We report on the biological performance of organic nanoparticles formed by a simple method based on rapid solvent removal from a volatile microemulsion. The particular focus of the study was on testing the suitability of the method for substances soluble in partially water-miscible organic solvents as well as on evaluating the therapeutic activity of the resultant nanoparticles. Curcumin was employed as a model for hydrophobic drugs, and, as it is soluble in water-miscible organic solvents, it was successfully incorporated into a new cyclopentanone-water microemulsion system. During rapid solvent removal by spray-drying, the nanometric droplets of the microemulsion were converted into nanoparticles containing amorphous curcumin with an average size of 20.2 ± 3.4 nm, having a ς potential of -36.2 ± 1.8 mV. These nanoparticles were dispersible in water and retained the high loading of the active substance. The therapeutic activity of the resulting nanoparticles was demonstrated in a pancreatic cancer cell line, PANC-1. The effective concentration for reducing the metabolic activity by 50% (EC50) was found to be 11.5 µM for nanoparticles compared with 19.5 µM for free curcumin. [ABSTRACT FROM AUTHOR]Copyright of Journal of Materials Chemistry B 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.)

We report on the biological performance of organic nanoparticles formed by a simple method based on rapid solvent removal from a volatile microemulsion. The particular focus of the study was on testing the suitability of the method for substances soluble in partially water-miscible organic solvents as well as on evaluating the therapeutic activity of the resultant nanoparticles. Curcumin was employed as a model for hydrophobic drugs, and, as it is soluble in water-miscible organic solvents, it was successfully incorporated into a new cyclopentanone-water microemulsion system. During rapid solvent removal by spray-drying, the nanometric droplets of the microemulsion were converted into nanoparticles containing amorphous curcumin with an average size of 20.2 ± 3.4 nm, having a ζ potential of -36.2 ± 1.8 mV. These nanoparticles were dispersible in water and retained the high loading of the active substance. The therapeutic activity of the resulting nanoparticles was demonstrated in a pancreatic cancer cell line, PANC-1. The effective concentration for reducing the metabolic activity by 50% (EC50) was found to be 11.5 mM for nanoparticles compared with 19.5 µM for free curcumin. [ABSTRACT FROM AUTHOR]Copyright of Journal of Materials Chemistry B 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.)

In this paper we describe the preparation of novel Near Infrared (NIR) fluorescent nanoparticles for application in medical imaging of colorectal tumors. The nanoparticles are prepared by using only non-covalent binding processes of molecules which are approved for clinical use. The preparation process is based on the precipitation of a polycation, Eudragit-RS, followed by sequential adsorption of a blocking protein, sodium caseinate, NIR fluorescent dye, Indocyanine Green (ICG) and optionally, a targeting molecule, anti-CEA antibody. Fluorescence measurements have shown that these nanoparticles have higher resistance to photobleaching and higher quantum yield relatively to free ICG. Imaging experiments in orthotopic colorectal cancer mice models have shown that these fluorescent nanoparticles are capable of binding to LS174T human colon tumors in vivo with high specificity, even without the targeting molecule. These nanoparticles, composed of all FDA approved materials, open the way to clinical bioimaging and diagnostics of colon cancer.

This is a review on recent developments in the field of conductive nanomaterials and their application in printed electronics, with particular emphasis on inkjet printing of ink formulations based on metal nanoparticles, carbon nanotubes, and graphene sheets. The review describes the basic properties of conductive nanomaterials suitable for printed electronics (metal nanoparticles, carbon nanotubes, and graphene), their stabilization in dispersions, formulations of conductive inks, and obtaining conductive patterns by using various sintering methods. Applications of conductive nanomaterials for electronic devices (transparent electrodes, metallization of solar cells, RFID antennas, TFTs, and light emitting devices) are also briefly reviewed.

Vanadium dioxide is a well-known near room temperature phase transition material with a transition temperature (tau(C)) at 68 degrees C. In this paper, Eu3+ dopant with different doping levels was introduced into the crystal lattice of VO2. The thermochromic properties, including the integrated visible transmittance (T-lum) and the solar modulating ability (Delta T-sol) were favorably affected by the Eu-doping. It is of great interest that the substitution of V4+ by Eu3+ in the VO2 crystal structure reduced the tau(C) from 68 degrees C to 47.5 degrees C with an approximate decreasing rate of 6.5 degrees C/at% up to 4 at%. More importantly, the Eu dopant helped in improving the properties of luminous transmittance and solar modulating ability, which were difficult to be achieved by other dopants.

•A new method for production of organic nanoparticles is demonstrated for curcumin.•The method is based on flash nanoprecipitation from partially water-soluble emulsions.•A simple hand-operated mixer is employed for flash nanoprecipitation process.•Dry nanometric powders obtained by spray drying are easily dispersible in water.•The resultant particles are 40nm in diameter and contain above 20wt% active substance.Nanometric particles of a model hydrophobic substance curcumin were prepared by a novel method, namely, flash nanoprecipitation from a coarse oil-in-water emulsion. The method employs turbulent co-mixing of water with curcumin-loaded emulsion using manually-operated confined impingement jets mixer. A clear and stable dispersion of nanoparticles was formed in this process, and could be converted to dry, easily water-dispersible powder by spray drying. The mean size of the particles was about 40nm by DLS, confirmed by Cryo-TEM. The obtained particles contained 20.4wt% curcumin, X-ray analysis showed it was amorphous. The significant advantages of the studied process are its feasibility, speed and low cost. It does not require any special high-energy input equipment to reduce the droplet size of the initial emulsion as required by the vast majority of other methods, and relies on rapid turbulent mixing and on flow-induced shear stress formed in the simple, manually-operated mixer. Control experiments clearly indicate that employing emulsion, instead of a plain solution and flash nanoprecipitation instead of a simple antisolvent precipitation are advantageous in terms of particle size and stability.

This study presents a method for one step incorporation of lipophilic compounds in hydrophilic nanofibers. By this method nanodroplets of oil and of volatile solvent are entrapped within polymer nanofibers during an electrospinning process. While performing the process with a volatile oil with dissolved lipophilic material, such as the drug celecoxib, nanofiber-nanoparticle composites are formed. The polymer used to form the fibers is a high molecular weight poly(vinyl alcohol) which enables rapid dissolution and release of the incorporated lipophilic material. The resulting celecoxib nanoparticles that are embedded within the nanofiber are amorphous and their average size is in between 21 and 93nm, thus potentially lead to their increased dissolution rate. The preparation of such a solid matrix containing nanodroplets or nanoparticles may be applied as a fast dissolving delivery system for water insoluble materials.; Copyright © 2014 Elsevier B.V. All rights reserved.

The cover page of the December 2014 issue of the journal "Chemistry and Sustainability" is presented.

Ensuring drug loading efficiency and consistency is one of the most critical stages in engineering drug delivery vectors based on porous materials. Here we propose a technique to significantly enhance the efficiency of loading by employing simple and widely available methods: applying low pressure with and without centrifugation. Our results point toward the advantages the proposed method over the passive loading, especially where the size difference of loaded materials and the pore size of the porous silicon particles is smaller, an increase up to 20-fold can be observed. The technique described in the study can be used for efficient and reproducible loading of porous materials with therapeutic molecules, nanoparticles and contrast imaging agents for biomedical application.;

The welding and sintering of nanomaterials is relevant, for example, to form electrical contacts between metallic particles in printed electronic devices. Usually the welding of nanoparticles is achieved at high temperatures. Here we find that merging of two different metals, silver and gold nanoparticles, occurs on contact at room temperature. The merging process was investigated by experimental and molecular dynamics simulations. We discovered that the merging of these particles is driven by selective wettability of silver nanoparticles, independent of their size and shape (spheres or rods); silver behaves as a soft matter, whereas gold as a hard surface being wetted and retaining its original morphology. During that process, the silver atoms move towards the surface of the Au nanoparticles and wrap the Au nanoparticles in a pulling up-like process, leading to the wetting of Au nanoparticles.

A "nano to nano" electrodeposition approach for preparing nano-structured thin films from the dispersion of nano-objects is reported. A typical WO3 system is demonstrated, where nanocrystalline films are electrodeposited onto transparent conductive electrodes such as ITO and Ag grid printed PET (Ag grid/PET) from the water dispersion of WO3 nanoparticles without applying high potential, adding surfactants or polymers. The process is based on the reduction of WO3, which eliminates the electrostatic repulsion between the nanoparticles causing film deposition on the cathode. The reduced WO3 (HWO3) is conductive, thus it allows further film growth towards higher thickness and coverage. The electrodeposited films consist of stacked crystalline nanoparticles, which provide a highly active surface area, facilitate the penetration of electrolyte and the intercalation/deintercalation of Li+ in the nanocrystals and therefore result in outstanding electrochromic performance and stability (92% contrast, 9 s coloring and 15 s bleaching, retaining 76% contrast after 1000 coloring-bleaching cycles). The thickness, electrochromic performance and surface coverage of the films are well tuned by potential and time. This novel "nano to nano" electrodeposition approach based on the electrochemical redox of nano-objects can be extended to various transition metal oxide nano-objects with different sizes and shapes. [ABSTRACT FROM AUTHOR]Copyright of Journal of Materials Chemistry A 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.)

Vanadium dioxide is the most widely researched thermochromic material with a phase transition temperature (tau(c)) of around 68 degrees C, and its thermochromic performance can be enhanced by adding nanoporosity. Freeze-drying has been employed to fabricate nanostructures with different porosities from 16 to 45% by varying the prefreezing temperature and precursor concentration. The luminous transmittance (T-lum) and solar modulating ability (Delta T-sol) are greatly enhanced as a result of increasing pore size and pore density. The freeze-dried sample with 7.5 mL of H2O2 precursor dip-coated at 300 mm/min gives the best combination of thermochromic properties (T-lum approximate to 50%, Delta T-sol = 14.7%), which Surpasses the best combined thermochromic performance reported to date that we are aware of (T-lum approximate to 41%, Delta T-sol = 14.1%).

Vanadiumdioxide is the most widely researched thermochromic materialwith a phase transition temperature (τc) of around68 °C, and its thermochromic performance can be enhanced by addingnanoporosity. Freeze-drying has been employed to fabricate nanostructureswith different porosities from 16 to 45% by varying the prefreezingtemperature and precursor concentration. The luminous transmittance(Tlum) and solar modulating ability (ΔTsol) are greatly enhanced as a result of increasingpore size and pore density. The freeze-dried sample with 7.5 mL ofH2O2precursor dip-coated at 300 mm/min givesthe best combination of thermochromic properties (Tlum≈ 50%, ΔTsol= 14.7%), which surpasses the best combined thermochromic performancereported to date that we are aware of (Tlum≈ 41%, ΔTsol= 14.1%). [ABSTRACT FROM AUTHOR]Copyright of Langmuir is the property of American Chemical Society 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.)

Printed electrochromic flexible films were obtained by combining transparent silver grid electrodes formed by self-assembly and inkjet printed WO3 nanoparticles. Concd. dispersions of WO3 nanoparticles were inkjet printed on transparent plastic silver grid electrodes with a high transparency of 83% in the spectral range of 400-800 nm, and a low sheet resistance in the range of 1-5 Ω sq-1. These electrodes were used for electrochromic applications for the first time. The resultant patterned nanostructured electrochromic films maintained their coloring and bleaching performance after bending of the flexible films. [on SciFinder(R)]