947150-46-1Relevant articles and documents
Calix[4]arene-Functionalised Silver Nanoparticles as Hosts for Pyridinium-Loaded Gold Nanoparticles as Guests
Vita, Francesco,Boccia, Alice,Marrani, Andrea G.,Zanoni, Robertino,Rossi, Francesca,Arduini, Arturo,Secchi, Andrea
, p. 15428 - 15438 (2015)
A series of lipophilic gold nanoparticles (AuNPs) circa 5 nm in diameter and having a mixed organic layer consisting of 1-dodecanethiol and 1-(11-mercaptoundecyl) pyridinium bromide was synthesised by reacting tetraoctylammonium bromide stabilised AuNPs in toluene with different mixtures of the two thiolate ligands. A bidentate ω-alkylthiolate calix[4]arene derivative was instead used as a functional protecting layer on AgNPs of approximately 3 nm. The functionalised nanoparticles were characterised by transmission electron microscopy (TEM), and by UV/Vis and X-ray photoelectron spectroscopy (XPS). Recognition of the pyridinium moieties loaded on the AuNPs by the calix[4]arene units immobilised on the AgNPs was demonstrated in solution of weakly polar solvents by UV/Vis titrations and DLS measurements. The extent of Au-AgNPs aggregation, shown through the low-energy shift of their surface plasmon bands (SPB), was strongly dependent on the loading of the pyridinium moieties present in the organic layer of the AuNPs. Extensive aggregation between dodecanethiol-capped AuNPs and the Ag calix[4]arene-functionalised NPs was also promoted by the action of a simple N-octyl pyridinium difunctional supramolecular linker. This linker can interdigitate through its long fatty tail in the organic layer of the dodecanethiol-capped AuNPs, and simultaneously interact through its pyridinium moiety with the calix[4]arene units at the surface of the modified AgNPs.
Effect of Chemical Binding of Doxorubicin Hydrochloride to Gold Nanoparticles, Versus Electrostatic Adsorption, on the In Vitro Drug Release and Cytotoxicity to Breast Cancer Cells
Zayed, Gamal M.,Kamal, Islam,Abdelhafez, Wael A.,M. Alsharif, Fahd,Amin, Mohamed A.,Shaykoon, Montaser Sh. A.,Sarhan, Hatem A.,Abdelsalam, Ahmed M.
, (2018)
Purpose: The selective delivery of chemotherapeutic agent to the affected area is mainly dependent on the mode of drug loading within the delivery system. This study aims to compare the physical method to the chemical method on the efficiency of loading DOX.HCl to GNPs and the specific release of the loaded drug at certain tissue. Method: Bifunctional polyethylene glycol with two different functionalities, the alkanethiol and the carboxyl group terminals, was synthesized. Then, DOX·HCl was covalently linked via hydrazone bond, a pH sensitive bond, to the carboxyl functional group and the produced polymer was used to prepare drug functionalized nanoparticles. Another group of GNPs was coated with carboxyl containing polymer; loading the drug into this system by the means of electrostatic adsorption. Finally, the prepared system were characterized with respect to size, shape and drug release in acetate buffer pH?5 and PBS pH?7.4 Also, the effect of DOX.HCl loaded systems on cell viability was assessed using MCF-7 breast cancer cell line. Results: The prepared nanoparticles were spherical in shape, small in size and monodisperse. The release rate of the chemically bound drug in the acidic pH was higher than the electrostatically adsorbed one. Moreover, both systems show little release at pH?7.4. Finally, cytotoxicity profiles against human breast adenocarcinoma cell line (MCF-7) exhibited greater cytotoxicity of the chemically bound drug over the electrostatically adsorbed one. Conclusion: Chemical binding of DOX·HCl to the carboxyl group of PEG coating GNPs selectively delivers high amount of drug to tumour-affected tissue which leads to reducing the unwanted effects of the drug in the non-affected ones.
Redox-active organic-inorganic hybrid polyoxometalate micelles
Kastner, Katharina,Kibler, Alexander J.,Karjalainen, Erno,Fernandes, Jesum A.,Sans, Victor,Newton, Graham N.
, p. 11577 - 11581 (2017)
A redox-active hybrid organic-inorganic polyoxometalate surfactant showed solvent-dependent self-assembly to form nano-scale architectures. The supramolecular assemblies exhibited contrasting electronic structure and redox activity to their molecular building units, and were found to be stable under electrochemical reduction and re-oxidation.
Redox-Active Hybrid Polyoxometalate-Stabilised Gold Nanoparticles
Alves Fernandes, Jesum,Cameron, Jamie M.,Gibson, Emma K.,Hampson, Elizabeth,Kastner, Katharina,Martin, Carmen,Newton, Graham N.,Sans, Victor,Walsh, Darren A.
, (2020)
We report the design and preparation of multifunctional hybrid nanomaterials through the stabilization of gold nanoparticles with thiol-functionalised hybrid organic–inorganic polyoxometalates (POMs). The covalent attachment of the hybrid POM forms new na
POSITIVELY CHARGED NANOPARTICLES, USE THEREOF, AND PREPARATION METHOD THEREOF
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Paragraph 0069-0070; 0075, (2021/05/07)
Provided are positively charged nanoparticles and use thereof. According to the nanoparticles of an aspect, cucurbituril may limit electrostatic attraction between a guest for cucurbituril and a metal salt, thereby generating nanoparticles with a uniform size. Accordingly, the nanoparticles may have an effect of being capable of efficient intracellular gene delivery.
“Precipitation on Nanoparticles”: Attractive Intermolecular Interactions Stabilize Specific Ligand Ratios on the Surfaces of Nanoparticles
Chu, Zonglin,Han, Yanxiao,Král, Petr,Klajn, Rafal
supporting information, p. 7023 - 7027 (2018/06/15)
Confining organic molecules to the surfaces of inorganic nanoparticles can induce intermolecular interactions between them, which can affect the composition of the mixed self-assembled monolayers obtained by co-adsorption from solution of two different molecules. Two thiolated ligands (a dialkylviologen and a zwitterionic sulfobetaine) that can interact with each other electrostatically were coadsorbed onto gold nanoparticles. The nanoparticles favor a narrow range of ratios of these two molecules that is largely independent of the molar ratio in solution. Changing the solution molar ratio of the two ligands by a factor of 5 000 affects the on-nanoparticle ratio of these ligands by only threefold. This behavior is reminiscent of the formation of insoluble inorganic salts (such as AgCl), which similarly compensate positive and negative charges upon crystallizing. Our results pave the way towards developing well-defined hybrid organic–inorganic nanostructures.
Synthesis and co-assembly of gold nanoparticles functionalized by a pyrene-thiol derivative
Mi, Yongsheng,Liang, Pengxia,Yang, Zhou,Wang, Dong,He, Wanli,Cao, Hui,Yang, Huai
, p. 140 - 145 (2015/02/05)
We successfully synthesized a series of gold nanoparticles capped with 11-(4-(pyren-1-yl)phenoxy)undecane-1-thiol (A-SH) and with 1-dodecanethiol. The homodispersed gold nanoparticles were fully verified by TEM, UV-Vis and PL spectroscopy. TEM images of the nanoparticles showed similar particle sizes at approximately 2.5 nm also evidenced by the absorption spectra. By solvent-exchange co-self-assembly of a pyrene derivative composited with these functionalized nanoparticles, the different arrangements of Au nanoparticles were observed. Compared to Au nanoparticles functionalized by 1-dodecanethiol (GNP), the pyrene-thiol-capped gold nanoparticles (GNP-A) showed better dispersity in the pyrene derivative matrix because of their π-π interactions. This journal is
Microwave-Assisted Catalytic Acetylation of Alcohols by Gold-Nanoparticle-Supported Gadolinium Complex
Chang, Tsao-Ching,Yu, Shuchun Joyce
supporting information, p. 661 - 672 (2015/10/29)
A gold nanoparticle (AuNP)-supported gadolinium complex (RS-Au-L-Gd) catalyst was prepared through simple chelation of GdCl3 to the surface-bound spacer, 1,4,7-tris(carboxymethyl)-10-(11-mercaptoundecyl)-1,4,7,10-tetraazacyclododecane (HSDO3A). This AuNP-supported Gd complex was found to be a highly effective catalyst for the acetylation of various alcohols and phenol in the presence of acetic anhydride. With a loading of 0.4 mol% of RS-Au-L-Gd, the almost complete transformation can be achieved in 60 s under microwave irradiation conditions. This hybrid catalyst was air stable, water soluble, dissolvable in many organic media, and precipitable. It can be readily recycled more than eight times without any significant loss of its catalytic activity. GRAPHICAL ABSTRACT.
"Click" synthesis of thermally stable au nanoparticles with highly grafted polymer shell and control of their behavior in polymer matrix
Lim, Jongmin,Yang, Hyunseung,Paek, Kwanyeol,Cho, Chul-Hee,Kim, Seyong,Bang, Joona,Kim, Bumjoon J.
experimental part, p. 3464 - 3474 (2012/05/19)
Thermally stable core-shell gold nanoparticles (Au NPs) with highly grafted polymer shells were synthesized by combining reversible addition-fragmentation transfer (RAFT) polymerization and click chemistry of copper-catalyzed azide-alkyne cycloaddition (CuAAC). First, alkyne-terminated poly(4-benzylchloride-b-styrene) (alkyne-PSCl-b-PS) was prepared from the alkyne-terminated RAFT agent. Then, an alkyne-PSCl-b-PS chain was coupled to azide-functionalized Au NPs via the CuAAC reaction. Careful characterization using FT-IR, UV-Vis, and TGA showed that PSCl-b-PS chains were successfully grafted onto the Au NP surface with high grafting density. Finally, azide groups were introduced to PSCl-b-PS chains on the Au NP surface to produce thermally stable Au NPs with crosslinkable polymer shell (Au-PSN3-b-PS 1). As the control sample, PS-b-PSN3-coated Au NPs (Au-PSN3-b-PS 2) were made by the conventional "grafting to" approach. The grafting density of polymer chains on Au-PSN3-b-PS 1 was found to be much higher than that on Au-PSN3-b-PS 2. To demonstrate the importance of having the highly packed polymer shell on the nanoparticles, Au-PSN 3-b-PS 1 particles were added into the PS and PS-b-poly(2- vinylpyridine) matrix, respectively. Consequently, it was found that Au-PSN 3-b-PS 1 nanoparticles were well dispersed in the PS matrix and PS-b-P2VP matrix without any aggregation even after annealing at 220 °C for 2 days. Our simple and powerful approach could be easily extended to design other core-shell inorganic nanoparticles.
Immobilized aza-bis(oxazoline) copper catalysts on alkanethiol self-assembled monolayers on gold: Selectivity dependence on surface electronic environments
Paluti, Christy C.,Gawalt, Ellen S.
experimental part, p. 149 - 157 (2011/03/01)
Aza-bis(oxazoline) copper complexes have been immobilized onto alkanethiol self-assembled monolayers on gold utilizing five background tail groups with different electronic characteristics. The catalyst was tested in the standard cyclopropanation reaction of ethyl diazoacetate and styrene. The five different tail groups were hydroxyl, bromine, carboxylic acid, ester, and nitrile. Enantioselectivity improved to 95% when the surrounding tail groups were hydroxyl- and bromine-terminated surfaces. The carboxylic acid and ester tail groups reduced the enantioselectivity compared to the homogeneous phase. Additionally, the homogeneous cyclopropanation reaction was performed in methanol, acetonitrile, ethyl acetate, and acetic acid to determine whether similar trends in selectivity could be obtained by varying the homogenous electronic environment. However, the cyclopropanation reaction in these solvents gave greatly reduced selectivity and yield of the cyclopropane products demonstrating the positive aspects of immobilization of self-assembled monolayer supports.
