Publications/Patents

2012
Frusic-Zlotkin M, Soroka Y, Tivony R, Larush L, Verkhovsky L, Bregegere FM, Neuman R, Magdassi S, Milner Y. Penetration and biological effects of topically applied cyclosporin A nanoparticles in a human skin organ culture inflammatory model. [Internet]. 2012;21 (12) :938 - 943. Publisher's VersionAbstract

Systemic antipsoriatic therapies have potentially life-threatening, long-term side effects. The efficacy of topical drugs is poor, but may be improved by the use of delivery systems based on drug nanoparticles. To produce nanoparticles (NP) composed of cyclosporin A, a classical antipsoriatic drug, and to investigate their penetration and biological effects in human skin affected by psoriatic symptoms, poly-e-caprolactone (PCL) and cyclosporin A (CsA) NP were prepared by the solvent evaporation method. Skin penetration was followed using fluorescently labeled NP in human skin organ cultures (hSOC). Psoriatic symptoms were mimicked in hSOC by the treatment with epidermal growth factor (EGF) and bacterial lipopolysaccharide (LPS). Cell viability in hSOC was evaluated by the resazurin test, and cytokine secretion into the growth medium was measured by immunodetection. We showed that topically applied NP diffused throughout the epidermis within two hours and through the dermis within the following day. They significantly reduced the secretion of inflammatory cytokines IL1 beta, IL6, IL8, IL20 and IL23. At active doses, no cytotoxicity was detected. This type of NP display relevant properties for the use as topical anti-inflammatory agents and may help to resorb psoriatic lesions.

Frušić-Zlotkin M, Soroka Y, Verkhovsky L, Brégégère FM, Milner Y, Tivony R, Larush L, Magdassi S, Neuman R. Penetration and biological effects of topically applied cyclosporin A nanoparticles in a human skin organ culture inflammatory modelPenetration and biological effects of topically applied cyclosporin A nanoparticles in a human skin organ culture inflammat. Experimental Dermatology [Internet]. 2012;21 (12) :938-943. Publisher's Version
Perelaer J, Jani R, Grouchko M, Kamyshny A, Magdassi S, Schubert US. Plasma and Microwave Flash Sintering of a Tailored Silver Nanoparticle Ink, Yielding 60% Bulk Conductivity on Cost- Effective Polymer Foils. [Internet]. 2012;24 (29) :3993 - 3998. Publisher's Version
2011
Kamyshny A, Steinke J, Magdassi S. Metal-based ink jet inks for printed electronics. Open Appl. Phys. J.Open Applied Physics Journal [Internet]. 2011;4 :19 - 36. Publisher's VersionAbstract
A review on applications of metal-based ink-jet inks for printed electronics with a particular focus on inks contg. metal nanoparticles, complexes and metallo-org. compds. The review describes the prepn. of such inks and obtaining conductive patterns by using various sintering methods: thermal, photonic, microwave, plasma, elec., and chem. triggered. Various applications of metal-based ink-jet inks (metalization of solar cell, RFID antennas, OLEDs, thin film transistors, electroluminescence devices) are reviewed. [on SciFinder(R)]
Salzman AL, Magdassi S, Margulis-Goshen K.; 2011. Compositions and methods for prevention and treatment of pulmonary hypertension.Abstract
The invention provides compns. and methods for prevention, treatment, or management of pulmonary hypertension using piperidine, pyrrolidine, or azepane derivs. comprising one to four nitric oxide (NO) donor groups and a reactive oxygen species (ROS) degrdn. catalyst. The invention further provides a water dispersible powder comprising nanoparticles comprising said derivs., as well as pharmaceutical compns. thereof and methods of use. Rat exptl. models of pulmonary hypertension were treated for 10 days with 3-nitratomethyl-2,2,5,5-tetramethylpyrrolidinyloxy for effective treatment. Dispersible powders contg. nanoparticles of 3-nitratomethyl-2,2,5,5-tetramethylpyrrolidinyloxy were prepd. [on SciFinder(R)]
Magdassi S, Grouchko M, Layani M.; 2011. Production of transparent conductive coatings with ring-like microstructures for optoelectronic and electronic devices and the coated substrates and devices.Abstract
Methods for the manuf. of a conductive transparent film on a substrate are described which entail coating the substrate with a first material to form a wet film of the first material on at least a region of a surface of the substrate; treating the film with at least one second material capable of displacing the first material in the film at the point of contact to expose the substrate to provide an array of spaced apart ring-voids in the film; and optionally treating the film to render the first material conductive. Methods for the manuf. of a conductive transparent pattern on a substrate are also described which entail treating a substrate with a plurality of droplets of a conductive material and permitting the droplets to form an array of intersecting ring structures on the substrate, the conductive material being selected from a combination of one or more metals or metal precursors, a semiconductor material, a carbon-based material, and/or quantum dots to obtain a conductive transparent pattern on the substrate. The substrate may comprise a material selected from glass, paper, inorg. or org. semiconductor materials, polymeric materials, and ceramics. Substrates are also described which are provided with a conductive transparent film of a material having a plurality of spaced apart material-free voids. Devices (e.g., photoconductors, photodiodes, solar cells, light emitting diodes, org. light emitting diodes, lasers, light sensors, transistors, org. transistors, inorg. transistors, hybrid transistors, touch screens, display backplanes, large area display arrays, flexible displays, electromagnetic interference shielding layers, and e-paper) provided with ≥1 of the conductive films are also described. [on SciFinder(R)]
Layani M, Magdassi S. Flexible transparent conductive coatings by combining self-assembly with sintering of silver nanoparticles performed at room temperature. Journal of Materials Chemistry [Internet]. 2011;21 (39) :15378. Publisher's VersionAbstract
Transparent conductive coatings are essential for fabrication of a variety of printed electronic devices such as flexible displays and solar cells. We report on a simple method to obtain such coatings by using aqueous dispersions of silver nanoparticles in an evaporative lithography process which is performed directly onto plastic substrates. In essence, a droplet containing silver nanoparticles is placed on top of a metallic mesh, instantaneously spreading over the mesh and the plastic substrate, and after the flow of the dispersion towards the wires of the mesh and drying, a transparent grid composed of the nanoparticles is formed. The silver nanoparticles are tailored to self-sinter upon short exposure to HCl vapors, due to the presence of polyacrylic acid salt on the surface of the particles. Therefore, immediate sintering of the silver nanoparticles in the thin lines of the grid occurs even at room temperature, enabling formation of transparent, flexible conductive grid on heat-sensitive substrates. The process yielded a conductive array having a very low sheet resistance, 9 ± 0.8 Ω/, and a transparency above 75%. The application of the flexible conductive grid, which can replace conventional and expensive ITO, is demonstrated in an electroluminescent (EL) device. [ABSTRACT FROM AUTHOR]Copyright of Journal of Materials Chemistry is the property of Royal Society of Chemistry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Portnoy E, Lecht S, Lazarovici P, Danino D, Magdassi S. Cetuximab-labeled liposomes containing near-infrared probe for in vivo imaging. [Internet]. 2011;(4) :480. Publisher's VersionAbstract
A new liposome-based near-infrared probe that combines both imaging and targeting abilities was developed for application in medical imaging. The near-infrared fluorescent molecule indocyanine green (ICG), and the cetuximab monoclonal antibody for epidermal growth factor receptor (EGFR) were attached to liposomes by passive adsorption. It was found that ICG molecules adsorbed to the liposomes are more fluorescent than free ICG and have a larger quantum yield. Cetuximab-adsorbed fluorescent liposomes preserved EGFR recognition, as is evident from internalization and selective binding to A431 colon carcinoma cells overexpressing EGFR. The binding of cetuximab-targeted fluorescent liposomes to A431 compared with IEC-6 cells (normal enterocytes expressing physiological EGFR levels) was greater by a factor of 3.5, ensuring imaging abilities with available fluorescent equipment. Due to relatively high quantum yield and specific tumor cell-recognizing ability, this technology deserves further in vivo evaluation for imaging and diagnostic purposes.
Levchenko V, Grouchko M, Magdassi S, Saraidarov T, Reisfeld R. Enhancement of luminescence of Rhodamine B by gold nanoparticles in thin films on glass for active optical materials applications. Optical Materials [Internet]. 2011;34 (Selected papers from the 7th European-Israeli Workshop on "Materials for and by Optics"Claude Bernard/Lyon 1 University December) :360 - 364. Publisher's VersionAbstract
Fluorescent dyes in solid matrices have many potential applications provided that their high optical efficiencies are achieved. We present here gold nanoparticles formed and incorporated together with fluorescent dye Rhodamine B into a film of polyvinyl alcohol (PVA). The increase of fluorescence of the dye results from its interaction with surface plasmons. The electric charge on the gold nanoparticles and the distance between them and the dye molecules has a significant effect on the fluorescence intensity. Fluorescence enhancement of 74% was achieved for the negatively charged particles. Dynamic measurements reveal decrease of fluorescent lifetimes of the dye in presence of gold nanoparticles. Our findings enable utilization of films with enhanced fluorescence in optical materials such as luminescence solar concentrators, solid state tunable laser and active waveguides.
Larush L, Magdassi S. Formation of near-infrared fluorescent nanoparticles for medical imaging. [Internet]. 2011;(2) :233. Publisher's VersionAbstract
Author(s): Liraz Larush [sup.1], Shlomo Magdassi [sup.] [sup.2] KEYWORDS : fluorescence; imaging; indocyanine green; nanoparticles; NIR In the last few decades, much attention has been focused on the potential use [...]Aims: Indocyanine green (ICG) is a US FDA-approved near-infrared fluorescent, water-soluble dye used for diagnostics in vitro and in vivo. The aim of this study was to develop insoluble nanoparticles based on a cationic polymer, ICG and a targeting molecule. The particles are intended for oral administration in the colon, having fluorescence in near-infrared, thus enabling remote detection. Materials methods: An aqueous dispersion of particles formed from Eudragit-RS by simple precipitation method possessing a mean size of approximately 100 nm and zeta potential of +16 mV was produced. Results: These particles are capable of binding both ICG and fluorescein isothiocyanate-IgG via noncovalent interactions. These composite particles retain the emission characteristics of the fluorescent precursors and also exhibit potential specific recognition ability. The particles were stable in intestinal fluid and are composed only of materials that are FDA approved. Conclusion: The nanoparticles may be suitable for in vivo imaging and therapy by oral delivery systems.
Kamyshny A, Zakharov VN, Zakharov MA, Yatsenko AV, Savilov SV, Aslanov LA, Magdassi S. Photoluminescent silicon nanocrystals stabilized by ionic liquid. [Internet]. 2011;(5) :1971. Publisher's VersionAbstract
Silicon nanocrystals stabilized by an ionic liquid, dimethylimidazolium iodide, were synthesized by chemical reduction of SiBr.sub.4 with metallic Na in an organic solvent, diglyme. The nanoparticles were crystalline with a diamond cubic lattice and average size of 3.5 nm. Solid state 13.sup.C- and 29.sup.Si-NMR CP MAS spectra indicate the formation of imidazolium carbene, which ligates the Si atoms at the surface of the nanoparticles. The synthesized Si nanoparticles exhibit photoluminescence with an emission maximum in the red spectral range when excited at 320 nm. The origin of this luminescence is suggested to be mainly related to quantum confinement.
Kudryashova EV, Bronza VL, Vinogradov AA, Kamyshny A, Magdassi S, Levashov AV. Regulation of acid phosphatase in reverse micellar system by lipids additives: Structural aspects. Journal of Colloid And Interface Science [Internet]. 2011;353 :490 - 497. Publisher's VersionAbstract
Reverse micelles system is suggested as a direct tool to study the influence of membrane matrix composition on the activity and structure of membrane-associated enzymes with the use of acid phosphatase (AP) as an example. In reverse micelles the functioning of the monomeric and dimeric forms of AP could be separately observed by variation of the size of the micelles. We found that including the lipids into the micellar system can dramatically affect the enzyme functioning even at low lipid content (2% w/w), and this effect depends on the lipid nature. Structural studies using CD spectroscopy and DLS methods have shown that the influence of lipid composition on the enzyme properties might be caused by the interaction of lipids with the enzyme as well as by the influence of lipids on structure and properties of the micellar matrix.
Portnoy E, Lecht S, Lazarovici P, Danino D, Magdassi S. Research Article: Cetuximab-labeled liposomes containing near-infrared probe for in vivo imaging. Nanomedicine: Nanotechnology, Biology, and Medicine [Internet]. 2011;7 :480 - 488. Publisher's VersionAbstract
A new liposome-based near-infrared probe that combines both imaging and targeting abilities was developed for application in medical imaging. The near-infrared fluorescent molecule indocyanine green (ICG), and the cetuximab monoclonal antibody for epidermal growth factor receptor (EGFR) were attached to liposomes by passive adsorption. It was found that ICG molecules adsorbed to the liposomes are more fluorescent than free ICG and have a larger quantum yield. Cetuximab-adsorbed fluorescent liposomes preserved EGFR recognition, as is evident from internalization and selective binding to A431 colon carcinoma cells overexpressing EGFR. The binding of cetuximab-targeted fluorescent liposomes to A431 compared with IEC-6 cells (normal enterocytes expressing physiological EGFR levels) was greater by a factor of 3.5, ensuring imaging abilities with available fluorescent equipment. Due to relatively high quantum yield and specific tumor cell-recognizing ability, this technology deserves further in vivo evaluation for imaging and diagnostic purposes.From the Clinical Editor A new liposome-based near-infrared probe combining both imaging and targeting abilities is reported. Due to relatively high quantum yield and EGFR-expressing tumor cell specificity, this technology deserves further in vivo evaluation for imaging and diagnostic purposes.
Perelaer J, Schubert US, Abbel R, Layani M, Grouchko M, Magdassi S. Combined sintering approaches for fast sintering of inkjet printed nanoparticles for R2R applicationsCombined sintering approaches for fast sintering of inkjet printed nanoparticles for R2R applications, in International Conference on Digital Printing Technologies. ; 2011 :193-196. Publisher's Version
Grouchko M, Kamyshny A, Mihailescu CF, Anghel DF, Magdassi S. Conductive Inks with a "Built-In" Mechanism That Enables Sintering at Room Temperature. ACS nano 5.4. 2011;5 (4) :3354 - 3359.Abstract

At present there is no metallic ink that enables formation of conductive patterns at room temperature by a single printing step. Printing conductive features by metallic nanoparticle-based inks must be followed by sintering while heating to elevated temperatures, thus preventing their utilization on most plastic substrates used in plastic electronics. In this report we present a new silver nanoparticle-based conductive ink, having a built-in sintering mechanism, which is triggered during drying of the printed pattern. The nanoparticles that are stabilized by a polymer undergo self-sintering spontaneously, due to the presence of a destabilizing agent, which comes into action only during drying of the printed pattern. The destabilizing-agent, which contains Cl- ions, causes detachment of the anchoring groups' of the stabilizer from the nanoparticles surface and thus enables their coalescence and sintering. It was found that the new metallic ink leads to very high conductivities, by a single printing step: up to 41% of the conductivity of bulk silver was achieved, the highest reported conductivity of a printed pattern that is obtained from nanoparticles at room temperature.

Layani M, Magdassi S. Flexible transparent conductive coatings by combining self-assembly with sintering of silver nanoparticles performed at room temperature. Journal of Materials Chemistry. 2011;21 (39) :15378-15382.Abstract

Transparent conductive coatings are essential for fabrication of a variety of printed electronic devices such as flexible displays and solar cells. We report on a simple method to obtain such coatings by using aqueous dispersions of silver nanoparticles in an evaporative lithography process which is performed directly onto plastic substrates. In essence, a droplet containing silver nanoparticles is placed on top of a metallic mesh, instantaneously spreading over the mesh and the plastic substrate, and after the flow of the dispersion towards the wires of the mesh and drying, a transparent grid composed of the nanoparticles is formed. The silver nanoparticles are tailored to self-sinter upon short exposure to HCl vapors, due to the presence of polyacrylic acid salt on the surface of the particles. Therefore, immediate sintering of the silver nanoparticles in the thin lines of the grid occurs even at room temperature, enabling formation of transparent, flexible conductive grid on heat-sensitive substrates. The process yielded a conductive array having a very low sheet resistance, 9 ± 0.8 Ω/□, and a transparency above 75%. The application of the flexible conductive grid, which can replace conventional and expensive ITO, is demonstrated in an electroluminescent (EL) device.

Margulis-Goshen K, Silva BFB, Marques EF, Magdassi S. Formation of solid organic nanoparticles from a volatile catanionic microemulsion. SOFT MATTER [Internet]. 2011;7 (19) :9359 - 9365. Publisher's VersionAbstract

A novel volatile microemulsion formed by the catanionic surfactant hexadecyltrimethylammonium octylsulfonate (TA(16)So(8)), heptane and water has been explored as a template for producing nanoparticles of hydrophobic organic materials. Butylated hydroxytoluene (BHT) was employed as the model hydrophobic substance. First, the oil-in-water microemulsion was formed, containing TA16So8 as the single emulsifier and BHT dispersed in the volatile microphase. Microstructure characterization by self-diffusion NMR revealed that BHT was indeed incorporated into the oil droplets and that the mean diameter of the main droplet population was 30 nm, larger than in the BHT-free microemulsion. Next, a rapid solvent and water removal by freeze drying allowed converting the microemulsion droplets into nanoparticles in the form of a dry, fine powder. This powder was freely dispersible in water to yield a stable suspension of amorphous BHT particles with a mean size of 19 nm and zeta-potential of +37 mV. The solid nanoparticles in the aqueous dispersion were thus smaller than the initial microemulsion droplets. For comparison, a conventional o/w microemulsion composed of CTAB and sec-butanol was also tested as a template for BHT particle formation by the same process, and it was found that it yielded crystalline particles of micrometre size. On the basis of our results, we anticipate the catanionic microemulsion method to be an efficient one for producing size-controlled, water-dispersible nanoparticles of other hydrophobic organic materials.

Margulis-Goshen K, Weitman M, Major DT, Magdassi S. Inhibition of Crystallization and Growth of Celecoxib Nanoparticles Formed from Volatile Microemulsions. [Internet]. 2011;100 (10) :4390 - 4400. Publisher's VersionAbstract

The inhibitory effect of ammonium glycyrrhizinate (AG) on crystallization of celecoxib (CXB) nanoparticles in aqueous medium was studied. CXB nanoparticles in powder form were prepared by rapid evaporation of all solvents from a volatile oil-in-water microemulsion. A powder containing 13 wt % CXB was obtained by immediate conversion of microemulsion droplets into nanoparticles by spray drying. CXB was amorphous in this powder, which could be easily dispersed 1 wt % in water as nanoparticles. However, these particles crystallized rapidly upon dispersion, and a significant particle growth was observed. The natural surfactant, AG, which is US Food and Drug Administration approved for oral administration, inhibited crystallization of CXB, enabling a stable dispersion of nanoparticles with average size of 14 nm. Molecular dynamics simulations revealed rapid attachment of glycyrrhizinate to the growing CXB crystal and suggested that crystallization inhibition is due to interactions between the hydrophobic part of glycyrrhizinate and the phenyl moieties of CXB. (C) 2011 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 100:4390-4400, 2011

Spernath L, Magdassi S. Polyurea nanocapsules obtained from nano-emulsions prepared by the phase inversion temperature method. [Internet]. 2011;22 (12) :2469 - 2473. Publisher's VersionAbstract

We describe here a new and simple method for preparation of polyurea nanocapsules from nanodroplets that were obtained by the phase inversion temperature (PIT) method. In the first stage, a nano-emulsion was prepared, by a heating-cooling cycle, in which the oil phase contained an oil soluble monomer (toluene 2,4-diisocyanate (TDI)). In the second stage, a water-soluble monomer and crosslinker (diethylenetriamine (DETA)) was added, leading to formation of a polymeric shell by an interfacial polycondensation reaction. The new method was demonstrated for obtaining nanocapsules of about 100 nm, in which hexadecane, dodecane, or decane were the core materials, without using any special equipment. The morphology and structure of the nanocapsules were evaluated by attenuated total reflection Fourier transform infrared (ATR-FTIR) measurements and electron microscopy. The thermal behavior of the nanocapsules containing hexadecane was studied by Differential Scanning Calorimetry (DSC) measurements, indicating that such nanocapsules can be utilized in thermal energy storage. Copyright (C) 2010 John Wiley & Sons, Ltd.

2010
Magdassi S ed. The chemistry of inkjet inks. Magdassi, Shlomo. Singapore : World Scientific Publishing Company; 2010.Abstract

Modern printing is based on digitizing information and then representing it on a substrate, such as paper, pixel by pixel. One of the most common methods of digital printing is through inkjet printers. The process of inkjet printing is very complicated, and the ink used must meet certain chemical and physicochemical requirements including those related to storage stability; jetting performance; color management; wetting; and adhesion on substrates. Obviously, these requirements — which represent different scientific disciplines such as colloid chemistry, chemical engineering, and physics — indicate the need for an interdisciplinary book that will cover all aspects of making and utilizing inkjet inks.

This book provides basic and essential information on the important parameters which determine ink performance. It covers not only the conventional use of inkjet technology on graphic applications, but also the extension of this method to print various functional materials, such as the use of conductive inks to print light-emitting diodes (LEDs) and three-dimensional structures. Thus, the book will serve a large community: industrial chemists who deal with ink formulations and synthesis of chemicals for inks; chemical engineers and physicists who deal with the rheological and flow properties of inks; and researchers in academic institutes who seek to develop novel applications based on inkjet printing of new materials.

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