In-Situ Intercalating of Silica Nanospheres into Polypyrrole During Its Electropolymerization to Prepare a Sorbent for Headspace Microextraction of Aldehydes in Edible Oils.

The quality of edible oils is significantly affected by autoxidation of lipids, which alters their flavor and nutritional quality through production of toxic materials like aldehydes (an important class of oil deterioration markers). Herein, an amino-silica nanospheres/polypyrrole (ASNS/PPy) nanocomposite sorbent was synthesized and used as the fiber coating for headspace solid-phase microextraction (HS-SPME) of aldehydes in edible oils, followed by gas chromatography (GC) separation and determination. Amino-silica nanoparticles were prepared by an amended Stöber method and composited with polypyrrole during its electropolymerization on the surface of a platinized stainless-steel fiber. The synergy between in-situ electropolymerization and rough surface of the platinized metal substrate created a durable fiber coating with unique uniformity, cohesiveness, and adsorption properties. The synthesized nanocomposite was characterized using Fourier transform infrared spectroscopy and scanning electron microscopy techniques. The performance of the prepared fiber was optimized by investigating the affecting variables including extraction temperature and time, stirring rate, and desorption conditions. The obtained limits of detection for hexanal and heptanal in sunflower oil were 0.005-0.009 µg mL-1. The prepared fiber exhibited excellent repeatability and reproducibility with the intra-fiber and inter-fiber relative standard deviations in the ranges of 3.9-8.8% and 7.3-15.1%, respectively. The proposed HS-SPME-GC strategy was successfully applied for the analysis of aldehydes in commercial edible oil samples.

Tumor recognition of peanut agglutinin-immobilized fluorescent nanospheres in biopsied human tissues.

We are investigating an imaging agent for early detection of colorectal cancer. The agent, named the nanobeacon, is coumarin 6-encapsulated polystyrene nanospheres whose surfaces are covered with poly(N-vinylacetamide) and peanut agglutinin that reduces non-specific interactions with the normal mucosa and exhibits high affinity for terminal sugars of the Thomsen-Friedenreich antigen, which is expressed cancer-specifically on the mucosa, respectively. We expect that cancer can be diagnosed by detecting illumination of intracolonically administered nanobeacon on the mucosal surface. In the present study, biopsied human tissues were used to evaluate the potential use of the nanobeacon in the clinic. Prior to the clinical study, diagnostic capabilities of the nanobeacon for detection of colorectal cancer were validated using 20 production batches whose characteristics were fine-tuned chemically for the purpose. Ex vivo imaging studies on 66 normal and 69 cancer tissues removed from the colons of normal and orthotopic mouse models of human colorectal cancer, respectively, demonstrated that the nanobeacon detected colorectal cancer with excellent capabilities whose rates of true and false positives were 91% and 5%, respectively. In the clinical study, normal and tumor tissues on the large intestinal mucosa were biopsied endoscopically from 11 patients with colorectal tumors. Histological evaluation revealed that 9 patients suffered from cancer and the rest had adenoma. Mean fluorescence intensities of tumor tissues treated with the nanobeacon were significantly higher than those of the corresponding normal tissues. Correlation of magnitude relation of the intensity in individuals was observed in cancer patients with a high probability (89%); however, the probability reduced to 50% in adenoma patients. There was a reasonable likelihood for diagnosis of colorectal cancer by the nanobeacon applied to the mucosa of the large intestine.

Intracellular Assembly of Nuclear-Targeted Gold Nanosphere Enables Selective Plasmonic Photothermal Therapy of Cancer by Shifting Their Absorption Wavelength toward Near-Infrared Region.

Despite the important applications of near-infrared (NIR) absorbing nanomaterials in plasmonic photothermal therapy (PPT), their high yield synthesis and nonspecific heating during the active- and passive-targeted cancer therapeutic strategies remain challenging. In the present work, we systematically demonstrate that in situ aggregation of typical non-NIR absorbing plasmonic nanoparticles at the nuclear region of the cells could translate them into an effective NIR photoabsorber in plasmonic photothermal therapy of cancer due to a significant shift of the plasmonic absorption band to the NIR region. We evaluated the potential of nuclear-targeted AuNSs as photoabsorber at various stages of endocytosis by virtue of their inherent in situ assembling capabilities at the nuclear region of the cells, which has been considered as one of the most thermolabile structures within the cells, to selectively destruct cancer cells with minimal damage to healthy cells. Various plasmonic nanoparticles such as rods and cubes have been exploited to elucidate the role of plasmonic field coupling in assembled nanoparticles and their subsequent killing efficiency. The NIR absorbing capabilities of aggregated AuNSs have been further demonstrated both experimentally and theoretically using discrete dipolar approximation (DDA) techniques, which was in concordance with the observed results in plasmonic photothermal therapeutic studies. While the current work was able to demonstrate the utility of non-NIR absorbing plasmonic nanoparticles as a potential alternative for plasmonic photothermal therapy by inducing localized plasmonic heating at the nuclear region of the cells, these findings could potentially open up new possibilities in developing more efficient nanoparticles for efficient cancer treatment modalities.

A new method for measuring lung deposition efficiency of airborne nanoparticles in a single breath.

Assessment of respiratory tract deposition of nanoparticles is a key link to understanding their health impacts. An instrument was developed to measure respiratory tract deposition of nanoparticles in a single breath. Monodisperse nanoparticles are generated, inhaled and sampled from a determined volumetric lung depth after a controlled residence time in the lung. The instrument was characterized for sensitivity to inter-subject variability, particle size (22, 50, 75 and 100 nm) and breath-holding time (3-20 s) in a group of seven healthy subjects. The measured particle recovery had an inter-subject variability 26-50 times larger than the measurement uncertainty and the results for various particle sizes and breath-holding times were in accordance with the theory for Brownian diffusion and values calculated from the Multiple-Path Particle Dosimetry model. The recovery was found to be determined by residence time and particle size, while respiratory flow-rate had minor importance in the studied range 1-10 L/s. The instrument will be used to investigate deposition of nanoparticles in patients with respiratory disease. The fast and precise measurement allows for both diagnostic applications, where the disease may be identified based on particle recovery, and for studies with controlled delivery of aerosol-based nanomedicine to specific regions of the lungs.

Characterization of Nanoparticle Tracking Analysis for Quantification and Sizing of Submicron Particles of Therapeutic Proteins.

Submicron particles may play important roles in therapeutic protein product quality, stability, and adverse effects in patients. However, quantitation of these particles has been challenging. Nanoparticle tracking analysis (NTA) is capable of both sizing and counting submicron particles. We investigated the effects of product and instrument parameters on NTA results for nanoparticle standards and therapeutic protein samples. To obtain proper particle size distributions, complete tracking numbers of at least 200 and 400 were required for latex nanobeads and protein nanoparticles, respectively. In addition, when set at suboptimal values, the minimum expected particle size parameter led to inaccurate sizing and counting for all particles types investigated. A syringe pump allowed for higher sampling volumes, and results were reproducible for nanoparticle sizing and counts at flow rates ≤7 µL/min. Finally, because therapeutic protein products are being formulated at relatively high protein concentrations, we investigated the effects of protein concentration on nanoparticle characterization. With high protein concentrations, nanoparticle sizing was not affected, whereas particle concentrations were significantly reduced. Linear relationships between particle count and dilution factor were obtained when a high protein concentration formulation was diluted into particle-free solutions at the same protein concentrations, but not when dilutions were made into buffer.

DNA detection based on fluorogenic nanospheres.

High and dry fluorescence: Fluorogenic nanospheres (green, see scheme) are conjugated to DNA (pink) and used to detect target DNA (aqua). Upon addition of N-butylmorpholine (droplet), the nanospheres dissolve, releasing fluorophores, and intense blue fluorescence is emitted at the site of DNA hybridization. The separation of DNA hybridization and signal amplification gives high sensitivity (100 zmol) and selectivity.

Multimodality animal rotation imaging system (Mars) for in vivo detection of intraperitoneal tumors.

PROBLEM Ovarian cancer stem cells (OCSCs) have been postulated as the potential source of recurrence and chemoresistance. Therefore identification of OvCSC and their complete removal is a pivotal stage for the treatment of ovarian cancer. The objective of the following study was to develop a new in vivo imaging model that allows for the detection and monitoring of OCSCs. METHOD OF STUDY OCSCs were labeled with X-Sight 761 Nanospheres and injected intra-peritoneally (i.p.) and sub-cutaneously (s.c.) to Athymic nude mice. The Carestream In-Vivo Imaging System FX was used to obtain X-ray and, concurrently, near-infrared fluorescence images. Tumor images in the mouse were observed from different angles by automatic rotation of the mouse. RESULTS X-Sight 761 Nanospheres labeled almost 100% of the cells. No difference on growth rate was observed between labeled and unlabeled cells. Tumors were observed and monitoring revealed strong signaling up to 21 days. CONCLUSION We describe the use of near-infrared nanoparticle probes for in vivo imaging of metastatic ovarian cancer models. Visualization of multiple sites around the animals was enhanced with the use of the Carestream Multimodal Animal Rotation System.

Disordered spheres with extensive overlap in projection: image simulation and analysis.

This article simulates highly overlapped projections of spherical particles that are distributed randomly in space. The size and number of the features in the projections are examined as well as how these features change with particle size and concentration. First, there are discernable features in projection even when particles overlap extensively, and the size of these discernable features is the expected size of an individual particle. Second, the number of features increases with specimen thickness at a rate of t(0.543) when the specimen thickness is below a critical value and becomes independent of specimen thickness at higher thicknesses. A criterion is established for the critical thickness based on particle size and particle volume fraction. When the specimen thickness is known and smaller than the critical thickness, a single representative transmission electron microscopy (TEM) (or scanning TEM) image exhibiting extensive particle overlap can be used to determine the size and number density of the spherical particles.

Evaluation of closed incision management with negative pressure wound therapy (CIM): hematoma/seroma and involvement of the lymphatic system.

The objective of this porcine study was to evaluate the effect of closed incision management with negative pressure wound therapy (CIM) on hematoma/seroma formation, fluid removal into the CIM canister, and involvement of the lymphatic system. In each swine (n = 8), two sets of ventral contralateral subcutaneous dead spaces with overlying sutured incisions were created. Stable isotope-labeled nanospheres were introduced into each subcutaneous dead space. Each contralateral incision was assigned to CIM (continuous -125 mmHg negative pressure) and control (semipermeable film dressing), respectively. Following 4 days of therapy, hematoma/seroma was weighed, total fluid volume in canisters was measured, five pre-identified lymph nodes were harvested, and five key organs were biopsied. There was 25 ± 8 g (standard error [SE]) (63%) less hematoma/seroma in CIM sites compared to control sites (p = 0.002), without any fluid collection in the CIM canister. In lymph nodes, there were ∼60 µg (∼50%) more 30- and 50-nm nanospheres from CIM sites than from control sites (p = 0.04 and 0.05, respectively). There was significantly greater nanosphere incidence from CIM sites than from control sites in lungs, liver, and spleen (p < 0.05); no nanospheres were detected in kidney biopsies. Thus, in this porcine model, application of CIM significantly decreased hematoma/seroma levels without fluid collection in the canister, which may be explained by increased lymph clearance.

Magnetic and fluorescent glycopolymer hybrid nanoparticles for intranuclear optical imaging.

The synthesis of galactose-displaying core-shell nanospheres exhibiting both fluorescent and magnetic properties by grafting a glycocopolymer consisting of 6-O-methacryloylgalactopyranose (MAGal) and 4-(pyrenyl)butyl methacrylate (PyMA) onto magnetic silica particles via thiol-ene chemistry is reported. Magnetization measurements indicated that neither the encapsulation of the iron oxide particles into silica nor the grafting of the glycocopolymer chains had a significant influence on the superparamagnetic properties. This not only simplifies the purification of the particles but may facilitate the use of the particles in applications such as hyperthermia or magnetic resonance imaging (MRI). Furthermore, the hydrophilic glycopolymer shell provided solubility of the particles in aqueous medium and enabled the uptake of the particles into the cytoplasm and nucleus of lung cancer cells via carbohydrate-lectin recognition effects.

Effects of chemical and physical parameters in the generation of microspheres by hydrodynamic flow focusing.

Hydrodynamic flow focusing is a seminal, easy-to-use technology for micro- and nanodroplet generation. It is characterized by the co-axial focusing of two (or more) immiscible liquid streams forced through a small orifice. In this method, the outer continuous phase has a much higher flow velocity than the inner disperse phase. While passing through the orifice, the prevailing pressure drop and shear stress force the inner phase to break up into uniform droplets. Using a biodegradable poly(lactide-co-glycolide) (PLGA) polymer solution as the disperse phase, monodisperse and user-defined polymer micro- and nanospheres can be generated. Here we present a consecutive parameter study of hydrodynamic flow focusing to study the effect of chemical and physical parameters that effect the dispersity of the droplets generated in the 1-5 µm range. The parameter study shows the applicability and challenges of hydrodynamic flow focusing in the preparation of biodegradable microspheres. Applications for microspheres made with this method can be found in the medical, pharmaceutical and technical fields.

Preparation, characterization, pharmacokinetics, and tissue distribution of curcumin nanosuspension with TPGS as stabilizer.

BACKGROUND: CUR is a promising drug candidate based on its good bioactivity, but use of CUR is potentially restricted because of its poor solubility and bioavailability. AIM: The aim of this study was to prepare an aqueous formulation of curcumin nanosuspension (CUR-NS) to improve its solubility and change its in vivo behavior. METHODS: CUR-NS was prepared by high-pressure homogenization method. Drug state in CUR-NS was evaluated by powder X-ray diffraction. Pharmacokinetics and biodistribution of CUR-NS after intravenous administration in rabbits and mice were studied. RESULTS: The solubility and dissolution of CUR in the form of CUR-NS were significantly higher than those of crude CUR. X-ray crystallography diffraction indicated that the crystalline state of CUR in nanosuspension was preserved. Pharmacokinetics and biodistribution results of CUR-NS after intravenous administration in rabbits and mice showed that CUR-NS presented a markedly different pharmacokinetic property as compared to the CUR solution. AUC(0-infinity) of CUR-NS (700.43 +/- 281.53 microg/mL, min) in plasma was approximately 3.8-fold greater than CUR solution (145.42 +/- 9.29 microg/mL min), and the mean residence time (194.57 +/- 32.18 versus 15.88 +/- 3.56 minutes) was 11.2-fold longer. CONCLUSION: Nanosuspension could serve as a promising intravenous drug-delivery system for curcumin.

Nanorods versus nanospheres: a bifurcation mechanism revealed by principal component TEM analysis.

A quantitative analysis of object populations obtained by TEM images is performed for the classical scheme of aqueous seedless synthesis of nanorods. Using an effective way to represent nanoparticle size distributions, we unravel that spheres, usually considered to be a side-product, are in fact coming from a competing route during nanorod formation. The differentiation between spheres and rods appears above a critical size of 5 nm and is due to different growth rates between faces. The initial repartition of faces on nuclei or on the nanoparticles at the critical size can be the source for the final differentiation between globules and rods. The efficiency of the selection is strongly influenced by the production of the initial seeds and, in particular, by the amount of borohydride added in the present scheme.

Synthesis and photoluminescence properties of spherical fine red (Y(1-x-y)Gd(x)EU(y))BO3 (0 < or = x < or = 0.36, 0.06 < or = y < or = 0.13) phosphors using ultrasonic spray pyrolysis.

The post-heat treated (Y(1-x-y)Gd(x)Eu(y))BO3 (0 < or = x < or = 0.36, 0.06 < or = y < or = 0.13) powders crystallized in a solution of (Y(1-x-y)Gd(x)Eu(y))BO3 with the hexagonal vaterite crystal structure, irrespective of composition. The lattice parameter of the (Y(0.9-x)Gd(x)Eu(0.1))BO3 (0 < or = x < or = 0.36) powders slightly increased with an increase in Gd content. The average powder sizes were sub-micron order and the powders showed relatively uniform size distribution and smooth surface. We obtained improved powder morphologies by adding organic additives such as ethylene glycol and citric acid. For the post-treated (Y(0.9-x)Gd(x)Eu(0.1))BO3, the emission intensity became stronger with increasing Gd content up to x = 0.27. In addition, for the post-treated (Y(0.73-y)Gd(0.27)Eu(y))BO3, the emission intensity gradually increased with Eu content up to y = 0.13. In particular, the emission intensity of the (Y(0.6)Gd)0.27)Eu(0.13))BO3 powders synthesized was higher than that of the commercial (Y,Gd)BO3:Eu3+ product.

Examination of edge effects with different storage conditions of preplated dimethyl sulfoxide nanospots in ChemLib 1,536- and 3,456-well assay-ready plates.

For ultra-high-throughput screening, 10-30 nl of compound dissolved in 75% dimethyl sulfoxide (DMSO)/25% water (vol/vol) is spotted into 1,536- and 3,456-well ChemLib plates (Aurora Biotechnologies, Carlsbad, CA) and stored appropriately for a short time before screening. Although this practice eliminates the compound plating bottleneck, plated volumes of DMSO slowly evaporate from assay wells if plates are not properly stored in the interim. Since many assays are sensitive to DMSO concentrations, even slight evaporation may cause intra-plate variation and thus decrease assay quality. Using a cytochrome P450 3A4 Vivid Blue assay (Invitrogen, Carlsbad), we investigated the rate, pattern, and quantity of evaporation over a 1-year time frame to identify best practices for long-term (i.e., 6 months or greater) storage of assay-ready compound plates. Our findings regarding evaporation at plate edges indicate that nanospots preplated in ChemLib 1,536- or 3,456-well plates are best stored at -80 degrees C, in a bag, with or without the outer evaporation wells filled or at -20 degrees C, in a bag, with evaporation wells filled.