Strong polyelectrolyte brushes(SPBs)play an important role in enabling material surface functionalization due to their unique stimuli-responsive properties.Although the unexpected pH responsiveness of SPBs has been re...Strong polyelectrolyte brushes(SPBs)play an important role in enabling material surface functionalization due to their unique stimuli-responsive properties.Although the unexpected pH responsiveness of SPBs has been revealed in the past ten years,it is still unclear if the pH-responsive properties of SPBs are affected by the brush thickness.In this study,we employed the positively charged poly[2-(methacryloyloxy)ethyl]trimethylammonium chloride(PMETAC)and negatively charged sodium poly(styrenesulfonate)(NaPSS)brushes as model systems to explore the effect of thickness on the pH-responsive properties of SPBs.The results demonstrate that the pH-responsive properties of SPBs manifest different dependences on the brush thickness.Specifically,for both PMETAC and NaPSS brushes,the pH-responsive hydration and stiffness are influenced by the thickness,and the pH-responsive wettability and adhesion are almost unaffected by the thickness.This work not only provides a clear understanding of the relationship between the brush thickness and the pH responsiveness of SPBs,but also offers a new method to control the pH-responsive properties of SPBs.展开更多
pH responsive polymeric Janus nanosheets with poly（maleic acid） moiety and crosslinked PS onto the corresponding sides have been synthesized by free radical polymerization. The Janus nanosheets can serve as solid em...pH responsive polymeric Janus nanosheets with poly（maleic acid） moiety and crosslinked PS onto the corresponding sides have been synthesized by free radical polymerization. The Janus nanosheets can serve as solid emulsifier to stabilize an oil/water emulsion, whose stability is easily triggered by changing pH across pKa of the poly（maleic acid）.展开更多
Constructing high strength pH sensitive supramolecular polymer hydrogel remains very challenging due to the unavoidable network swelling caused by ionization of acid or basic groups at a specified pH.In this work,we p...Constructing high strength pH sensitive supramolecular polymer hydrogel remains very challenging due to the unavoidable network swelling caused by ionization of acid or basic groups at a specified pH.In this work,we proposed a simple and very convenient approach to fabricate high strength pH responsive supramolecular polymer(SP) hydrogels by one-pot copolymerization of N-acryloyl glycinamide(NAGA) and 2-vinyl-4,6-diamino-1,3,5-triazine(VDT),two feature hydrogen bonding monomers.In these PNAGA-PVDT SP hydrogels obtained,the hydrogen bonding of NAGA was shown to play a dominant role in reinforcing strength,while the hydrogen bonding of diaminotriazine served as a pH sensitive moiety.At pH 3,the mechanical properties of PNAGA-PVDT hydrogels decreased to a different extent due to the breakup of hydrogen bonding;in contrast,the hydrogel resumed the original strength while pH was raised to 7.4 because of reconstruction of hydrogen bonding.Over the selected pH range,the PNAGA-PVDT hydrogels exhibited up to 1.25 MPa tensile strength,845% breaking strain,69 kPa Young's modulus and 21 MPa compressive strength.This novel high strength pH-responsive SP hydrogels may find applications in biomedical and industrial fields.展开更多
pH-responsive charge reversal loaded miRNA nanocomposite was prepared by electrostatic self-assembly.The morphology,particle size and zeta potential of the nanocomposites were analyzed by transmission electron microsc...pH-responsive charge reversal loaded miRNA nanocomposite was prepared by electrostatic self-assembly.The morphology,particle size and zeta potential of the nanocomposites were analyzed by transmission electron microscopy and dynamic light scattering.The synthesis of the polymer was analyzed by^(1)H-NMR.The zeta-potential changes and cellular uptake effects of the nanocomplexes under different pH environments were investigated.The experimental results show that the surface morphology of the nanocomposite is spherical,and the average particle size is about 135 nm.As the pH value of the solution gradually decreases,the surface charge of the nanocomposite reverses from negative charge to positive charge(from-9.4 to+17.1 mV).Cellular uptake mediated by pH-responsive nanocomposite is selective for tumor cells,and the cellular uptake effect in tumor cells at pH 6.5 was approximately 3 times higher than that at pH 7.4.This pH responsive charge reversal nanocomposite has promising application prospects for gene delivery in the weak acid environment of tumors.展开更多
Hydrogels show versatile properties and are of great interest in the fields of bioelectronics and tissue engineering.Understanding the dynamics of the water molecules trapped in the three-dimensional polymeric network...Hydrogels show versatile properties and are of great interest in the fields of bioelectronics and tissue engineering.Understanding the dynamics of the water molecules trapped in the three-dimensional polymeric networks of the hydrogels is crucial to elucidate their mechanical and swelling properties at the molecular level.In this report,the poly(DMAEMA-co-AA)hydrogels were synthesized and characterized by the macroscopic swelling measurements under different pH conditions.Furthermore,the microscopic structural dynamics of pH stimulus-responsive hydrogels were studied using FTIR and ultrafast IR spectroscopies from the viewpoint of the SCN-anionic solute as the local vibrational reporter.Ultrafast IR spectroscopic measurements showed the time constants of the vibrational population decay of SCN-were increased from 14±1 ps to 20±1 ps when the pH of the hydrogels varied from2.0 to 12.0.Rotational anisotropy measurements further revealed that the rotation of SCNanionic probe was restricted by the three-dimensional network formed in the hydrogels and the rotation of SCN-anionic probe cannot decay to zero especially at the pH of 7.0.These results are expected to provide a molecular-level understanding of the microscopic structure of the cross-linked polymeric network in the pH stimulus-responsive hydrogels.展开更多
The rapid urbanization underscores the urgency of efficient treatment and resource utilization of municipal sludge for environmental conservation.To address this,a novel pH-responsive dual network polyvinyl alcohol/so...The rapid urbanization underscores the urgency of efficient treatment and resource utilization of municipal sludge for environmental conservation.To address this,a novel pH-responsive dual network polyvinyl alcohol/sodium alginate sludge hydrogel was devised by integrating municipal sludge with acrylic acid monomers,ammonium persulphate initiator,N,N’-methylene bisacrylamide crosslinking agent,reinforced by polyvinyl alcohol and sodium alginate through free radical cross-linking polymerization.The hydrogel’s optimal formulation was identified by adjusting the monomer,crosslinking agent,and initiator dosage while assessing its swelling behavior across various pH environments.Results revealed excellent swelling capacity,notably exhibiting a remarkable swelling capacity of up to 7265.64% at pH 11.0,suggesting the hydrogel’s potential in environmental remediation and innovative material design.This research presents a pioneering approach to harnessing municipal sludge and developing intelligent hydrogels,fostering sustainable resource management.展开更多
The appearance of multidrug-resistant bacteria and the formation of bacterial biofilms have necessitated the development of alternative antimicrobial therapeutics.Antibiotics conjugated with or embedded in nano-drug c...The appearance of multidrug-resistant bacteria and the formation of bacterial biofilms have necessitated the development of alternative antimicrobial therapeutics.Antibiotics conjugated with or embedded in nano-drug carriers show a great potential and advantage over free drugs,but the mass proportion of carriers generally exceeds 90%of the nano-drug,resulting in low drug loading and limited therapeutic output.Herein,we fabricated a nanocarrier using antibiotics as the building blocks,minimizing the use of carriermaterials,significantly increasing the drug loading content and treatment effect.Firstly,we conjugated betaine carboxylate with ciprofloxacin(CIP)through an ester bond to form the amphiphilic conjugate(CIP-CB),which self-assembled into micelles(CIP-CBMs)in aqueous solutions,with a CIP loading content as high as 65.4%and pH-induced surface charge reversal properties.Secondly,a model photosensitizer(5,10,15,20-tetraphenylporphyrin(TPP))was encapsulated in CIP-CBMs,generating infection-targeted photodynamic/antibiotic combined nanomedicines(denoted as TPP@CIP-CBMs).Upon accumulation at infection sites or in deep bacterial biofilms,the ester bond between the betaine carboxylate and CIP is cleaved to release free TPP and CIP,leading to a synergetic antibacterial and antibiofilm activity in vitro and in vivo.展开更多
pH responsive composite Janus cages of PS-silica-PEO are prepared using silica nanoparticles to crosslink two PAA contained di-block copolymers at an emulsion interface sequentially. Transverse channels are in situ cr...pH responsive composite Janus cages of PS-silica-PEO are prepared using silica nanoparticles to crosslink two PAA contained di-block copolymers at an emulsion interface sequentially. Transverse channels are in situ created across the shell, which facilitates mass transfer. Shell is pH responsive owing to the presence of residual PAA chains tethered onto the silica nanoparticles. The Janus cages are capable to preferentially capture oil from their aqueous surroundings. The saturation absorption capacity is determined by pH and oil property. Other composite Janus cages are expected by extension the method using other copolymers and functional nanoparticles.展开更多
The colloidal crystal template or opal with a closed-packed face-centered cubic （fcc） lattice was prepared from monodisperse polystyrene （PS） spheres by vertical sedimentation. The template provided void space for...The colloidal crystal template or opal with a closed-packed face-centered cubic （fcc） lattice was prepared from monodisperse polystyrene （PS） spheres by vertical sedimentation. The template provided void space for infiltration of monomer precursor composed of acrylate acid, acrylamide and ammonium-persulfate, as well as microgel from the subsequent copolymerization. The sample was immersed in dimethylbenzene for completely removing PS spheres to form PAM inverse opal hydrogels （IOHPAM） or PAM/PAA inverse opal hydrogels （IOHPAM/PAA） photonic crystals. The PS spheres were replaced by air spheres, which interconnected each other through the windows. The study of responses to pH show that there are two peaks for both IOHPAM and IOHPAM/PAA films, but the IOHPAM/PAA peaks shift to higher pH, and the peaks are independent with the AA content.展开更多
Developing fluorescence probes with multiple responses has vital significance but remains challenging.Herein,for the first time,we present a mitochondrial DNA(mtDNA)-triggered pH response signalamplified fluorescent p...Developing fluorescence probes with multiple responses has vital significance but remains challenging.Herein,for the first time,we present a mitochondrial DNA(mtDNA)-triggered pH response signalamplified fluorescent probe(QCY-DBT)for multiple cell detection.The probe exhibited a large stokes shift(229 nm),excellent DNA selectivity over RNA,and ultrasensitivity of detection limit(DL;74.0 ng/mL).Thus,QCY-DBT was successfully applied to analyze multiple human peripheral blood cells and visualize mtDNA in healthy and apoptotic cells.In the tumor acidic environment(pH 6.0–7.0),the absorbance of QCY-DBT at 436 nm increased,and the fluorescence signal(665 nm)was amplified by mtDNA,which enabled the direct observation of tumor cells.Our study provides help in designing smart probes with multiple responses for efficient abnormal cell detection.展开更多
To explore the effects of microenvironmental adjustments on fluorescence,a pH-sensitive nanocomposite system based on fluorescence resonance energy transfer(FRET)was constructed.The model system included a modified tr...To explore the effects of microenvironmental adjustments on fluorescence,a pH-sensitive nanocomposite system based on fluorescence resonance energy transfer(FRET)was constructed.The model system included a modified triblock copolymer(polyhistidine-b-polyethylene glycol-b-polycaprolactone)and gold nanoparticles.A near-infrared dye was used as the donor,and spectrally matched gold nanorods,attached after C-terminus modification with α-lipoic acid,were used as the receptor to realize control of the FRET effect over the fluorescence intensity for two polymer configurational changes(i.e.,"folded"and"stretched"states)in response to pH.After synthesis and characterization,we investigated the self-assembly behavior of the system.Analysis by quartz crystal microbalance revealed the pH sensitivity of the polymer,which exhibited"folding"and"stretching"states with changes in pH,providing a structural basis for the FRET effect.Fluorescence spectrophotometry investigations also revealed the regulatory impact of the assembled system on fluorescence.展开更多
Background:Diabetic wounds feature a high-glucose and acidic microenvironment that impairs macrophage polarization and healing.Adiposederived stem cell-derived exosomes(ADSC-exos)show therapeutic potential but suffer ...Background:Diabetic wounds feature a high-glucose and acidic microenvironment that impairs macrophage polarization and healing.Adiposederived stem cell-derived exosomes(ADSC-exos)show therapeutic potential but suffer from rapid clearance.This study aimed to develop a smart hydrogel for glucose/pH-responsive ADSC-exos release.Methods:A dual-responsive hydrogel(HAP/OCS/PEG/Ag-E)was fabricated via dynamic triple cross-linking.Characterization included rheometry,mechanical tests,and microscopy.In vitro macrophage polarization was assessed via flow cytometry and Western blot.A diabetic mouse wound model evaluated healing rates,histology,angiogenesis,and inflammation.Proteomics and pathway inhibition studies explored mechanisms.Statistical analysis used t-tests and ANOVA.Results:The hydrogel exhibited excellent self-healing,adhesion,and controlled ADSC-exos release under high-glucose/acidic conditions.It promoted M2 macrophage polarization,reduced pro-inflammatory cytokines(IL-1β,IL-6,TNF-α),and accelerated wound healing with enhanced angiogenesis and collagen deposition.Mechanistically,the hydrogel suppressed the Notch/NF-κB/NLRP3 signaling pathway.Conclusion:The smart hydrogel facilitates diabetic wound healing through microenvironment-responsive ADSC-exos release and Notch/NFκB/NLRP3 pathway inhibition,offering a promising strategy for chronic wound treatment.展开更多
Yanmin Ju1,2,Zhiyi Wang1,Zeeshan Ali1,Hongchen Zhang1,Yazhou Wang1,Nuo Xu3,Hui Yin4,Fugeng Sheng4,and Yanglong Hou1✉1 Beijing Key Laboratory for Magnetoelectric Materials and Devices(BKL-MMD),Beijing Innovation Centre...Yanmin Ju1,2,Zhiyi Wang1,Zeeshan Ali1,Hongchen Zhang1,Yazhou Wang1,Nuo Xu3,Hui Yin4,Fugeng Sheng4,and Yanglong Hou1✉1 Beijing Key Laboratory for Magnetoelectric Materials and Devices(BKL-MMD),Beijing Innovation Centre for Engineering Science and Advanced Technology(BIC-ESAT),School of Materials Science and Engineering,Peking University,Beijing 100871,China 2 College of Pharmacy,China Pharmaceutical University,Nanjing 211198,China 3 Synthetic and Functional Biomolecules Center,Department of Chemical Biology,College of Chemistry and Molecular Engineering,Peking University,Beijing 100871,China 4 Fifth Medical Center of Chinese PLA General Hospital,Beijing 100071,China.展开更多
Cancer chemotherapy can be hindered by drug resistance which leads to lower drug efficiency.Here,we have developed a drug delivery system that tethers doxorubicin to the surface of gold nanorods via a pHsensitive link...Cancer chemotherapy can be hindered by drug resistance which leads to lower drug efficiency.Here,we have developed a drug delivery system that tethers doxorubicin to the surface of gold nanorods via a pHsensitive linkage(AuNRs@DOX),for a combined photothermal and chemical therapy for cancer.First,AuNRs@DOX is ingested by HepG2 liver cancer cells.After endocytosis,the acidic pH triggers the release of doxorubicin,which leads to chemotherapeutic effects.The gold nanorods are not only carriers of DOX,but also photothermal conversion agents.In the presence of an 808 nm near-infrared laser,AuNRs@DOX significantly enhance the cytotoxicity of doxorubicin via the photothermal effect,which induces elevated apoptosis of hepG2 cancer cells,leading to better therapeutic effects in vitro and in vivo.展开更多
Nanocapsule-based targeted delivery and stimulus-responsive release can increase drug effectiveness, while reducing the side effects of the drug. However, difficulties in the scale-up synthesis, fast burst release, an...Nanocapsule-based targeted delivery and stimulus-responsive release can increase drug effectiveness, while reducing the side effects of the drug. However, difficulties in the scale-up synthesis, fast burst release, and low degradability, could hamper the translation of drug nanocapsules from lab to clinic. Here we have controllably functionalized the biodegradable and widely available polysuccinimide, in order to obtain an amphiphilic poly（amino acid）. Using this polymer, we designed nanocapsules （〈 100 nm） for hydrophobic drug delivery, which could facilitate tumor targeting, hydrogen bond-based pH-responsive release, and real-time fluorescence tracking, in the second near-infrared region. This method is versatile, eco-friendly, and easy to scale up at low costs. In addition, this system can carry a cocktail of drugs, obtained by loading multiple anticancer drugs to the same vehicle. Our nanocapsules were observed to be stable in blood vessels （pH = 7.4）, and the pH-responsive release （pH = 5.0 in lysosome） was sustained. The chemotherapy results in tumor-xenografted mice suggested that our nanocapsule was safe and efficient, and may be a useful tool for drug delivery.展开更多
pH-responsive 1O2 photosensitizing systems may serve as selective photodynamic therapy(PDT)agents by targeting the acidic interstitial fluid of many kinds of tumors.In this work,a natural and clinically used photosens...pH-responsive 1O2 photosensitizing systems may serve as selective photodynamic therapy(PDT)agents by targeting the acidic interstitial fluid of many kinds of tumors.In this work,a natural and clinically used photosensitizer(Hypocrellin B,HB)and a pH indicator(Bromocresol Purple,BCP)were co-encapsulated in organically modified silica nanoparticles.BCP successfully regulated the 1O2 generation efficiency of HB through the"inner filter"effect,which shows much stronger 1O2 generation ability in an acidic than in a basic environment.In vitro experiments also demonstrated that HB-doped nanoparticles are effective in killing tumor cells by PDT.展开更多
Mesoporous silica nanoparticles （MSN） were coated by pH-responsive polymer chitosan-poly （methacrylic acid） （CS-PMAA）. This nano drug delivery system showed good application prospects and the polymer-coated micr...Mesoporous silica nanoparticles （MSN） were coated by pH-responsive polymer chitosan-poly （methacrylic acid） （CS-PMAA）. This nano drug delivery system showed good application prospects and the polymer-coated microspheres were promising site-specific anticancer drug delivery carriers in biomedical field. A continuous detection of pH-responsive drug delivery system in cells in situ, utilizing MSN/CS-PMAA composite microspheres, was pro- posed. Two kinds of different cell lines, tumor cell line （Hela） and normal somatic cells （293T）, were used to inves- tigate the behaviours of the drug loaded system in the cells. Conclusions could be drawn from the fluorescent im- ages obtained by confocal laser scanning microscopy （CLSM）, modified drug-loaded microspheres （MSN/CS-PMAA） were ingested into cells more easily, the uptake of DOX@FITC-MSN/CS-PMAA by HeLa/293T cells were performed at pH 7.4/pH 6.8, DOX was released during the ingestion process, fluorescence intensity de- creased with time because of efflux transport and photo-bleaching. Fluoresence detection by flow cytometry was performed as comparison. The continuous fluorescent observation in situ could be widely used in the pH-responsive releasing process of drug delivery system in the cells.展开更多
Cisplatin is broad-spectrum chemotherapeutic agent that has been widely used for the treatment of a variety of malignant tumors including breast cancer.However,the cisplatin chemoresistance,which derives from the inac...Cisplatin is broad-spectrum chemotherapeutic agent that has been widely used for the treatment of a variety of malignant tumors including breast cancer.However,the cisplatin chemoresistance,which derives from the inactivation by glutathione(GSH)depletion,remains a scientific issue to solve.Here,we report a novel type of smart disulfide switchable nanoparticles complexing cisplatin(switch NPs-cisplatin)that is rationally designed,and engineered by synthesizing a hyaluronic acid disulfide bonded polyaspartic acid(HA-ss-Pasp)and complexing cisplatin.The results showed that the switch NPs-cisplatin had a nanoscale of particle size(150 nm),higher drug encapsulation efficiency(>90%),and suitable drug release profile.They demonstrated evident pH responsiveness and GSH responsiveness,and targeting effect in the resistant breast cancer cells.Furthermore,they were able to block the cisplatin depletion by GSH in the resistant cancer cells,thereby circumventing the chemoresistance.Consequently,switch NPs-cisplatin displayed a remarkable killing effect in the resistant breast cancer cells in vitro,and in the resistant breast cancer-bearing mice.In conclusion,switch NPs-cisplatin could be used as a smart formulation of cisplatin for overcoming the chemoresistance of breast cancer.The present study also offers a universal drug delivery carrier platform for highly efficient but low systemic toxic chemotherapy.展开更多
Partially hydrolyzed polyacrylamide （HPAM） has been widely used for water shut-off and profile control to enhance oil recovery. Herein, we reported a novel technique by which the crosslinking between HPAM and Cr3＋ ...Partially hydrolyzed polyacrylamide （HPAM） has been widely used for water shut-off and profile control to enhance oil recovery. Herein, we reported a novel technique by which the crosslinking between HPAM and Cr3＋ in aqueous solutions at 60 ℃ can be delayed effectively. Citric acid was selected as an organic complexing agent of Cr3＋ so that the crosslinking between HPAM and Cr3＋ can be prevented completely. Due to the decomposi- tion of the bicarbonate （HCO3-） embedded in solution, CO2 released from solution and the pH value of solution increased gradually. The degree of ionization of HPAM and its ability to complex with Cr3＋ increased accordingly. When the complexation of Cr3＋ with HPAM is stronger than that with citric acid, the viscosity of the HPAM solution increased signif- icantly. Under the closed condition, together with the existence of potassium dihydrogen phosphate （KH2PO4）, the release of CO2 was very slow and the condition was highly con- trolled so that the ionization of HPAM was prevented initially. Furthermore, the hydrogen bonding interactions between HPAM and melamine embedded in solution previously also postponed the ionization of HPAM. As a result, the crosslinking between HPAM and Cr3＋ can be delayed for almost one month, completely meeting the requirements for deep water shut-off and profile control to enhance oil recovery.展开更多
In this research;the release of 5-Fluorouracil (5-FU) from different ionically crosslinked alginate (Alg) beads was investigated by using Fe3+, Al3+, Zn2+, and Ca2+, ions as crosslinking agent. The prepared beads were...In this research;the release of 5-Fluorouracil (5-FU) from different ionically crosslinked alginate (Alg) beads was investigated by using Fe3+, Al3+, Zn2+, and Ca2+, ions as crosslinking agent. The prepared beads were characterized by Fourier Transform Infrared Spectroscopy (FTIR) Differential Scanning Calorimetry (DSC) and Scanning Electron Micros-copy (SEM). The drug release studies were carried out at three pH values 1.2, 6.8 and 7.4 respectively each for two hours. The effects of the preparation conditions as crosslinker type, drug/polymer (w/w) ratio, crosslinker concentration and time of exposure to crosslinker on the release of 5-FU were investigated for 6 hours at 37℃. It was observed that 5-FU release from the beads followed the order of Fe > Zn > Al > Ca-Alg and increased with increasing drug/polymer ratio. At the end of 6 hours, the highest 5-FU release was found to be 90% (w/w) for Fe-Alg beads at the drug/polymer ratio of 1/8 (w/w), crosslinker concentration of 0.05 M, exposure time of 10 minutes respectively. The swelling measurements of the beads supported the release results. Release kinetics was described by Fickian and non-Fickian approaches.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.22273098,52033001 and 22303032)the Key Project of Anhui Province Science and Technology Innovation Platform(No.S202305a12020030)+1 种基金the Science and Technology Program Project of Zhejiang Province,China(No.2025ZY01057)partially carried out at the USTC Center for Micro and Nanoscale Research and Fabrication。
文摘Strong polyelectrolyte brushes(SPBs)play an important role in enabling material surface functionalization due to their unique stimuli-responsive properties.Although the unexpected pH responsiveness of SPBs has been revealed in the past ten years,it is still unclear if the pH-responsive properties of SPBs are affected by the brush thickness.In this study,we employed the positively charged poly[2-(methacryloyloxy)ethyl]trimethylammonium chloride(PMETAC)and negatively charged sodium poly(styrenesulfonate)(NaPSS)brushes as model systems to explore the effect of thickness on the pH-responsive properties of SPBs.The results demonstrate that the pH-responsive properties of SPBs manifest different dependences on the brush thickness.Specifically,for both PMETAC and NaPSS brushes,the pH-responsive hydration and stiffness are influenced by the thickness,and the pH-responsive wettability and adhesion are almost unaffected by the thickness.This work not only provides a clear understanding of the relationship between the brush thickness and the pH responsiveness of SPBs,but also offers a new method to control the pH-responsive properties of SPBs.
基金supported by Ministry of Science and Technology of China (No.2012CB933200)the NSF of China (Nos.51233007 and 51203169)
文摘pH responsive polymeric Janus nanosheets with poly（maleic acid） moiety and crosslinked PS onto the corresponding sides have been synthesized by free radical polymerization. The Janus nanosheets can serve as solid emulsifier to stabilize an oil/water emulsion, whose stability is easily triggered by changing pH across pKa of the poly（maleic acid）.
基金supported by the National Natural Science Foundation of China(Grant No.51325305)National Key Research and Development Program(GrantNo.2016YFC1101301)Tianjin Municipal Natural Science Foundation(Grant Nos.13ZCZDSY00900,15JCZDJC38000)
文摘Constructing high strength pH sensitive supramolecular polymer hydrogel remains very challenging due to the unavoidable network swelling caused by ionization of acid or basic groups at a specified pH.In this work,we proposed a simple and very convenient approach to fabricate high strength pH responsive supramolecular polymer(SP) hydrogels by one-pot copolymerization of N-acryloyl glycinamide(NAGA) and 2-vinyl-4,6-diamino-1,3,5-triazine(VDT),two feature hydrogen bonding monomers.In these PNAGA-PVDT SP hydrogels obtained,the hydrogen bonding of NAGA was shown to play a dominant role in reinforcing strength,while the hydrogen bonding of diaminotriazine served as a pH sensitive moiety.At pH 3,the mechanical properties of PNAGA-PVDT hydrogels decreased to a different extent due to the breakup of hydrogen bonding;in contrast,the hydrogel resumed the original strength while pH was raised to 7.4 because of reconstruction of hydrogen bonding.Over the selected pH range,the PNAGA-PVDT hydrogels exhibited up to 1.25 MPa tensile strength,845% breaking strain,69 kPa Young's modulus and 21 MPa compressive strength.This novel high strength pH-responsive SP hydrogels may find applications in biomedical and industrial fields.
基金Funded by the National Key R&D Program of China(No.2023YFC2412300)the Natural Science Foundation of Hubei Province(No.2022CFB386)the National Natural Science Foundation of China(No.52073222)。
文摘pH-responsive charge reversal loaded miRNA nanocomposite was prepared by electrostatic self-assembly.The morphology,particle size and zeta potential of the nanocomposites were analyzed by transmission electron microscopy and dynamic light scattering.The synthesis of the polymer was analyzed by^(1)H-NMR.The zeta-potential changes and cellular uptake effects of the nanocomplexes under different pH environments were investigated.The experimental results show that the surface morphology of the nanocomposite is spherical,and the average particle size is about 135 nm.As the pH value of the solution gradually decreases,the surface charge of the nanocomposite reverses from negative charge to positive charge(from-9.4 to+17.1 mV).Cellular uptake mediated by pH-responsive nanocomposite is selective for tumor cells,and the cellular uptake effect in tumor cells at pH 6.5 was approximately 3 times higher than that at pH 7.4.This pH responsive charge reversal nanocomposite has promising application prospects for gene delivery in the weak acid environment of tumors.
基金supported by the National Natural Science Foundation of China(No.21873062)the Fundamental Research Funds for the Central Universities(GK202001009)+2 种基金the Natural Science Basis Research Plan in Shaanxi Province of China(No.2020JM-295)the 111 Project(B14041)Program for Changjiang Scholars and the Innovative Research Team in University(IRT-14R33)。
文摘Hydrogels show versatile properties and are of great interest in the fields of bioelectronics and tissue engineering.Understanding the dynamics of the water molecules trapped in the three-dimensional polymeric networks of the hydrogels is crucial to elucidate their mechanical and swelling properties at the molecular level.In this report,the poly(DMAEMA-co-AA)hydrogels were synthesized and characterized by the macroscopic swelling measurements under different pH conditions.Furthermore,the microscopic structural dynamics of pH stimulus-responsive hydrogels were studied using FTIR and ultrafast IR spectroscopies from the viewpoint of the SCN-anionic solute as the local vibrational reporter.Ultrafast IR spectroscopic measurements showed the time constants of the vibrational population decay of SCN-were increased from 14±1 ps to 20±1 ps when the pH of the hydrogels varied from2.0 to 12.0.Rotational anisotropy measurements further revealed that the rotation of SCNanionic probe was restricted by the three-dimensional network formed in the hydrogels and the rotation of SCN-anionic probe cannot decay to zero especially at the pH of 7.0.These results are expected to provide a molecular-level understanding of the microscopic structure of the cross-linked polymeric network in the pH stimulus-responsive hydrogels.
基金the Hubei Provincial Key Scientific Research Project on Water Resources“Study on the Distribution and Characteristics of Sediment Siltation in the Key Waters of Zhanghe Reservoir(HBSLKY202302)”Wuhan Municipal Bureau of Science and Technology 2023 Knowledge and Innovation Special Project,“Research on key technology for fine traceability of total phosphorus in urban lakes in Wuhan”(No.2023020201010119)+1 种基金the National Visiting Scholar Program for Key Young Teachers of Central and Western Universities,and the Ministry of Education(19042)Science and Technology Tackling Projects in Henan Province in 2025(Research on key technology for removing microdust from the surface of photovoltaic power generation panels by spray coating with high-efficiency hydrogel coatings prepared from multi-source solid wastes).
文摘The rapid urbanization underscores the urgency of efficient treatment and resource utilization of municipal sludge for environmental conservation.To address this,a novel pH-responsive dual network polyvinyl alcohol/sodium alginate sludge hydrogel was devised by integrating municipal sludge with acrylic acid monomers,ammonium persulphate initiator,N,N’-methylene bisacrylamide crosslinking agent,reinforced by polyvinyl alcohol and sodium alginate through free radical cross-linking polymerization.The hydrogel’s optimal formulation was identified by adjusting the monomer,crosslinking agent,and initiator dosage while assessing its swelling behavior across various pH environments.Results revealed excellent swelling capacity,notably exhibiting a remarkable swelling capacity of up to 7265.64% at pH 11.0,suggesting the hydrogel’s potential in environmental remediation and innovative material design.This research presents a pioneering approach to harnessing municipal sludge and developing intelligent hydrogels,fostering sustainable resource management.
基金This work was financially supported by Fundamental Research Funds for the Central Universities(2020NYB10).
文摘The appearance of multidrug-resistant bacteria and the formation of bacterial biofilms have necessitated the development of alternative antimicrobial therapeutics.Antibiotics conjugated with or embedded in nano-drug carriers show a great potential and advantage over free drugs,but the mass proportion of carriers generally exceeds 90%of the nano-drug,resulting in low drug loading and limited therapeutic output.Herein,we fabricated a nanocarrier using antibiotics as the building blocks,minimizing the use of carriermaterials,significantly increasing the drug loading content and treatment effect.Firstly,we conjugated betaine carboxylate with ciprofloxacin(CIP)through an ester bond to form the amphiphilic conjugate(CIP-CB),which self-assembled into micelles(CIP-CBMs)in aqueous solutions,with a CIP loading content as high as 65.4%and pH-induced surface charge reversal properties.Secondly,a model photosensitizer(5,10,15,20-tetraphenylporphyrin(TPP))was encapsulated in CIP-CBMs,generating infection-targeted photodynamic/antibiotic combined nanomedicines(denoted as TPP@CIP-CBMs).Upon accumulation at infection sites or in deep bacterial biofilms,the ester bond between the betaine carboxylate and CIP is cleaved to release free TPP and CIP,leading to a synergetic antibacterial and antibiofilm activity in vitro and in vivo.
基金financially supported by the Ministry of Science and Technology of China(No.2012CB933200)the National Natural Science Foundation of China(Nos.51233007 and 51173191)
文摘pH responsive composite Janus cages of PS-silica-PEO are prepared using silica nanoparticles to crosslink two PAA contained di-block copolymers at an emulsion interface sequentially. Transverse channels are in situ created across the shell, which facilitates mass transfer. Shell is pH responsive owing to the presence of residual PAA chains tethered onto the silica nanoparticles. The Janus cages are capable to preferentially capture oil from their aqueous surroundings. The saturation absorption capacity is determined by pH and oil property. Other composite Janus cages are expected by extension the method using other copolymers and functional nanoparticles.
基金supported by the National Natural Science Foundation of China(No.50473044).
文摘The colloidal crystal template or opal with a closed-packed face-centered cubic （fcc） lattice was prepared from monodisperse polystyrene （PS） spheres by vertical sedimentation. The template provided void space for infiltration of monomer precursor composed of acrylate acid, acrylamide and ammonium-persulfate, as well as microgel from the subsequent copolymerization. The sample was immersed in dimethylbenzene for completely removing PS spheres to form PAM inverse opal hydrogels （IOHPAM） or PAM/PAA inverse opal hydrogels （IOHPAM/PAA） photonic crystals. The PS spheres were replaced by air spheres, which interconnected each other through the windows. The study of responses to pH show that there are two peaks for both IOHPAM and IOHPAM/PAA films, but the IOHPAM/PAA peaks shift to higher pH, and the peaks are independent with the AA content.
基金financially supported by the National Key Research and Development Plan(No.2018AAA0100301)National Science Foundation of China(No.21925802)+1 种基金Research Funds for the Central Universities(No.DUT22LAB601)the Basic Research Project of Free Exploration(No.2021Szvup019)。
文摘Developing fluorescence probes with multiple responses has vital significance but remains challenging.Herein,for the first time,we present a mitochondrial DNA(mtDNA)-triggered pH response signalamplified fluorescent probe(QCY-DBT)for multiple cell detection.The probe exhibited a large stokes shift(229 nm),excellent DNA selectivity over RNA,and ultrasensitivity of detection limit(DL;74.0 ng/mL).Thus,QCY-DBT was successfully applied to analyze multiple human peripheral blood cells and visualize mtDNA in healthy and apoptotic cells.In the tumor acidic environment(pH 6.0–7.0),the absorbance of QCY-DBT at 436 nm increased,and the fluorescence signal(665 nm)was amplified by mtDNA,which enabled the direct observation of tumor cells.Our study provides help in designing smart probes with multiple responses for efficient abnormal cell detection.
基金the funding and generous support of Zhejiang Province Natural Science Foundation(Nos.LY17C100003,Y17E030032)Key Research Project of Traditional Chinese Medicine of Zhejiang Province of China(No.2019ZZ015)Medical Health Science and Technology Project of Zhejiang Provincial Health Commission(No.2018KY131)。
文摘To explore the effects of microenvironmental adjustments on fluorescence,a pH-sensitive nanocomposite system based on fluorescence resonance energy transfer(FRET)was constructed.The model system included a modified triblock copolymer(polyhistidine-b-polyethylene glycol-b-polycaprolactone)and gold nanoparticles.A near-infrared dye was used as the donor,and spectrally matched gold nanorods,attached after C-terminus modification with α-lipoic acid,were used as the receptor to realize control of the FRET effect over the fluorescence intensity for two polymer configurational changes(i.e.,"folded"and"stretched"states)in response to pH.After synthesis and characterization,we investigated the self-assembly behavior of the system.Analysis by quartz crystal microbalance revealed the pH sensitivity of the polymer,which exhibited"folding"and"stretching"states with changes in pH,providing a structural basis for the FRET effect.Fluorescence spectrophotometry investigations also revealed the regulatory impact of the assembled system on fluorescence.
基金supported by the Natural Science Foundation of Shaanxi Province(No.2024JC-YBQN-0407)National Natural Science Foundation of China(No.81530064)+3 种基金China Postdoctoral Science Foundation(No.2023 M732753)National Natural Science Foundation of China(No.81772071)National Natural Science Foundation of China(No.82172210)Open Fund of Key Laboratory for Intelligent Nano Materials and Devices of the Ministry of Education NJ2023002(INMD-2023 M01).
文摘Background:Diabetic wounds feature a high-glucose and acidic microenvironment that impairs macrophage polarization and healing.Adiposederived stem cell-derived exosomes(ADSC-exos)show therapeutic potential but suffer from rapid clearance.This study aimed to develop a smart hydrogel for glucose/pH-responsive ADSC-exos release.Methods:A dual-responsive hydrogel(HAP/OCS/PEG/Ag-E)was fabricated via dynamic triple cross-linking.Characterization included rheometry,mechanical tests,and microscopy.In vitro macrophage polarization was assessed via flow cytometry and Western blot.A diabetic mouse wound model evaluated healing rates,histology,angiogenesis,and inflammation.Proteomics and pathway inhibition studies explored mechanisms.Statistical analysis used t-tests and ANOVA.Results:The hydrogel exhibited excellent self-healing,adhesion,and controlled ADSC-exos release under high-glucose/acidic conditions.It promoted M2 macrophage polarization,reduced pro-inflammatory cytokines(IL-1β,IL-6,TNF-α),and accelerated wound healing with enhanced angiogenesis and collagen deposition.Mechanistically,the hydrogel suppressed the Notch/NF-κB/NLRP3 signaling pathway.Conclusion:The smart hydrogel facilitates diabetic wound healing through microenvironment-responsive ADSC-exos release and Notch/NFκB/NLRP3 pathway inhibition,offering a promising strategy for chronic wound treatment.
文摘Yanmin Ju1,2,Zhiyi Wang1,Zeeshan Ali1,Hongchen Zhang1,Yazhou Wang1,Nuo Xu3,Hui Yin4,Fugeng Sheng4,and Yanglong Hou1✉1 Beijing Key Laboratory for Magnetoelectric Materials and Devices(BKL-MMD),Beijing Innovation Centre for Engineering Science and Advanced Technology(BIC-ESAT),School of Materials Science and Engineering,Peking University,Beijing 100871,China 2 College of Pharmacy,China Pharmaceutical University,Nanjing 211198,China 3 Synthetic and Functional Biomolecules Center,Department of Chemical Biology,College of Chemistry and Molecular Engineering,Peking University,Beijing 100871,China 4 Fifth Medical Center of Chinese PLA General Hospital,Beijing 100071,China.
基金The authors are grateful to the financial support from the National Key Research and Development Program of China(2016YFB0700804)the National Natural Science Foundation of China(51673171)+2 种基金Zhejiang Provincial Natural Science Foundation of China(LR16E030001,LR15H160001)the Fundamental Research Funds for the Central Universities of China(2018QNA4057)This study is supported in part by Key Laboratory of Reproductive Genetics(Zhejiang University),Ministry of Education,P.R.China/Women’s Reproductive Health Key Laboratory of Zhejiang Province/Uterine Tumors Research Center of Zhejiang Province(ZDFY2017-RG/RH-001).
文摘Cancer chemotherapy can be hindered by drug resistance which leads to lower drug efficiency.Here,we have developed a drug delivery system that tethers doxorubicin to the surface of gold nanorods via a pHsensitive linkage(AuNRs@DOX),for a combined photothermal and chemical therapy for cancer.First,AuNRs@DOX is ingested by HepG2 liver cancer cells.After endocytosis,the acidic pH triggers the release of doxorubicin,which leads to chemotherapeutic effects.The gold nanorods are not only carriers of DOX,but also photothermal conversion agents.In the presence of an 808 nm near-infrared laser,AuNRs@DOX significantly enhance the cytotoxicity of doxorubicin via the photothermal effect,which induces elevated apoptosis of hepG2 cancer cells,leading to better therapeutic effects in vitro and in vivo.
文摘Nanocapsule-based targeted delivery and stimulus-responsive release can increase drug effectiveness, while reducing the side effects of the drug. However, difficulties in the scale-up synthesis, fast burst release, and low degradability, could hamper the translation of drug nanocapsules from lab to clinic. Here we have controllably functionalized the biodegradable and widely available polysuccinimide, in order to obtain an amphiphilic poly（amino acid）. Using this polymer, we designed nanocapsules （〈 100 nm） for hydrophobic drug delivery, which could facilitate tumor targeting, hydrogen bond-based pH-responsive release, and real-time fluorescence tracking, in the second near-infrared region. This method is versatile, eco-friendly, and easy to scale up at low costs. In addition, this system can carry a cocktail of drugs, obtained by loading multiple anticancer drugs to the same vehicle. Our nanocapsules were observed to be stable in blood vessels （pH = 7.4）, and the pH-responsive release （pH = 5.0 in lysosome） was sustained. The chemotherapy results in tumor-xenografted mice suggested that our nanocapsule was safe and efficient, and may be a useful tool for drug delivery.
基金the financial support from the National Natural Science Foundation of China(20772133,20873170)Chinese Academy of Sciences(KJCX2YWH08)
文摘pH-responsive 1O2 photosensitizing systems may serve as selective photodynamic therapy(PDT)agents by targeting the acidic interstitial fluid of many kinds of tumors.In this work,a natural and clinically used photosensitizer(Hypocrellin B,HB)and a pH indicator(Bromocresol Purple,BCP)were co-encapsulated in organically modified silica nanoparticles.BCP successfully regulated the 1O2 generation efficiency of HB through the"inner filter"effect,which shows much stronger 1O2 generation ability in an acidic than in a basic environment.In vitro experiments also demonstrated that HB-doped nanoparticles are effective in killing tumor cells by PDT.
基金the National Natural Science Foundation of China，the Shanghai Committee of Science and Technology
文摘Mesoporous silica nanoparticles （MSN） were coated by pH-responsive polymer chitosan-poly （methacrylic acid） （CS-PMAA）. This nano drug delivery system showed good application prospects and the polymer-coated microspheres were promising site-specific anticancer drug delivery carriers in biomedical field. A continuous detection of pH-responsive drug delivery system in cells in situ, utilizing MSN/CS-PMAA composite microspheres, was pro- posed. Two kinds of different cell lines, tumor cell line （Hela） and normal somatic cells （293T）, were used to inves- tigate the behaviours of the drug loaded system in the cells. Conclusions could be drawn from the fluorescent im- ages obtained by confocal laser scanning microscopy （CLSM）, modified drug-loaded microspheres （MSN/CS-PMAA） were ingested into cells more easily, the uptake of DOX@FITC-MSN/CS-PMAA by HeLa/293T cells were performed at pH 7.4/pH 6.8, DOX was released during the ingestion process, fluorescence intensity de- creased with time because of efflux transport and photo-bleaching. Fluoresence detection by flow cytometry was performed as comparison. The continuous fluorescent observation in situ could be widely used in the pH-responsive releasing process of drug delivery system in the cells.
基金supported by the National Natural Science Foundation of China(Nos.81874303,82173752)。
文摘Cisplatin is broad-spectrum chemotherapeutic agent that has been widely used for the treatment of a variety of malignant tumors including breast cancer.However,the cisplatin chemoresistance,which derives from the inactivation by glutathione(GSH)depletion,remains a scientific issue to solve.Here,we report a novel type of smart disulfide switchable nanoparticles complexing cisplatin(switch NPs-cisplatin)that is rationally designed,and engineered by synthesizing a hyaluronic acid disulfide bonded polyaspartic acid(HA-ss-Pasp)and complexing cisplatin.The results showed that the switch NPs-cisplatin had a nanoscale of particle size(150 nm),higher drug encapsulation efficiency(>90%),and suitable drug release profile.They demonstrated evident pH responsiveness and GSH responsiveness,and targeting effect in the resistant breast cancer cells.Furthermore,they were able to block the cisplatin depletion by GSH in the resistant cancer cells,thereby circumventing the chemoresistance.Consequently,switch NPs-cisplatin displayed a remarkable killing effect in the resistant breast cancer cells in vitro,and in the resistant breast cancer-bearing mice.In conclusion,switch NPs-cisplatin could be used as a smart formulation of cisplatin for overcoming the chemoresistance of breast cancer.The present study also offers a universal drug delivery carrier platform for highly efficient but low systemic toxic chemotherapy.
基金supported by the National Natural Science Foundation of China(No.51273189)the National Science and Technology Major Project of the Ministry of Science and Technology of China(No.2016ZX05016)the National Science and Technology Major Project of the Ministry of Science and Technology of China(No.2016ZX05046)
文摘Partially hydrolyzed polyacrylamide （HPAM） has been widely used for water shut-off and profile control to enhance oil recovery. Herein, we reported a novel technique by which the crosslinking between HPAM and Cr3＋ in aqueous solutions at 60 ℃ can be delayed effectively. Citric acid was selected as an organic complexing agent of Cr3＋ so that the crosslinking between HPAM and Cr3＋ can be prevented completely. Due to the decomposi- tion of the bicarbonate （HCO3-） embedded in solution, CO2 released from solution and the pH value of solution increased gradually. The degree of ionization of HPAM and its ability to complex with Cr3＋ increased accordingly. When the complexation of Cr3＋ with HPAM is stronger than that with citric acid, the viscosity of the HPAM solution increased signif- icantly. Under the closed condition, together with the existence of potassium dihydrogen phosphate （KH2PO4）, the release of CO2 was very slow and the condition was highly con- trolled so that the ionization of HPAM was prevented initially. Furthermore, the hydrogen bonding interactions between HPAM and melamine embedded in solution previously also postponed the ionization of HPAM. As a result, the crosslinking between HPAM and Cr3＋ can be delayed for almost one month, completely meeting the requirements for deep water shut-off and profile control to enhance oil recovery.
基金The authors are grateful to the Gazi University Scientific Research Foundation for support of this study.
文摘In this research;the release of 5-Fluorouracil (5-FU) from different ionically crosslinked alginate (Alg) beads was investigated by using Fe3+, Al3+, Zn2+, and Ca2+, ions as crosslinking agent. The prepared beads were characterized by Fourier Transform Infrared Spectroscopy (FTIR) Differential Scanning Calorimetry (DSC) and Scanning Electron Micros-copy (SEM). The drug release studies were carried out at three pH values 1.2, 6.8 and 7.4 respectively each for two hours. The effects of the preparation conditions as crosslinker type, drug/polymer (w/w) ratio, crosslinker concentration and time of exposure to crosslinker on the release of 5-FU were investigated for 6 hours at 37℃. It was observed that 5-FU release from the beads followed the order of Fe > Zn > Al > Ca-Alg and increased with increasing drug/polymer ratio. At the end of 6 hours, the highest 5-FU release was found to be 90% (w/w) for Fe-Alg beads at the drug/polymer ratio of 1/8 (w/w), crosslinker concentration of 0.05 M, exposure time of 10 minutes respectively. The swelling measurements of the beads supported the release results. Release kinetics was described by Fickian and non-Fickian approaches.
