The present review aims to highlight the applications of thermoresponsive polymers.Thermo-responsive polymers show a sharp change in properties upon a small or modest change in temperature.This behaviour can be utiliz...The present review aims to highlight the applications of thermoresponsive polymers.Thermo-responsive polymers show a sharp change in properties upon a small or modest change in temperature.This behaviour can be utilized for the preparation of so-called‘smart’drug delivery systems,which mimic biological response behaviour to a certain extent.Such materials are used in the development of several applications,such as drug delivery systems,tissue engineering scaffolds and gene delivery.Advances in this field are particularly relevant to applications in the areas of regenerative medicine and drug delivery.This review addresses summary of the main applications of thermoresponsive polymers which are categorized based on their 3-dimensional structure;hydrogels,interpenetrating networks,micelles,films and particles.The physico-chemical behaviour underlying the phase transition is also discussed in brief.展开更多
Hybrid drug delivery systems(DDS) have been prepared by grafting poly(NIPAM-co-MPS) chains on multimodal porous silica nanoparticles having an inner mesoporous structure and an outer thin layer of micropores. The hybr...Hybrid drug delivery systems(DDS) have been prepared by grafting poly(NIPAM-co-MPS) chains on multimodal porous silica nanoparticles having an inner mesoporous structure and an outer thin layer of micropores. The hybrid thermoresponsive DDS were fully characterized and loaded with a model drug. The in vitro drug release tests are carried out at below and above the lower critical solution temperature(LCST) of the copolymer. The results have revealed that due to the presence of small diameter(~1.3 nm) micropores at the periphery of the particles, the collapsed globules of the thermoresponsive copolymer above its LCST hinders the complete release of the drug which resulted in a reverse thermoresponsive drug release profile by the hybrid DDS.展开更多
The monomer 6-O-vinyladipoyl-D-glucopyranose( VAG)was synthesized by lipase catalyzed trans-esterification of divinyladipate with D-glucopyranose. A novel double hydrophilic glycopolymer poly( diethyleneglycol methacr...The monomer 6-O-vinyladipoyl-D-glucopyranose( VAG)was synthesized by lipase catalyzed trans-esterification of divinyladipate with D-glucopyranose. A novel double hydrophilic glycopolymer poly( diethyleneglycol methacrylate-co-6-Ovinyladipoyl-D-glucopyranose)( P( DEGMA-co-VAG)) with narrow polydispersity( PDI) and thermosensitivity was prepared by reversible addition-fragmentation chain transfer( RAFT)polymerization. P( DEGMA-co-VAG) was characterized by1 H NMR,FTIR and gel permeation chromatography( GPC). The characterization of UV-visible spectroscopy showed that the micelles from glycopolymer P( DEGMA-co-VAG) were thermo-responsive and the low critical solution temperature( LCST) could be controlled by the molar ratio of monomers. When the molar ratio of DEGMA and VAG was 2∶ 1,the LCST of P( DEGMA-co-VAG) was36 ℃ in aqueous solution,which could form nano micelles in the human body environment. It was found that P( DEGMA-co-VAG)was non-toxic at 0. 1-1 mg / m L concentrations when incubated with pig iliac endothelial cells( PIECs) for 24 h. Thus,the synthesized glycopolymers has great potential as drug delivery carriers.展开更多
Modulating reversible isomerization of hydrophobic dyes in aqueous solutions is greatly desired. Here we report on reversible isomerization of solvatochromic donor-acceptor Stenhouse adducts(DASAs) in water through th...Modulating reversible isomerization of hydrophobic dyes in aqueous solutions is greatly desired. Here we report on reversible isomerization of solvatochromic donor-acceptor Stenhouse adducts(DASAs) in water through the confinement from dendritic oligoethylene glycols(OEGs). Dendronization of DASAs with dendritic OEGs affords them characteristic thermoresponsiveness. These dendronized DASAs spontaneously isomerize in water from hydrophobic linear state into hydrophilic cyclic state at room temperature due to the strong hydration. However, hydrophobic microenvironment through thermally dehydration and collapse of the dendritic OEGs at elevated temperatures confines hydration of the DASA moieties and mediates their interactions with the collapsed hydrophobic OEG domains, affording their isomerization recovery in water efficiently from the hydrophilic cyclic state into the hydrophobic linear state. The confinement-mediated reversible isomerization of DASA moieties in water can be repeated through alternative photo-irradiation and thermal dehydrations, exhibiting excellent fatigue resistance.展开更多
The dynamic regulation of circularly polarized luminescence(CPL)holds profound significance in various fields,such as highlevel information storage and encryption.Here we developed a chiral amphiphilic molecule,CPSB-G...The dynamic regulation of circularly polarized luminescence(CPL)holds profound significance in various fields,such as highlevel information storage and encryption.Here we developed a chiral amphiphilic molecule,CPSB-GLU-PEG350(CGP),composed of aggregation-induced emission(AIE)chromophores(Z)-4-(1-cyano-2-phenylvinyl)benzoic acid(CPSB),a chiral linker Glutamic acid and polyethylene glycol(PEG)thermoresponsive segments.Within the self-assembled supramolecular system formed by CGP,we have achieved in-situ temperature-responsive chiral structures,facilitating the thermal control switch of the CPL signal.Molecular dynamics simulations demonstrate the distinct behaviors of AIE and PEG units during the temperature-variable assembly process.Furthermore,by co-assembling achiral dye molecules with CGP,we have expanded the color range of the temperature-responsive CPL assembly system in situ and confirmed the occurrence of circularly polarizedF?rster resonance energy transfer(C-FRET)phenomenon in this process,which successfully enriched the strategies for in-situ CPL control in aqueous phases.In addition,the contactless radiative energy transfer of CPL can also be realized in this system,exhibiting more flexible temperature regulation of the CPL signal.This study provides a convenient and universal strategy for the construction of dynamically smart chiroptical materials.展开更多
Fluorescent poly(N-isopropylacrylamide-co-Nile blue)(pNIPAm-co-NB)microgels were synthesized that exhibited fluorescence intensity changes in a water temperature-dependent fashion.NB is well known to exhibit fluoresce...Fluorescent poly(N-isopropylacrylamide-co-Nile blue)(pNIPAm-co-NB)microgels were synthesized that exhibited fluorescence intensity changes in a water temperature-dependent fashion.NB is well known to exhibit fluorescence intensity that depends on the hydrophobicity of the environment,while pNIPAm-based microgels are well known to transition from swollen(hydrophilic)to collapsed(relatively hydrophobic)at temperatures greater than 32℃;hence,we attribute the above behavior to the hydrophobicity changes of the microgels with increasing temperature.This phenomenon is ultimately due to NB dimers(relatively quenched fluorescence)being broken in the hydrophobic environment of the microgels leading to relatively enhanced fluorescence.We went on to show that the introduction of cucurbit[7]uril(CB[7])into the pNIPAm-co-NB microgels enhanced their fluorescence allowing them to be used for polyamine(e.g.,spermine[SPM])detection.Specifically,CB[7]forms a host–guest interaction with NB in the microgels,which prevents NB dimerization and enhances their fluorescence.When SPM is present,it forms a host–guest complex that is favored over the CB[7]-NB host–guest interaction,which frees the NB for dimerization and leads to fluorescence quenching.As a result,we could generate an SPM sensor capable of SPM detection down to~0.5µmol/L in complicated matrixes such as serum and urine.展开更多
Polymers with tunable helicity and naked-eye structural change under external stimuli are valuable for fabricating smart materials. Herein, we report a novel thermoresponsive color and fluorescent polyphenylacetylene ...Polymers with tunable helicity and naked-eye structural change under external stimuli are valuable for fabricating smart materials. Herein, we report a novel thermoresponsive color and fluorescent polyphenylacetylene switch with a tunable critical temperature. It relies on the temperature and solvent sensitivity of intramolecular n→π* interactions between the vicinal carbonyl groups of ester substituents located at 3,5-positions, which are indispensable for forming the cis-cisoid helical conformation of polyene backbones. In a properly chosen solvent, a compressed cis-cisoid helix is stabilized by n→π* interactions at low temperatures and yields a colorless solution. Increasing temperature causes the conformational transition toward an extended cis-transoid helix due to the disruption of n→π* interactions and produces a yellow solution. Reducing the hydrogen bond donating ability or polarity of solvents increases the switching temperature. By introducing a fluorogenic pendant, this conformational transition can also be read out by fluorescence quenching. This work may open a new window for developing intelligent materials through precisely tuning conformational transitions.展开更多
Reversal of cancer drug resistance remains a critical challenge in chemotherapy.Mitochondria-targeted drug delivery has been suggested to mitigate drug resistance in cancer.To overcome the intrinsic limitations in con...Reversal of cancer drug resistance remains a critical challenge in chemotherapy.Mitochondria-targeted drug delivery has been suggested to mitigate drug resistance in cancer.To overcome the intrinsic limitations in conventional mitochondrial targeting strategies,we develop mitochondrial temperature-responsive drug delivery to reverse doxorubicin(DOX)resistance in lung cancer.Results demonstrate that the thermoresponsive nanocarrier can prevent DOX efflux and facilitate DOX accumulation and mitochondrial targeting in DOX-resistant tumors.As a consequence,thermoresponsive nanocarrier enhances the cytotoxicity of DOX and reverses the drug resistance in tumor-bearing mice.This work represents the first example of mitochondrial temperature-responsive drug delivery for reversing cancer drug resistance.展开更多
Generalized two-dimensional correlation spectroscopy (2DCOS) and its derivate technique, perturbation correlation moving window (PCMW), have found great potential in studying a series of physico-chemical phenomena...Generalized two-dimensional correlation spectroscopy (2DCOS) and its derivate technique, perturbation correlation moving window (PCMW), have found great potential in studying a series of physico-chemical phenomena in stimuli-responsive polymeric systems. By spreading peaks along a second dimension, 2DCOS can significantly enhance spectral resolution and discern the sequence of group dynamics applicable to various external perturbation-induced spectroscopic changes, especially in infrared (IR), near-infrared (NIR) and Raman spectroscopy. On the basis of 2DCOS synchronous power spectra changing, PCMW proves to be a powerful tool to monitor complicated spectral variations and to find transition points and ranges. This article reviews the recent work of our research group in the application of 2DCOS and PCMW in thermoresponsive polymers, mainly focused on liquid crystalline polymers and lower critical solution temperature (LCST)-type polymers. Details of group motions and chain conformational changes upon temperature perturbation can thus be elucidated at the molecular level, which contribute to the understanding of their phase transition nature.展开更多
Thermoresponsive fluorescent polymers(TFPs) with unique temperature-dependent luminescent properties are of great importance for the development of new functional devices in recent years. Herein, we facilely synthesiz...Thermoresponsive fluorescent polymers(TFPs) with unique temperature-dependent luminescent properties are of great importance for the development of new functional devices in recent years. Herein, we facilely synthesized an efficient blue-emissive polymer, abbreviated as PCB-TPE, using tetraphenylethene(TPE) as the main building block. PCB-TPE is thermally stable with a novel property of aggregation induced emission(AIE). The thermoresponsive property and mechanism of PCB-TPE were investigated. Its emission shows temperature-dependent features and reveals fine details in the thermal transitions from-10 °C to 60 °C. The polymer offers a platform for the development of efficient luminescent materials for further biological and optoelectronic applications.展开更多
Plants are capable of coordination of their growth and development with ambient temperatures.EARLY FLOWERING3(ELF3), an essential component of the plant circadian clock, is also involved in ambient temperature sensing...Plants are capable of coordination of their growth and development with ambient temperatures.EARLY FLOWERING3(ELF3), an essential component of the plant circadian clock, is also involved in ambient temperature sensing, as well as in inhibiting the expression and protein activity of the thermoresponsive regulator phytochrome interacting factor4(PIF4). The ELF3 activity is subjected to attenuation in response to warm temperature;however,how the protein level of ELF3 is regulated at warm temperature remains less understood. Here, we report that the E3 ligase XB3 ORTHOLOG 5 IN ARABIDOPSIS THALIANA, XBAT35, mediates ELF3 degradation. XBAT35 interacts with ELF3 and ubiquitinates ELF3. Loss-of-function mutation of XBAT35 increases the protein level of ELF3 and confers a short-hypocotyl phenotype under warm temperature conditions. Thus, our findings establish that XBAT35 mediates ELF3 degradation to lift the inhibition of ELF3 on PIF4 for promoting thermoresponsive hypocotyl growth in plants.展开更多
Certain amount of primary amine (NH2) groups of hyperbranched polyethylenimine (HPEI) was first protected by Boc groups. Subsequently, the residual reactive amine groups were reacted with isobutyric anhydride to i...Certain amount of primary amine (NH2) groups of hyperbranched polyethylenimine (HPEI) was first protected by Boc groups. Subsequently, the residual reactive amine groups were reacted with isobutyric anhydride to introduce isobutyramide (IBAm) groups to HPEI. Finally, Boc groups were deprotected to result in HPEI-IBAm-NH2 with 18% of primary amine terminals on the periphery and 80% of IBAm terminal groups (abbreviated as HPEI-IBAm0.80-NH2). 1H-NMR characterization proved the successful preparation of the product in each step. Compared with its spatial isomer HPEI- IBAm0.8o without primary amine groups, IH-NMR spectra verified that more IBAm groups were located in the interior of HPEI-IBAm0.80-NH2. The further modification of HPEI-IBAmo.so-NH2 and HPEI-IBAmo.8o with p-nitrobenzaldehyde demonstrated that HPEI-IBAm0.so-NH2 was more reactive than HPEI-IBAm0.80 due to its possession of primary amines. Turbidimetry measurements showed that HPEI-IBAm0.80-NH2 was thermoresponsive in water. In the pH range of 9.5-10 its cloud point temperature (Top) was constant, and it increased obviously upon decreasing the pH below 9.5. The thermoresponsive HPEI-IBAmo.8 exhibited the similar trend, but the pH threshold to achieve the constant Top was around 8.5. Moreover, HPEI-IBAm0.8-NH2 showed higher Top and broader phase transition than HPEI-IBAm0.8. The mechanism leading to the different thermoresponsive properties between HPEI-IBAm0.8-NH2 and its spatial isomer HPEI-IBAm0.8 was discussed.展开更多
Safe and long lifespan batteries facilitate the development of portable electronics and electric vehicles.Owing to the low-cost,naturally abundance,and trivalent charge carrier of aluminum with the highest theoretical...Safe and long lifespan batteries facilitate the development of portable electronics and electric vehicles.Owing to the low-cost,naturally abundance,and trivalent charge carrier of aluminum with the highest theoretical volumetric capacity,rechargeable aqueous aluminum-ion-based batteries are considered as promising next-generation secondary batteries.However,traditional electrolytes and frequent collapse of the host structure of electrode materials greatly jeopardize the cycle stability of the batteries.Here,we develop a novel hydrogel-based electrolyte coupled with stable layered intercalation electrodes for the first time to fabricate a highly safe and flexible rechargeable hybrid Al^(3^(+))/H^(+)battery.The as-fabricated hybrid-ion battery(HIB)delivers a high specific capacity of 125 mAh·g^(−1) at 0.1 A·g^(−1) and exhibits an unprecedented super long-term cycling stability with no capacity fading over 10,000 cycles at 2 A·g^(−1).In addition,the hydrogel-based electrolyte possesses smart function of thermoresponsive switching,which can effectively prevent thermal runaway for the batteries.The unprecedented long cycle stability,highly intrinsic safety as well as low-cost indicate that the flexible aqueous HIBs are promising for applications.展开更多
Pillar[n]arenes are a new kind of supramolecular macrocyclic hosts which have developed rapidly due to their unique topology and high functionality, giving rise to many applications in the construction of interesting ...Pillar[n]arenes are a new kind of supramolecular macrocyclic hosts which have developed rapidly due to their unique topology and high functionality, giving rise to many applications in the construction of interesting and functional materials. Among them, water-soluble pillar[n]arenes bearing triethylene oxide (TEO) chains have drawn increasing research interest due to their advantageous properties. In this review, we summarized the recent progress of dynamic materials fabricated from water soluble pillar[n]arenes bearing TEO groups, including thermo responsive materials with lower critical solution temperature (LCST) behavior, cyclic host liquids, and smart windows. It is anticipated that more and more ‘smart' supramolecular materials based on modified pillar[n]arenes will be developed in this burgeoning area of research.展开更多
Although many material designs or strategic methods have been proposed for treating oil spills and oily wastewater,the complex oily state,dealing with the harsh operating conditions of oil–water separation(such as th...Although many material designs or strategic methods have been proposed for treating oil spills and oily wastewater,the complex oily state,dealing with the harsh operating conditions of oil–water separation(such as the recovery of viscous spilled crude oil,bacteria-containing oily wastewater,and removal of spilled oil under fire),and the autorecycling of oil and absorption materials remain a great challenge.This work proposed an ingenious design strategy of“several birds with one stone”to prepare p H/thermoresponsive flame-retardant/photothermal bactericidal P-Fe_(3)O_(4)-polydopamine(PDA)@melamine–formaldehyde(MF)foams.This design makes the foams remarkably effective in the recovery of spilled viscous crude oil as well as in the separation of bacteria-containing oily emulsions,particularly for instant fire extinguishing by magnetically controlled oil absorption as well as for fire alarms.The photothermal effect and p H response induce a change in the surface wettability of the foams,facilitating excellent autoadsorption/desorption of the spilled oil.The photothermal bactericidal activity and fouling resistance of the foam are beneficial to the separation of bacteria-containing oily wastewater.Outstanding flame-retardant properties and maneuverable magnetic control enable the foam to rapidly recover the spilled oil in a large range of fires,extinguish fires instantly,and facilitate early fire warning.The proposed strategy is expected to inspire further research on treating oil spills under complex conditions.展开更多
Stimuli-responsive hydrogels hold an irreplaceable statue in intelligent actuation materials because of their reversible stretchability and excellent biocompatibility.However,the poor mechanical performance and compli...Stimuli-responsive hydrogels hold an irreplaceable statue in intelligent actuation materials because of their reversible stretchability and excellent biocompatibility.However,the poor mechanical performance and complicated fabrication process of anisotropic structures severely limit their further applications.Herein,we report a high-strength thermoresponsive wood-PNIPAM composite hydrogel actuator with complex deformations,through a simple in-situ polymerization.In this composite hydrogel actuator,the anisotropic wood and the thermoresponsive PNIPAM hydrogel hydroel can work together to pro-vide bending and even other complex deformations.Owing to strong interfacial interaction,this actuator perfectly realized the combination of good mechanical properties(∼1.1 MPa)and fast actuation speed(∼0.9 s).In addition,by adjusting the orientation direction of wood,this actuator can achieve various complex deformations.Such composite hydrogel actuator could be a good candidate for intelligent appli-cations,such as intelligent actuators,smart valves,manipulators and even soft robots.展开更多
A double thermoresponsive ABC-type triblock copolymer (poly(ethyleneglycol)-block-poly (2-(2-methoxyethoxy)ethyl methacrylate)-block-poly(2-(2-methoxy ethoxy) ethyl methacrylate-co-oligo(ethylene glycol)...A double thermoresponsive ABC-type triblock copolymer (poly(ethyleneglycol)-block-poly (2-(2-methoxyethoxy)ethyl methacrylate)-block-poly(2-(2-methoxy ethoxy) ethyl methacrylate-co-oligo(ethylene glycol) methyl ether methacrylate, PEG-b-PMEO2MA-b-P(MEO2MA-co-OEGMA)) was designed and synthesized by reversible addition- fragmentation chain transfer polymerization (RAFT). The ABC-type triblock copolymer endowed a thermal-induced two- step phase transition at 29 and 39 ℃corresponding to the thermosensitive properties of PMEOzMA and P(MEO2MA-co- OEGMA) segments, respectively. The two-step self-assembly of copolymer solutions was studied by UV transmittance measurement, dynamic light scattering (DLS), transmission electron microscopy (TEM) and so on. The triblock copolymers showed the distinct thermosensitive behavior with respect to transition temperatures, aggregate type and size, which was correlated to the degree of polymerization of thermosensitive blocks and the molar fraction of OEGMA in the P(MEO2MA- co-OEGMA) segments. In addition, micelles could further aggregate to form the hydrogel by the self-associate of PEG chains under the abduction of the concentration and temperature. The transition from sol to gel was investigated by a test tube inverting method and dynamic rheological measurement.展开更多
Thermoresponsive polymers with simultaneous biodegradability and signal“self-reporting”outputs that meet for advanced applications are hard to obtain.To address this issue,we developed fluorescence signal“self-repo...Thermoresponsive polymers with simultaneous biodegradability and signal“self-reporting”outputs that meet for advanced applications are hard to obtain.To address this issue,we developed fluorescence signal“self-reporting”biodegradable thermoresponsive polycarbonates through the immortal copolymerization of CO_(2)and oligoethylene glycol monomethyl ether-functionalized epoxides in the presence of hydroxyl-modified tetraphenylethylene(TPE-OH).TPE-OH was used as chain transfer agent to afford well-defined polycarbonates with controlled molecular weight(6000—17000 g·mol^(–1))and aggregation-induced emission characteristics.Through temperature-dependent fluorescence intensity study,low critical solution transition of TPE-labeled polycarbonates were determined and the fine details of thermal-induced phase transition process were monitored.Further research indicated that temperature-controlled aggregation and dissociation of TPE moieties are the main reason for fluorescence intensity variations.We anticipate that this work could offer a method to visualize the thermal transition process of thermoresponsive polycarbonates and broaden their application fields as smart materials.展开更多
A base-free catalytic system for the aerobic oxidation of 5-hydroxymethyl-2-furfural was exploited by using Pt nanoparticles immobilized onto a thermoresponsive poly(acrylamide-co-acrylonitrile)-b-poly(N-vinylimidazol...A base-free catalytic system for the aerobic oxidation of 5-hydroxymethyl-2-furfural was exploited by using Pt nanoparticles immobilized onto a thermoresponsive poly(acrylamide-co-acrylonitrile)-b-poly(N-vinylimidazole)block copolymer,with an upper critical solution temperature of about 45°C.The Pt nanocatalysts were well-dispersed and highly active for the base-free oxidation of 5-hydroxymethyl-2-furfural by molecular oxygen in water,affording high yields of 2,5-furandicarboxylic acid(up to>99.9%).The imidazole groups in the block copolymer were conducive to the improvement of catalytic performance.Moreover,the catalysts could be easily separated and recovered based on their thermosensitivity by cooling the reaction system below the upper critical solution temperature.Good stability and reusability were observed over these copolymer-immobilized catalysts with no obvious decrease in catalytic activity in the five consecutive cycles.展开更多
Nonvolatile ionogels have recently emerged as promising soft electrolyte materials due to their high ionic conductivity and good durability.However,the compatibility between polymer networks and ionic liquids(ILs),whi...Nonvolatile ionogels have recently emerged as promising soft electrolyte materials due to their high ionic conductivity and good durability.However,the compatibility between polymer networks and ionic liquids(ILs),which show significant influence on the physicochemical properties of the ionogels,has been rarely studied.Herein,we elucidate a lower critical solution temperature(LCST)-type phase behavior of ionogels composed of polyacrylates and hydrophobic 1-alkyl-3-methylimidazolium bis{(trifluoromethyl)sulfonyl}amide ILs.We systematically study the structural effects of ILs and monomers on the LCST of ionogels.Our work illustrates that the LCST of ionogels is primarily determined by the polarity of polymer side chains and the alkyl chain on cations of ILs.The oriented solvation between polymers and ILs caused by hydrogen-bonding effects and van der Waals interactions may serve as the driving force for the LCST phase behavior in our system.Furthermore,by varying the mixing ratio of two structurally similar ILs in their blends,the LCST of ionogels can be tuned to exhibit a linear variation within a wide temperature range(from subzero to over 200℃).Finally,thermoresponsive ionogels with desired patterns are prepared using photomasks.These nonvolatile ionogels with tunable LCST enriched the functionality of state-of-the-art ionogels,which provides insight into the design and fabrication of smart and flexible electronic/optical devices.展开更多
文摘The present review aims to highlight the applications of thermoresponsive polymers.Thermo-responsive polymers show a sharp change in properties upon a small or modest change in temperature.This behaviour can be utilized for the preparation of so-called‘smart’drug delivery systems,which mimic biological response behaviour to a certain extent.Such materials are used in the development of several applications,such as drug delivery systems,tissue engineering scaffolds and gene delivery.Advances in this field are particularly relevant to applications in the areas of regenerative medicine and drug delivery.This review addresses summary of the main applications of thermoresponsive polymers which are categorized based on their 3-dimensional structure;hydrogels,interpenetrating networks,micelles,films and particles.The physico-chemical behaviour underlying the phase transition is also discussed in brief.
文摘Hybrid drug delivery systems(DDS) have been prepared by grafting poly(NIPAM-co-MPS) chains on multimodal porous silica nanoparticles having an inner mesoporous structure and an outer thin layer of micropores. The hybrid thermoresponsive DDS were fully characterized and loaded with a model drug. The in vitro drug release tests are carried out at below and above the lower critical solution temperature(LCST) of the copolymer. The results have revealed that due to the presence of small diameter(~1.3 nm) micropores at the periphery of the particles, the collapsed globules of the thermoresponsive copolymer above its LCST hinders the complete release of the drug which resulted in a reverse thermoresponsive drug release profile by the hybrid DDS.
基金National Natural Science Foundation of China(No.21303014)
文摘The monomer 6-O-vinyladipoyl-D-glucopyranose( VAG)was synthesized by lipase catalyzed trans-esterification of divinyladipate with D-glucopyranose. A novel double hydrophilic glycopolymer poly( diethyleneglycol methacrylate-co-6-Ovinyladipoyl-D-glucopyranose)( P( DEGMA-co-VAG)) with narrow polydispersity( PDI) and thermosensitivity was prepared by reversible addition-fragmentation chain transfer( RAFT)polymerization. P( DEGMA-co-VAG) was characterized by1 H NMR,FTIR and gel permeation chromatography( GPC). The characterization of UV-visible spectroscopy showed that the micelles from glycopolymer P( DEGMA-co-VAG) were thermo-responsive and the low critical solution temperature( LCST) could be controlled by the molar ratio of monomers. When the molar ratio of DEGMA and VAG was 2∶ 1,the LCST of P( DEGMA-co-VAG) was36 ℃ in aqueous solution,which could form nano micelles in the human body environment. It was found that P( DEGMA-co-VAG)was non-toxic at 0. 1-1 mg / m L concentrations when incubated with pig iliac endothelial cells( PIECs) for 24 h. Thus,the synthesized glycopolymers has great potential as drug delivery carriers.
基金supported by the National Natural Science Foundation of China (21971160, 21971161, 22271183 and 22371179)the Program for Professor of Special Appointment (Eastern Scholar TP2019039) at Shanghai Institutions of Higher Learning。
文摘Modulating reversible isomerization of hydrophobic dyes in aqueous solutions is greatly desired. Here we report on reversible isomerization of solvatochromic donor-acceptor Stenhouse adducts(DASAs) in water through the confinement from dendritic oligoethylene glycols(OEGs). Dendronization of DASAs with dendritic OEGs affords them characteristic thermoresponsiveness. These dendronized DASAs spontaneously isomerize in water from hydrophobic linear state into hydrophilic cyclic state at room temperature due to the strong hydration. However, hydrophobic microenvironment through thermally dehydration and collapse of the dendritic OEGs at elevated temperatures confines hydration of the DASA moieties and mediates their interactions with the collapsed hydrophobic OEG domains, affording their isomerization recovery in water efficiently from the hydrophilic cyclic state into the hydrophobic linear state. The confinement-mediated reversible isomerization of DASA moieties in water can be repeated through alternative photo-irradiation and thermal dehydrations, exhibiting excellent fatigue resistance.
基金supported by the National Natural Science Foundation of China(22301206,22301208 and 92356305)the Natural Science Foundation of Anhui Province(2308085J15)+3 种基金the China Postdoctoral Science Foundation(2022M722312)the Jiangsu Natural Science Foundation(BK20230505)the Jiangsu Funding Program for Excellent Postdoctoral Talentthe Natural Science Foundation of Anhui Provincial Higher Education Institutions(2023AH010012)。
文摘The dynamic regulation of circularly polarized luminescence(CPL)holds profound significance in various fields,such as highlevel information storage and encryption.Here we developed a chiral amphiphilic molecule,CPSB-GLU-PEG350(CGP),composed of aggregation-induced emission(AIE)chromophores(Z)-4-(1-cyano-2-phenylvinyl)benzoic acid(CPSB),a chiral linker Glutamic acid and polyethylene glycol(PEG)thermoresponsive segments.Within the self-assembled supramolecular system formed by CGP,we have achieved in-situ temperature-responsive chiral structures,facilitating the thermal control switch of the CPL signal.Molecular dynamics simulations demonstrate the distinct behaviors of AIE and PEG units during the temperature-variable assembly process.Furthermore,by co-assembling achiral dye molecules with CGP,we have expanded the color range of the temperature-responsive CPL assembly system in situ and confirmed the occurrence of circularly polarizedF?rster resonance energy transfer(C-FRET)phenomenon in this process,which successfully enriched the strategies for in-situ CPL control in aqueous phases.In addition,the contactless radiative energy transfer of CPL can also be realized in this system,exhibiting more flexible temperature regulation of the CPL signal.This study provides a convenient and universal strategy for the construction of dynamically smart chiroptical materials.
文摘Fluorescent poly(N-isopropylacrylamide-co-Nile blue)(pNIPAm-co-NB)microgels were synthesized that exhibited fluorescence intensity changes in a water temperature-dependent fashion.NB is well known to exhibit fluorescence intensity that depends on the hydrophobicity of the environment,while pNIPAm-based microgels are well known to transition from swollen(hydrophilic)to collapsed(relatively hydrophobic)at temperatures greater than 32℃;hence,we attribute the above behavior to the hydrophobicity changes of the microgels with increasing temperature.This phenomenon is ultimately due to NB dimers(relatively quenched fluorescence)being broken in the hydrophobic environment of the microgels leading to relatively enhanced fluorescence.We went on to show that the introduction of cucurbit[7]uril(CB[7])into the pNIPAm-co-NB microgels enhanced their fluorescence allowing them to be used for polyamine(e.g.,spermine[SPM])detection.Specifically,CB[7]forms a host–guest interaction with NB in the microgels,which prevents NB dimerization and enhances their fluorescence.When SPM is present,it forms a host–guest complex that is favored over the CB[7]-NB host–guest interaction,which frees the NB for dimerization and leads to fluorescence quenching.As a result,we could generate an SPM sensor capable of SPM detection down to~0.5µmol/L in complicated matrixes such as serum and urine.
基金supported by the National Natural Science Foundation of China(51833001,51921002,52103001)the China Postdoctoral Science Foundation(2021T140007,2020M680191).
文摘Polymers with tunable helicity and naked-eye structural change under external stimuli are valuable for fabricating smart materials. Herein, we report a novel thermoresponsive color and fluorescent polyphenylacetylene switch with a tunable critical temperature. It relies on the temperature and solvent sensitivity of intramolecular n→π* interactions between the vicinal carbonyl groups of ester substituents located at 3,5-positions, which are indispensable for forming the cis-cisoid helical conformation of polyene backbones. In a properly chosen solvent, a compressed cis-cisoid helix is stabilized by n→π* interactions at low temperatures and yields a colorless solution. Increasing temperature causes the conformational transition toward an extended cis-transoid helix due to the disruption of n→π* interactions and produces a yellow solution. Reducing the hydrogen bond donating ability or polarity of solvents increases the switching temperature. By introducing a fluorogenic pendant, this conformational transition can also be read out by fluorescence quenching. This work may open a new window for developing intelligent materials through precisely tuning conformational transitions.
基金We are grateful to Beijing Natural Science Foundation(7212212)National Natural Science Foundation of China(11875269 and 21574136)Hundred Talents Program of CAS for financial support。
文摘Reversal of cancer drug resistance remains a critical challenge in chemotherapy.Mitochondria-targeted drug delivery has been suggested to mitigate drug resistance in cancer.To overcome the intrinsic limitations in conventional mitochondrial targeting strategies,we develop mitochondrial temperature-responsive drug delivery to reverse doxorubicin(DOX)resistance in lung cancer.Results demonstrate that the thermoresponsive nanocarrier can prevent DOX efflux and facilitate DOX accumulation and mitochondrial targeting in DOX-resistant tumors.As a consequence,thermoresponsive nanocarrier enhances the cytotoxicity of DOX and reverses the drug resistance in tumor-bearing mice.This work represents the first example of mitochondrial temperature-responsive drug delivery for reversing cancer drug resistance.
基金financially supported by the National Natural Science Foundation of China(Nos.21274030,51473038 and 21604024)the Natural Science Foundation of Shanghai(No.17ZR1440400)+1 种基金the Open Project of State Key Laboratory of Chemical Engineering(No.SKL-Ch E-16C02)“Chenguang Plan”
文摘Generalized two-dimensional correlation spectroscopy (2DCOS) and its derivate technique, perturbation correlation moving window (PCMW), have found great potential in studying a series of physico-chemical phenomena in stimuli-responsive polymeric systems. By spreading peaks along a second dimension, 2DCOS can significantly enhance spectral resolution and discern the sequence of group dynamics applicable to various external perturbation-induced spectroscopic changes, especially in infrared (IR), near-infrared (NIR) and Raman spectroscopy. On the basis of 2DCOS synchronous power spectra changing, PCMW proves to be a powerful tool to monitor complicated spectral variations and to find transition points and ranges. This article reviews the recent work of our research group in the application of 2DCOS and PCMW in thermoresponsive polymers, mainly focused on liquid crystalline polymers and lower critical solution temperature (LCST)-type polymers. Details of group motions and chain conformational changes upon temperature perturbation can thus be elucidated at the molecular level, which contribute to the understanding of their phase transition nature.
基金financially supported by the National Natural Science Foundation of China (No. 21374136)the Fundamental Research Funds for the Central Universities (Nos. 17lgjc03 and 18lgpy04)the Opening Project of the Key Laboratory of Polymer Processing Engineering (South China University of Technology, Ministry of Education, No. KFKT1703)
文摘Thermoresponsive fluorescent polymers(TFPs) with unique temperature-dependent luminescent properties are of great importance for the development of new functional devices in recent years. Herein, we facilely synthesized an efficient blue-emissive polymer, abbreviated as PCB-TPE, using tetraphenylethene(TPE) as the main building block. PCB-TPE is thermally stable with a novel property of aggregation induced emission(AIE). The thermoresponsive property and mechanism of PCB-TPE were investigated. Its emission shows temperature-dependent features and reveals fine details in the thermal transitions from-10 °C to 60 °C. The polymer offers a platform for the development of efficient luminescent materials for further biological and optoelectronic applications.
基金project was financially supported by grants from the National Natural Science Foundation of China(31625004 and 31872653)the Zhejiang Provincial Talent Program(2019R52005)+1 种基金the BBSRC(BB/N018540/1)the 111 Project(B14027)。
文摘Plants are capable of coordination of their growth and development with ambient temperatures.EARLY FLOWERING3(ELF3), an essential component of the plant circadian clock, is also involved in ambient temperature sensing, as well as in inhibiting the expression and protein activity of the thermoresponsive regulator phytochrome interacting factor4(PIF4). The ELF3 activity is subjected to attenuation in response to warm temperature;however,how the protein level of ELF3 is regulated at warm temperature remains less understood. Here, we report that the E3 ligase XB3 ORTHOLOG 5 IN ARABIDOPSIS THALIANA, XBAT35, mediates ELF3 degradation. XBAT35 interacts with ELF3 and ubiquitinates ELF3. Loss-of-function mutation of XBAT35 increases the protein level of ELF3 and confers a short-hypocotyl phenotype under warm temperature conditions. Thus, our findings establish that XBAT35 mediates ELF3 degradation to lift the inhibition of ELF3 on PIF4 for promoting thermoresponsive hypocotyl growth in plants.
基金financially supported by the financial support from the Program for New Century Excellent Talents in Universitiesthe National Natural Science Foundation of China(Nos.20804027 and 21274106)
文摘Certain amount of primary amine (NH2) groups of hyperbranched polyethylenimine (HPEI) was first protected by Boc groups. Subsequently, the residual reactive amine groups were reacted with isobutyric anhydride to introduce isobutyramide (IBAm) groups to HPEI. Finally, Boc groups were deprotected to result in HPEI-IBAm-NH2 with 18% of primary amine terminals on the periphery and 80% of IBAm terminal groups (abbreviated as HPEI-IBAm0.80-NH2). 1H-NMR characterization proved the successful preparation of the product in each step. Compared with its spatial isomer HPEI- IBAm0.8o without primary amine groups, IH-NMR spectra verified that more IBAm groups were located in the interior of HPEI-IBAm0.80-NH2. The further modification of HPEI-IBAmo.so-NH2 and HPEI-IBAmo.8o with p-nitrobenzaldehyde demonstrated that HPEI-IBAm0.so-NH2 was more reactive than HPEI-IBAm0.80 due to its possession of primary amines. Turbidimetry measurements showed that HPEI-IBAm0.80-NH2 was thermoresponsive in water. In the pH range of 9.5-10 its cloud point temperature (Top) was constant, and it increased obviously upon decreasing the pH below 9.5. The thermoresponsive HPEI-IBAmo.8 exhibited the similar trend, but the pH threshold to achieve the constant Top was around 8.5. Moreover, HPEI-IBAm0.8-NH2 showed higher Top and broader phase transition than HPEI-IBAm0.8. The mechanism leading to the different thermoresponsive properties between HPEI-IBAm0.8-NH2 and its spatial isomer HPEI-IBAm0.8 was discussed.
基金This research was supported by the National Natural Science Foundation of China (No. 21805063)the Natural Science Foundation of Guangdong Province for Distinguished Young Scholars (No. 2018B030306022)+1 种基金the Economic, Trade and Information Commission of Shenzhen Municipality through the Graphene Manufacture Innovation Center (No. 201901161514)and Research Innovation Fund of Harbin Institute of Technology (No. HIT.NSRIF.2020063).
文摘Safe and long lifespan batteries facilitate the development of portable electronics and electric vehicles.Owing to the low-cost,naturally abundance,and trivalent charge carrier of aluminum with the highest theoretical volumetric capacity,rechargeable aqueous aluminum-ion-based batteries are considered as promising next-generation secondary batteries.However,traditional electrolytes and frequent collapse of the host structure of electrode materials greatly jeopardize the cycle stability of the batteries.Here,we develop a novel hydrogel-based electrolyte coupled with stable layered intercalation electrodes for the first time to fabricate a highly safe and flexible rechargeable hybrid Al^(3^(+))/H^(+)battery.The as-fabricated hybrid-ion battery(HIB)delivers a high specific capacity of 125 mAh·g^(−1) at 0.1 A·g^(−1) and exhibits an unprecedented super long-term cycling stability with no capacity fading over 10,000 cycles at 2 A·g^(−1).In addition,the hydrogel-based electrolyte possesses smart function of thermoresponsive switching,which can effectively prevent thermal runaway for the batteries.The unprecedented long cycle stability,highly intrinsic safety as well as low-cost indicate that the flexible aqueous HIBs are promising for applications.
基金financial support from the National Natural Science Foundation of China(No. 21702020)and Maynooth University
文摘Pillar[n]arenes are a new kind of supramolecular macrocyclic hosts which have developed rapidly due to their unique topology and high functionality, giving rise to many applications in the construction of interesting and functional materials. Among them, water-soluble pillar[n]arenes bearing triethylene oxide (TEO) chains have drawn increasing research interest due to their advantageous properties. In this review, we summarized the recent progress of dynamic materials fabricated from water soluble pillar[n]arenes bearing TEO groups, including thermo responsive materials with lower critical solution temperature (LCST) behavior, cyclic host liquids, and smart windows. It is anticipated that more and more ‘smart' supramolecular materials based on modified pillar[n]arenes will be developed in this burgeoning area of research.
基金financially supported by the National Natural Science Foundation of China(No.22078077)the National Science Foundation of Guangdong Province(No.2021A1515010078)financial support of Taif University Researchers Supporting Project(No.TURSP-2020/14),Taif University,Taif,Saudi Arabia。
文摘Although many material designs or strategic methods have been proposed for treating oil spills and oily wastewater,the complex oily state,dealing with the harsh operating conditions of oil–water separation(such as the recovery of viscous spilled crude oil,bacteria-containing oily wastewater,and removal of spilled oil under fire),and the autorecycling of oil and absorption materials remain a great challenge.This work proposed an ingenious design strategy of“several birds with one stone”to prepare p H/thermoresponsive flame-retardant/photothermal bactericidal P-Fe_(3)O_(4)-polydopamine(PDA)@melamine–formaldehyde(MF)foams.This design makes the foams remarkably effective in the recovery of spilled viscous crude oil as well as in the separation of bacteria-containing oily emulsions,particularly for instant fire extinguishing by magnetically controlled oil absorption as well as for fire alarms.The photothermal effect and p H response induce a change in the surface wettability of the foams,facilitating excellent autoadsorption/desorption of the spilled oil.The photothermal bactericidal activity and fouling resistance of the foam are beneficial to the separation of bacteria-containing oily wastewater.Outstanding flame-retardant properties and maneuverable magnetic control enable the foam to rapidly recover the spilled oil in a large range of fires,extinguish fires instantly,and facilitate early fire warning.The proposed strategy is expected to inspire further research on treating oil spills under complex conditions.
基金supported by the National Natural Science Foundation of China(Nos.51803093,51903123)Natu-ral Science Foundation of Jiangsu Province(No.BK20190760)+1 种基金Open Project of Chemistry Department of Qingdao University of Science and Technology(No.QUSTHX201921)Open Fund of Fujian Provincial Key Laboratory of Eco-Industrial Green Technology,China(Nos.WYKF-EIGT2020–3,WYKF-GC2021–1).
文摘Stimuli-responsive hydrogels hold an irreplaceable statue in intelligent actuation materials because of their reversible stretchability and excellent biocompatibility.However,the poor mechanical performance and complicated fabrication process of anisotropic structures severely limit their further applications.Herein,we report a high-strength thermoresponsive wood-PNIPAM composite hydrogel actuator with complex deformations,through a simple in-situ polymerization.In this composite hydrogel actuator,the anisotropic wood and the thermoresponsive PNIPAM hydrogel hydroel can work together to pro-vide bending and even other complex deformations.Owing to strong interfacial interaction,this actuator perfectly realized the combination of good mechanical properties(∼1.1 MPa)and fast actuation speed(∼0.9 s).In addition,by adjusting the orientation direction of wood,this actuator can achieve various complex deformations.Such composite hydrogel actuator could be a good candidate for intelligent appli-cations,such as intelligent actuators,smart valves,manipulators and even soft robots.
基金financially supported by the National Natural Science Foundation of China(No.20973106)the Program for Changjiang Scholars and Innovative Research Team in University(No.IRT_14R33)
文摘A double thermoresponsive ABC-type triblock copolymer (poly(ethyleneglycol)-block-poly (2-(2-methoxyethoxy)ethyl methacrylate)-block-poly(2-(2-methoxy ethoxy) ethyl methacrylate-co-oligo(ethylene glycol) methyl ether methacrylate, PEG-b-PMEO2MA-b-P(MEO2MA-co-OEGMA)) was designed and synthesized by reversible addition- fragmentation chain transfer polymerization (RAFT). The ABC-type triblock copolymer endowed a thermal-induced two- step phase transition at 29 and 39 ℃corresponding to the thermosensitive properties of PMEOzMA and P(MEO2MA-co- OEGMA) segments, respectively. The two-step self-assembly of copolymer solutions was studied by UV transmittance measurement, dynamic light scattering (DLS), transmission electron microscopy (TEM) and so on. The triblock copolymers showed the distinct thermosensitive behavior with respect to transition temperatures, aggregate type and size, which was correlated to the degree of polymerization of thermosensitive blocks and the molar fraction of OEGMA in the P(MEO2MA- co-OEGMA) segments. In addition, micelles could further aggregate to form the hydrogel by the self-associate of PEG chains under the abduction of the concentration and temperature. The transition from sol to gel was investigated by a test tube inverting method and dynamic rheological measurement.
基金the financial support from the Fundamental Science Center projector in National Natural Science Foundation of China(Grant No.51988102)Key Research Program of Frontier Sciences,CAS(Grant No.QYZDJ-SSW-JSC017).
文摘Thermoresponsive polymers with simultaneous biodegradability and signal“self-reporting”outputs that meet for advanced applications are hard to obtain.To address this issue,we developed fluorescence signal“self-reporting”biodegradable thermoresponsive polycarbonates through the immortal copolymerization of CO_(2)and oligoethylene glycol monomethyl ether-functionalized epoxides in the presence of hydroxyl-modified tetraphenylethylene(TPE-OH).TPE-OH was used as chain transfer agent to afford well-defined polycarbonates with controlled molecular weight(6000—17000 g·mol^(–1))and aggregation-induced emission characteristics.Through temperature-dependent fluorescence intensity study,low critical solution transition of TPE-labeled polycarbonates were determined and the fine details of thermal-induced phase transition process were monitored.Further research indicated that temperature-controlled aggregation and dissociation of TPE moieties are the main reason for fluorescence intensity variations.We anticipate that this work could offer a method to visualize the thermal transition process of thermoresponsive polycarbonates and broaden their application fields as smart materials.
基金supported by the National Natural Science Foundation of China(Grant No.21203102)the Nankai University&Cangzhou Bohai New Area Institute of Green Chemical Engineering Fund(Grant No.NCC2020PY02)+2 种基金the Tianjin Municipal Natural Science Foundation(Grant No.17JCYBJC22600)the Innovative Team Project of Ministry of Education of China(IRT13R30)the Fundamental Research Funds for the Central Universities.
文摘A base-free catalytic system for the aerobic oxidation of 5-hydroxymethyl-2-furfural was exploited by using Pt nanoparticles immobilized onto a thermoresponsive poly(acrylamide-co-acrylonitrile)-b-poly(N-vinylimidazole)block copolymer,with an upper critical solution temperature of about 45°C.The Pt nanocatalysts were well-dispersed and highly active for the base-free oxidation of 5-hydroxymethyl-2-furfural by molecular oxygen in water,affording high yields of 2,5-furandicarboxylic acid(up to>99.9%).The imidazole groups in the block copolymer were conducive to the improvement of catalytic performance.Moreover,the catalysts could be easily separated and recovered based on their thermosensitivity by cooling the reaction system below the upper critical solution temperature.Good stability and reusability were observed over these copolymer-immobilized catalysts with no obvious decrease in catalytic activity in the five consecutive cycles.
基金financially supported by theNationalNatural Science Funds for Distinguished Young Scholar(no.21725401)the National Key R&D Program of China(grant no.2017YFA0207800)+2 种基金the China Postdoctoral Science Foundation(no.2019M650434)the National Natural Scientific Foundation of China(nos.21774004,22073094)the supports of Computing Center of Jilin Province and Computing Center of CIAC,CAS.
文摘Nonvolatile ionogels have recently emerged as promising soft electrolyte materials due to their high ionic conductivity and good durability.However,the compatibility between polymer networks and ionic liquids(ILs),which show significant influence on the physicochemical properties of the ionogels,has been rarely studied.Herein,we elucidate a lower critical solution temperature(LCST)-type phase behavior of ionogels composed of polyacrylates and hydrophobic 1-alkyl-3-methylimidazolium bis{(trifluoromethyl)sulfonyl}amide ILs.We systematically study the structural effects of ILs and monomers on the LCST of ionogels.Our work illustrates that the LCST of ionogels is primarily determined by the polarity of polymer side chains and the alkyl chain on cations of ILs.The oriented solvation between polymers and ILs caused by hydrogen-bonding effects and van der Waals interactions may serve as the driving force for the LCST phase behavior in our system.Furthermore,by varying the mixing ratio of two structurally similar ILs in their blends,the LCST of ionogels can be tuned to exhibit a linear variation within a wide temperature range(from subzero to over 200℃).Finally,thermoresponsive ionogels with desired patterns are prepared using photomasks.These nonvolatile ionogels with tunable LCST enriched the functionality of state-of-the-art ionogels,which provides insight into the design and fabrication of smart and flexible electronic/optical devices.