BIOMATERIALS
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2019
·
IF 10.273
Xiao-Juan Wang,Gao-Feng Shu,Xiao-Ling Xu,Chen-Han Peng,Chen-Ying Lu,Xing-Yao Cheng,Xiang-Chao Luo,Jie Li,Jing Qi,Xu-Qi Kang,Fei-Yang Jin,Min-Jiang Chen,Xiao-Ying Ying,Jian You,Yong-Zhong Du,Jian-Song Ji
Spinal cord injury (SCI) leads to immediate disruption of neuronal membranes and loss of neurons, followed by extensive secondary injury process. Treatment of SCI still remains a tremendous challenge clinically. Minocycline could target comprehensive secondary injury via anti-inflammatory, anti-oxidant and anti-apoptotic mechanisms. Polyethylene glycol (PEG), a known sealing agent, is able to seal the damaged cell membranes and reduce calcium influx, thereby exerting neuroprotective capacity. Here, an E-selectin-targeting sialic acid - polyethylene glycol – poly (lactic-co-glycolic acid) (SAPP) copolymer was designed for delivering hydrophobic minocycline to achieve combinational therapy of SCI. The obtained SAPP copolymer could self-assemble into micelles with critical micelle concentration being of 13.40 μg/mL, and effectively encapsulate hydrophobic minocycline. The prepared drug-loaded micelles (SAPPM) displayed sustained drug release over 72 h, which could stop microglia activation and exhibited excellent neuroprotective capacity in vitro . The SAPP micelles were efficiently accumulated in the lesion site of SCI rats via the specific binding between sialic acid and E-selectin. Due to the targeting distribution and combinational effect between PEG and minocycline, SAPPM could obviously reduce the area of lesion cavity, and realize more survival of axons and myelin sheaths from the injury, thus distinctly improving hindlimb functional recovery of SCI rats and conferring superior therapeutic effect in coparison with other groups. Our work presented an effective and safe strategy for SCI targeting therapy. Besides, neuroprotective capacity of PEG deserves further investigation on other central nervous system diseases.
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高影响因子
Catalysis Science & Technology
·
2018
·Vol. 8
·期 10
·2624-2635
·
IF 5.365
Jingxia Tian,Wei Chen,Peng Wu,Zhirong Zhu,Xiaohong Li
A Cux–Mgy–Zrz/SiO2 catalyst with a total metal loading of 60 wt% prepared by a deposition–precipitation method was applied for the selective hydrogenation of ethylene carbonate to methanol and ethylene glycol in a fixed-bed reactor. As a result, the Cu8–Mg1–Zr0.47/SiO2 catalyst furnished 99% ethylene carbonate conversion with 85% selectivity to methanol and 99% selectivity to ethylene glycol under the optimized reaction conditions. Moreover, the Cu8–Mg1–Zr0.47/SiO2 catalyst also showed a good lifetime and neither the activity nor the selectivity decreased the during 208 h test. The reaction was found to depend sensitively on the Cu particle size, the surface acidity and the catalyst surface composition. The synergistic effect of balanced Cu0 and Cu+ sites was considered to play a critical role in attaining high yields of methanol and ethylene glycol. Boric oxide also had a positive effect on the hydrogenation of ethylene carbonate, affording higher selectivity to methanol under much milder conditions.
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JOURNAL OF MATERIALS SCIENCE
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2018
·Vol. 53
·期 24
·16539-16556
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IF 2.993
Chen Changzhong,Chen Jun,Jia Yifan,Topham Paul D.,Wang Linge
Novel binary shape-stabilized composite phase change materials (CPCMs) have been successfully prepared using a crosslinked polyurethane (PU) copolymer with a solid–solid phase transition as the supporting framework for loading additional (‘free’) poly(ethylene glycol) (PEG). The PU copolymer was synthesized by a two-step method using 2-hydroxypropyl-β-cyclodextrin (Hp-β-CD) as a chain extender and PEG as a soft segment. The composition, morphology, phase transition behavior and thermal properties of the prepared CPCMs have been elucidated by a wide range of techniques. Investigation of FTIR spectra and SEM images reveal that the ‘free’ PEG and the PU copolymer network within the CPCMs have good compatibility and high affinity due to the noncovalent interactions. Polarized light optical microscopy shows that the CPCMs produce smaller spherulites than pristine PEG, and homogeneous nucleation was prevalent during the crystallization process. Due to the dual-phase transition of the CPCMs (the solid–liquid phase transition of ‘free’ PEG and solid–solid phase transition of the PU matrix) occurring within the same, narrow temperature window, the CPCMs have far higher heat storage density compared with that of traditional shape-stabilized PCMs with the same ‘free’ PEG content. Importantly, thermal cycling and thermogravimetric analyses show that the CPCMs have good reusability and excellent thermal stability for potential use in thermoregulation or energy storage applications.
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BIOMATERIALS
·
2018
·
IF 8.806
Ji-Long Wang,Xiao-Jiao Du,Jin-Xian Yang,Song Shen,Hong-Jun Li,Ying-Li Luo,Shoaib Iqbal,Cong-Fei Xu,Xiao-Dong Ye,Jie Cao,Jun Wang
Engineering nanoparticles of reasonable surface poly(ethylene glycol) (PEG) length is important for designing efficient drug delivery systems. Eliminating the disturbance by other nanoproperties, such as size, PEG density, etc., is crucial for systemically investigating the impact of surface PEG length on the biological behavior of nanoparticles. In the present study, nanoparticles with different surface PEG length but similar other nanoproperties were prepared by using poly(ethylene glycol)-block-poly(ε-caprolactone) (PEG- b -PCL) copolymers of different molecular weights and incorporating different contents of PCL 3500 homopolymer . The molecular weight of PEG block in PEG-PCL was between 3400 and 8000 Da, the sizes of nanoparticles were around 100 nm, the terminal PEG density was controlled at 0.4 PEG/nm 2 (or the frontal PEG density was controlled at 0.16 PEG/nm 2 ). Using these nanoproperties well-designed nanoparticles, we demonstrated PEG length-dependent changes in the biological behaviors of nanoparticles and exhibited nonmonotonic improvements as the PEG molecular weight increased from 3400 to 8000 Da. Moreover, under the experimental conditions, we found nanoparticles with a surface PEG length of 13.8 nm (MW = 5000 Da) significantly decreased the absorption with serum protein and interaction with macrophages, which led to prolonged blood circulation time , enhanced tumor accumulation and improved antitumor efficacy. The present study will help to establish a relatively precise relationship between surface PEG length and the in vivo behavior of nanoparticles.
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DYES AND PIGMENTS
·
2019
·
IF 4.018
Mingguang Yu,Songjing Zhong,Yusi Quan,Houhe Liu,Junyang Zhong,Xinlin Jiang,Yisi Wang,Guodong Ye,Chunping Ma,Yugang Huang
A synthetic polypeptide-based bioconjugate bearing tetraphenylethylene (TPE) at the polypeptide side chains, named mPEG-PPLGgTPE, was synthesized by ring-opening polymerization (ROP) of α -amino acid- N -carboxyanhydride (NCA) along with post-polymerization modification method. Interestingly, the bioconjugate enabled both the aggregation induced emission (AIE) effect at 469 nm and the aggregation caused quenching (ACQ) effect around 365 nm depending on water fraction in the tetrahydrofuran/water (THF/H 2 O) mixed solution, and this feature was very different from the commonly used TPE-based AIE polymers. The strong emission at the 365 nm was a rarely seen monomeric emission for the TPE units. Further studies on the fluorescence spectra indicated that the monomeric emission was not related with the secondary structure of polypeptides, but caused by the TPE unit itself. The mPEG-PPLGgTPE could self-assemble to AIE nanoparticles (NPs) in water in a mean size of 253 nm with polyethylene glycol (PEG) as the shells in surface. In addition, HeLa cell uptake level of the NPs was unsatisfactory according to the cell imaging results, which was independent of the polypeptides conformation, the PEG length and the size of NPs.
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Materials Science & Engineering C-Materials for Biological Applications
·
2018
·
IF 5.08
Jiru Jia,Chaoxia Wang
High water absorption aerogels with three-dimensional porous structures and high specific surface areas have been fabricated from methoxy polyethylene glycol‑polycaprolactone block copolymer (mPEG‑PCL) via a facile approach by electrospinning, mechanical homogeneous shearing and dispersing short fibers in the water, freeze-drying, and heat crosslinking. The three-dimensional nanofiber aerogels (TNAs) exhibit continuous porous structures which are restructured with crisscrossed and dispersed nanofibers. The aerogel displays a low density (36 ± 3 mg/cm 3 ), a high specific surface area (230 m 2 /g), a high pore volume (5.9 cm 3 /g), a high porosity of 85% as well as an average pore diameter (1.12 μm). The as-made mPEG-PCL TNAs deliver a high average water-absorption capacity of 24.11 g/g and a good retention ability owing to the three-dimensional porous structures and large micropores population. The water absorption could still reach approximately 25 g/g after 10 compression cycles of TNAs. The average dehydration weight loss of 3.1% demonstrates that the materials are hardly soluble in the water, and the structural characteristic would not be changed after water adsorption. The antimicrobial activity against the bacteria Staphylococcus aureus and Escherichia coli are assessed that the TNAs are suitable carriers of antimicrobial agents. Moreover, as showed by cytotoxic tests, the TNAs are neglectable toxic, which are suitable for applications in environmental bioengineering. Based on the high water absorption and biocompatibility, the TNAs could be suitable candidates for health care materials and medical products.
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INTERNATIONAL JOURNAL OF PHARMACEUTICS
·
2018
·
IF 3.862
Chenguang Yang,Wantong Song,Dawei Zhang,Haiyang Yu,Lei Yin,Na Shen,Mingxiao Deng,Zhaohui Tang,Jingkai Gu,Xuesi Chen
Gemcitabine is widely used for anticancer therapy. However, its short blood circulation time and poor stability greatly impair its application. To solve this problem, we prepared a poly ( l -glutamic acid)- g -methoxy poly (ethylene glycol)-gemcitabine conjugate ( l -Gem) with a 14.3 wt% drug-loading content. l -Gem showed concentration- and time-dependent cytotoxicity towards 4T1, LLC, MIA PaCa-2 and A2780 in vitro . Pharmacokinetic and biodistribution studies indicated that l -Gem had remarkably enhanced blood stability, prolonged blood circulation time and greatly improved selective tumor distribution compared with free gemcitabine. The area under the concentration–time curve from zero to infinity [AUC (0–∞) ] of l -Gem in plasma was 43-fold higher than that of free gemcitabine. The AUC (0–∞) of the inactive metabolite, 2′-deoxy-2′,2′-difluorouridine in the l -Gem group was ∼20% of that observed in the free gemcitabine group. The drug tumor accumulation ratio in the l -Gem group relative to the free gemcitabine group was 9.9 at 36 h, while the tumor AUC ratio was 15.8. Testing on Balb/C mice bearing the 4T1 tumor further demonstrated that l -Gem had significantly higher anticancer efficacy than free gemcitabine in vivo . These findings indicated that l -Gem has great potential for cancer treatment.
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Acta Biomaterialia
·
2013
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IF 5.093
Jiang Wu,Zhen Wang,Weifeng Lin,Shengfu Chen
A comprehensive insight into the interaction between proteins and poly(ethylene glycol) (PEG) is crucial to understand the behavior of PEG, which is widely used in pharmaceutical and medical applications. Although PEG is believed to be an excellent material to resist non-specific protein adsorption , there is a lack of quantitative information about the interactions between proteins and PEG. In this paper the interactions of bovine serum albumin (BSA) and lysozyme (LYZ) with different molecular weight (MW) PEGs were investigated through the T 2 relaxation time of PEGs measured by low field nuclear magnetic resonance spectroscopy. The integrated signal intensity of PEGs was quantified under various conditions from the concentrations and MWs of PEG, and ionic strength of solutions, as well as the molar ratios of PEG to protein. The results show that a large number of PEG molecules could associate with protein molecules with association constants in the range ∼10 4 –10 5 M −1 . The association constant is insensitive to the ionic strength change in the physiological range and the lowest associate constant occurs at the medium MW PEG with protein. This suggests that the interaction between PEG and protein molecules might not be negligible in investigations of the resistance to non-specific protein adsorption. Long chain PEG coatings might cause modest protein adsorption, which could interfere with any weak specific interaction between ligand and receptor. Thus, it is necessary to reconsider the popular accepted method of protecting nanoparticles (NP) in blood with long chain PEG coatings since these NPs might be surrounded by a layer of weakly adsorbed plasma protein in the circulatory system.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2012
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IF 2.237
Duan-Jian Tao,Zhang-Min Li,Zheng Cheng,Na Hu,Xiang-Shu Chen
It is remarkable that Brønsted acidic ionic liquids (BAILs) have several unique advantages in the acid-catalysis reaction, which avoids the technical issues raised from mineral acids. The kinetics for the ketalization of cyclohexanone with glycol using BAILs as catalysts was therefore studied for the first time. The effects of various parameters such as kind of BAILs, temperature, catalyst loading, and molar ratio of the reactants on the conversion of cyclohexanone were examined in detail, and a pseudohomogeneous (PH) kinetic model was used successfully to correlate the experimental data in the temperature range from 313.15 to 343.15 K. The kinetic parameters such as reaction rate constant, activation energy, and chemical equilibrium constant then were proposed and utilized to interpret the catalytic activities of the BAILs catalysts. It was also validated from the comparison of catalytic performance among the BAILs, H2SO4, and solid resin that the BAILs were considered to be environmentally friendly and high efficient catalysts, and were suggested to replace mineral and solid acids in the synthesis of ketal.
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Journal of the Taiwan Institute of Chemical Engineers
·
2014
·
IF 2.637
Shidong Tian,Yucui Hou,Weize Wu,Shuhang Ren,Jianguo Qian
In this work, three kinds of ammonium salts containing chloride ion [DETA]· n Cl ( n = 1, 2, 3) were synthesized via the reactions between diethylenetriamine (DETA) and hydrochloric acid . And ethylene glycol (EG) was chosen as a solvent to dissolve [DETA]· n Cl to prepare liquid hybrid absorbents for the capture of CO 2 . Effects of amount of chloride ion, absorption temperature, CO 2 partial pressure and [DETA]·Cl concentration on the absorption of CO 2 were systematically studied. It has been found that [DETA]·Cl (1) + EG (2) (mole ratio of EG to [DETA]·Cl R = 4.0) shows a high absorption capacity of CO 2 . The mole ratio of CO 2 to [DETA]·Cl could reach 0.765 (0.0868 g CO 2 /g absorbent) at 50 °C under atmospheric pressure. Importantly, the viscosity of [DETA]·Cl (1) + EG (2) ( R = 4.0) is quite low (105.3 mPa s) even when it is saturated with CO 2 at 50 °C. Finally, [DETA]·Cl (1) + EG (2) ( R = 4.0) could be reused to absorb CO 2 for five times without obvious loss of absorption capacity. The result indicates that [DETA]·Cl (1) + EG (2) is a promising reversible absorbent for the capture of CO 2 .
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JOURNAL OF MOLECULAR STRUCTURE
·
2014
·
IF 1.599
Yugang Huang,Weiang Luo,Guodong Ye
A new polypeptide-based copolymer brush composed of poly (γ-propargyl- L -glutamate)- block -poly (propylene oxide)- block -poly (γ-propargyl- L -glutamate) backbone (PPLG- b -PPO- b -PPLG) and oligo (ethylene glycol) (PEG) side-chain was synthesized by combination of N -carboxyanhydride ring-opening polymerization and click chemistry. Nearly 100% grafting efficiency was achieved by copper-catalyzed azide-alkyne Huisgen 1,3-dipolar cycloaddition (CuAAc) reaction. The α -helical conformation adopted by the grafted polypeptide blocks in water was relatively stable and showed a reversible change in a heating–cooling circle from 5 to 70 °C. It displayed weak stability against elevated temperature but still reversible changes in the presence of 0.47 M NaCl. The brushes were amphiphilic and could self-assemble into thermo-sensitive micelles in water. Big micelles could break into small micelles upon heating due to the improved solubility.
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POLYMER INTERNATIONAL
·
2014
·Vol. 63
·期 10
·1875-1880
·
IF 2.247
Chunfang Li,Zhupeng Zhang,Jinrong Wu,Dongxiang Li,Wanguo Hou
Dendritic amphiphiles as novel building blocks are very important for self-assembling in the supramolecular chemistry area. In this work, a carbosilane dendrimer with hexamethylene as the branching unit (G1) was first synthesized as a hydrophobic core and then linked with poly(ethylene glycol) (PEG) units as the periphery by a hydrosilylation reaction to prepare an amphiphilic dendrimer (G1-PEG) with a yield of 27%. The aggregation behavior of G1-PEG in water was studied with surface tension, dynamic light scattering and transmission electron microscopy methods. The surface tension data showed that the critical aggregation concentration of such dendrimers in water is approximately 0.75 g L −1 . The results of dynamic light scattering and transmission electron microscopy indicated that the aggregate size of G1-PEG dendrimers in water is related to the concentration. Small micelles of about 10 nm were found at high concentration, large vesicles of about 100 nm were observed at low concentration, and a mixture of micelles and vesicles was found at middle concentrations. The encapsulation of G1-PEG to a fluorescence probe verified the existence of a hydrophobic microenvironment in the aggregates at high concentrations of the amphiphilic dendrimer. © 2014 Society of Chemical Industry
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