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News Article | April 17, 2017
Site: www.eurekalert.org

PORTLAND, Ore. - A new cancer-drug delivery system shows the ability to exploit the oxygen-poor areas of solid tumors that make the growths resistant to standard chemotherapy and radiation treatment. Carcinomas that affect the breast, lung, prostate and colon are among these solid-tumor cancers, as are malignancies in the lymphatic system, known as lymphomas, and the much less common sarcomas that arise in connective tissue. These solid masses often contain hypoxic regions, where the concentration of oxygen in the tissue is low. Hypoxic cancer cells grow slowly, and that makes them less susceptible to the drugs prescribed to kill or damage them. Researchers at Oregon State University have found a way to turn the tables on those cells using a "prodrug" loaded into nanostructured platforms. A prodrug is a pharmacologically inactive compound that the body metabolizes into an active drug, in this case the cancer drug vinblastine. Provided with the prodrug vinblastine-N-oxide by research partners at Cascade Prodrug Inc. of Eugene, Oregon, OSU scientists developed two different lipid-based platform formulations known as liposomes to carry the prodrug to the tumor's hypoxic regions. There, the lack of oxygen triggers its metabolic conversion to vinblastine. In both formulations - one with polyethylene glycol on its surface, one without - the prodrug proved both safe and much more effective against non-small cell lung cancer than when it was delivered without a liposome. "One of the hallmarks of these solid tumors is their hypoxic regions," said the study's lead author, Adam Alani of the OSU College of Pharmacy. "One reason these cancers become very aggressive is the development of this hypoxia. Since the late 1990s, researchers have been trying to take advantage of the hypoxia. "The tumor model we chose, lung cancer, is one of the very well established tumors and there's a very strong hypoxia associated with that - as well as, lung cancer is one of these cancers that in its advanced stages, it's a terminal disease, and there's a need for new treatments." By itself, vinblastine-N-oxide had shown less than optimal efficacy in testing by Cascade Prodrug because of how fast the body clears it from the system - it has a half-life of less than half an hour. "When it was tested in mice and dogs, it did not have a chance to assimilate in the cancer tissue to produce the desired pharmacological effect," Alani said. But the liposomes - both the "pegylated" one containing polyethylene glycol, and the non-pegylated one - increased the half-life dramatically to 9.5 and 5.5 hours, respectively. "The nano carriers performed much better than the prodrug itself," Alani said. "We were able to literally cure the tumor." Alani's research began with laboratory cultures and progressed to safety and efficacy testing in animals. "We made sure the nanostructure platform worked properly against lung cancer in vitro, then looked at the safety of the formulation in healthy mice and looked at the maximum tolerated dose - the biggest dose you can use without producing side effects," Alani said. "Then we determined how long the nano carriers could keep the drug in the blood compared to the drug without the nanostructures." When those data were "very encouraging," Alani's team assessed the efficacy of the formulations in mice that had tumors grafted into them. Without any liposome, the drug showed some tumor suppression, but the mice that had received the drug alone had to be euthanized after 70 days because of tumors that were no longer being controlled. Mice that had received the drug with one of the liposomes were healthy and tumor-free for the nearly 100-day run of the experiment. "The formulations clearly performed better than the unformulated drug as well as much better than Cisplatin, the standard-of-care drug for this research," Alani said. "Now we're collaborating with Cascade Prodrug and the College of Veterinary Medicine to assess safety and efficacy in dog models, and trying to look at other tumors, like bladder cancer, associated with dogs." One goal, Alani said, is to develop a new treatment for cancer in dogs, and another is to look at dogs as a model for drug development - "to get data Cascade can use to move the process forward for approval for use in dogs, as well as preliminary data for a new drug application with the FDA," Alani said. The Oregon Nanoscience and Microtechnologies Institute supported this research. Findings were recently published in the Journal of Controlled Release. Co-authors on the paper were Alani's colleagues in the Department of Pharmaceutical Sciences, Vidhi Shah, Duc Nguyen and Adel Alfatease, and Shay Bracha of the OSU veterinary college's Department of Clinical Sciences.


Carroll C.N.,University of Oregon | Carroll C.N.,Oregon Nanoscience and Microtechnologies Institute | Naleway J.J.,Oregon Nanoscience and Microtechnologies Institute | Naleway J.J.,Marker Gene Technologies | And 4 more authors.
Chemical Society Reviews | Year: 2010

This critical review will focus on the application of shape-persistent receptors for anions that derive their rigidity and optoelectronic properties from the inclusion of arylethynyl linkages. It will highlight a few of the design strategies involved in engineering selective and sensitive fluorescent probes and how arylacetylenes can offer a design pathway to some of the more desirable properties of a selective sensor. Additionally, knowledge gained in the study of these receptors in organic media often leads to improved receptor design and the production of chromogenic and fluorogenic probes capable of detecting specific substrates among the multitude of ions present in biological systems. In this ocean of potential targets exists a large number of geometrically distinct anions, which present their own problems to the design of receptors with complementary binding for each preferred coordination geometry. Our interest in targeting charged substrates, specifically how previous work on receptors for cations or neutral guests can be adapted to anions, will be addressed. Additionally, we will focus on the design and development of supramolecular arylethynyl systems, their shape-persistence and fluorogenic or chromogenic optoelectronic responses to complexation. We will also examine briefly how the "chemistry in the cuvet" translates into biological media (125 references). © 2010 The Royal Society of Chemistry.


Atkins R.,University of Oregon | Atkins R.,Oregon Nanoscience and Microtechnologies Institute | Wilson J.,University of Oregon | Wilson J.,Oregon Nanoscience and Microtechnologies Institute | And 5 more authors.
Chemistry of Materials | Year: 2012

A modification of the modulated elemental reactants synthetic technique was developed and used to synthesize eleven members of the [(SnSe) 1.15]m(TaSe2)n family of compounds, with m and n equal to integer values between 1 and 6. Each of the intergrowth compounds contained highly oriented intergrowths of SnSe bilayers and TaSe 2 monolayers with abrupt interfaces perpendicular to the c-axis. The c-lattice parameter increased 0.579(1) nm per SnSe bilayer and 0.649(1) nm per Se-Ta-Se trilayer (TaSe2) as m and n were varied. ab-plane X-ray diffraction patterns and transmission electron microscope images revealed a square in-plane structure of the SnSe constituent, a hexagonal in-plane structure for the TaSe2 constituent, and rotational disorder between the constituent layers. Temperature dependent electrical resistivity, measured on several specimens, revealed metallic behavior, and a simple model is presented to explain the differences in resistivity as a function of m and n. © 2012 American Chemical Society.


Mensinger Z.L.,University of Oregon | Mensinger Z.L.,Oregon Nanoscience and Microtechnologies Institute | Mensinger Z.L.,Oregon State University | Wang W.,Oregon Nanoscience and Microtechnologies Institute | And 6 more authors.
Chemical Society Reviews | Year: 2012

This tutorial review surveys the wide variety of oligomeric hydroxide structures formed from aluminum, gallium, and indium. Both inorganic and ligand-supported structures are reviewed, providing a leading introduction to this research area. In addition to homometallic clusters comprising only one metal type, a series of heterometallic structures are described. This review highlights the synthesis and characterization of these nanoscale cluster compounds that have implications in a variety of fields, including catalysis, mineral mimicry, environmental chemistry, geochemistry, materials science, and semiconductors. © 2012 The Royal Society of Chemistry.


Enneti R.K.,Global Tungsten and Powders Corporation | Park S.J.,Pohang University of Science and Technology | German R.M.,San Diego State University | Atre S.V.,Oregon Nanoscience and Microtechnologies Institute
Materials and Manufacturing Processes | Year: 2012

Developing a rapid and efficient method for removing polymers (termed binders) from a shaped powder component, know as a green body, is important to forming defect-free metal, ceramic, and cermet structures. The rapid growth in powder injection molding to form complex shapes at high precision in large quantities has increased the need for faster, cleaner, and cheaper polymer removal processes. Binder removal using controlled heating of the component in gaseous atmosphere is the most popular method. This thermal debinding or burnout process is a delicate process, since it is easy to crack, blister, slump, or otherwise damage the component with an improperly designed cycle. To avoid these issues, often long heating cycles are used to remove the binder, but with a loss of productivity. Considerable progress has been made over the past several decades in understanding various phenomena during polymer burnout, resulting in substantial reduction in the thermal debinding time. This article provides an overview of the research carried out on thermal debinding process (primarily from powder injection molded samples) with major emphasis on progress reported over the last fifteen years. This review article proposes a model to predict the formation of defects during all stages of thermal debinding and suggests future research direction in the field. © 2012 Copyright Taylor and Francis Group, LLC.


News Article | December 22, 2016
Site: www.eurekalert.org

CORVALLIS, Ore. - Faster production of advanced, flexible electronics is among the potential benefits of a discovery by researchers at Oregon State University's College of Engineering. Taking a deeper look at photonic sintering of silver nanoparticle films -- the use of intense pulsed light, or IPL, to rapidly fuse functional conductive nanoparticles -- scientists uncovered a relationship between film temperature and densification. Densification in IPL increases the density of a nanoparticle thin-film or pattern, with greater density leading to functional improvements such as greater electrical conductivity. The engineers found a temperature turning point in IPL despite no change in pulsing energy, and discovered that this turning point appears because densification during IPL reduces the nanoparticles' ability to absorb further energy from the light. This previously unknown interaction between optical absorption and densification creates a new understanding of why densification levels off after the temperature turning point in IPL, and further enables large-area, high-speed IPL to realize its full potential as a scalable and efficient manufacturing process. Rajiv Malhotra, assistant professor of mechanical engineering at OSU, and graduate student Shalu Bansal conducted the research. The results were recently published in Nanotechnology. "For some applications we want to have maximum density possible," Malhotra said. "For some we don't. Thus, it becomes important to control the densification of the material. Since densification in IPL depends significantly on the temperature, it is important to understand and control temperature evolution during the process. This research can lead to much better process control and equipment design in IPL." Intense pulsed light sintering allows for faster densification -- in a matter of seconds - over larger areas compared to conventional sintering processes such as oven-based and laser-based. IPL can potentially be used to sinter nanoparticles for applications in printed electronics, solar cells, gas sensing and photocatalysis. Earlier research showed that nanoparticle densification begins above a critical optical fluence per pulse but that it does not change significantly beyond a certain number of pulses. This OSU study explains why, for a constant fluence, there is a critical number of pulses beyond which the densification levels off. "The leveling off in density occurs even though there's been no change in the optical energy and even though densification is not complete," Malhotra said. "It occurs because of the temperature history of the nanoparticle film, i.e. the temperature turning point. The combination of fluence and pulses needs to be carefully considered to make sure you get the film density you want." A smaller number of high-fluence pulses quickly produces high density. For greater density control, a larger number of low-fluence pulses is required. "We were sintering in around 20 seconds with a maximum temperature of around 250 degrees Celsius in this work," Malhotra. "More recent work we have done can sinter within less than two seconds and at much lower temperatures, down to around 120 degrees Celsius. Lower temperature is critical to flexible electronics manufacturing. To lower costs, we want to print these flexible electronics on substrates like paper and plastic, which would burn or melt at higher temperatures. By using IPL, we should be able to create production processes that are both faster and cheaper, without a loss in product quality." Products that could evolve from the research, Malhotra said, are radiofrequency identification tags, a wide range of flexible electronics, wearable biomedical sensors, and sensing devices for environmental applications. The advance in IPL resulted from a four-year, $1.5 million National Science Foundation Scalable Nanomanufacturing Grant in collaboration with OSU researchers Chih-hung Chang, Alan Wang and Greg Herman. The grant focuses on overcoming scientific barriers to industry-level nanomanufacturing. Support also came from the Murdock Charitable Trust and the Oregon Nanoscience and Microtechnologies Institute.


News Article | December 23, 2016
Site: www.nanotech-now.com

Abstract: Faster production of advanced, flexible electronics is among the potential benefits of a discovery by researchers at Oregon State University's College of Engineering. Taking a deeper look at photonic sintering of silver nanoparticle films -- the use of intense pulsed light, or IPL, to rapidly fuse functional conductive nanoparticles -- scientists uncovered a relationship between film temperature and densification. Densification in IPL increases the density of a nanoparticle thin-film or pattern, with greater density leading to functional improvements such as greater electrical conductivity. The engineers found a temperature turning point in IPL despite no change in pulsing energy, and discovered that this turning point appears because densification during IPL reduces the nanoparticles' ability to absorb further energy from the light. This previously unknown interaction between optical absorption and densification creates a new understanding of why densification levels off after the temperature turning point in IPL, and further enables large-area, high-speed IPL to realize its full potential as a scalable and efficient manufacturing process. Rajiv Malhotra, assistant professor of mechanical engineering at OSU, and graduate student Shalu Bansal conducted the research. The results were recently published in Nanotechnology. "For some applications we want to have maximum density possible," Malhotra said. "For some we don't. Thus, it becomes important to control the densification of the material. Since densification in IPL depends significantly on the temperature, it is important to understand and control temperature evolution during the process. This research can lead to much better process control and equipment design in IPL." Intense pulsed light sintering allows for faster densification -- in a matter of seconds - over larger areas compared to conventional sintering processes such as oven-based and laser-based. IPL can potentially be used to sinter nanoparticles for applications in printed electronics, solar cells, gas sensing and photocatalysis. Earlier research showed that nanoparticle densification begins above a critical optical fluence per pulse but that it does not change significantly beyond a certain number of pulses. This OSU study explains why, for a constant fluence, there is a critical number of pulses beyond which the densification levels off. "The leveling off in density occurs even though there's been no change in the optical energy and even though densification is not complete," Malhotra said. "It occurs because of the temperature history of the nanoparticle film, i.e. the temperature turning point. The combination of fluence and pulses needs to be carefully considered to make sure you get the film density you want." A smaller number of high-fluence pulses quickly produces high density. For greater density control, a larger number of low-fluence pulses is required. "We were sintering in around 20 seconds with a maximum temperature of around 250 degrees Celsius in this work," Malhotra. "More recent work we have done can sinter within less than two seconds and at much lower temperatures, down to around 120 degrees Celsius. Lower temperature is critical to flexible electronics manufacturing. To lower costs, we want to print these flexible electronics on substrates like paper and plastic, which would burn or melt at higher temperatures. By using IPL, we should be able to create production processes that are both faster and cheaper, without a loss in product quality." Products that could evolve from the research, Malhotra said, are radiofrequency identification tags, a wide range of flexible electronics, wearable biomedical sensors, and sensing devices for environmental applications. ### The advance in IPL resulted from a four-year, $1.5 million National Science Foundation Scalable Nanomanufacturing Grant in collaboration with OSU researchers Chih-hung Chang, Alan Wang and Greg Herman. The grant focuses on overcoming scientific barriers to industry-level nanomanufacturing. Support also came from the Murdock Charitable Trust and the Oregon Nanoscience and Microtechnologies Institute. For more information, please click If you have a comment, please us. Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.


Moeck P.,Oregon Nanoscience and Microtechnologies Institute | Rouvimov S.,Oregon Nanoscience and Microtechnologies Institute
Zeitschrift fur Kristallographie | Year: 2010

The foundations of precession electron diffraction in a transmission electron microscope are outlined. A brief illustration of the fact that laboratory-based powder X-ray diffraction fingerprinting is not feasible for nano-crystals is given. A procedure for structural fingerprinting of nanocrystals on the basis of structural data that can be extracted from precession electron diffraction spot patterns is proposed. © Oldenbourg Wissenschaftsverlag, München.


Lindquist N.R.,Oregon Nanoscience and Microtechnologies Institute | Carter T.G.,Oregon Nanoscience and Microtechnologies Institute | Cangelosi V.M.,Oregon Nanoscience and Microtechnologies Institute | Zakharov L.N.,Oregon Nanoscience and Microtechnologies Institute | Johnson D.W.,Oregon Nanoscience and Microtechnologies Institute
Chemical Communications | Year: 2010

Three discrete supramolecular self-assembled arsenic(iii) complexes including an unusual S4-symmetric tetranuclear [As4L 2Cl4] metallacyclophane and two diastereomeric cis/trans-[As2LCl2] metallacycle intermediates co-crystallize within a single crystal lattice. © 2010 The Royal Society of Chemistry.


Kim K.-T.,Oregon Nanoscience and Microtechnologies Institute | Truong L.,Oregon Nanoscience and Microtechnologies Institute | Wehmas L.,Oregon Nanoscience and Microtechnologies Institute | Tanguay R.L.,Oregon Nanoscience and Microtechnologies Institute
Nanotechnology | Year: 2013

The mechanism of action of silver nanoparticles (AgNPs) is unclear due to the particles' strong tendency to agglomerate. Preventing agglomeration could offer precise control of the physicochemical properties that drive biological response to AgNPs. In an attempt to control agglomeration, we exposed zebrafish embryos to AgNPs of 20 or 110 nm core size, and polypyrrolidone (PVP) or citrate surface coatings in media of varying ionic strength. AgNPs remained unagglomerated in 62.5 μM CaCl2 (CaCl2) and ultrapure water (UP), but not in standard zebrafish embryo medium (EM). Zebrafish embryos developed normally in the low ionic strength environments of CaCl2 and UP. Exposure of embryos to AgNPs suspended in UP and CaCl2 resulted in higher toxicity than suspensions in EM. 20 nm AgNPs were more toxic than 110 nm AgNPs, and the PVP coating was more toxic than the citrate coating at the same particle core size. The silver tissue burden correlated well with observed toxicity but only for those exposures where the AgNPs remained unagglomerated. Our results demonstrate that size- and surface coating-dependent toxicity is a result of AgNPs remaining unagglomerated, and thus a critical-design consideration for experiments to offer meaningful evaluations of AgNP toxicity. © 2013 IOP Publishing Ltd.

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