查找使用阿拉丁产品的科研文献

Self-cleaning pH-responsive polyvinyl alcohol/chitosan hydrogel membrane for reusable and efficient dye removal

Seongeom Jeong,Siyoung Byun,Sanghyun Jeong

A pH-responsive membrane represents a promising avenue for sustainable water treatment, yet its broader application remains limited by stability and reusability concerns. In this study, a polyvinyl alcohol/chitosan (PVA/CS) hydrogel membrane was fabricated and systematically evaluated for its pH-dependent transport behavior and dye removal performance. The hydrogel membrane exhibited distinct pH responsiveness, achieving the highest water flux (22.45 ± 0.66 L m −2  h −1  bar −1 ) at neutral pH (6.5) when tested using pure water. Flux declined under acidic conditions (3.43 ± 0.26 L m −2  h −1  bar −1 ) due to CS swelling and under alkaline conditions due to polymer chain densification. At pH 2, the membrane removed both cationic and anionic dyes with efficiencies exceeding 99.9 % removal. Under neutral conditions, cationic dyes (crystal violet, methylene blue) were consistently removed (>97 %). In contrast, anionic dyes, including Congo red and methyl orange, showed significantly lower rejection (66.04 % and 24.57 %, respectively), attributable to electrostatic repulsion and size-dependent transport. Importantly, the PVA/CS hydrogel membrane demonstrated regeneration capability, enabling up to three reuse cycles with >99 % dye rejection and limited flux decline for cationic dyes at pH 6.5. CS's reversible swelling-contraction behavior facilitated the recovery of membrane performance. Overall, these findings demonstrate that PVA/CS hydrogel membranes functions as pH-responsive separation platforms capable of chemical-free regeneration and limited reuse across a range of pH conditions. In particular, this study experimentally clarifies how intrinsic pH responsiveness can be leveraged to enable regeneration without chemical treatment, while also highlighting the need for further optimization to address performance limitations toward anionic contaminants.

pH-responsive and NIR-triggered nanopesticide for precision control of sclerotinia sclerotiorum in oilseed rape

Rao Qin,Yuhan Jing,Tianqi Wan,Guangliang Lu,Dabiao Zhai,Xingyu Li,Feng Zhang,Jiangang Jiang,Dan Zhang,Ping Zhang,Yiping Wang,Yong Wang,He Wang

A composite consisting of upconversion nanoparticles (UCNPs) and methylene blue (MB)-loaded zeolitic imidazolate framework-8 (ZIF-8), referred to as UCNP@ZIF-8@MB, was synthesized via a simple hydrothermal and one-pot approach for the targeted control of Sclerotinia sclerotiorum ( S. sclerotiorum ) in oilseed rape ( Brassica napus L. ). Taking advantage of the pH-responsive nature of ZIF-8, the composite responds selectively to the acidic microenvironment associated with pathogen infection. Upon 980 nm excitation, UCNPs emit at 650 nm, which activates MB to generate reactive oxygen species (ROS) via photolysis, thereby exerting antifungal effects. The physicochemical properties of UCNP@ZIF-8@MB, including its optical behavior, MB release profile, and adhesion capacity, were systematically characterized. Under mildly acidic conditions (pH 5.5–4.0), MB release exceeded 80 %, indicating efficient responsiveness to the infection milieu. In vitro antifungal assays demonstrated a minimum inhibitory concentration (MIC) of approximately 10 μg/mL under 980 nm laser irradiation. Pot experiments further confirmed significant antifungal activity under light exposure. Additionally, UCNP@ZIF-8@MB exhibited targeted release and favorable biocompatibility with plant tissues and the surrounding environment. These results underscore the potential of UCNP@ZIF-8@MB as an environmentally friendly nanopesticide for the precise management of sclerotinia disease, offering a promising strategy for sustainable agriculture.

Preparation of pH-Sensitive Astragalus Polysaccharide Nanoparticles Loaded with Paclitaxel and Evaluation of Antitumor Activity

Wang Kaibin,Li Yanqiang,Zhao Xiaoliang,Zhu Tianke,Luo Li,Zhang Hanwen,Wang Yonggang,Zhang Jing,Wang Cunjin,Zhang Weijie

Purpose Chinese medicine polysaccharide are considered as promising medical materials due to their good biocompatibility and safety. The aim of this study was to develop a novel amphiphilic drug carrier based on astragalus polysaccharide (APS) to optimise the delivery of paclitaxel. Methods The pH-sensitive histidine (His) and hydrophobic stearic acid (SA) were grafted onto astragalus polysaccharide and self-assembled into nanoparticles by ultrasonication. The nanoparticles were characterised by Fourier transform infrared (FTIR), dynamic light scattering (DLS), zeta potential, transmission electron microscopy (TEM), and X-ray diffraction, and tested for encapsulation efficiency (EE%), drug loading capacity(LC%) and in vitro release of paclitaxel. The effects of nanoparticles on the proliferation of immune cells RAW264.7 and breast cancer cells SUM149 were assessed by cck-8 assay, and their effects on SUM149 cell cycle block and apoptotic protein expression were detected. Results The EE% of nanoparticles on paclitaxel was 77.61% and the LC% was 9.96%. Under acidic conditions, the surface charge of nanoparticles was reversed and the structure was swollen to promote drug release. Cellular experiments showed that blank nanoparticles could promote the proliferation of immune cells, and the anticancer effect of drug-loaded nanoparticles was significantly better than that of paclitaxel alone. Conclusion The prepared pH-sensitive nanoparticles can effectively enhance the uptake of paclitaxel by tumour cells and induce apoptosis in breast cancer cells, making them a promising new type of paclitaxel drug carrier.

A well-defined thermo- and pH-responsive double hydrophilic graft copolymer bearing pyridine-containing backbone

Rang Chen,Xue Jiang,Guolin Lu,Wenbin Liu,Weize Jin,Guojian Tian,Xiaoyu Huang

Graft copolymers have extensive applications in material science because of the tunable nature of their backbones and side chains and the diverse morphologies of their aggregates. Recent studies have mainly focused on amphiphilic graft copolymers containing hydrophobic backbones and hydrophilic side chains. To the best of our knowledge, no studies have reported amphiphilic graft copolymers bearing pyridine-containing hydrophilic backbones. Based on the design of functional monomers, a new trifunctional acrylate monomer, PyMCIBMA, was prepared in two steps via a Morita–Baylis–Hillman reaction, followed by reaction with 2-chloroisobutyryl chloride. Reversible addition–fragmentation chain transfer (RAFT) polymerization of PyMCIBMA monomer was performed to generate a well-defined poly(PyMCIBMA) homopolymer possessing a Cl-containing ATRP initiating group in each repeat unit. Next, a series of well-defined double hydrophilic graft copolymers bearing densely distributed poly(N-isopropyl acrylamide) (PNIPAM) side chains along the backbone on every unit, PPyMA-g-PNIPAM, was synthesized via atom transfer radical polymerization (ATRP) initiated by poly(PyMCIBMA) homopolymer. The resulting graft copolymers exhibited intriguing dual temperature- and pH-sensitive behavior, signifying their potential applications in controlled delivery as polymer–drug nanocarrier.

pH-Responsive Biomimetic Polymeric Micelles as Lymph Node-Targeting Vaccines for Enhanced Antitumor Immune Responses

Xiqin Yang,Tong Yu,Yingping Zeng,Keke Lian,Xueqing Zhou,Jia Ke,Yinghong Li,Hong Yuan,Fuqiang Hu

Lymph nodes are proposed as the intriguing target in cancer immunotherapy, and cellular immunity is vital for vaccines to fight against cancer. However, inefficient delivery of vaccines to lymph nodes and deficient lysosomal escape of antigens result in weak cellular immunity, which restrains the strength of vaccines in inducing antitumor immune responses. Hence, dendritic cell membrane (DCM)/histidine-modified stearic acid-grafted chitosan (HCtSA)/ovalbumin (OVA) micelles, as pH-responsive biomimetic vaccines, were fabricated to target lymph nodes and induce cellular immunity for enhanced antitumor immune responses. DCM/HCtSA/OVA micelles exhibited pH-dependent antigen release behavior, which resulted in efficient escape of antigens from dendritic cell (DC) lysosomes. Besides, DCM/HCtSA/OVA micelles accumulated and reserved in the lymph nodes, which ensured effective uptake by DCs. Importantly, DCM/HCtSA/OVA micelles induced potent T cell immune responses, promoted secretion of antitumor-related cytokines, and notably inhibited tumor growth. Overall, DCM/HCtSA/OVA micelles exhibit great potential in targeted immunotherapy and can provide guidance for the design of vaccines.

L-proline functionalized pH-responsive copolymers as supported organocatalysts for asymmetric aldol reaction in water

Yu Tang,Qinya Wang,Lexuan Wu,Kuan Liu,Wenjing Wang,Yinghua Shen,Yuyuan Xue,Sheng Dai

pH-Responsive copolymers with reversible transformation ability have been investigated as new effective carriers for L-proline to catalyze asymmetric aldol reaction in water. A series of block copolymers of mPEG- b -P(DEA x - co -L-ProlA y ) (mPEG-PDL) bearing L-proline catalytic sites and pH-responsive poly (diethylaminoethyl methacrylate) (PDEA) segments were synthesized by the reversible addition-fragmentation chain transfer (RAFT) polymerization in the presence of methyl polyethylene glycol (mPEG) trithiocarbonate macro-RAFT agent. The pH-induced self-assembly behaviors of three copolymer catalysts with different contents of PDEA were investigated via the combination of UV–visible spectrometer (UV–vis), dynamic light scattering (DLS) and transmission electron microscopy (TEM). Catalytic activity and stereoselectivity of these copolymer catalysts were evaluated by direct asymmetric aldol reaction of p -nitrobenzaldehyde and cyclohexanone in water. The results indicated that catalytic activity and stereoselectivity effected by the pH value of aqueous solution and the structures of copolymer catalyst assemblies. mPEG-PDL-2 give the aldol product with high conv., yield, anti/syn , and ee (92%, 91%, 92/8 , 96%), respectively at pH 7.0. Furthermore, these pH-responsive copolymers supported L-proline are easily recycled by a reversible phase transition.

A benzimidazole-based highly selective colorimetric and far-red fluorometric pH sensor for intracellular imaging

Tao Gong,Rong Li,Yangyang Yuan,Baofeng Yu,Hong Zhao,Zhizhen Liu,Rui Guo,Dan Su,Wenting Liang,Chuan Dong

A turn-on fluorescent probe (E)-4-(2-(1H-benzo[d]imidazol-2-yl)vinyl)-N,N-diphenylaniline (BVD) was facilely synthesized via the ethylene bridging of triphenylamine and benzimidazole. The probe exhibited strong emission enhancement in the far-red fluorescence region at 605 nm with a pKa value of 4.14 and linear response to the acidity range of 4.52–3.37. BVD displayed a large Stokes shift of 105 nm under acidic conditions, high sensitivity, quick response, excellent reversibility and good photostability, which are favorable for monitoring the pH variation in real time. More importantly, BVD had excellent cell membrane permeability and was applied successfully to visualize intracellular pH fluctuations in living cells without the influence of autofluorescence.

Stretchable Optical Sensing Patch System Integrated Heart Rate, Pulse Oxygen Saturation, and Sweat pH Detection

Guangming Wang,Shaomin Zhang,Shurong Dong,Dong Lou,Lie Ma,Xiachuan Pei,Hongsheng Xu,Umar Farooq,Wei Guo,Jikui Luo

pH/ROS-responsive magnesium scaffold functionalized via hydrazone bonds for localized postoperative bone tumor therapy

Yanfeng Ding,Xing Fen,Song Chen,Yiqing Zhang,Qingjiang Pang

Surgery remains the primary treatment strategy for bone tumors such as osteosarcoma; however, patients typically require postoperative radiotherapy and/or chemotherapy to prevent recurrence and metastasis. The implantation of scaffolds to restore bone mechanics is a routine surgical measure. Scaffold systems capable of localized drug release hold great clinical potential, as they can minimize systemic side effects associated with chemotherapy. In this work, we designed a pH/ROS-responsive magnesium scaffold functionalized via hydrazone bonds using micro-arc oxidation technology for controlled release of doxorubicin. Compared with simple physical adsorption, this chemical adsorption strategy markedly enhanced drug loading efficiency (508.4 ng vs. 793.5 ng). Under physiological conditions (pH 7.4), the scaffold released only 2.43 % of doxorubicin over 12 days, whereas in the tumor-mimicking acidic environment (pH 6.2), release reached 84.82 %. In contrast, scaffolds with simple adsorption released 27.68 % and 83 % under the same respective conditions. In vivo studies demonstrated that the intelligent scaffold did not impair wound healing but significantly inhibited osteosarcoma growth (87.67 %). These findings indicate that this responsive scaffold system provides a promising approach for localized postoperative bone tumor therapy with reduced systemic toxicity.

A pH-responsive prodrug delivery system of 10-HCPT for controlled release and tumor targeting

Yang Liu,Dan Li,Xinhong Guo,Haiwei Xu,Zhi Li,Yanling Zhang,Chuanjun Song,Ruhan Fan,Xing Tang,Zhenzhong Zhang

We synthesized a pH-responsive conjugate of 10-hydroxycamptothecin-thiosemicarbazide-linear polyethylene glycol 2000 (PEG2000). The conjugate was confirmed by matrix-assisted laser desorption time of flight mass spectrometry, 1 H NMR, and 13 C NMR. The water solubility of the prodrug was increased by over 3,000 times; much longer body circulation time, higher tumor-targeting ability, and reduced toxicity were observed, compared with commercial 10-HCPT injection. The linker contains a pH-sensitive hydrazone bond, which breaks under low pH conditions in the tumor microenvironment. The conjugates showed good stability in phosphate-buffered saline (pH 7.4) and rat plasma. This amphiphilic conjugate could self-assemble into nanosized micelles of 80–100 nm. Cytotoxicity assay results indicate significantly higher efficacy of the conjugate (IC 50 [half maximal inhibitory concentration] =0.117 µM on SW180 cells) than 10-HCPT solution (IC 50 =0.241 µM on SW480 cells). Cellular uptake analysis suggested its rapid internalization and nuclear transport. Pharmacokinetic analysis of the conjugates demonstrated that the conjugate circulated for a longer time in the blood circulation system ( T 2/1 =10.516±1.158 h) than did 10-HCPT solution ( T 2/1 =1.859±1.385 h), and that it also enhanced the targeting and mean residence time (MRT 0–inf =39.873±4.549 h) in the tumor site, compared with 10-HCPT (MRT 0–inf =9.247±1.026 h). Finally, the conjugate demonstrated an increased tumor growth inhibition effect (TIR =82.66%±7.175%) in vivo and lower side effects than 10-HCPT (TIR =63.85%±5.233%). This prodrug holds great promise in improving therapeutic efficacy and overcoming multidrug resistance.

A novel ratiometric fluorescent probe for the detection of mitochondrial pH dynamics during cell damage

Gaoqing Fu,Guoxing Yin,Tingting Niu,Wei Wu,Hui Han,Haimin Chen,Peng Yin

A sensitive fluorescent probe (E)-4-(3-(benzo[d]thiazol-2-yl)-4-hydroxy-5-methylstyryl)-1-methylpyridin-1-ium iodide (HBTMP) for the monitoring of pH in mitochondria was rationally exploited. This novel probe exhibited remarkable pH-dependent behavior in the linear range of 5.5–8.0, along with a pKa value of 6.829 ± 0.02627. A large Stokes shift of 205 nm was obtained. This fluorescent probe demonstrated good biocompatibility and high sensitivity for detecting the dynamic changes in mitochondrial pH in living cells and zebrafish. The results of the CCCP (m-chlorophenyl hydrazone) treatment experiment indicated that the probe can effectively monitor changes in mitochondrial pH caused by cell damage.

Effect of precursor pH value on the structure and electrical properties of Bi1.5Zn1.0Nb1.5O7 thin films

Kailong Wei,Helei Dong,Qiulin Tan,Wenfang Kang,Shihui Yu,Jijun Xiong

Bi 1.5 Zn 1.0 Nb 1.5 O 7 (BZN) thin films are synthesized on a FTO (Fluorine -doped SnO 2 transparent conductive glass) substrate by an improved sol-gel method. The pH of the precursor is controlled by citric acid and ammonia, and the effect of pH on the crystal structure and electrical properties of the BZN films is studied. When the precursor pH is 5, the relative intensity of the diffraction peak of BZN films is the highest, the FWHM is the narrowest, and the crystallization degree is the highest, compared to those of BZN films synthesized from precursors at other pH, the crystallization energy offset of the element binding energy of the thin films is the smallest and the phase difference of the binding energy is the closest to the theoretical value, and the films have excellent electrical properties with permittivity of 120, loss tangent of 0.003, tunability of 14.8%, breakdown voltage of 0.43 MV/cm and energy storage density of 9.82 × 10 −2  J/cm 3 .