Microarray analysis of gene expression in lung cancer cell lines treated by fractionated irradiation.

BACKGROUND: To identify differentially expressed genes between parent and radioresistant lung cancer cell lines established by fractionated irradiation. MATERIALS AND METHODS: Lung cancer cell lines (A549, NCI-H1650) were irradiated with several fractionation schemes. Clonogenic assays were used to identify radioresistant cell lines. We compared the gene expression profiles on a cDNA microarray. RESULTS: Four established cell (A549-2G, A549-5G, H1650-2G and H1650-5G) were shown to be radioresistant (p≤0.05). Seventy-two genes were commonly altered in A549-G and 655 genes in H1650-G, compared to their parental cells. Genes in the wingless-type MMTV integration site family (WNT) signaling pathway were the ones most frequently altered in both A549-G and H1650-G cells. Those involved in inflammation; integrin, platelet-derived growth factor (PDGF), interleukin, transforming growth factor-beta (TGFB), epidermal growth factor receptor (EGFR) signaling, were commonly altered in radioresistant H1650 sublines. CONCLUSION: The major gene expression changes during irradiation are related to WNT signaling pathway.

Antimicrobial polymer nanostructures: synthetic route, mechanism of action and perspective.

Protection against bacterial infections is an important research field in modern society. Antimicrobial polymers have received considerable attention as next-generation biocides because they represent an ecologically friendly approach that does not promote resistance. In the last decade, many authors have reported the development of nano-sized antimicrobial polymers with enhanced bactericidal performance by increasing the active-area of biocides. This review presents several suitable methods of synthesis of antimicrobial polymer nanomaterials with various shapes, including a nanosphere and fibrous and tubular structures. We also discuss the antimicrobial mechanisms of these polymers. In addition, antimicrobial polymer thin films, which can inhibit bacterial adhesion, are introduced briefly with examples. Our aim is to present synthetic routes and formation mechanisms of various antimicrobial polymer nanostructures.

A phase III concurrent chemoradiotherapy trial with cisplatin and paclitaxel or docetaxel or gemcitabine in unresectable non-small cell lung cancer: KASLC 0401.

PURPOSE: Concurrent chemoradiotherapy (CCRT) is recommended for the management of patients with unresectable non-small cell lung cancer (NSCLC). This prospective study aimed to compare the efficacy of concurrently delivered cisplatin doublets with paclitaxel, or docetaxel, or gemcitabine. METHODS: The main eligibility criteria consisted of previously untreated stage IIIB NSCLC. The subjects were randomized into three arms: paclitaxel 45 mg/m(2)/week (TP), docetaxel 20 mg/m(2)/week (DP), and gemcitabine 350 mg/m(2)/week (GP) in addition to cisplatin 20 mg/m(2)/week. Three-dimensional conformal radiotherapy was given once daily, weekly 5 fractions and the total prescription dose was 60-66 Gy. The primary endpoint was response rate, and the secondary endpoints were survival and toxicity. RESULTS: A total of 101 patients were recruited into this trial of whom 93 (TP: 33, DP: 29, GP: 31) patients were treated with CCRT from March 2005 to July 2007. Similar response rates were observed across arms: TP: 63.6 %, DP: 72.4 %, GP: 61.3 % (p = 0.679). There was no statistically significant difference of median survival (TP: 27.3, DP: 27.6, GP: 16.5 months, p = 0.771). In subgroup analysis, a survival benefit of consolidation chemotherapy was not seen, but leucopenia (63.2 %) and neutropenia (68.4 %) more than grade 3 were significantly high in DP arm. The grade ≥3 radiation esophagitis was more frequent in the GP arm (22.6 %, p = 0.163). CONCLUSIONS: Among the three arms, no statistically significant difference in response rate, survival, and toxicity was observed. However, clinically significant radiation toxicity was more frequent in the GP arm.

Enhanced antibacterial activity of silver/polyrhodanine-composite-decorated silica nanoparticles.

This work describes the synthesis of silver/polyrhodanine-composite-decorated silica nanoparticles and their antibacterial activity. Polymerization of polyrhodanine proceeded preferentially on the surface of the silica nanoparticles where Ag(+) ions were located. In addition, the embedded Ag(+) ions were reduced to form metallic Ag nanoparticles; consequently, silver/polyrhodanine-composite nanoparticles (approximately 7 nm in diameter) were formed on the surface of the silica nanoparticles. The resulting nanostructure was investigated using electron microscopy, Fourier-transform infrared spectroscopy, ultraviolet-visible spectroscopy, and X-ray photoelectron spectroscopy. The silver/polyrhodanine-nanocomposite-decorated silica nanoparticles exhibited excellent antimicrobial activity toward gram-negative Escherichia coli and gram-positive Staphylococcus aureus because of the antibacterial effects of the silver nanoparticles and the polyrhodanine. The silver/polyrhodanine-composite nanoparticles may therefore have potential for use as a long-term antibacterial agent.

Low temperature aqueous phase synthesis of silver/silver chloride plasmonic nanoparticles as visible light photocatalysts.

A one pot and environmentally benign synthetic route for plasmonic photocatalytic Ag@AgCl nanoparticles in a PVA-dissolved aqueous solution system is presented. The synthesized AgCl has a cubic-shape and its edge length can be controlled from ~57 to ~170 nm by varying the reaction temperature. In this system, PVA was used as a stabilizer for the formation of Ag@AgCl nanoparticles through interaction with Ag(+) ions. After partial reduction with l-arginine, the metallic Ag is formed on the surface of the AgCl substrates and the contents of the metallic Ag mainly affect both the visible-light absorption properties and the plasmonic photocatalytic efficiency of the Ag@AgCl nanocomposites. A plausible growth mechanism of metallic silver during the reduction process is proposed. More importantly, it is verified that the size of the AgCl substrate affected the light absorption region of the Ag@AgCl nanocomposite.

Fabrication of pDMAEMA-coated silica nanoparticles and their enhanced antibacterial activity.

Thin pDMAEMA shells were formed on the surface of silica nanoparticles via vapor deposition polymerization. Scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and elemental analysis have been used to characterize the resulting pDMAEMA-coated silica nanoparticles. Electron microscopy studies reveal that the thin polymer shell is formed on the silica surface. In this work, the particle diameter can be controlled (from ~19 to ~69 nm) by varying the size of silica core. The antibacterial performance of the core-shell nanoparticles was investigated against both Gram-positive (Escherichia coli) and Gram-negative (Staphylococcus aureus) bacteria. Importantly, the nano-sized pDMAEMA particles presented antibacterial activity against both bacteria without additional quaternization due to its enlarged surface area. Additionally, the bactericidal efficiency was enhanced by reducing the particle size, because the expanded surface area of the cationic polymer nanoparticles provides more active sites that can kill the bacteria.

Simple acupoints prescription flow chart based on meridian theory: a retrospective study in 102 dogs.

To help the clinicians prescribe acupoints easily and effectively, we developed one simple flow chart to select acupoints. This study aimed to evaluate the usefulness of flow chart to select acupoints in dogs. Total 102 dogs showing intervertebral disc disease (IVDD) (n = 12), vomiting (n = 11), diarrhea (n = 2), abdominal pain (n = 5), cough (n = 66), or epilepsy (n = 6) received acupuncture treatment according to the chart, and its outcomes were evaluated as regards clinical symptoms, duration, treatment numbers, and recovery time. Dogs (8/8) with IVDD from grades I to III recovered over periods of 5 days to 6 weeks after 1-12 treatments, while 1/4 dogs with grade IV recovered over 7 weeks after 15 treatments. Vomiting dogs with acute/subacute (n = 8) and chronic symptoms (n = 3) required about 1 and 7 treatments to recover fully, respectively. All dogs (n = 5) with abdominal pain showed fast relief within 24 hours after acupuncture. Two diarrhea cases recovered over 2-9 days after 1-2 treatments. Fifty-four of 66 coughing dogs were recovered by 1-2 treatments. And 5 of 6 epilepsy dogs under a regular acupuncture treatment had no epileptic episode during followup of 12 months. These results suggest that this flow chart can help the clinicians prescribe acupoints effectively.

Controllable synthesis of highly conductive polyaniline coated silica nanoparticles using self-stabilized dispersion polymerization.

Highly conductive silica/polyaniline (PANi) core/shell nanoparticles (NPs) were synthesized in various diameters (from 18 to 130 nm) using self-stabilized dispersion polymerization. The polymerization was carried out in an aqueous/organic liquid system at -30 °C. In this system, the organic phase plays a key role in directing para-direction oriented polymerization of the PANi on the surface of silica NPs. Because of its para-direction polymerized structure, the synthesized silica/PANi core/shell NPs exhibited enhanced electrical conductivity (25.6 S cm(-1)) compared with NPs (1.4 S cm(-1)) prepared by homogeneous polymerization. The conductivities and BET surface areas were 25.6 S cm(-1)/170 m(2) g(-1) (18 nm in diameter), 22.5 S cm(-1)/111 m(2) g(-1) (35 nm in diameter), 18.3 S cm(-1)/78 m(2) g(-1) (63 nm in diameter), and 16.4 S cm(-1)/53 m(2) g(-1) (130 nm in diameter). In this series, increased para-coupling along the polymer backbone was elucidated using several characterization techniques, including Fourier transform infrared (FTIR), X-ray diffraction (XRD), and nuclear magnetic resonance (NMR) spectroscopy. As-prepared silica/PANi core/shell NPs exhibited capacitance as high as 305 F g(-1).

Aqueous synthesis of silver nanoparticle embedded cationic polymer nanofibers and their antibacterial activity.

This paper describes the one-pot, aqueous synthesis of cationic polymer nanofibers with embedded silver nanoparticles. Poly[2-(tert-butylaminoethyl) methacrylate] (PTBAM) was used as a cationic polymer substrate to reinforce the antimicrobial activity of the embedded silver nanoparticles. Electron microscope analyses revealed that the as-synthesized nanofibers had diameters of approximately 40 nm and lengths up to about 10 µm. Additionally, silver nanoparticles of approximately 8 nm in diameter were finely embedded into the prepared nanofibers. The embedded silver nanoparticles had a lower tendency to agglomerate than colloidal silver nanoparticles of comparable size. In addition, the nanofibers with embedded silver nanoparticles exhibited excellent antibacterial performance against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. Interestingly, the prepared nanofibers exhibited enhanced bactericidal performance compared with the silver-embedded poly(methyl methacrylate) (PMMA) nanofibers, presumably because of the antibacterial properties of the PTBAM substrate.

Fluorescent europium-modified polymer nanoparticles for rapid and sensitive anthrax sensors.

Novel fluorescent polyacrylonitrile nanoparticles were synthesized by microemulsion polymerization and Schiff base modification. By further modification with europium, the polyacrylonitrile nanoparticles could be used as a highly sensitive and rapid sensor for Bacillus anthracis spore detection in aqueous solution. The europium-modified polyacrylonitrile nanoparticles were readily combined with dipicolinic acid as a unique biomarker of B. anthracis, leading to high fluorescence emission. These nanoparticles enabled ratiometric detection without instrument-specific calibration due to the internal fluorescence reference. Additionally, the europium-modified polyacrylonitrile nanoparticle sensors exhibited a remarkable limit of detection (10pM) for dipicolinic acid and outstanding selectivity (160×) over aromatic ligands in aqueous solution. The ultrafine nanoparticle sensor showed a high capability for detecting anthrax due to the increased surface area-to-volume ratio and enhanced dispersibility.

Electrospun ZnO/TiO2 composite nanofibers as a bactericidal agent.

Novel ZnO/TiO(2) composite nanofibers were fabricated by an electrospinning method and showed excellent antimicrobial activity against gram-negative Escherichia coli and gram-positive Staphylococcus aureus under UV irradiation and in the absence of light.

Adsorption of heavy metal ions from aqueous solution by polyrhodanine-encapsulated magnetic nanoparticles.

Polyrhodanine-coated γ-Fe(2)O(3) nanoparticles, synthesized by one-step chemical oxidation polymerization, were applied to the process of removal of heavy metal ions from aqueous solution. Factors influencing the uptake of heavy metal ions such as solution pH, initial metal ion concentration, contact time, and species of metal ions were investigated systematically by batch experiments. The adsorption equilibrium study exhibited that the Hg(II) ion adsorption of polyrhodanine-coated magnetic nanoparticles followed a Freundlich isotherm model than a Langmuir model. The kinetic data of adsorption of Hg(II) ion on the synthesized adsorbents were best described by a pseudo-second-order equation, indicating their chemical adsorption. In addition, the synthesized nano-adsorbents can be repeatedly used with help of an external magnetic field due to their magnetic properties. This work demonstrates that the magnetic polyrhodanine nanoparticles can be considered as a potential recyclable adsorbent for hazardous metal ions from wastewater.

Polyrhodanine modified anodic aluminum oxide membrane for heavy metal ions removal.

Polyrhodanine was immobilized onto the inner surface of anodic aluminum oxide (AAO) membrane via vapor deposition polymerization method. The polyrhodanine modified membrane was applied to remove heavy metal ions from aqueous solution because polyrhodanine could be coordinated with specific metal ions. Several parameters such as initial metal concentration, contact time and metal species were evaluated systematically for uptake efficiencies of the fabricated membrane under continuous flow condition. Adsorption isotherms of Hg(II) ion on the AAO-polyrhodanine membrane were analyzed with Langmuir and Freundlich isotherm models. The adsorption rate of Hg(II) ion on the membrane was obeyed by a pseudo-second order equation, indicating the chemical adsorption. The maximum removal capacity of Hg(II) ion onto the fabricated membrane was measured to be 4.2 mmol/g polymer. The AAO-polyrhodanine membrane had also remarkable uptake performance toward Ag(I) and Pb(II) ions. Furthermore, the polyrhodanine modified membrane could be recycled after recovery process. These results demonstrated that the polyrhodanine modified AAO membrane provided potential applications for removing the hazardous heavy metal ions from wastewater.

Bacterial adhesion inhibition of the quaternary ammonium functionalized silica nanoparticles.

Quaternary ammonium compounds have been considered as excellent antibacterial agents due to their effective biocidal activity, long term durability and environmentally friendly performance. In this work, 3-(trimethoxysilyl)-propyldimethyloctadecylammonium chloride as a quaternary ammonium silane was applied for the surface modification of silica nanoparticles. The quaternary ammonium silane provided silica surface with hydrophobicity and antibacterial properties. In addition, the glass surface which was coated with the surface modified silica nanoparticles presented bacterial growth inhibition activity. For comparison of bacterial growth resistance, hydrophobic silane (alkyl functionalized silane) modified silica nanoparticles and pristine silica nanoparticles were prepared. As a result of bacterial adhesion test, the quaternary ammonium functionalized silica nanoparticles exhibited the enhanced inhibition performance against growth of Gram-negative Escherichia coli (96.6%), Gram-positive Staphylococcus aureus (98.5%) and Deinococcus geothermalis (99.6%) compared to pristine silica nanoparticles. These bacteria resistances also were stronger than that of hydrophobically modified silica nanoparticles. It could be explained that the improved bacteria inhibition performance originated from the synergistic effect of hydrophobicity and antibacterial property of quaternary ammonium silane. Additionally, the antimicrobial efficacy of the fabricated nanoparticles increased with decreasing size of the nanoparticles.

One-step fabrication of magnetic gamma-Fe2O3/polyrhodanine nanoparticles using in situ chemical oxidation polymerization and their antibacterial properties.

Ferromagnetic gamma-Fe(2)O(3)/polyrhodanine nanoparticles with average diameters of ca. 10 nm were prepared by a one-step synthetic procedure and applied as a recyclable antibacterial agent towards Gram-negative/positive bacteria.

Photoluminescent polymer nanoparticles for label-free cellular imaging.

Novel polymer based photoluminescent nanoparticles were fabricated by ultra-sound induced emulsion polymerization and applied to bioimaging of human breast cancer SK-BR-3 cells after ethylenediamine treatment and conjugation with anti-ErbB2 antibody.

Photocatalytic antibacterial capabilities of TiO(2)-biocidal polymer nanocomposites synthesized by a surface-initiated photopolymerization.

Novel biocidal polymer-functionalized TiO(2) nanoparticles were prepared by surface-initiated photopolymerization using titania as an initiator. Vinyl monomer mixtures of nontoxic secondary amine-containing biocidal 2-(tert-butylamino)ethyl methacrylate and antifouling ethylene glycol dimethacrylate were used for the antimicrobial polymer shell. It was shown that the synthesized TiO(2)/poly[2-(tert-butylamino)ethyl methacrylate-co-ethylene glycol dimethacrylate] core/shell nanoparticles had enhanced photocatalytic antibacterial properties compared to the pristine TiO(2) nanoparticles due to the combined antibacterial activities of light-driven anti-infective TiO(2) core and biocidal polymer shell. In the dark condition, the TiO(2)/biocidal polymer nanoparticles exhibited high antimicrobial efficiency (95.7%) against gram-positive S. aureus. Furthermore, during UV irradiation, the TiO(2)/biocidal polymer showed improved inhibition of bacterial growth against gram-negative E. coli and gram-positive S. aureus in comparison to the pristine TiO(2) nanoparticles.

Enhanced antibacterial performance of cationic polymer modified silica nanoparticles.

Vapor deposition polymerization was applied for the fabrication of cationic polymer modified silica nanoparticles and the synthesized nanoparticles exhibited enhanced antimicrobial properties compared to bulk polycations and reduced bioadhesion on the surface of glass.

One-step preparation of antimicrobial polyrhodanine nanotubes with silver nanoparticles.

A simple synthetic method has been developed for the fabrication of antimicrobial polyrhodanine nanotubes with silver nanoparticles. Rhodanine monomer first forms one-dimensional complexes with silver ions due to coordinative interactions and consecutively reduces the silver ions during chemical-oxidation polymerization. The polymerization procedure is analyzed by transmission electron microscopy and scanning electron microscopy in situ. The synthesized silver nanoparticles/polyrhodanine nanotubes are applied as an antimicrobial agent against Gram-negative bacteria, E. coli and Gram-positive bacteria, S. aureus. The antimicrobial tests demonstrate that the silver/polyrhodanine nanotubes have superior antimicrobial properties to silver nanoparticles and rhodanine monomer.

Development of a rapid planning technique based on heuristic target shaping for stereotactic radiosurgery.

Stereotactic radiosurgery (SRS) is a technique to delivering a high dose to a target region and a low dose to a critical organ by using only one or a few irradiations. Traditionally, SRS is performed using a Gamma knife with using 201 cobalt 60 sources or a linear accelerator with equally spaced noncoplanar arcs. Finding a specific condition that includes the target in the prescription dose while sparing the critical organ is tedious, because there are many combinations of positions and collimator sizes for each isocenter. Many methods of identifying suitable planning condition automatically have been proposed. However, there are some limitations using these methods. These include a long calculation time to obtain the final plan, and difficulties finding a unique solution due to different tumor shapes. This study uses three steps to solve these problems. (1) The dose distribution of one isocenter is modeled as a sphere. This makes it possible to reduce the time needed to obtain the result due to the absence of a dose calculation. (2) The target was constructed by piling up cylinders along a virtual axis, which was the longest line in a given target. (3) Spheres were then packed in each cylinder according to the position and diameter of each cylinder in order to cover each target divided by the height of the cylinder. The results of applying three imaginary targets were found to be satisfactory in terms of: target coverage-more than 50%, the reproducibility of the result and the calculation time-several tens of seconds. The PITV ratio was less than 2.0. However, the dose applied to normal tissue around the target must be reduced slightly. Planner or conventional optimization algorithms might easily solve this limitation.