobilized lipase(p2-MS-CRL)reached27.6 mg·g^-1 dry carrier and displayed a specific activity 1.5 times higher than free CRL.The increase of Vmax and decrease of Kmwere also observed,indicating the improvement of catalytic activity and enzyme-substrate affinity of the immobilized lipase.Besides,p2-MS-CRL exhibited significantly enhanced thermal stability and pH tolerance.The improved performance was considered due to the interfacial activation regulated by the hydrophobic interaction and stabilization effect arisen by the zwitterionic polymer coating.This study has thus proved the advantages of the zwitterionic polymer-coated porous carrier for lipase immobilization and its potential for further development in various enzyme immobilizations.
基金funded by the National Natural Science Foundation of China(21621004)the National Key Research and Development Program of China(2018YFA0900702)。
文摘Our previous work proved that the thermal stability of Candida rugosa lipase(CRL)immobilized on zwitterionic polymer(poly(carboxybetaine methacrylate))grafted silica nanoparticle(SNP)was much higher than that on poly(glycidyl methecrylate)(pGMA)grafted SNP,while the latter showed significantly increased activity.Inspired by the research,we have herein proposed to synthesize copolymers of zwitterionic sulfobetaine methacrylate(SBMA)and GMA for CRL immobilization.The copolymers were grafted onto SNP surface at three GMA/SBMA(G/S)molar ratios(G100/S0,G50/S50,G10/S90),followed by the covalent coupling of CRL to the surface copolymers.The immobilized CRLs on the corresponding supports were denoted as p(G100-S0)-CRL,p(G50-S50)-CRL and p(G10-S90)-CRL.The enzyme loading increased with the increase of GMA content in the copolymer,while the activity varied with the grafted copolymer composition.Kinetic study proved the improvement of enzyme-substrate affinity after immobilization.In comparison to p(G100-S0)-CRL,p(G50-S50)-CRL and p(G10-S90)-CRL presented remarkably enhanced thermal stability and pH tolerance,and p(G10-S90)-CRL showed the highest stability.These results suggest that the copolymer design is promising for development as a versatile platform for enzyme immobilization.
基金financially supported by the Fundamental Research Funds for the Central Universities(No.06500230)the National Natural Science Foundation of China(No.32071391)the Beijing Nova Program(No.Z201100006820140).
文摘Nanocarriers play an important role in drug delivery for disease treatment.However,nanocarriers face a series of physiological barriers after administration such as blood clearance,nonspecific tissue/cell localization,poor cellular uptake,and endosome trapping.These physiological barriers seriously reduce the accumulation of drugs in target action site,which results in poor therapeutic efficiency.Although polyethylene glycol(PEG)can increase the blood circulation time of nanocarriers,its application is limited due to the“PEG dilemma”.Zwitterionic polymers have been emerging as an appealing alternative to PEG owing to their excellent performance in resisting nonspecific protein adsorption.Importantly,the diverse structures bring functional versatility to zwitterionic polymers beyond nonfouling.This review focuses on the structures and characters of zwitterionic polymers,and will discuss and summarize the application of zwitterionic polymers for drug delivery.We will highlight the strategies of zwitterionic polymers to address the physiological barriers during drug delivery.Finally,we will give some suggestions that can be utilized for the development of zwitterionic polymers for drug delivery.This review will also provide an outlook for this field.Our aim is to provide a comprehensive and systemic review on the application of zwitterionic polymers for drug delivery and promote the development of zwitterionic polymers.
基金This work was financially supported by the Special Funds for Major State Basic Research Projects of China(G1999064705).
文摘N,N-dimethyl-N-methacryloyloxyethyl-N-carboxyethyl ammonium(DMMCA)was graft-copolymerized onto thesurface of segmented poly(ether urethane)(SPEU)and PE film.The carboxybetaine structure on SPEU and PE filmsurfaces was confirmed by ATR-FTIR,XPS and water contact angle measurements.Through the experiments with plateletadhesion and protein adhesion assay in vitro,the two materials studied,including poly-DMMCA gel,all show excellentnonthrombogenicity.This confirms once again that the zwitterionic molecular structure on the surfaces of materials isessential for improving their nonthrombogenicity and biocompatibility.
基金financially supported by the National Natural Science Foundation of China (21921006, 21706115)the National Key Research and Development Program of China (2017YFC0403702)+1 种基金the Project for Marine Science and Technology Innovation of Jiangsu Province (HY2018-10)Jiangsu Students’ Innovation and Entrepreneurship Training Program (201810291044Z)
文摘Enormous demands on the separation of oil/water(O/W)emulsions in various industries,such as petrochemical,food and pharmaceutical industries,are looking for high performance and energy-efficient separation methods.Ceramic membranes have been used to deal with O/W emulsions,for its outstanding characteristics of easy-operation,high-flux,and long-term stability.However,membrane fouling is still a challenge in the industrial application of ceramic membranes.Herein,antifouling ceramic membranes were fabricated by grafting zwitterions on the membrane surface via an environment-friendly two-step grafting method,which improves the antifouling property and permeability.Successful grafting of such zwitterion on the ceramic surface was assessed by the combination of FTIR and XPS characterization.More importantly,the hydration can be formed by electrostatic interactions layer on the modified membrane,which was confirmed by TGA characterization.The antifouling performance of prepared zwitterionic ceramic membranes in the separation of O/W emulsions was systematically tested.The results suggested that zwitterion can significantly improve the flux of ceramic ultrafiltration membrane,and can also improve antifouling property dramatically by reducing the irreversible fouling in the separation of O/W emulsions.Therefore,zwitterionic ceramic membranes hold promising potentials as an antifouling,highly efficient and green method in the practical purification of the O/W emulsions.
文摘Five new zwitterionic surfactants with long chain alkyl betaine structure incorporated with hydroxylpropyl group have been synthesized. Their structures were identified by elemental analysis, IR (HNMR)-H-1, and (CNMR)-C-13. Surface tension experiments showed that these surfactants have higher surface activity than those without hydroxypropyl group. The values of CMC and gamma(CMC) of these surfactants have been determined.
基金funded by the National Key Research and Development Program of China(2018YFA0900702)the National Natural Science Foundation of China(21621004).
文摘Enzyme-polymer conjugates are complex molecules with great practical significance.This work was designed to develop a novel enzyme-polymer conjugate by covalently coupling a zwitterionic polymer with side dimethyl chains(pID)to Candida rugosa lipase(CRL)via the reaction between the anhydrides of polymer chains with the amino groups of the enzyme.The resulting two CRL-pID conjugates with different pID grafting densities were investigated in term of the catalytic activity,stability and structural changes.In comparison with native CRL,both the CRL conjugates displayed 2.2 times higher activity than the native enzyme,and showed an increase in the maximum reaction rate(V_(max))and a decrease in the Michaelis constant(K_(m)),thus resulting in about three-fold increases in the catalytic efficiency(k_(cat)/K_(m)).These are mainly attributed to the activation of lipase by the hydrophobic alky side chains.Moreover,the thermostability and pH tolerance of the lipase conjugates were significantly enhanced due to the stabilizing effect of the zwitterion moieties.For instance,a five-fold increase of the enzyme half-life at 50℃ for the high-pID conjugated CRL was observed.Spectroscopic studies reveal that the pID conjugation protected the enzyme in the changes in its microenvironment and conformation,well correlating with enhanced activity and stability of lipase conjugates.The findings indicate that enzyme conjugation to the zwitterionic polymer is promising for improving enzyme performance and deserves further development.
基金financially supported by the National Natural Science Foundation of China(Nos.51771029 and 51771122)the Shanghai International Science and Technology Cooperation Project(No.17520731800)the China Postdoctoral Science Foundation(No.2019M660453)。
文摘Developing an effective and durable antibacterial surface is important for surgical tools and biomedical implants.In this work,a zwitterionic copolymer containing catechol groups as biomimetic anchoring segments was coated onto 316 L stainless steel via drop-casting.Energy-dispersive X-ray spectroscopy(EDS)and water contact angle(WCA)measurements indicated that the coatings made of the copolymers containing zwitterionic and dopamine segments at the molar ratios of 8:2 and 6:4 exhibited stronger stability and mechanical durability than the one at 9:1 after inducing tape-peeling and ultrasonication damage.The mechanically durable nanocoatings exhibited excellent antibacterial performance against Staphylococcus aureus and Escherichia coli in a period of 3 days.The nanocoatings with zwitterionic and dopamine segments at the molar ratio of 8:2 were further evaluated and demonstrated durable antibacterial performance after tape-peeling and ultrasonication treatments.
基金This work was financially supported by the Six Talent Peaks Project in Jiangsu Province(No.SWYY-060)the National Natural Science Foundation of China(No.21504046)the Projects of Nanjing Normal University(Nos.184080H20192,184080H10386 and 184080H202B283).
文摘Antifouling ability and blood compatibility are critically important in the development of medical metallic implants for clinical applications.Here,we report the zwitterionic-phosphonate block polymer as a new type of high-efficiency antifouling coating for metallic substrates.Six block polymers(pSBMA-b-pDEMMP)with different segment lengths(nSBMA:nDEMMP=10:25,40:25,100:25,75:5,75:40,75:100)were prepared and anchored on titanium alloy(TC4)substrates.1H nuclear magnetic resonance(NMR)results clearly showed the precise preparation of the block polymers.XPS analysis and water contact angle measurement indicated the successful construction of the block polymer on TC4 substrates.The relationship between the antifouling performance of the polymer coating and the length of pDEMMP and pSBMA segments in the block polymer was established.Results showed that the polymer containing the pSBMA segment above 40 repeat units could significantly inhibit protein adsorption,platelet adhesion,bacterial adhesion and cell adhesion,while the pDEMMP segment above 5 repeat units is able to generate stable zwitterionic polymer coating on TC4 substrates.This ease of production and high-efficiency antifouling modification strategy elucidated here may find broad application for biomedical implants and devices in clinical applications.
基金supported by the National Natural Science Foundation(No.21006077)the foundation of science and technology in Shaanxi Province(No.2010K12-01-05)the foundation for construction of key disciplines of analytical chemistry in Shaanxi Province
文摘In this work, a kind of preparation method of zwitterionic ion chromatography （ZIC） stationary phase modified with phosphorylcholine （PC） was obtained by hydrolyzing after bonding phosphorylcholine dichloride to diol-silica to better explore the characteristics of the PC groups as ZIC stationary phase ligand in simultaneous separation of acidic proteins and basic proteins. The results showed that tv^o kinds of acidic proteins and three kinds of basic proteins can be separated completely, meanwhile, hen egg white was separated and purified and three kinds of egg white components ovalbumin, G2 ovoglobulin and ovotransfemin proteins were separated completely by one single step on PC-ZIC column, the purity of all proteins reached above 95%. PC-ZIC stationary phase was successfully improved with better separation capacity and selectivity than previously reported in this paper.
