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Nan Jiang, Guo-Liang Ying, Ali K Yetisen, Yunuen Montelongo, Ling Shen, Yu-Xuan Xiao, Henk J Busscher, Xiao-Yu Yang, Bao-Lian Su
Single cell surface engineering provides the most efficient, non-genetic strategy to enhance cell stability. However, it remains a huge challenge to improve cell stability in complex artificial environments. Here, a soft biohybrid interfacial layer is fabricated on individual living-cell surfaces by their exposure to a suspension of gold nanoparticles and l-cysteine to form a protecting functional layer to which porous silica layers were bound yielding pores with a diameter of 3.9 nm. The living cells within the bilayered nanoshells maintained high viability (96 ± 2%) as demonstrated by agar plating, even after five cycles of simultaneous exposure to high temperature (40 °C), lyticase and UV light...
June 7, 2018: Chemical Science
Jianxiong Li, Erfan Saydanzad, Uwe Thumm
We propose a scheme for the reconstruction of plasmonic near fields at isolated nanoparticles from infrared-streaked extreme-ultraviolet photoemission spectra. Based on quantum-mechanically modeled spectra, we demonstrate and analyze the accurate imaging of the IR-streaking-pulse-induced transient plasmonic fields at the surface of gold nanospheres and nanoshells with subfemtosecond temporal and subnanometer spatial resolution.
June 1, 2018: Physical Review Letters
Seounghun Kang, Woojun Shin, Myung-Ho Choi, Minchul Ahn, Young-Kwan Kim, Seongchan Kim, Dal-Hee Min, Hongje Jang
Rhodium nanoparticles are promising transition metal nanocatalysts for electrochemical and synthetic organic chemistry applications. However, notwithstanding their potential, to date, Rh nanoparticles have not been utilized for biological applications; there has been no cytotoxicity study of Rh reported in literature. In this regard, the absence of a facile and controllable synthetic strategy of Rh nanostructures with various sizes and morphologies might be responsible for the lack of progress in this field...
June 14, 2018: ACS Nano
Guoqing Sheng, Jiahui Chen, Yunming Li, Huangqing Ye, Zhixiong Hu, Xian-Zhu Fu, Rong Sun, Weixin Huang, Ching-Ping Wong
Flower-like NiCo2S4 hollow sub-microspheres are synthesized through Cu2O templates to support Pd nanoparticles as high-efficiency catalysts for HER. The diameter and shells size of NiCo2S4 hollow sub-microspheres are about 400 nm and 16 nm, respectively. In addition, the surface of shells is constructed by petal-like nanosheets. About 3 nm Pd particles uniformly incorporate with the flower-like NiCo2S4 hollow sub-microsphere to form NiCo2S4/Pd heterostructure. The NiCo2S4/Pd catalysts exhibit significantly lower overpotential of only 87 mV and 83 mV at 10 mA/cm2 for HER in both acidic and alkaline conditions, respectively, relative to NiCo2S4 (247 mV, 226 mV) and Pd (175 mV, 385mV) catalysts...
June 14, 2018: ACS Applied Materials & Interfaces
Rohit Kumar Nair, Catherine Christie, David Ju, Diane Shin, Aftin Pomeroy, Kristian Berg, Qian Peng, Henry Hirschberg
Light-based treatment modalities such as photothermal therapy (PTT) or photochemical internalization (PCI) have been well documented both experimentally and clinically to enhance the efficacy of chemotherapy. The main purpose of this study was to examine the cytotoxic effects of silica-gold nanoshell (AuNS)-loaded macrophage-mediated (MaNS ) PTT and bleomycin BLM-PCI on monolayers of squamous cell carcinoma cells. The two modalities were applied separately and in simultaneous combination. Two different wavelengths of light were employed simultaneously, one to activate a highly efficient PCI photosensitizer, AlPcS2 a (670 nm) and the other for the MaNS -mediated PTT (810 nm), to evaluate the combined effects of these modalities...
May 26, 2018: Lasers in Medical Science
Stefano Danesi, Marco Gandolfi, Luca Carletti, Nicolò Bontempi, Costantino De Angelis, Francesco Banfi, Ivano Alessandri
Light-to-heat conversion in non-plasmonic, high refractive index nanoantennas is a key topic for many applications, including Raman sensing, laser writing, nanofabrication and photo-thermal therapy. However, heat generation and propagation in non-plasmonic antennas is increasingly debated and contradictory results have been reported so far. Here we report a finite element analysis of the steady-state temperature distribution and heat flow in SiO2/Si core/shell systems (silicon nanoshells) irradiated with different continuous wave lasers (λ = 532, 633 and 785 nm), under real working conditions...
June 6, 2018: Physical Chemistry Chemical Physics: PCCP
Mario D'Acunto
Photothermal therapy (PTT) takes advantage of unique properties of gold nanoparticles (AuNPs) (nanospheres, nanoshells (AuNSs), nanorods (AuNRs)) to destroy cancer cells or tumor tissues. This is made possible thanks principally to both to the so-called near-infrared biological transparency window, characterized by wavelengths falling in the range 700⁻1100 nm, where light has its maximum depth of penetration in tissue, and to the efficiency of cellular uptake mechanisms of AuNPs. Consequently, the possible identification of intracellular AuNPs plays a key role for estimating the effectiveness of PTT treatments...
May 24, 2018: Materials
Mahi R Singh
In this chapter, we explain why metallic nanomaterials are used in nanomedicine. We have shown that the electron density in metallic nanomaterials oscillates and creates electron density waves. When laser light falls on metallic nanoparticles, light interacts with electron density waves. According to Einstein, light, which is electromagnetic waves, consists of particles called photons. Similarly, electron density waves are also made of particles called surface plasmons. Therefore, photons from laser light and surface plasmons from metallic nanostructures interact with each other and create new particles called surface plasmon polaritons...
2018: Advances in Experimental Medicine and Biology
Felix Sigmund, Christoph Massner, Philipp Erdmann, Anja Stelzl, Hannes Rolbieski, Mitul Desai, Sarah Bricault, Tobias P Wörner, Joost Snijder, Arie Geerlof, Helmut Fuchs, Martin Hrabĕ de Angelis, Albert J R Heck, Alan Jasanoff, Vasilis Ntziachristos, Jürgen Plitzko, Gil G Westmeyer
We genetically controlled compartmentalization in eukaryotic cells by heterologous expression of bacterial encapsulin shell and cargo proteins to engineer enclosed enzymatic reactions and size-constrained metal biomineralization. The shell protein (EncA) from Myxococcus xanthus auto-assembles into nanocompartments inside mammalian cells to which sets of native (EncB,C,D) and engineered cargo proteins self-target enabling localized bimolecular fluorescence and enzyme complementation. Encapsulation of the enzyme tyrosinase leads to the confinement of toxic melanin production for robust detection via multispectral optoacoustic tomography (MSOT)...
May 18, 2018: Nature Communications
Siwen Li, Yuxi Liu, Yalan Rui, Liping Tang, Samuel Achilefu, Yueqing Gu
Although EML4-ALK transforming fusion gene is represented in only 8% of non-small cell lung cancer (NSCLC) cases, its expression is partly responsive for the failure of current NSCLC treatments. Preventing secondary mutation of the ALK protein through direct gene manipulation could overcome NSCLC drug resistance. Method: In this study, we developed a gold nanoshell (HAuNs) drug carrier for delivery and selective photo-thermal release of genes that target ALK and microRNA-301 in NSCLC. Additionally, the densely-coated nanoshell adsorbed high amounts of the positively-charged anticancer drug doxorubicin (DOX), generating an exciting multidimensional treatment strategy that includes gene-, thermal- and chemo- therapy...
2018: Theranostics
Jie Sun, Shuyan Han, Ying Wang, Guanyu Zhao, Weiping Qian, Jian Dong
To detect the redox state evolution during wound healing process, a redox-sensitive surface-enhanced Raman scattering (SERS) probe was constructed by attaching anthraquinone as a redox-sensitive molecule onto gold nanoshells, and the redox-sensitive SERS probes were loaded on one surface of a chitosan membrane as a redox-sensitive wound dressing. The redox-sensitive wound dressing covered an acute wound as both a wound dressing and a redox state sensor. The spatiotemporal evolution of the redox states of the healing wound was obtained by collecting the SERS spectra of the SERS probes in situ and noninvasively...
May 14, 2018: Analytical Chemistry
Jun-Yu Piao, Shu-Yi Duan, Xi-Jie Lin, Xian-Sen Tao, Yan-Song Xu, An-Min Cao, Li-Jun Wan
A surface doping strategy is demonstrated for the stabilization of LiMn2O4, which is achieved by the surface solid reaction between the LiMn2O4 particle and its ZnO nanoshell. The surface treated sample shows a much improved high temperature performance with evidently suppressed Mn dissolution.
May 8, 2018: Chemical Communications: Chem Comm
Akbar Samadi, Henrik Klingberg, Liselotte Jauffred, Andreas Kjær, Poul Martin Bendix, Lene B Oddershede
Absorption of near infrared (NIR) light by metallic nanoparticles can cause extreme heating and is of interest for instance in cancer treatment since NIR light has a relatively large penetration depth into biological tissue. Here, we quantify the extraordinary thermoplasmonic properties of platinum nanoparticles and demonstrate their efficiency in photothermal cancer therapy. Although platinum nanoparticles are extensively used for catalysis, they are much overlooked in a biological context. Via direct measurements based on a biological matrix we show that individual irradiated platinum nanoparticles with diameters of 50-70 nm can easily reach surface temperatures up to 900 K...
May 17, 2018: Nanoscale
Emese Lantos, Nirmali Prabha Das, Dániel Simon Berkesi, Dorina Dobó, Ákos Kukovecz, Dezső Horváth, Ágota Tóth
Amino-functionalized inorganic silica nanoshells with a diameter of 511 ± 57 nm are efficiently used as hydrogen ion binders with a base dissociation constant of (1.2 ± 0.1) × 10-4. The hydrogen removal has been shown to produce reaction-diffusion fronts of constant propagation velocity in the autocatalytic chlorite-tetrathionate reaction when it is run in thin planar slices of nanoshell-containing agarose gel to exclude all convection related effects. By controlling the exact amount of amino-functionalized hollow nanospheres in the gel matrix it is possible to finely tune the propagation velocity of the chemical front in the 0...
May 16, 2018: Physical Chemistry Chemical Physics: PCCP
Rachel S Riley, Megan N Dang, Margaret M Billingsley, Baxter Abraham, Lars Gundlach, Emily S Day
The ability to regulate intracellular gene expression with exogenous nucleic acids such as small interfering RNAs (siRNAs) has substantial potential to improve the study and treatment of disease. However, most transfection agents and nanoparticle-based carriers that are used for the intracellular delivery of nucleic acids cannot distinguish between diseased and healthy cells, which may cause them to yield unintended widespread gene regulation. An ideal delivery system would only silence targeted proteins in diseased tissue in response to an external stimulus...
June 13, 2018: Nano Letters
Chan Ho Chung, Joong Hyun Kim
We developed a one-step isothermal method for typing multiple KRAS mutations using a designed set of primers to form a hairpin on a gold nanoshell upon being ligated by a SNP specific DNA ligase after binding of targets. As a result, we could detect as low as 20 attomoles of KRAS mutations within 1 h.
April 24, 2018: Analyst
Jian Zhu, Zai-Jie Xu, Guo-Jun Weng, Jing Zhao, Jian-Jun Li, Jun-Wu Zhao
In this report, Ag-dielectric-Au three-layered nanoshells with controlled inner core size were synthesized. The fluorescence emission of the rhodamine 6G (R6G) could be quenched by the three-layered nanoshells distinctly. What's more, the fluorescence quenching efficiency could be further improved by tuning the etching of inner Ag nanosphere. The maximum fluorescence quenching efficiency is obtained when the separate layer just appears between the inner Ag core and the outer Au shell. Whereas the fluorescence quenching efficiency is weakened when no gaps take place around the inner Ag core or the separate layer is too thick and greater than 13nm...
July 5, 2018: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Alexander Parobek, Jacob W Black, Maria Kamenetska, Ziad Ganim
Measuring absorption spectra of single molecules presents a fundamental challenge for standard transmission-based instruments because of the inherently low signal relative to the large background of the excitation source. Here we demonstrate a new approach for performing absorption spectroscopy in solution using a force measurement to read out optical excitation at the nanoscale. The photoinduced force between model chromophores and an optically trapped gold nanoshell has been measured in water at room temperature...
April 14, 2018: Journal of Chemical Physics
Linyu Hu, Chunlong Dai, Jin-Myoung Lim, Yuming Chen, Xin Lian, Minqiang Wang, Yi Li, Penghao Xiao, Graeme Henkelman, Maowen Xu
Li-S batteries have attracted enormous interest due to their potentially high energy density, non-toxicity and the low cost of sulfur. The main challenges of sulfur cathodes are the short cycling life and limited power density caused by the low conductivity of sulfur and dissolution of Li polysulfides. Here we design a new double-hierarchical sulfur host to address these problems. Hierarchical carbon spheres (HCSs), constructed from building blocks of hollow carbon nanobubbles for loading sulfur, are sealed within a thin, polar MoS2 coating composed of ultrathin nanosheets...
January 21, 2018: Chemical Science
Corinne J Hofer, Robert N Grass, Elia M Schneider, Lyndsey Hendriks, Antoine F Herzog, Martin Zeltner, Detlef Günther, Wendelin J Stark
Selective dealloying of metal nanoparticles results in rattle-type hollow carbon nanoshells enclosing platinum nanoparticles, which are able to perform size-selective catalysis. Selective functionalization of the outer graphene-like carbon surface prevents agglomeration and leads to well dispersible nanocatalysts in aqueous solutions. The synthesis starts with the production of nanoparticles with a cobalt-platinum-alloy core surrounded by graphene-like carbon via reducing flame spray synthesis. After surface functionalization, simultaneous pore formation in the shell-wall and dissolution of the cobalt results in platinum encapsulated in hollow carbon nanospheres...
January 14, 2018: Chemical Science
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