APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
·
2014
·Vol. 98
·期 12
·5765-5774
·
IF 3.811
Shang Yaping,Su Rongxin,Huang Renliang,Yang Yang,Qi Wei,Li Qiujin,He Zhimin
Recycling of cellulases is an effective way to reduce the cost of enzymatic hydrolysis for the production of cellulosic ethanol. In this study, we examined the adsorption and desorption behaviors of cellulase at different pH values and temperatures. Furthermore, we developed a promising way to recover both free and bound cellulases by pH-triggered adsorption-desorption. The results show that acidic pH (e.g., pH 4.8) was found to favor adsorption, whereas alkaline pH (e.g., pH 10) and low temperature (4–37 °C) favored desorption. The adsorption of cellulases reached an equilibrium within 60 min at pH 4.8 and 25 °C, leading to approximately 50 % of the added cellulases bound to the substrate. By controlling the pH of eluent (citrate buffer, 25 °C), we were able to increase the desorption efficiency of bound cellulases from 15 % at pH 4.8 to 85 % at pH 10. To recover cellulases after enzymatic hydrolysis, we employed adsorption by fresh substrate and desorption at pH 10 to recover the free cellulases in supernatant and the bound cellulases in residue, respectively. The recycling performance (based on the glucose yield) of this simple strategy could reach near 80 %. Our results provided a simple, low-cost, and effective approach for cellulase recycling during the enzymatic hydrolysis of lignocellulosic biomass.
研究领域:
生物化学
·
可再生能源
✓ 已验证
DOI
PubMed
高影响因子
Journal of Materials Chemistry B
·
2020
·Vol. 8
·期 35
·8002-8009
·
IF 5.344
Yuman Dong,Pengcheng Du,Peng Liu
Carbon dots (CDs) have attracted intense attention in tumor nanotheranostics recently; however, those nanotheranostics exhibited similar fluorescence in both normal and tumor tissues, limiting their practical application. In the present work, absolutely “off–on” fluorescent CD-based nanotheranostics was designed for tumor intracellular real-time imaging and pH-triggered DOX delivery via both static quenching by the crosslinking of benzaldehyde-containing diblock copolymers and dynamic quenching because of the surrounding conjugated DOX molecules. The proposed PPEGMA42-b-PFPMA122–(CDs)–DOX nanotheranostics did not exhibit fluorescence in a normal physiological medium, while strong fluorescence recovery occurred in the tumor intracellular microenvironment due to pH-triggered disintegration, releasing the CDs and DOX. The pH-triggered DOX release and absolute “off–on” fluorescence make the proposed nanotheranostics promising for tumor-specific pH-triggered DOX delivery and imaging.
研究领域:
生物医学工程
·
纳米医学
·
药物递送系统
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2018
·
IF 8.097
Xiao-Ling Xu,Kong-Jun Lu,Meng-Lu Zhu,Yang-Long Du,Ya-Fang Zhu,Nan-Nan Zhang,Xiao-Juan Wang,Xu-Qi Kang,De-Min Xu,Xiao-Ying Ying,Ri-Sheng Yu,Chen-Ying Lu,Jian-Song Ji,Jian You,Yong-Zhong Du
Both targeted and stimuli-sensitive drug-delivery systems (DDSs) have been developed to augment antitumor effects. However, lack of knowledge regarding tumor tissue targeting and different effects of the stimuli-sensitive DDSs in orthotropic and ectopic tumors have impeded further advances in their clinical applications. Herein, we first reported a pH-triggered micelle with sialic acid (SA)-driven targeting ability (SA–poly(ethylene glycol)–hydrazone linker-doxorubicin (DOX), SPD). The SPD micelles encapsulated with DOX (SPDD) showed sustained drug release over 48 h in response to the pH gradient in vivo, slow under physical conditions and accelerated in the acid tumor microenvironment. In addition, the SPD micelles showed 2.3-fold higher accumulation in tumors after 48 h compared to the micelles lacking the SA moiety. The overexpression of E-selectin on the inflammatory vascular endothelial cells surrounding the tumors increased the accumulation of SPD micelles in tumor tissues, whereas that on the tumor cells increased the internalization of micelles. Consequently, SPDD micelles exerted remarkable antitumor effects in both orthotopic and ectopic models. Application of SPDD micelles in the in situ model reduced the tumor volume (77.57 mm3 vs 62.13 mm3) and metastasis after treatment for 25 days. These results suggest that SA-driven targeted DDS with a pH-responsive switch has the potential to treat hepatocarcinoma effectively both ectopically and orthotopically.
研究领域:
药剂学
·
肿瘤学
✓ 已验证
DOI
PubMed
高影响因子
Materials Science & Engineering C-Materials for Biological Applications
·
2019
·
IF 4.959
Chengqiang Ding,Hongwei Wu,Zheng-Zhi Yin,Jun Gao,Datong Wu,Yong Qin,Yong Kong
Hydrophilic poly (acrylic acid) (PAA) and hydrophobic α-tocopherol succinate (TOS) were integrated via a two-step amidation with cystamine (Cys) as the linkage, and then the self-assembly of amphiphilic PAA-cys-TOS occurred in the aqueous solution of methotrexate (MTX), an anti-cancer drug, resulting a vesicle structured drug carrier. Since the disulfide (–S–S–) bridge of Cys is sensitive to glutathione (GSH) and the amide bonds in PAA-cys-TOS are sensitive to pH, disulfide-cleavage- and pH-triggered drug delivery was achieved with the amphiphilic self-assembly. Of particular interest was that the topography of the self-assembly varied remarkably during the triggered delivery, which was indicated by TEM results.
研究领域:
药剂学
·
生物化学
·
肿瘤学
✓ 已验证
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Xiaofeng Jiang,Wenjun Long,Liangqiong Peng,Teng Xu,Faming He,Yuling Tang,Wenhua Zhang
The rapid reductive immobilization of Cr(VI) from the aqueous solution was achieved by reduction to Cr(III) using tannic acid (TA), and subsequent pH-triggering precipitation of the organo-Cr(III) complexes formed in the redox reaction. The effects of TA concentration, temperature, and solution pH on the reduction of Cr(VI) were examined by batch experiments, and the rapid redox reduction followed a second-order kinetics with respect to Cr(VI) concentration in the pH range of 2.0–3.0. UV–visible spectra, FTIR, and XPS confirmed the complete detoxification of Cr(VI) concomitant with carboxylation of partial phenolic hydroxyls in TA. Synchronously, the reduced Cr(III) coordinated with carboxyl groups in oxidized TA (OTA) to form complexes, which exhibited remarkable pH-dependent size distribution characteristics as illustrated by SEM images and sequential filtration/ultrafiltration. The resulted Cr(III) complexes could aggregate into colloids with larger size and precipitate out at pH range of 6.0–8.0 via cross-linking, thereby leading to 93% Cr and 89% TOC immobilization. An eco-friendly and cost-effective method for Cr(VI) elimination and immobilization is provided because polyphenols are natural polymers derived from plants.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2019
·
IF 4.784
Pengwei Xie,Peng Liu
Core-shell-corona chitosan-based micelles were designed for the tumor intracellular pH-triggered doxorubicin (DOX) delivery, via a facile in-situ micellization in an aqueous solution of DOX and polyethylene glycol (PEG) and poly(2-(diisopropylamino) ethyl methacrylate) (PDPA) dual-modified chitosan (PEG-g-CS-g-PDPA). The effect of the PDPA modification on the diameter, drug loading-capacity (DLC) and pH-triggered drug release was investigated for the three different polymerization degrees of PDPA (25, 32, and 42) with a similar modification degree of ~22%. The optimized ones, the core-shell-corona DOX/PEG-g-CS-g-PDPA 32 micelles possessed a mean hydrodynamic diameter (D h ) of 211 nm and DLC of 54%, showing an excellent pH-triggered drug release with negligible premature drug leakage in 60 h. Such results indicated that grafting polycation could efficiently improve the performance of the chitosan-based drug delivery system (DDS) for tumor chemotherapy.
研究领域:
药剂学
·
生物材料学
·
肿瘤学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2020
·Vol. 138
·期 20
·50416
·
IF 2.52
Shaohua Wang,Ping Yang,Xiangfei Sun,Honglong Xing,Jianjun Shi
A highly-efficient nano-medical carrier system was constructed for drug release based on a facile synthesis, excellent fluorescence, and structure of phenol formaldehyde resin (PFR). The PFR was easily synthesized through a simple one-step hydrothermal reaction, reduction and etching process, and a silane coupling agent modification process. The multiple functionalized drug delivery system, defined as PFR-NH 2 @DOX was constructed by loading Adriamycin (DOX) into PFR. Drug release results in vitro displayed a DOX content of 145 mg g −1 prodrug nanosphere has excellent pH-triggered drug release (about 84.71%) within 72 h at pH 5 solution. The fluorescence recovery of PFR after DOX release indicates the potential application in fluorescence imaging and controlled drug release.
研究领域:
生物医学工程
·
材料科学
·
药学
✓ 已验证
产品关联
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2024
·
IF 5.8
Dan Ji,Yaping Wang,Mengqing Luo,Zihao Zhang,Xiaohua Chang,Yutian Zhu
Dual-responsive shape-transformable block copolymer (BCP) particles have arisen great attentions because of their tunable physical and chemical characteristics triggered by external stimuli. Herein, we developed a simple yet effective strategy to realize pH and light dual-triggered shape-switchable BCP particles through the co-assembly of BCPs with photo-responsive additive 4-hydroxyazobenzene (Azo-OH) within the evaporation emulsion droplets. The formation of hydrogen bonding interactions between the Azo-OH and 4-vinylpyridine (4VP) unit increases the volume fraction of P4VP domain, in turn leading to a morphological transition of the particles from onions to pupas by tuning the Azo-OH content. Subsequent light-induced trans – cis transition of the Azo unit induces the enhancement of the hydrophilicity of the P4VP domains, giving rise to internal shape transitions of the BCP particles from pupas to onions with P4VP at the outmost-layer. Furtherly, since the hydrogen bonds between Azo-OH and 4VP group are sensitive to pH, the interfacial properties of the emulsion droplets and the assembled structures are tuned through adjusting the environment pH of the aqueous solution, causing the formation of various particle shape, including pupas, raspberries, and onions. This work offers a promising method to engineer the microstructures of polymeric assemblies, which may attract more attention on the applications of the stimuli-responsive particles.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2015
·
IF 3.005
Jiawei Lu,Huiyan Jia,Leijia Guo,Genghui Zhang,Youjia Cao,Husheng Yan,Keliang Liu
To achieve a good stealth property and to enhance the uptake by tumor cells, polymeric micelles containing a slightly negatively charged and zwitterionic corona at pH 7.4 (i.e., blood pH) and a positively charged surface at a slightly acidic pH (i.e., tumor extracellular pH) were prepared. The amphiphilic diblock copolymer which was used to prepare the polymeric micelles contains a hydrophilic block comprised of nonionic hydrophilic groups, negatively charged groups (carboxyl groups) and pH-triggered positive charge-generation groups (morpholino groups). The zeta potential of the micelles was found to increase as the pH decreased over the pH range covering the blood and tumor tissue pH ranges, and the corona of the micelles should contain zwitterionic groups. This could be due to that, in the pH range studied, more morpholino groups become protonated as the pH decreased, whereas the carboxyl groups were almost completely deprotonated to form carboxylate anions. Furthermore, by adjusting the molar ratio of morpholino to carboxyl groups, the zeta potential of the polymeric micelles was controlled to achieve a slightly negative value at pH 7.4. Thus, the combination of a slightly negatively charged surface and a zwitterionic corona suggests that these micelles would possess good stealth property. When the pH decreased from 7.4 to 6.8 or 6.5, the zeta potential value of the micelles became positive due to increased protonation of the morpholino groups. Correspondingly, the cellular uptake of the micelles by HeLa cells was enhanced.
研究领域:
生物材料
·
药剂学
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2021
·Vol. 45
·期 16
·7210-7216
·
IF 3.591
Dan Liu,Shanshan Dai,Li Wang,Ya Liu,Hongsheng Lu
Organogelators have received extensive attention in the recovery of leaked organic solvents or oil spills. However, due to the interactions of organogelators with the organic solvents/oil, the separation and recovery of organic solvents/oil and organogelators from organogels is difficult. In this study, we have developed an organogelator with pH-triggered recyclable property, realizing the recovery of oil and organogelator. The organogelator (HSA-N) is synthesized with 12-hydroxystearic acid (HSA) and 3-dimethylaminopropylamine by an amidation reaction. Here, HSA-N can gelate several organic solvents and fuel oils at a low concentration (less than 1 wt%), which is induced by the strong hydrogen bond interaction and van der Waals forces demonstrated by X-ray diffraction (XRD) and infrared spectroscopy (IR). As HSA-N can reversibly transform between hydrophilicity and hydrophobicity by regulating pH, the separation and recovery of organic solvents/oil and organogelator can be achieved at room temperature. Herein, organogelators with pH responsiveness make it promising to recover organic solvents/oil and organogelators from organogels at room temperature.
研究领域:
化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2015
·
IF 6.723
Yike Fu,Xiang Li,Chuanbin Sun,Zhaohui Ren,Wenjian Weng,Chuanbin Mao,Gaorong Han
The design of multifunctional localized drug delivery systems (LDDSs) has been endeavored in the past decades worldwide. The matrix material of LDDSs is known as a crucial factor for the success of its transformation from the laboratory to clinical practices. Herein, a biocompatible ceramic, strontium titanate (SrTiO3, STO), was utilized as the matrix. A variety of fine Er doped SrTiO3 (STO:Er) nanofibers were fabricated via electrospinning. After the surface functionalization with amino groups, the drug loading capacity of STO:Er nanofibers is dramatically increased. The nanofibers present a rather sustained drug releasing behavior in the media with pH of 7.4, and the release kinetics is significantly accelerated with the decreased pH value from 7.4 to 4.7. Furthermore, the intensity of the spectrum emitted from the STO:Er nanofibers corresponds well with the drug releasing progress under the excitation of near-infrared spectrum (∼980 nm). Fast drug release behavior (in an acid environment) induces a rapid intensity enhancing effect of photoluminescence emission and vice versa. The main mechanism is attributed to the quenching effect induced by the C-Hx groups of IBU molecules with vibration frequencies from 2850 to 3000 cm–1. Such new STO:Er nanofibers with pH-triggered and optically monitored drug delivery functionalities have therefore been considered as another new localized drug delivery platform for modern tumor diagnosis and therapy.
研究领域:
材料科学
·
生物医学工程
·
肿瘤学
✓ 已验证
DOI
高影响因子
SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS
·
2019
·
IF 3.585
Jiajie Chen,Jiaxing Liu,Yaping Hu,Zhengfang Tian,Yufang Zhu
In nanoplatform-based tumor treatment, combining chemotherapy with hyperthermia therapy is an interesting strategy to achieve enhanced therapeutic efficacy with low dose of delivery drugs. Compared to photothermal therapy, magnetic hyperthermia has few restrictions on penetrating tissue by an alternating magnetic field, and thereby could cure various solid tumors, even deep-tissue ones. In this work, we proposed to construct magnetic nanocomposites (Fe3O4@PDA@ZIF-90) by the external growth of metal-organic framework ZIF-90 on polydopamine (PDA)-coated Fe3O4 nanoparticles for synergistic magnetic hyperthermia and chemotherapy. In such multifunctional platform, Fe3O4 nanoparticle was utilized as a magnetic heating seed, PDA layer acted as an inducer for the growth of ZIF-90 shell and porous ZIF-90 shell served as drug nanocarrier to load doxorubicin (DOX). The well-defined Fe3O4@PDA@ZIF-90 core-shell nanoparticles were displayed with an average size of ca. 200 nm and possessed the abilities to load high capacity of DOX as well as trigger drug release in a pH-responsive way. Furthermore, the Fe3O4@PDA@ZIF-90 nanoparticles can raise the local temperature to meet hyperthermia condition under an alternating magnetic field owing to the magnetocaloric effect of Fe3O4 cores. In the in vitro experiments, the Fe3O4@PDA@ZIF-90 nanoparticles showed a negligible cytotoxicity to Hela cells. More significantly, after cellular internalization, the DOX-loaded Fe3O4@PDA@ZIF-90 nanoparticles exhibited distinctively synergistic effect to kill tumor cells with higher efficacy compared to chemotherapy or magnetic hyperthermia alone, presenting a great potential for efficient tumor therapy.
研究领域:
纳米医学
·
生物材料
·
肿瘤学
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）