查找使用阿拉丁产品的科研文献

Dual-Mode Fluorescence and Magnetic Resonance Imaging Nanoprobe Based on Aromatic Amphiphilic Copolymer Encapsulated CdSe@CdS and Fe3O4

Xiaohong He,Xue Shen,Dongming Li,Yiyao Liu,Kun Jia,Xiaobo Liu

Nanoparticles exhibiting good biocompatibility and multifunctional optical, magnetic, and reactive properties are essential materials for the construction of next generation theranostics platforms. The core–shell structured CdSe@CdS is one of few semiconductor quantum dots (QD) that shows ideal photoluminescence for biological application including unity quantum yields, identical photoluminescence for ensembles and single dot, nonblinking, and antibleaching. However, overcoming toxicity concerns from Cd2+ is still a great challenge for promoting the practical medical application of the CdSe@CdS QD. Besides, the high quality luminescent and superparamagnetic nanoparticles at present are basically hydrophobic, which implies that the phase transfer of these functional nanoparticles into aqueous phase is the primary step to enable their biomedical application. Herein, we have developed a facile protocol to fabricate highly biocompatible nanoparticles showing both modulated luminescent and magnetic properties via a one-step self-assembling of amphiphilic block copolyarylene ether nitriles (amPEN), oleic acid stabilized CdSe@CdS QD, and Fe3O4 superparamagnetic nanoparticles (SP) in microemulsion system. Benefiting from the aromatic backbone structure of amPEN and its strong hydrophobic interaction with surface capping agent of QD/SP, the fabricated hybrid nanoprobe exhibits quite competitive colloids stability as well as fluorescent/magnetic properties, which ensures its application for in vitro fluorescence and magnetic resonance (MR) imaging of cancer cells.

Synthesis, micellization, and thermally-induced macroscopic micelle aggregation of poly(vinyl chloride)-g-poly(N-isopropylacrylamide) amphiphilic copolymer

Keyong Liu,Pengju Pan,Yongzhong Bao

A series of poly(vinyl chloride)-g-poly(N-isopropylacrylamide) (PVC-g-PNIPAM) amphiphilic copolymers with different graft lengths and densities were synthesized via the single electron transfer-living radical polymerization (SET-LRP) of NIPAM using poly(vinyl chloride-co-allyl α-bromoisobutyrate) as macroinitiator. The living nature of SET-LRP grafting copolymerization was verified by the kinetics study and narrow molecular weight distribution of PNIPAM grafts. The chemical structure, micellisation, and thermally-induced multistep aggregation of PVC-g-PNIPAMs were investigated. PVC-g-PNIPAMs form micelles comprised of a PVC core and PNIPAM corona in water at room temperature. These micelles are thermoresponsive and show a lower critical solution temperature (LCST). The micelle size and LCST of PVC-g-PNIPAM increase with increasing the graft density and length of PNIPAM. PVC-g-PNIPAM exhibits a very unique aggregation behavior above its LCST and forms a three-dimensional macroscopic aggregate with a well-defined and tunable shape at an extremely low concentration (∼0.1 wt%). The aggregate shrinks to a more compact structure with the further increase of temperature. Higher copolymer concentration, longer graft length, and lower graft density are favorable for the macroscopic micelle aggregation of PVC-g-PNIPAMs. A self-standing and superporous PVC-g-PNIPAM material having an extremely low density of ∼0.01 g cm−3 and a high porosity of >99% is attained after freeze-drying the micelle aggregate.

Versatile antifouling polyethersulfone filtration membranes modified via surface grafting of zwitterionic polymers from a reactive amphiphilic copolymer additive

Yi-Fan Zhao,Pei-Bin Zhang,Jian Sun,Cui-Jing Liu,Zhuan Yi,Li-Ping Zhu,You-Yi Xu

Here we describe the development of versatile antifouling polyethersulfone (PES) filtration membranes modified via surface grafting of zwitterionic polymers from a reactive amphiphilic copolymer additive. Amphiphilic polyethersulfone- block -poly(2-hydroxyethyl methacrylate) (PES- b -PHEMA) was beforehand designed and used as the blending additive of PES membranes prepared by phase inversion technique. The surface enriched PHEMA blocks on membrane surface acted as an anchor to immobilize the initiating site. Poly(sulfobetaine methacrylate) (PSBMA) were subsequently grafted onto the PES blend membranes by surface-initiated atom transfer radical polymerization (SI-ATRP). The analysis of surface chemistry confirmed the successful grafting of zwitterionic PSBMA brushes on PES membrane surface. The resulted PES- g -PSBMA membranes were capable of separating proteins from protein solution and oil from oil/water emulsion efficiently. Furthermore, the modified membranes showed high hydrophilicity and strongly antifouling properties due to the incorporation of well-defined PSBMA layer. In addition, the PES- g -PSBMA membranes exhibited excellent blood compatibility and durability during the washing process. The developed antifouling PES membranes are versatile and can find their applications in protein filtration, blood purification and oil/water separation, etc.

Biodegradable Amphiphilic Copolymer Containing Nucleobase: Synthesis, Self-Assembly in Aqueous Solutions, and Potential Use in Controlled Drug Delivery

Huihui Kuang,Suhong Wu,Zhigang Xie,Fanbo Meng,Xiabin Jing,Yubin Huang

Biodegradable nucleobase-grafted amphiphilic copolymer, the methoxyl poly (ethylene glycol)-b-poly (L-lactide-co-2-methyl-2(3-(2,3-dihydroxylpropylthio) propyloxycarbonyl)-propylene carbonate/1-carboxymethylthymine) (mPEG-b- P(LA-co-MPT)), was synthesized. 1H NMR titration and FT-IR spectroscopy indicated that the hydrogen-bonding could be formed between mPEG-b-P(LA-co-MPT) and 9-hexadecyladenine (A-C16). The hydrophobic microenvironment of the amphiphilic copolymer can protect the complementary multiple hydrogen bonds between mPEG-b-P(LA-co-MPT) and A-C16 from water effectively. The addition of A-C16 not only lowered the critical aggregation concentration (CAC) of mPEG-b-P(LA-co-MPT)/A-C16 nanoparticles (NPs) in aqueous solution but also induced different morphologies, which can be observed by transmission electron microscopy (TEM). Meanwhile, dynamic light scattering (DLS) and turbidometry was utilized to evaluate the effect of temperature and pH change on the stability of mPEG-b-P(LA-co-MPT)/A-C16 NPs. Cytotoxicity evaluation showed good biocompatibility of the mPEG-b-P(LA-co-MPT)/A-C16 NPs. The in vitro drug release profile showed that with the increase of A-C16 content, the doxorubiucin (DOX) release at pH 7.4 decreased, while the faster release rate was observed with the addition of A-C16 with a pH of 5.0. Importantly, DOX-loaded NPs exerted comparable cytotoxicity against MDA-MB-231 cells. This work provided a new method to stabilize NP structure using hydrogen-bonds and would have the potential to be applied in controlled drug delivery.

The antifouling and separation performance of an ultrafiltration membrane derived from a novel amphiphilic copolymer containing a crown ether

Sisheng Fang,Hai Tang,Meng Wang,Zhaozan Xu,Nanwen Li

Amphiphilic copolymers have attracted extensive attention for the preparation of ultrafiltration (UF) membranes processed with high separation and antifouling performances. Herein, hydrophilic crown ether (dibenzo-18-crown-6-ether, DE) units were introduced into poly( p -terphenyl, isatin) (PDTI) based on a polycondensation reaction via superacid-catalysis. The copolymers showed good thermal stability and membrane-forming properties, and the UF membranes fabricated by NIPS exhibited excellent separation performance. The content of the hydrophilic DE significantly influenced the morphology structure of the UF membranes. The cross-section structure of the membranes gradually converted from finger-like pores to loose sponge pores during delayed phase separation. The water flux of membranes ascended from 130.9 LMH bar −1 to 286.6 LMH bar −1 while the BSA rejection rate decreased from 99.4% to 90.8% as the DE content increased from 10% to 30%. These changes were associated with an enhanced surface porosity, larger surface pore diameter, and thinner top layer. Moreover, increasing the DE content in the copolymer greatly improved the antifouling performance due to greater hydrophilicity. Upon increasing the molar ratio of DE to p- terphenyl from 1: 9 to 3: 7, the flux recovery rate of the membranes surged from 58.5% to 91.5% and remained >80.2% after three fouling-cleaning cycles. In addition, the surface segregation of the hydrophilic DE segment in the copolymer was confirmed by the higher oxygen element content of the UF membrane on the top surface (18.62%) than that of the polymer (13.97%). Therefore, the amphiphilic copolymer containing a crown ether synthesized by a one-pot polycondensation reaction provides an effective way for the preparation and property adjustment of UF membranes.

Microwave-assisted preparation of paramagnetic zwitterionic amphiphilic copolymer hybrid molybdenum disulfide for T1-weighted magnetic resonance imaging-guided photothermal therapy

Yiming Yu,Bin Chi,Leping Lin,Zhe Yang,Qianyuan He,Zushun Xu,Changfeng Yi,Jing Wang

Magnetic resonance imaging (MRI)-guided photothermal therapy (PTT) has recently attracted tremendous attention. In this study, a paramagnetic zwitterionic amphiphilic copolymer (PZAC) was successfully prepared and utilized as a multifunctional surfactant to form micelles in diethylene glycol to coordinate with a molybdenum disulfide precursor (MoS2). Uniform spherical MoS2 nanohybrids (MoS2@PZAC) were first prepared by a microwave-assisted solvothermal process, which is simpler, easier and more efficient than hydrothermal methods or exfoliation processes. In this nanoplatform, MoS2 serves as a phototherapeutic agent possessing a high photothermal conversion efficiency (33.8%), while PZAC acts as a T1-weighted MRI contrast agent. This nanoplatform has the advantages of ultralow toxicity, prolonged circulation time and bio-imaging guided capability. The cytotoxicity assessment showed the good cytocompatibility of MoS2@PZAC. Furthermore, MoS2@PZAC could effectively kill cancer cells upon 2 W cm−2 808 nm laser irradiation for 10 min in both in vitro and in vivo experiments. This work provides a novel and efficient solution to synthesize a multifunctional and uniform theranostic agent, and the results show that the as-prepared MoS2@PZAC can be used as a promising theranostic agent for T1-weighted MRI-guided PTT of cancer cells.

Synergy effect of bactericidal and antifouling with structure reversion and hydrolysis of cationic amphiphilic copolymer PHMA-b-PCBMAE to zwitterionic copolymer

Xiuhua Sun,Shanshan Pan,Zhiren Guo,Yingxin Cui,Liang Ma,Xiaosong Yu,Taijiang Gui,Shougang Chen,Yan Liu,Changlu Gao

In this study, cationic amphiphilic copolymers of poly(hexadecyl methacrylate)-b-poly(carboxybetaine methacrylate ester) (PHMA-b-PCBMAE) with hydrophobic unit of 100 were synthesized, which can be self-assembled as core-shell nanoparticles with PCBMAE as core and PHMA as shell in chloroform . In response to the change of solvent polarity from chloroform to methanol, the reversion ability of core-shell structure occurred to cationic amphiphilic polymers of PHMA 100 -b-PCBMAE 40 , PHMA 100 -b-PCBMAE 50 , PHMA 100 -b-PCBMAE 75 and PHMA 100 -b-PCBMAE 100 in an ascending order, which was verified by 1 H NMR results. Coatings embedded with the cationic copolymers with PHMA:PCBMAE block ratios of 100:75 and 100:100 showed remarkably decreased water contact angle and protein adsorption amount due to the resulted zwitterionic copolymers upon hydrolysis in aqueous solution. Moreover, dynamic recording of the bactericidal activity against E. coli and S. aureus showed that it took ∼18 h for the copolymers PHMA 100 -b-PCBMAE 75 and PHMA 100 -b-PCBMAE 100 to take effect in bacteria killing and foulant repelling, and the bacteria left on the coating surfaces were <1.0 % in 24 h. The bactericidal results were in good accord with the trend of the nanoparticle reversion ability, indicating that higher PCBMAE contents of the cationic diblock copolymer facilitated core-shell reversion and subsequent hydrolysis to zwitterionic copolymer. Moreover, the regenerable surfaces of the coating furtherly ensured the sustainable bactericidal and antifouling activities.

Co-Delivery of Curcumin and Paclitaxel by “Core-Shell” Targeting Amphiphilic Copolymer to Reverse Resistance in the Treatment of Ovarian Cancer

Meng-Dan Zhao,Jun-Qin Li,Feng-Ying Chen,Wei Dong,Li-Juan Wen,Wei-Dong Fei,Xiao Zhang,Pei-Lei Yang,Xin-Mei Zhang,Cai-Hong Zheng

A reconstituted “two into one” thermosensitive hydrogel system assembled by drug-loaded amphiphilic copolymer nanoparticles for the local delivery of paclitaxel

Weiwei Wang,Liandong Deng,Shuxin Xu,Xiumei Zhao,Nan Lv,Guixian Zhang,Na Gu,Renjie Hu,Jianhua Zhang,Jinjian Liu,Anjie Dong

Combination delivery systems composed of injectable hydrogels and drug-incorporated micelles or nanoparticles with tunable and convenient properties for clinical operation and storage are urgently demanded in regional cancer chemotherapy to prolong and control drug release, enhance antitumor efficiency and decrease side effects. Previously, we developed a novel thermosensitive amphiphilic triblock copolymer, poly(ε-caprolactone-co-1,4,8-trioxa[4.6]spiro-9-undecanone)–poly(ethylene glycol)–poly(ε-caprolactone-co-1,4,8-trioxa[4.6]spiro-9-undecanone) (PECT), and fabricated a reconstituted “two into one” combination system of thermosensitive injectable hydrogel PTX/PECTGel, assembled from paclitaxel (PTX)-loaded PECT nanoparticles (NPs). PTX/PECTGel could be stored as freeze-dried powders of paclitaxel-loaded PECT NPs, which could be reconstituted into aqueous fluid dispersions at ambient temperature just by mixing with water after gentle stirring for several minutes, and form a hydrogel at the injected site in vivo. Herein, the drug release, in vivo morphology, antitumor efficiency and pharmacokinetic properties of PTX/PECTGel were evaluated. The PTX/PECTGel combination system could continuously release PTX in a near linear manner over 42 days in vitro, and simultaneously, PTX/PECT NPs containing 75% of the total released PTX could dissociate from the PTX/PECTGel. PTX/PECTGel exhibited remarkable in vitro anti-proliferative activities against Ehrlich ascites carcinoma (EAC) cancer cells. The peritumorally or intratumorally injected PECT gel could cover the entire surface or fill up the interior space of the tumor, respectively. A single peritumoral injection of the PTX/PECTGel formulation at a low dosage of 10 mg kg−1 could completely inhibit the growth of an EAC tumor inoculated in Balb/c mice after the first week, and the inhibition could be sustained for more than 21 days. The plasma pharmacokinetic study demonstrated that PTX/PECTGel could greatly decrease the systemic exposure of PTX, as confirmed by the rather low plasma concentration. On the other hand, the PTX concentration in normal tissues with the intratumoral injection of PTX/PECTGel was approximately 2 μg g−1, which was 3–10 times lower than that with the intraperitoneal or intratumoral injection of Taxol®, implying fewer off-target side effects. These data confirmed that the PTX/PECTGel combination local delivery system could vastly prolong the in vitro and in vivo paclitaxel release, enhance the local tumor inhibition effect and lower the systemic exposure and tissue distribution of paclitaxel. Hence, the “two into one” PTX/PECTGel system holds underlying value for regional cancer chemotherapy.

Novel 4-Arm Poly(Ethylene Glycol)-Block-Poly(Anhydride-Esters) Amphiphilic Copolymer Micelles Loading Curcumin: Preparation, Characterization, and In Vitro Evaluation

Li Lv,Yuanyuan Shen,Min Li,Xiaofen Xu,Mingna Li,Shengrong Guo,Shengtang Huang

A novel 4-arm poly(ethylene glycol)-block-poly(anhydride-esters) amphiphilic copolymer (4-arm PEG-b-PAE) was synthesized by esterization of 4-arm poly(ethylene glycol) and poly(anhydride-esters) which was obtained by melt polycondensation of α-, ω-acetic anhydride terminated poly(L-lactic acid). The obtained 4-arm PEG-b-PAE was characterized by 1H-NMR and gel permeation chromatography. The critical micelle concentration of 4-arm PEG-b-PAE was 2.38 μg/mL. The curcumin-loaded 4-arm PEG-b-PAE micelles were prepared by a solid dispersion method and the drug loading content and encapsulation efficiency of the micelles were 7.0% and 85.2%, respectively. The curcumin-loaded micelles were spherical with a hydrodynamic diameter of 151.9 nm. Curcumin was encapsulated within 4-arm PEG-b-PAE micelles amorphously and released from the micelles, faster in pH 5.0 than pH 7.4, presenting one biphasic drug release pattern with rapid release at the initial stage and slow release later. The hemolysis rate of the curcumin-loaded 4-arm PEG-b-PAE micelles was 3.18%, which was below 5%. The IC50 value of the curcumin-loaded micelles against Hela cells was 10.21 μg/mL, lower than the one of free curcumin (25.90 μg/mL). The cellular uptake of the curcumin-loaded micelles in Hela cell increased in a time-dependent manner. The curcumin-loaded micelles could induce G2/M phase cell cycle arrest and apoptosis of Hela cells.

Synthesis of an amphiphilic copolymer bearing rhodamine moieties and its self-assembly into micelles as chemosensors for Fe3+ in aqueous solution

Yu Wang,Haiqiang Wu,Jing Luo,Xiaoya Liu

We report on the fabrication of an amphiphilic random copolymer-based colorimetric and fluorescent chemosensor for Fe 3+ ions that was prepared by free radical polymerization of a novel rhodamine-based Fe 3+ -recognizing monomer , R6GEM, with N -vinylpyrrolidone (NVP). Because of its amphiphilic property, the copolymer P(NVP-co-R6GEM) can self-assemble into micelles , which allows it to be used as a chemosensor in aqueous solution. Upon addition of Fe 3+ ions to the micelle solution, visual color change and fluorescence enhancement were observed. Moreover, other metal ions did not induce obvious changes to the absorption and fluorescence spectra . The water dispersibility and biocompatibility of these polymer micelles could provide a new strategy for detecting analytes in environmental and biological systems.

Design and characterization of oil-in-water nanoemulsion for enhanced oil recovery stabilized by amphiphilic copolymer, nonionic surfactant, and LAPONITE® RD

Yi Zhao,Fangfang Peng,Yangchuan Ke

The application of nanotechnology in the oil and gas industry has attracted widespread attention in recent years. This study aims to develop a nanoemulsion (NE) for use in enhanced oil recovery (EOR). The NE stabilized by anion amphiphilic copolymer, nonionic surfactant (Brij30) and modified LAPONITE® RD was prepared by the phase inversion composition (PIC) method. The appearance of the emulsion is translucent and the average particle size is less than 60 nm. The micromorphology and interfacial tension (IFT) are examined using transmission electron microscopy (TEM) and a spinning drop IFT meter, respectively. The NE possesses good stability evaluated by conductivity and particle size tests. The absolute value of the zeta potential of NE increases when modified LAPONITE® RD is added. In a core flooding experiment with an artificial sandstone core, the NE flooding increased oil recovery by 23.53% compared to water flooding.