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Iram Fozia Iqbal Mohammad S. Khan Irfan U. Rasheed Rashid Khalid Aqsa Khalid Muhammad Aftab Saira Shakoori Abdul R. 《Biological trace element research》2020,193(1):282-293
Biological Trace Element Research - Radioactive gold-198 is a useful diagnostic and therapeutic agent. Gold in the form of nanoparticles possesses even more exciting properties. This work aimed at... 相似文献
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As the fundamental understanding of metal–light interactions gains solid grounds, further research has been devoted to construct
novel structures that take full advantage of such unique interactions, which is called plasmonics. In this report, the preparation
of Au–Ag core–shell structures obtained by coating the Au surface with peptide and Raman reporter molecule and depositing
an Ag layer on it is reported. The prepared Au–Ag NPs are tested for their surface-enhanced Raman scattering (SERS) performance.
The negatively charged peptides with three different lengths, which are 3 (P1), 15 (P2), and 21 (P3) amino acid long, were
chemically attached to 13 nm AuNPs along with Raman reporter molecule, carboxytetramethylrhodamine, and these modified AuNPs
were coated with three different shell thickness of Ag metal. The prepared Au–Ag NPs were tested for their SERS performance
and found that the Au–Ag NPs prepared with P2 and thickest shell performs best as SERS label. 相似文献
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Herein we present an unusual phosphine-free method to fabricate water soluble CdSeS nanocrystals in cubic structure. In this method, glycerin was used as a stabilizing agent replacing tri-n-octylphosphine oxide (TOPO). Water solution of Na2SeO3 in polyethylene glycol was utilized as Se source. 3-Mercaptopropionic acid (MPA) provides S source. The phosphine-free Se and S sources were found to be highly reactive and suitable for the synthesis of CdSeS nanocrystals. XRD and HRTEM images confirm the formation of CdSeS nanocrystals in zinc blende structure. The absorption peaks on UV-vis spectra of as-prepared CdSeS nanocrystals are tunable from 330 nm to 440 nm, which blue shifts to shorter wavelength side in comparison with that of pure CdSe nanocrystals. The cubic CdSeS nanocrystals demonstrate narrow PL emissions spectra between 464 and 615 nm. Transmission electron microscopy images show the uniformity for the size distribution of the ternary QDs. Series water soluble CdSe1–xSx (x = 0∼1) nanocrystals have also been synthesized using Na2SeO3 and Na2S solution as the Se-S co-sources. Tunable band gap energies of CdSe1–xSx (x = 0∼1) nanocrystals upon chemical composition x have been achieved, the gap ranges from 290 nm to 558 nm. 相似文献
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Plasmonic nanoparticles are an attractive material for light harvesting applications due to their easily modified surface, high surface area and large extinction coefficients which can be tuned across the visible spectrum. Research into the plasmonic enhancement of optical transitions has become popular, due to the possibility of altering and in some cases improving photo-absorption or emission properties of nearby chromophores such as molecular dyes or quantum dots. The electric field of the plasmon can couple with the excitation dipole of a chromophore, perturbing the electronic states involved in the transition and leading to increased absorption and emission rates. These enhancements can also be negated at close distances by energy transfer mechanism, making the spatial arrangement of the two species critical. Ultimately, enhancement of light harvesting efficiency in plasmonic solar cells could lead to thinner and, therefore, lower cost devices. The development of hybrid core/shell particles could offer a solution to this issue. The addition of a dielectric spacer between a gold nanoparticles and a chromophore is the proposed method to control the exciton plasmon coupling strength and thereby balance losses with the plasmonic gains. A detailed procedure for the coating of gold nanoparticles with CdS and ZnS semiconductor shells is presented. The nanoparticles show high uniformity with size control in both the core gold particles and shell species allowing for a more accurate investigation into the plasmonic enhancement of external chromophores. 相似文献
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Antimicrobial action of nanomaterials is typically assigned to the nanomaterial composition, size and/or shape, whereas influence of complex corona stabilizing the nanoparticle surface is often neglected. We demonstrate sequential surface functionalization of tyrosine-reduced gold nanoparticles (AuNPsTyr) with polyoxometalates (POMs) and lysine to explore controlled chemical functionality-driven antimicrobial activity. Our investigations reveal that highly biocompatible gold nanoparticles can be tuned to be a strong antibacterial agent by fine-tuning their surface properties in a controllable manner. The observation from the antimicrobial studies on a gram negative bacterium Escherichia coli were further validated by investigating the anticancer properties of these step-wise surface-controlled materials against A549 human lung carcinoma cells, which showed a similar toxicity pattern. These studies highlight that the nanomaterial toxicity and biological applicability are strongly governed by their surface corona. 相似文献
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Wen‐Yao Kong Xiao‐Feng Chen Jing Shi Shahla Karim Baloch Jin‐Liang Qi Hai‐Liang Zhu Xiao‐Ming Wang Yong‐Hua Yang 《Chirality》2013,25(11):757-762
A series of shikonin derivatives, selectively acylated by various fluorinated carboxylic acids at the side chain of shikonin, were synthesized and their anticancer activity evaluated, in which eight compounds are reported for the first time. Among all the compounds tested, compound S7 showed the most potent anticancer activity against B16‐F10 (malignant melanoma cells), MG63 (human osteosarcoma cells), and A549 (lung cancer cells) with IC50 0.39 ± 0.01, 0.72 ± 0.04 and 0.58 ± 0.02 µmol/L. Docking simulation of compound S7 was carried out to position S7 into a tubulin active site to determine the probable binding conformation. All the results suggested that compound S7 may be a potential anticancer agent. Chirality 25:757–762, 2013. © 2013 Wiley Periodicals, Inc. 相似文献
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Kirtee D. Wani Brijesh S. Kadu Prakash Mansara Preeti Gupta Avinash V. Deore Rajeev C. Chikate Pankaj Poddar Sanjay D. Dhole Ruchika Kaul-Ghanekar 《PloS one》2014,9(9)
Cinnamaldehyde, the bioactive component of the spice cinnamon, and its derivatives have been shown to possess anti-cancer activity against various cancer cell lines. However, its hydrophobic nature invites attention for efficient drug delivery systems that would enhance the bioavailability of cinnamaldehyde without affecting its bioactivity. Here, we report the synthesis of stable aqueous suspension of cinnamaldehyde tagged Fe3O4 nanoparticles capped with glycine and pluronic polymer (CPGF NPs) for their potential application in drug delivery and hyperthermia in breast cancer. The monodispersed superparamagnetic NPs had an average particulate size of ∼20 nm. TGA data revealed the drug payload of ∼18%. Compared to the free cinnamaldehyde, CPGF NPs reduced the viability of breast cancer cell lines, MCF7 and MDAMB231, at lower doses of cinnamaldehyde suggesting its increased bioavailability and in turn its therapeutic efficacy in the cells. Interestingly, the NPs were non-toxic to the non-cancerous HEK293 and MCF10A cell lines compared to the free cinnamaldehyde. The novelty of CPGF nanoparticulate system was that it could induce cytotoxicity in both ER/PR positive/Her2 negative (MCF7) and ER/PR negative/Her2 negative (MDAMB231) breast cancer cells, the latter being insensitive to most of the chemotherapeutic drugs. The NPs decreased the growth of the breast cancer cells in a dose-dependent manner and altered their migration through reduction in MMP-2 expression. CPGF NPs also decreased the expression of VEGF, an important oncomarker of tumor angiogenesis. They induced apoptosis in breast cancer cells through loss of mitochondrial membrane potential and activation of caspase-3. Interestingly, upon exposure to the radiofrequency waves, the NPs heated up to 41.6°C within 1 min, suggesting their promise as a magnetic hyperthermia agent. All these findings indicate that CPGF NPs prove to be potential nano-chemotherapeutic agents in breast cancer. 相似文献
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Berenjian Atefeh Sharifi Seyed Davood Mohammadi-Sangcheshmeh Abdollah Ghazanfari Shokoufe 《Biological trace element research》2018,184(2):474-481
Biological Trace Element Research - Chromium (Cr), as an essential trace element, plays a critical role in carbohydrate, protein, and lipid metabolism in animals. It has been suggested that the... 相似文献
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V Tessitore A Cardinale M Buscemi A Gerbino A Pasqualino 《Bollettino della Società italiana di biologia sperimentale》1979,55(3):219-223
The histochemical behaviour of succinic dehydrogenase, isocitric dehydrogenase, acid phosphatase and acetylglucosaminidase activities was studied in rat liver treated with Au198-colloidal. In these experimental conditions it was found that the hepatocytes present changes in the enzymatic activities examined, generally proportional to the doses employed. With lower doses of radionuclides, the histoenzymatic changes have a local character and are completely reversible after a month. With higher doses they take on a more extensive character. These findings suggest that Au198 could be used clinically with due precautions. 相似文献
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R. Singhal D. Kabiraj P. K. Kulriya J. C. Pivin R. Chandra D. K. Avasthi 《Plasmonics (Norwell, Mass.)》2013,8(2):295-305
Thin films of carbon-containing Au nanoparticles (NPs), prepared by the co-sputtering using a neutral Ar atom beam, were irradiated by 120 MeV Ag ions and also annealed, separately, at increasing temperatures in inert atmosphere. The surface plasmon resonance (SPR) band of the nanocomposite film was observed to be blue shifted (~50 nm) in both cases, with increasing fluence and temperature. The structural changes of Au NPs embedded in amorphous carbon matrix were investigated using X-ray diffraction and transmission electron microscopy. A growth of Au NPs was observed with increasing fluence and also with increasing temperature. A percolation of Au NPs was observed at 500 °C. A growth of Au NPs with ion irradiation is explained in the framework of a thermal spike model. Raman spectroscopy revealed the ordering of a-C thin films with increasing fluence and temperature, which is ascribed to a change of refractive index and the blue shift of the SPR band. 相似文献
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Lászió Puskás József Czombos Sándor Bottka 《Nucleosides, nucleotides & nucleic acids》2013,32(3-5):967-968
Abstract Phosphoramidite derivative of 1,4-diamino antraquinone was synthesized, characterized, and incorporated into oligonucleotides. Intercalative interaction between the dye and the nucleic acid was confirmed by CD spectroscopy. 相似文献
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Plasmonics - In the last two decades, plasmonic resonance in metallic nanoparticles (Au, Ag NPs) has created intensive research efforts in nanoscale optics, photonics and sensors. When light... 相似文献
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Chen Xiaojuan Wen Rui Zhang Lisheng Lahiri Abhishek Wang Peijie Fang Yan 《Plasmonics (Norwell, Mass.)》2014,9(4):945-949
In this paper, we highlight the formation of Ag/Au core-shell nanoparticles at room temperature by using a low-power laser. We have investigated the plasmon-induced reduction of Ag+ ions on bare Au nanoparticles synthesized by laser ablation technique, and citrate-capped Au nanoparticles synthesized by chemical method. It is demonstrated that citrate plays an important role for the reduction of silver ions. The citrate gets oxidized by the ‘hot’ holes produced due to the surface plasmon resonance (SPR) of the Au nanoparticles which then reduces the Ag+ ions to Ag. The importance of excitation laser wavelength is also demonstrated to facilitate the reduction process.
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P. A. Kotelnikova V. O. Shipunova U. F. Aghayeva O. A. Stremovskiy M. P. Nikitin I. A. Novikov A. A. Schulga S. M. Deyev R. V. Petrov 《Doklady. Biochemistry and biophysics》2018,481(1):198-200
A new method for obtaining biomodified magnetite nanoparticles for targeted delivery to cells was developed. The method is based on the use of the C-terminal fragment of the Mms6 protein, which is involved in the magnetite biomineralization during the synthesis of magnetosomes in magnetotactic bacteria Magnetospirillum magneticum AMB-1, and the barnase*barstar high-affinity protein pair. The Mms6 protein fragment is required for stabilizing magnetite, and the barnase*barstar pair mediates the interaction between nanoparticles and the component for modification. The efficiency of this method was confirmed in the synthesis of magnetite nanoparticles recognizing the HER2/neu tumor marker and in the selective labeling of HER2/neu with these nanoparticles on the surface of cancer cells. 相似文献