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1.
Reka Melinda Molnar Magdolna Bodnar John F. Hartmann Janos Borbely 《Colloid and polymer science》2009,287(6):739-744
The present investigation describes the synthesis and characterization of nanoparticles based on poly(acrylic acid) (PAA)
intramolecularly cross-linked with diamine, 2,2′-(ethylenedioxy)bis(ethylamine), using water-soluble carbodiimide. The aqueous
colloid dispersions of nanoparticles were clear or mildly opalescent depending on the ratio of cross-linking, pH of the solution,
and the molecular weight of PAA, finding consistent with values of transmittance between 3% and 99%. The structure was determined
by nuclear magnetic resonance spectroscopy, and the particle size was identified by dynamic light scattering (DLS) and transmission
electron microscopy (TEM) measurements. It was found that particle size depends on the pH, and at a given pH, it was caused
by the ratio of cross-linking and the molecular weight of PAA. Particle size measured by TEM varied in the range of 20 and
80 nm. In the swollen state, the average size of the particles measured by DLS was in the range of 35–160 nm. 相似文献
2.
ZHU ZhenFeng ZHAO XinYuan QIN Wei CHEN GuangDi QIAN Jun XU ZhengPing 《中国科学:化学(英文版)》2013,56(9):1247-1252
2,3-Bis(4-(phenyl(4-(1,2,2-triphenylvinyl)phenyl)amino)phenyl) fumaronitrile (TPE-TPA-FN or TTF), which possesses aggregation-induced emission (AIE) characteristic, is doped in organically modified silica (ORMOSIL) nanoparticles. By increasing the weight ratio of TTF to the precursor of silica nanoparticles (the quantities of the precursors were kept the same), the fluorescence intensity of nanoparticles increased correspondingly, due to the formation of larger AIE dots in the cores of ORMOSIL nanoparticles. The fluorescent and biocompatible nanoprobes were then utilized for in vitro imaging of HeLa cells. Two-photon fluorescence microscopy clearly illustrated that the nanoparticles have the capacity of nucleus permeability, as well as cytoplasm staining towards tumor cells. Our experimental results may offer a promising method for fast and bright fluorescence imaging, as well as bio-molecule/drug delivery to cell nucleus. 相似文献
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4.
Maghemite (gamma-Fe2O3) nanoparticles of 15 +/- 3 nm diameter were prepared by nucleation of gelatin/iron oxide followed by growth of gamma-Fe2O3 films onto these nuclei. The gamma-Fe2O3 nanoparticles were coated with polydivinylbenzene (PDVB) by emulsion polymerization of divinylbenzene (DVB) in an aqueous continuous phase containing the gamma-Fe2O3 nanoparticles. The PDVB-coated gamma-Fe2O3 nanoparticles, dispersed in water, were separated from homo-PDVB nanoparticles using the high gradient magnetic field (HGMF) technique. The influence of DVB concentration on the amount of PDVB coating, on the size and size distribution of the coated gamma-Fe2O3 nanoparticles and on their magnetic properties, has been investigated. Air-stable carbon-coated iron (alpha-Fe/C) crystalline nanoparticles of 41 +/- 12 nm diameter have been prepared by annealing the PDVB-coated gamma-Fe2O3 nanoparticles at 1050 degrees C in an inert atmosphere. These nanoparticles exhibit high saturation magnetization value (83 emu g(-1)) and excellent resistance to oxidation. Characterization of the PDVB-coated gamma-Fe2O3 and of the alpha-Fe/C nanoparticles has been accomplished by TEM, HRTEM, DLS, FTIR, XRD, thermal analysis, zeta-potential, and magnetic measurements. 相似文献
5.
Yan Zhang Qizhi Zhang Liusheng Zha Wuli Yang Changchun Wang Xinguo Jiang Shoukuan Fu 《Colloid and polymer science》2004,282(12):1323-1328
Pyrene-loaded biodegradable polymer nanoparticles were prepared by incorporating pyrene into the polymer nanoparticles formulated from amphiphilic diblock copolymer, methoxy poly(ethylene glycol)–poly(lactic acid) (MePEG–PLA). Their morphological structure and physical properties were characterized by nuclear magnetic resonance (NMR), dynamic light scattering, fluorescence spectroscopy, transmission electronic microscopy and zeta potential measurements. Further, MePEG–PLA nanoparticles containing pyrene as fluorescent marker were administered intranasally to rats, and the distribution of nanoparticles in the nasal mucosa and the olfactory bulb were visualized by fluorescence microscopy. NMR results confirmed that MePEG–PLA copolymer can form nanoparticles in water, and hydrophilic PEG chains were located on the surface of the nanoparticles. The particle size, zeta potential and pyrene loading efficiency of MePEG–PLA nanoparticles were dependent on the PLA block content in the copolymer. Following nasal administration, the absorption of nanoparticles across the epithelium was rapid, with fluorescence observed in the olfactory bulb at 5 min, and a higher level of fluorescence persisted in the olfactory mucosa than that in the respiratory mucosa. These results show that pyrene could serve as a useful fluorescence probe for incorporation into polymer nanoparticles to study tissue distribution and MePEG–PLA nanoparticles might have a great potential as carriers of hydrophobic drugs. 相似文献
6.
Georgi G. Yordanov Zorka A. Bedzhova Ceco D. Dushkin 《Colloid and polymer science》2010,288(8):893-899
The aim of the present study is the preparation and physicochemical characterization of chlorambucil-loaded poly(butylcyanoacrylate) nanoparticles. Chlorambucil is a lipophilic drug, which is used clinically against chronic lymphocytic leukemia, lymphomas, and other types of malignant diseases. However, the chlorambucil use is limited by its chemical instability and toxic side effects. A promising approach to circumvent these drawbacks is the entrapment of chlorambucil in a suitable nanosized carrier. Toward this goal, poly(butylcyanoacrylate) nanoparticles meet the requirements for a drug carrier system due to their biocompatibility, biodegradability, low toxicity, and ability to overcome the multidrug resistance in cancer cells. We prepared chlorambucil-loaded poly(butylcyanoacrylate) nanoparticles, which are characterized for chemical composition, particle size, drug content, and drug release. It is expected that the utilization of poly(butylcyanoacrylate) nanoparticles as a drug carrier system will pave the way toward more effective use of chlorambucil in the treatment of cancer. 相似文献
7.
Jingtian Han Patrick Silcock A. James McQuillan Phil Bremer 《Colloid and polymer science》2008,286(14-15):1605-1612
Block copolymers poly(styrene-alt-maleic anhydride)-b-polystyrene (P(St-alt-MAn)-b-PSt) were synthesized via radical addition fragmentation chain transfer copolymerization. The maleic anhydride-containing segments of the block copolymer were hydrolyzed to form amphiphilic poly(styrene-alt-maleic acid)-b-polystyrene (P(St-alt-MA)-b-PSt). In aqueous solution, P(St-alt-MA)73-b-PSt81 and P(St-alt-MA)58-b-PSt130 formed stable dispersed spherical aggregates of approximately 25 and 40 nm, respectively. Particle size was stable under alkaline conditions and was little affected by the polymer concentration in the range of 0.025–1.0 mg mL?1. The critical aggregation concentrations of the block copolymer self-aggregates were 1?×?10?3 and 3?×?10?3 mg mL?1 for hydrophobic PSt block lengths of 130 and 81 monomer units, respectively. The nanoparticles had a negative surface charge at pH?>?2. Scanning electron microscopy images revealed that particle–particle coalescence did not occur upon drying of the film and the nanoparticles remained discrete. Controlled aspirin release from the nanoparticles was dependent on the structure of the block polymers and release medium. 相似文献
8.
In the past decade, mesoporous silica nanoparticles (MSNs) as nanocarriers have showed much potential in advanced nanomaterials due to their large surface area and pore volume. Especially, more and more MSNs based nanodevices have been designed as efficient drug delivery systems (DDSs) or biosensors. In this paper, lipid, protein and poly(NIPAM) coated MSNs are reviewed from the preparation, properties and their potential application. We also introduce the preparative methods including physical adsorption, covalent binding and self-assembly on the MSNs' surfaces. Furthermore, the interaction between the aimed cells and these molecular modified MSNs is discussed. We also demonstrate their typical applications, such as photodynamic therapy, bioimaging, controlled release and selective recognition in biomedical field. 相似文献
9.
Tohru Ikegami Jun Ichimaru Wataru Kajiwara Nozomi Nagasawa Ken Hosoya Nobuo Tanaka 《Analytical sciences》2007,23(1):109-113
A novel method was developed for the preparation of highly efficient anion- and cation-exchange microHPLC columns using an on-column polymerization of methacrylates having amine or sulfonic acid functional groups onto monolithic silica capillary columns modified with 3-methacryloxypropyltriethoxysilane as the anchor groups. The chromatographic evaluation of the columns using nucleic acids, nucleotides, and inorganic anions as samples showed the characteristics of the ion-exchange-type stationary phases. These columns exhibited higher separation efficiency when compared with the conventional particle-packed columns. A capillary column for the simultaneous anion- and cation-exchange separation could be prepared by a step-by-step functionalization. The advantages of this column preparation will include: (1) no need of column packing; (2) no need of the preparation of silane reagents possessing anion- and cation-exchange functionalities; (3) the amount of immobilized polymer could be controlled by changing polymerization conditions. These columns should be suitable for the separation of biologically active compounds by the microHPLC modes. 相似文献
10.
The objective of this article is to fabricate poly(lactic acid) (PLA) and nano silica (SiO2) composites and investigate effect of SiO2 on the properties of PLA composites. Surface‐grafting modification was used in this study by grafting 3‐Glycidoxypropyltrimethoxysilane (KH‐560) onto the surface of silica nanoparticles. The surface‐grafting reaction was confirmed by Fourier transform infrared spectroscopy and thermogravimetric analysis. Then the hydrophilic silica nanoparticles became hydrophobic and dispersed homogeneously in PLA matrix. Scanning electron microscope and Dynamic thermomechanical analysis (DMA) results revealed that the compatibility between PLA and SiO2 was improved. Differential scanning calorimetry and polarized optical microscope tests showed that nano‐silica had a good effect on crystallization of PLA. The transparency analysis showed an increase in transparency of PLA, which had great benefit for the application of PLA. The thermal stability, fire resistance, and mechanical properties were also enhanced because of the addition of nano silica particles. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
11.
Narrowly distributed poly(N-vinyl caprolactam) obtained by the MADIX/RAFT process was used for the preparation of novel thermoresponsive gold nanoparticles presenting a sharp reversible response to temperature, which can be easily modulated near the physiological temperature by simply changing the polymer molecular weight or concentration. 相似文献
12.
Yamamoto S Fukui Y Kaihara S Fujimoto K 《Langmuir : the ACS journal of surfaces and colloids》2011,27(15):9576-9582
We created a free-standing membrane as a novel bioscaffold through the assembly of polymer-coated liposomes. Polyarginine (P(Arg)) possessing a cell-penetrating activity was used to form the polymer layer onto a negatively charged liposome (lipo-P(Arg)). The capsule wall of P(Arg) over liposomes made it possible to improve the mechanical property of capsules and to display deoxyribonucleic acid (DNA) over the vesicle surface through the electrostatic attraction (lipo-P(Arg)-DNA). The release rates of a fluorescent probe encapsulated in lipo-P(Arg) and lipo-P(Arg)-DNA were tunable by the number of polymeric layers of the capsule walls. To investigate the cell-membrane permeability of lipo-P(Arg)-DNA, polymer-coated liposomes were incubated with human umbilical vein endothelial cells (HUVECs) at 4 °C. It was found that lipo-P(Arg) underwent a significant cellular uptake, whereas bare liposomes and liposomes modified with chitosan were incapable of overcoming the plasma membrane barrier. To prepare a free-standing membrane composed of polymer-coated liposomes, a suspension of lipo-P(Arg)-DNA was cast over a mesh hole and dried up. SEM observation revealed that a free-standing membrane was obtained through drying-mediated assembly process without rupturing polymer-coated liposomes inside the membrane. On the other hand, it was not possible to obtain a complete membrane from a mixture of lipo-P(Arg) and DNA. In summary, lipo-P(Arg)-DNA capsules possess versatile functions as a drug carrier, and their assembly enables us to create a free-standing membrane applicable as a bioscaffold. 相似文献
13.
The preparation of stationary phases with enhanced chemical stability in alkaline eluents has been the principal objective of many chromatographers. New and improved silica substrates and advanced chemical modification methods are among the possibilities being investigated to reach this objective. The present work has evaluated these two possibilities for new stationary phases. First, the silica surface was modified by reaction with zirconium tetrabutoxide to produce zirconized silica particles having about 21% (w/w) of zirconium. Then poly(methyltetradecylsiloxane) (PMTDS) was immobilized onto this surface using different doses (50-120 kGy) of gamma radiation. These new phases were characterized using elemental analysis and infrared and solid-state (29)Si-nuclear magnetic resonance (NMR) spectroscopies. These new stationary phases presented column efficiencies of about 68,000 plates m(-1), symmetric peaks for apolar compounds and retention factors that depend on the irradiation dose and show improved stability in high pH mobile phases. The separation of several pharmaceuticals at pH 11 is presented. 相似文献
14.
Prathamesh P. Deshpande Meera Murali Pravin P. Deshpande Vidyanand S. Galphade Mahendra A. More 《Chemical Papers》2013,67(8):1066-1071
Conducting poly(o-anisidine) coatings were obtained on low carbon steel in aqueous oxalic acid solution by using the galvanostatic technique. The coatings were characterised by potential-time relations, UV-VIS absorption spectroscopy, scanning electron microscopy, and X-ray diffraction measurements. The electrochemical performance of coated steel electrodes was evaluated on the basis of galvanostatic charge-discharge performance and electrochemical impedance spectroscopy in 0.5 M H2SO4. Maximum charging current was found in the case of the coating obtained at a current density of 8 mA cm?2 for 600 s duration at the supply voltage of 0.5 V. The estimated capacitance of the coated steel electrode for charging is 42.67 mF and 7.2 mF for discharging. It was also found that there was an increase in capacitance as a function of supply voltage and the maximum value was obtained at 0.5 V. The study reveals the possibility of using conducting poly(o-anisidine)-coated low carbon steel from oxalic acid medium as supercapacitor electrode materials. 相似文献
15.
A temperature-responsive poly(N-isopropylacrylamide-co-N,N'-methylenebisacrylamide) [poly(NIPAAm-co-BIS)] monolith was prepared via a free-radical polymerization technique using an aqueous redox initiator in solution at -12°C. The effect of the % T (total monomer concentration/100 mL) and % C (cross-linker concentration/100 mL) on the visual form was investigated. The effect of the porogen on the pore structure was characterized by SEM. Under the optimum condition, the monolith for HPLC was successfully prepared and its mechanical strength and permeability have been studied. Furthermore, a temperature-dependent resolution of aromatic ketones was achieved using only water as mobile phase. The increasing interaction between solutes and the monolith was observed when temperature increased. The theoretical plate number of every analyte was more than 10(4). 相似文献
16.
Ga-Er Yu Prash Sinnathamby Tao Sun Frank Heatley Colin Price Colin Booth 《Macromolecular rapid communications》1997,18(12):1085-1093
Poly(propylene glycol) [α-hydro-ω-hydroxypoly(oxypropylene)] of number-average molar mass M̄n ≈ 2000 g · mol−1 (PPG2000) was cyclised with high conversion (ca. 75%) by reaction with dichloromethane in the presence of powdered KOH. The cyclic product was separated from chain extended polymer by preparative GPC, giving an overall yield of polymer (M̄n ≈ 2000 g · mol−1, narrow molar mass distribution) in excess of 50%. Characterisation by analytical GPC and 13C NMR spectroscopy confirmed cyclisation. DEPT and 1H-coupled NMR spectra were used to show that the links in cyclic poly(oxypropylene) were 77% single acetal, 12% double acetal and 11% triple acetal (or higher). This complexity probably results from competitive reaction with water introduced with KOH. 相似文献
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18.
Yuan JJ Armes SP Takabayashi Y Prassides K Leite CA Galembeck F Lewis AL 《Langmuir : the ACS journal of surfaces and colloids》2006,22(26):10989-10993
A well-defined, double-hydrophilic diblock copolymer comprising poly[2-(methacryloyloxy)ethyl phosphorylcholine]-block-(glycerol monomethacrylate) (PMPC30-PGMA30, where the numbers represent the average degrees of polymerization for each block) was evaluated for the synthesis of colloidally stable ultrafine magnetite sols. Sterically stabilized paramagnetic sols were prepared in aqueous solution by chemical coprecipitation of ferric and ferrous salts in the presence of this block copolymer. The PMPC30-PGMA30-stabilized magnetite sol had a mean transmission electron microscopy (TEM) diameter of 9.4 +/- 1.7 nm and a mean hydrodynamic diameter of 34 nm. This sol exhibited improved colloidal stability with respect to long-term storage and pH variation compared with magnetite sols prepared in the presence of alternative water-soluble homopolymers and diblock copolymers. Fourier transform infrared (FT-IR) spectroscopy, thermogravimetry, electron spectroscopy imaging (ESI), and zeta potential studies indicate that the PMPC30-PGMA30 diblock copolymer was adsorbed onto the surface of the sol via the PGMA30 block, with the PMPC30 chains acting as the stabilizing block. Such sterically stabilized sols are expected to be improved contrast agents for magnetic resonance imaging (MRI) applications. 相似文献
19.
Rui Wang Chao Zhang Weizhi Wang Tianxi Liu 《Journal of polymer science. Part A, Polymer chemistry》2010,48(21):4867-4874
Novel nanoparticles based on conjugated polymer with good fluorescent properties were synthesized by Suzuki coupling reaction using certain surfactants as one kind of special emulsion polymerization. The luminescent properties of the prepared nanoparticles could be controlled by selecting different monomers. Without using substances comprising any heavy metal element, these fluorescent nanoparticles show very good biocompatibility with cells, thus showing potential applications in cell biolabeling, drug delivery tracing, organic light‐emitting diodes, flat displays, and other areas. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010 相似文献
20.
Mardani Hanieh Izadi Mohammadreza Roghani-Mamaqani Hossein Salami-Kalajahi Mehdi 《Journal of Thermal Analysis and Calorimetry》2022,147(12):6679-6687
Journal of Thermal Analysis and Calorimetry - Polyurethane and novolac resins functionalized with epoxide groups were cured by a multifunctional crosslinking agent decorated with amine functional... 相似文献