查找使用阿拉丁产品的科研文献

Light-Triggered Cross-Linking of Linear Poly(ethylene glycol) Hydrogels for Enhanced Antibacterial Delivery

Siyuan Liu,Yuan Tian,Kaijie Zhao,Peiyu Zhang,Jia Li,Jiwei Cui

Due to the limited functional groups on poly(ethylene glycol) (PEG) terminals, hydrogels are usually prepared by PEG chains with multiple arms. It is challenging for the preparation of hydrogels using linear PEG. Herein, we report the light-triggered synthesis of hydrogels composed of linear PEG with bis-maleimide groups. In the presence of a photoinduced catalyst, the α–C–H bonds on the PEG chain are cleaved, allowing the maleimide groups to be incorporated into the main chain, forming a cross-linked structure. The cleavage of the unstable C–O bonds could result in degradation of hydrogels. The release of encapsulated tobramycin from degradable hydrogels shows better antibacterial properties compared to undegradable hydrogels, which results in highly effective antimicrobials at the wound site. This work presents a method for the preparation of degradable hydrogels using linear PEG as a component for biological applications.

Selective salt separation and resource recovery via nanofiltration in coal-to-ethylene glycol wastewater

Zheng-Jun Fu,Bo-Zhi Chen,Kai Yu,Jian-Guo Hu,Pengli Chen,Hui-Qin Zhang,Mei-Ling Liu,Shi-Peng Sun

Aiming to address the challenges of high treatment cost and low recycling degree in coal-to-ethylene glycol wastewater, this study conducted research on the application of nanofiltration membranes for salt separation in the resource utilization plant of coal-to-ethylene glycol wastewater, and studied the operation parameters of the nanofiltration system in this resource utilization process. First, membrane elements were screened based on the water quality characteristics of the wastewater. Subsequently, systematic characterization of the selected membrane elements was conducted, followed by long-term pilot-scale experiments to determine operational parameters for the project. During 3 months of continuous operation, the rejection rate of Na 2 SO 4 was >98 %, and the rejection rate of NaCl was <10 %. Among them, the mass ratio of NaCl and Na 2 SO 4 on the permeate side is 30, and the mass ratio of NaCl and Na 2 SO 4 on the concentrated water side is 3, which effectively realizes the separation of Na 2 SO 4 and NaCl. Through the reverse osmosis + evaporation + crystallization process, Na 2 SO 4 products with a purity of 98.4 % and NaCl products with a purity of 98.9 % were finally obtained. This study provides a reasonable process route for the recycling of coal chemical wastewater and verifies the feasibility of salt separation of nanofiltration system in the recycling of coal chemical wastewater, to provide corresponding guidance for the resource utilization of concentrated brine.

Enhancing the enzymatic coloration stability of cotton and silk fabrics via polyethylene glycol templates

Na-won Baek

Enzymatic coloration offers an eco-friendly alternative to synthetic dyeing but faces commercial limitations, including poor reproducibility, low colour fastness and restricted colour range. This study investigated horseradish peroxidase-catalysed oxidation and coloration of four phenolic compounds on silk and cotton fabrics, incorporating polyethylene glycol (PEG) templates to improve dye uptake and stability. Dyeing performance was evaluated using colorimetric analysis, with maximum K/S values reaching 11.6 for cotton and 19.2 for silk (with PEG), representing an improvement of 36.5% and 9.7%, respectively, compared with non-templated samples. Colour fastness to washing, rubbing and light was assessed according to ISO standards, showing that PEG-treated fabrics exhibited ratings that were generally one to two grades higher, or at least equivalent, compared with non-templated samples. Structural and morphological changes were examined by Fourier Transform–infrared spectroscopy, scanning electron microscopy and thermogravimetric analysis, while liquid chromatography–tandem mass spectrometry elucidated the polymerisation mechanism of the oxidised phenolic dyes. These results demonstrate that PEG-templated enzymatic coloration can enhance colour intensity and fastness while maintaining sustainability, providing a viable pathway towards greener textile processing.

Biocompatible propylene glycol alginate-g-polytetrahydrofuran amphiphilic graft copolymers for highly effective drug carriers

Yu-Zhuang Gao,Jun-Cai Chen,Zhe Cui,Cong-Lei Zhao,Yi-Xian Wu

The acylated propylene glycol alginate- g -polytetrahydrofuran amphiphilic graft copolymers (APGA- g -PTHF) with various grafting numbers ( G N ) of 3–23 per 1000 monosaccharide rings and PTHF (PTMG or PTMO) branches with different molecular weights ( M n,PTHF ) of 600–3400 g/mol could be successfully synthesized via nucleophilic substitution of PTHF living chains carrying oxonium ions with the –OH side groups of APGA backbone. The nanophase separation, the hydrophobicity and the surface roughness were increased due to the less restricted movement of hydrophobic PTHF branches to the surface. APGA- g -PTHF graft copolymers behave low cytotoxicity and good anti-protein performance. Interestingly, APGA- g -PTHF amphiphilic graft copolymers could form homogeneous nanospheres (<250 nm) via self-assembly in H 2 O/CH 2 Cl 2 medium which could be used for drug (ibuprofen or curcumin) carriers having high drug loading efficiency (∼45%) and fast release behavior. The nanospheres carried curcumin behave very higher (10-fold) anticancer effect against HeLa cells than that of curcumin and thus reduce the harmful drug dosage. Moreover, the nanospheres carried drug might enter into HeLa cells and present pH-sensitive drug release. To the best of our knowledge, this is the first example of PGA-based graft copolymers for highly effective nano-carriers and anti-protein surfaces, which would have a prospect in biomedical areas.

Synthesis of polycarbonate urethanes with functional poly(ethylene glycol) side chains intended for bioconjugates

Yashuo Xu,Xiangyang Wu,Xingyi Xie,Yinping Zhong,Robert Guidoin,Ze Zhang,Qiang Fu

Traditional poly(ethylene glycol) (PEG)-modified polyurethanes usually exhibit high biocompatibility, but still lack reactivity with biological molecules to induce appropriate cell and tissue responses. In this study, PEG diglycidyl ether ( M n  = 526 Da) and PEG bis(amine) ( M n  = 1000 Da) were respectively grafted onto carboxyl-group-containing poly(carbonate urethane) backbones that chain-extended with lysine, to generate reactivity while maintaining biocompatibility. The PEG chains disordered and plasticized the hard segments where they attached, reducing H-bonded urea groups and lowering glass transition temperatures . The M n ranged from 33,000 to 70,000 Da for the precursor polyurethanes, which largely decreased by 24–75% following PEG grafting. Hemocompatibility was enhanced due to the flexibility and hydrophilicity of the PEG chains. Solutions of the PEG-grafted polyurethanes were transformed into hydrocolloids when dropped into water. Reactivity was proved by immobilization of albumin onto the colloidal particles. These new functional PEG-grafted polyurethanes can potentially form multifunctional bioconjugates for applications as biomaterials and in pharmaceutics.

Cartilage-targeting poly(ethylene glycol) (PEG)-formononetin (FMN) nanodrug for the treatment of osteoarthritis

Xiong Wei,Lan Qiumei,Liang Xiaonan,Zhao Jinmin,Huang Hanji,Zhan Yanting,Qin Zainen,Jiang Xianfang,Zheng Li

Intra-articular (IA) injection is an efficient treatment for osteoarthritis, which will minimize systemic side effects. However, the joint experiences rapid clearance of therapeutics after intra-articular injection. Delivering system modified through active targeting strategies to facilitate localization within specific joint tissues such as cartilage is hopeful to increase the therapeutic effects. In this study, we designed a nanoscaled amphiphilic and cartilage-targeting polymer-drug delivery system by using formononetin (FMN)-poly(ethylene glycol) (PEG) (denoted as PCFMN), which was prepared by PEGylation of FMN followed by coupling with cartilage-targeting peptide (CollBP). Our results showed that PCFMN was approximately regular spherical with an average diameter about 218 nm. The in vitro test using IL-1β stimulated chondrocytes indicated that PCFMN was biocompatible and upregulated anabolic genes while simultaneously downregulated catabolic genes of the articular cartilage. The therapeutic effects in vivo indicated that PCFMN could effectively attenuate the progression of OA as evidenced by immunohistochemical staining and histological analysis. In addition, PCFMN showed higher intention time in joints and better anti-inflammatory effects than FMN, indicating the efficacy of cartilage targeting nanodrug on OA. This study may provide a reference for clinical OA therapy.

Patupilone-loaded poly(L-glutamic acid)-graft-methoxy-poly(ethylene glycol) micelle for oncotherapy

Jing Yan,Dawei Zhang,Haiyang Yu,Lili Ma,Mingxiao Deng,Zhaohui Tang,Xuefei Zhang

Excavated and dendritic Pt-Co nanocubes as efficient ethylene glycol and glycerol oxidation electrocatalysts

Hongyu Du,Kai Wang,Panagiotis Tsiakaras,Pei Kang Shen

Noble metal electrocatalysts with excavated and dendritic architectures have recently attracted growing attention for their large accessible surface areas and high density of under-coordinated atoms. However, it is a tough challenge to avoid the atoms migrating to the corners and kinks and finally obtain the excavated structure, after the complicated interaction among multiple factors during the synthesis process, let alone the growth control of dendritic shape. Herein we demonstrate a facile strategy to synthesize Pt-Co nanocubes having excavated and dendritic structure (Pt-Co EDNCs). Specifically, the Pt-Co EDNC nanocrystal is composed of a deeply excavated nanocube and nanodendrites selectively protruding on the vertexes. Further electrocatalytic investigations showed that Pt-Co EDNCs exhibited enhanced catalytic properties towards the electro-oxidation of ethylene glycol and glycerol compared with commercial Pt/C, which could be attributed to both its unique structure and the synergism between Pt and Co.

Ultrahigh thermally conductive graphene filled liquid crystalline epoxy composites: Preparation assisted by polyethylene glycol

Fubin Luo,Pinping Yan,Hongzhou Li,Qingrong Qian,Baoquan Huang,Qinghua Chen,Kun Wu,Mangeng Lu

How to prepare high thermal conductive epoxy composites is still a challenge. In this work, polyethylene glycol (PEG) is introduced to the interface of liquid crystalline epoxy/graphene composite (EO/GR) as a route to ultrahigh thermally conductive yet mechanically robust nanocomposites . Assisted by PEG, the EO/GR composite is prepared by a simple blending method. The thermal conductivity of the prepared composite can reach to 10.17 W m −1  K −1 , and its electromagnetic interference shielding effectiveness (EMI SE) shielding efficiency is about 50 dB. The ultrahigh thermally conductive composite is mechanically robust and thermal stable. The ultrahigh thermal conductivity of the composite might be originated from the improved interfacial compatibility between EO and GR, which facilitates the successful preparation of composite at a high loading fraction of GR. Highly filled graphene in the matrix makes it possible to form massive GR-GR thermal conductive paths , which contribute to the ultrahigh thermal conductivity of the composite. This work provides an effective and simple method to prepare ultrahigh thermally conductive yet mechanically robust epoxy composites.

Study on the biocomposites with poly(ethylene glycol) dimethacrylate and surfaced-grafted hydroxyapatite nanoparticles

Haibo Li,Yi Fu,Rui Niu,Ziyou Zhou,Jun Nie,Dongzhi Yang

In composites of hydroxyapatite (HA) nanoparticles with a polymer matrix, the aggregation of nanoparticles would induce structural defects. In order to improve the dispersibility of HA nanoparticles in poly(ethylene glycol) dimethacrylate (PEGDMA) matrix and enhance mechanical properties of the HA/PEGDMA composite as potential bone substitute material, surface-grafted HA nanoparticles with poly(ethylene glycol) monomethacrylate (PEGMA) were prepared, and crosslinked with PEGDMA under UV light to form a composite. The structure of HA- g -PEGMA was characterized by X-ray diffraction (XRD) and thermal gravimetric analysis (TGA). The dispersibility of HA- g -PEGMA nanoparticles in poly(PEGDMA) was evaluated by SEM. The mechanical properties of the composites were investigated by compressive test. The dispersibility of HA- g -PEGMA nanoparticles in poly(PEGDMA) matrix was better than the bare HA. At a 1 wt % content of loading, the strength of composites increased by 14%, and the modulus increased by 9%. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Iron-catalyzed selective oxidation of sulfides to sulfoxides with the polyethylene glycol/O2 system

Bin Li,An-Hua Liu,Liang-Nian He,Zhen-Zhen Yang,Jian Gao,Kai-Hong Chen

Readily available iron compounds were found to be active catalysts for the selective oxidation of sulfide to sulfoxide with molecular oxygen as the oxidant in polyethylene glycol (PEG). As an indispensable component, PEG had a great promotive effect on the reaction. Notably, high conversion (>99%) along with excellent chemo-selectivity of up to 94% could be attained by using Fe(acac)2 as the catalyst at 100 °C. This methodology was proved to be applicable for the transformation of various aromatic and aliphatic sulfides into the corresponding sulfoxides with high selectivity. PEG is considered to play a crucial role in stablizing the Fe(IV)-oxo species formed in situ which is supposed to be responsible for the sulfide oxidation.

Preparation of diethylene glycol monomethyl ether monolaurate catalyzed by active carbon supported KF/CaO

Lou Shengfeng,Jia Lihua,Guo Xiangfeng,Wu Ping,Gao Lianbing,Wang Jianjun

Diethylene glycol monomethyl ether monolaurate (DGMEML) was synthesized via the reaction of diethylene glycol monomethyl ether (DGME) with methyl laurate (ML) by a new solid base catalyst of KF/CaO/AC, which was prepared by impregnation method using active carbon as carrier. The catalysts were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), nitrogen physisorption-desorption and Hammett indicator methods; the effect of the mole ratio of KF to CaO, DGME to ML molar ratio, amount of catalyst, reaction time and temperature on the yield of DGMEML were studied; and the relationship between the structure of the catalyst and the yield of DGMEML was investigated. The formed KCaF3 and K2O were acting as the main active components in the catalytic transesterification; the highest yield of 96.3 % was obtained as KF-to-CaO molar ratio of 2.0, DGME to ML molar ratio of 4.0, catalyst amount of 5 wt%, and reaction time of 30 min at 75 °C; and the catalyst displayed good stability in the transesterification.