Polymer Chemistry
·
2015
·Vol. 6
·期 13
·2401-2406
·
IF 5.52
Rumei Cheng,Ruitao Zou,Shengju Ou,Rui Guo,Ruiying Yan,Haiyan Shi,Shanshan Yu,Xiaojian Li,Yexu Bu,Mimi Lin,Yong Liu,Liming Dai
A pH-sensitive, nanostructured antitumor drug, GO-CONH-Schiff base (GCS), was prepared from the chitosan-xanthone Schiff base (CS)-modified graphene oxide (GO) complex. The successful synthesis of GCS was confirmed using various spectroscopic techniques, including FT-IR, XPS, UV-vis and TGA. The resulting GCS showed superb antitumor activity with the pH-sensitive release of the antitumor part, CS, and decreased cytotoxicity of GCS to normal human cells. The release of CS was stable and thorough in the solution at pH 1 (the pH value for gastric juice), suggesting that the as-synthesized, pH-sensitive drug could provide new insights into the design of advanced nanostructured oral drugs.
研究领域:
纳米医学
·
药理学
·
生物材料学
✓ 已验证
DOI
高影响因子
Frontiers in Microbiology
·
2024
·
IF 4
Liu Chang,Cui Chenxuan,Tan Xiaoxin,Miao Junjie,Wang Wei,Ren Han,Wu Hua,Zheng Cuiying,Ren Huan,Kang Weijun
The emergence of multidrug-resistant Pseudomonas aeruginosa isolates is a growing concern for public health, necessitating new therapeutic strategies. Gallium nitrate [Ga(NO3)3], a medication for cancer-related hypercalcemia, has attracted great attention due to its ability to inhibit P. aeruginosa growth and biofilm formation by disrupting iron metabolism. However, the antibacterial efficacy of Ga(NO3)3 is not always satisfactory. It is imperative to investigate the factors that affect the bactericidal effects of Ga(NO3)3 and to identify new ways to enhance its efficacy. This study focused on the impact of pH on P. aeruginosa resistance to Ga(NO3)3, along with the underlying mechanism. The results indicate that acidic conditions could increase the effectiveness of Ga(NO3)3 against P. aeruginosa by promoting the production of pyochelin and gallium uptake. Subsequently, using glutamic acid, a clinically compatible acidic amino acid, the pH was significantly lowered and enhanced the bactericidal and inhibitory efficacy of Ga(NO3)3 against biofilm formation by P. aeruginosa, including a reference strain PA14 and several multidrug-resistant clinical isolates. Furthermore, we used an abscess mouse model to evaluate this combination in vivo; the results show that the combination of glutamic acid and Ga(NO3)3 significantly improved P. aeruginosa clearance. Overall, the present study demonstrates that acidic conditions can increase the sensitivity of P. aeruginosa to Ga(NO3)3. Combining glutamic acid and Ga(NO3)3 is a potential strategy for the treatment of P. aeruginosa infections.
研究领域:
微生物学
·
感染与免疫
·
药理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
·
2012
·
IF 3.456
Shufang Yu,Guolin Wu,Xin Gu,Jingjing Wang,Yinong Wang,Hui Gao,Jianbiao Ma
A dually responsive nanocarrier with multilayer core–shell architecture was prepared based on Fe 3 O 4 @SiO 2 nanoparticles coated with mPEG-poly( l -Asparagine). Imidazole groups (pK a ∼ 6.0) were tethered to the side chains of poly( l -Asparagine) segments by aminolysis. These nanoparticles were expected to be sensitive to both magnetic field and pH environment. The obtained materials were characterized with FTIR, dynamic light scattering, ζ -potential, TEM, TGA and hysteresis loop analysis. It was found that this Fe 3 O 4 @SiO 2 –polymer complex can form nano-scale core–shell–corona trilayer particles (∼250 nm) in aqueous solution. The Fe 3 O 4 @SiO 2 , poly( l -Asparagine) and mPEG segments serve as a super-paramagnetic core, a pH-sensitive shell, and a hydrophilic corona, respectively. An antitumor agent, doxorubicin (DOX), was successfully loaded into the nanocarrier via combined actions of hydrophobic interaction and hydrogen bonding. The drug release profiles displayed a pH-dependent behavior. DOX release rate increased significantly as the ambient pH dropped from the physiological pH (7.4) to acidic (5.5). This is most likely due to protonation and a change in hydrophilicity of the imidazole groups in the poly( l -Asparagine) segments. This new approach may serve as a promising platform to formulate magnetic targeted drug delivery systems.
研究领域:
生物医学工程
·
材料科学
·
药学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Yan Xu,Weitao Yang,Zhuoyao Wu,Hui Wang,Tianming Cui,Weiwei Zeng,Yanjing Yun,Bingbo Zhang
Effective monitoring of gastric fluid pH is crucial for diagnosing gastric diseases and evaluating anti-gastric-acid therapies. The invasiveness and low patient compliance with traditional gastric fluid aspiration methods highlight the need of a non-invasive, real-time technique for in situ gastric pH monitoring. This study introduces a novel chromium (Cr)-based magnetic resonance probe, Cr(OH) 3 @HSA, specifically designed for pH-sensitive gastric imaging. Synthesized via an albumin-mediated biomimetic mineralization process, Cr(OH) 3 @HSA possesses an amorphous structure that facilitates the sensitive release of paramagnetic Cr(III) ions in acidic environments. This release substantially decreases the longitudinal relaxation time of surrounding hydrogen protons, as demonstrated by an 18.29-fold increase in the longitudinal relaxation rate from pH 6.5 to pH 1.0. In vivo experiments show that Cr(OH) 3 @HSA accurately detects abnormal gastric pH levels and evaluates the efficacy of gastric antiacids, surpassing the performance of the conventional “always-on” contrast agent, Magnevist®. Notably, our research reveals that chromium picolinate, a common dietary supplement for diabetes, generates a “turn-on” signal in the gastrointestinal tract, suggesting potential MR signal interference in diabetic patients. Consequently, we recommend that diabetic patients avoid chromium-based dietary supplements prior to MRI procedures to prevent Cr(III)-induced signal alterations.
研究领域:
医学影像
·
胃肠病学
·
生物医学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Life-Basel
·
2020
·Vol. 10
·期 4
·45
·
IF 2.991
Rongcan Lin,Yueqiao Wang,Xin Li,Yan Liu,Yufen Zhao
Ultraviolet (UV) irradiation is considered an energy source for the prebiotic chemical synthesis of life’s building blocks. However, it also results in photodegradation of biology-related organic compounds on early Earth. Thus, it is important to find a process to protect these compounds from decomposition by UV irradiation. Herein, pH effects on both the adsorption of peptides on montmorillonite (MMT) and the abilities of peptides to resist UV irradiation due to this adsorption were systematically studied. We found that montmorillonite (MMT) can adsorb peptides effectively under acidic conditions, while MMT-adsorbed peptides can be released under basic conditions. Peptide adsorption is positively correlated with the length of the peptide chains. MMT’s adsorption of peptides and MMT-adsorbed peptide desorption are both rapid-equilibrium, and it takes less than 30 min to reach the equilibrium in both cases. Furthermore, compared to free peptides, MMT-adsorbed peptides under acidic conditions are well protected from UV degradation even after prolonged irradiation. These results indicate amino acid/peptides are able to concentrate from aqueous solution by MMT adsorption under low-pH conditions (concentration step). The MMT-adsorbed peptides survive under UV irradiation among other unprotected species (storage step). Then, the MMT-adsorbed peptides can be released to the aqueous solution if the environment becomes more basic (releasing step), and these free peptides are ready for polymerization to polypeptides. Hence, a plausible prebiotic concentration–storage–release cycle of amino acids/peptides for further polypeptide synthesis is established.Keywords:pH-dependent;adsorption;peptides;UV radiation protection;montmorillonite
研究领域:
前生物化学
·
地球化学
·
天体生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIOMACROMOLECULES
·
2015
·
IF 5.75
Xu Jia,Xubo Zhao,Kun Tian,Tingting Zhou,Jiagen Li,Ruinian Zhang,Peng Liu
A novel water-soluble pH stimuli-responsive fluorescent copolymer of P(PEGMA-b-(MAH-co-Rh6GEAm)) was synthesized by two-step sequential RAFT polymerization. The prodrug with drug content of 0.1560 mg/mg was prepared by coupling doxorubicin (DOX) onto the copolymer via acid-cleavable hydrazone bond, formed between the carbonyl group of DOX and abundant hydrazide functional groups in the copolymer. The amphiphilic DOX-conjugated prodrug (P(PEGMA-b-(MAH-DOX-co-Rh6GEAm))) could easily form a micelle in water with Dh of less than 100 nm. It could be transported into HepG2 cells and release DOX without burst release, while the leakage of DOX can be avoided in the simulated normal physiological media. Furthermore, its fluorescence intensity experienced a reversible change with the transformation of the media pH. The better biocompatibility, pH stimuli-responsiveness, and the strong fluorescence at low pH media make the nanoparticles a potential platform for the controlled release of anticarcinogens and real-time fluorescent imaging of tumor tissues.
研究领域:
生物材料
·
药物递送
·
肿瘤学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 95
·52808-52814
·
IF 3.708
Qiang Zhao,Yan-Li Ji,Jia-Kai Wu,Ling-Ling Shao,Quan-Fu An,Cong-Jie Gao
Nanofiltration (NF) membranes were prepared from a solution processable polyelectrolyte complex (PEC) between sodium carboxymethyl cellulose (CMCNa) and poly(2-methacryloyloxy ethyl trimethylammonium chloride) (PDMC). Electrostatic complexation structures of the PEC were studied by light transmittance and field emission electron scanning microscopy (FESEM). It is found that the electrostatic complexation structure of the PEC membranes determines their NF performance, which is conveniently tailored via the pH values of casting solutions. For membranes prepared at the optimum solution pH 2.1, their water flux and salt rejection to K2SO4 (1 g L−1) are 18 g m−2 h−1 and 97%, respectively, when the operation pressure and temperature are 0.6 MPa and 25 °C. Both the water permeability and the salt selectivity are substantially improved compared to the pristine CMCNa NF membrane. In addition, antifouling performance of the PEC membrane is improved, coupled with an exceptional stability versus the operation time.
研究领域:
材料科学
·
环境工程
✓ 已验证
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Yujian Bai,Rui Zhu,Jie Zhao,Guofeng Cui
A polyaniline pH sensor with super-Nernstian sensitivity (>59.12 mV/pH) was obtained through acid doping. After preparing polyaniline sensor by potentiostatic electropolymerization, the electrochemical property of sensor can be modulated by adjusting acid doping formulas. The result shows that when using doping solution containing 2.2 g/L sodium dihydrogen phosphate and 5 g/L sodium chloride at pH = 6, the polyaniline sensor exhibits a linear super-Nernstian behavior (−69.31 ± 1.66 mV/pH) in PBS buffer (pH 5.00 ∼ 9.00). We observed that the surface of electrode has a three-dimensional network structure which can greatly increase the surface area of the sensing film, thus improving the conductivity and the sensitivity of the senor. The mechanism of acid doping is revealed: phosphate and polyaniline form salt, which makes polyaniline change from insulator to metal state and improves the conductivity. This is one important reason for its super-Nernstian behavior. In order to better understand this behavior, a new super-Nernstian model is established. The parameter 1/r > 1 is introduced to represent the acid doping index of the sensor, which directly affects the sensitivity of the film. According to the formula, super-Nernstian behavior of pH sensor can be mathematically modeled. This investigation yields a consistently stable super-Nernstian pH sensor while providing enhanced insights into its super-Nernstian characteristics and underlying mechanisms.
研究领域:
材料科学
·
电化学
·
传感技术
✓ 已验证
产品关联
DOI
高影响因子
Biomaterials Science
·
2018
·Vol. 6
·期 11
·3075-3084
·
IF 5.831
Qiong Sun,Chunming Tang,Zhigui Su,Junjie Du,Yunkai Shang,Lingjing Xue,Can Zhang
Cationic lipids and polymers are the most common non-viral vectors for siRNA delivery; however, their intense positively charged character may give rise to serum-triggered aggregation, immune activation, inflammation stimulation and grievous toxicity. An ocean of charge shielding strategies is exploited, but the currently available siRNA delivery systems still remain ungratified and deficient. Herein, we developed a facile modular assembly strategy for a pH-sensitive charge reversal siRNA delivery system (PC), which can be easily obtained by adjusting the ratios of positively and negatively charged modules. This PC is electronegative at neutral pH and reverses to electropositive at an acidic pH value with increased tumor cellular uptake. Also, the PC can promote efficient intracellular release and cytoplasmic distribution of siRNA, due to its fusogenic potential with the lysosome membrane. Moreover, the PC loaded with siRNA targeting survivin mRNA (cpusiRNA2) specifically down-regulated the expression of survivin, possessing remarkable tumor therapeutic efficacy in vitro and in vivo. Accordingly, this handy and effective assembly strategy would provide a promising platform for the design of siRNA delivery systems in cancer therapy.
研究领域:
生物技术
·
药学科学
·
癌症研究
✓ 已验证
DOI
PubMed
高影响因子
Polymer Chemistry
·
2017
·Vol. 9
·期 2
·169-177
·
IF 5.375
Hongliang Cao,Chao Chen,Debiao Xie,Xin Chen,Ping Wang,Yibing Wang,Huajie Song,Wenxin Wang
Nanoparticles are appealing drug delivery systems since they promise prolonged circulation time and predictable release behaviors. The current work reports a novel hyperbranched amphiphilic block copolymer synthesized using deactivation-enhanced atom transfer radical polymerization (DE-ATRP) for smart drug delivery. PEG2000-Br was applied as a macroinitiator to initiate acid-cleavable divinyl (ACD) monomers linked by acetal groups, formulating the hydrophilic (PEG) and hydrophobic (ACD) segments. The polymer appeared to self-assemble into micelles with diameters in the range of 70–100 nm, and was examined for the controlled release of doxorubicin (DOX). Results showed that DOX-loaded micelles (∼90 nm) could achieve drug loading as high as 8.2 wt%, with interesting pH-dependent release behaviors. Studies with flow cytometry (FCM) and confocal laser scanning microscopy (CLSM) showed that DOX-loaded micelles exhibited a high cellular uptake performance by HeLa cells, which indicated promising anti-tumor efficacy for such a drug delivery system. Additionally, such DOX-loaded micelles exhibited remarkable cytotoxicity against HeLa cells in a dose- and time-dependent manner due to the enhanced cell uptake behavior of micelles. These results indicated that the polymeric micelles might be used as a promising candidate for a pH-responsive drug delivery for cancer therapy.
研究领域:
药剂学
·
肿瘤学
·
生物材料
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Polymeric Materials and Polymeric Biomaterials
·
2021
·
IF 2.604
Liwen Tang,Ruiting Yang,Haifang Liu,Ziyu Qin,Bining Qiu,Mengting Li,Xueqiong Yin
pH-sensitive magnetic dual drug-loaded microcapsules (MDDM) embracing magnetic nanoparticles Fe3O4@SiO2 and two drugs (roxithromycin (ROX) and theophylline (TH)) were prepared through self-assembly, with methylcellulose and alginate sodium as the wall materials. MDDM was characterized with FTIR, XRD, TGA, vibrating sample magnetometer. The amount of Fe3O4@SiO2 affected the drug encapsulation efficiency lightly whereas affected the diameter of MDDM obviously. The drug loading of ROX and TH was 6.44% and 7.70% at the optimized conditions, respectively. The drug releasing of MDDM expressed obvious pH-sensitivity and increased with the pH value of the medium. The total cumulative release of ROX and TH in the simulative body fluid (pH 7.4) was 83.16% and 81.86% after 12 h, while was 24.54%, 21.21% in simulative gastric liquid. MDDM had higher antibacterial activity and lower cytotoxicity than the pure drugs with same amount, showing good capability on drug protection, controlled-releasing and toxicity elimination.
研究领域:
药学
·
材料科学
·
纳米技术
·
药物递送系统
✓ 已验证
产品关联
DOI
高影响因子
Polymer Chemistry
·
2016
·Vol. 7
·期 6
·1330-1336
·
IF 5.687
Fei Chen,Jiangna Guo,Dan Xu,Feng Yan
Thermo- and pH-responsive poly(ionic liquid) (PIL) membranes were synthesized via photo-crosslinking of imidazolium type IL monomers with acrylic acid (AA), N-isopropylacrylamide (NIPAM), and acrylonitrile (AN). The transmittance of the prepared PIL membranes was determined by the concentration of AA units and the hydrophobicity of PIL counter anions, and could be altered in response to temperature and (or) pH. The shape deformation of the PIL membranes can be reversibly tuned by changing the pH value of aqueous solutions or gas atmospheres (NH3/HCl). The dual-responsive PIL membranes prepared in this work can act as a soft actuator, and would have potential applications in advanced sensors and functional materials for inscription of information.
研究领域:
高分子化学
·
智能材料
·
响应性聚合物
·
生物医用材料
·
功能材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）