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Nanoparticles and molecular imaging

Michael I Jacobs, Bo Xu, Oleg Kostko, Nadja Heine, Musahid Ahmed, Kevin R Wilson
The heterogeneous reaction of ozone (O3) with 200 nm squalene nanoparticles is studied using near edge X-ray absorption fine structure (NEXAFS), ultraviolet (UPS) and X-ray photoelectron spectroscopy (XPS). Photoelectrons are detected from free nanoparticle beams using a velocity map imaging (VMI) spectrometer capable of detecting photoelectrons with up to 40 eV of kinetic energy. Heterogeneous kinetics are quantified using changes in the UPS, XPS and NEXAFS spectrum, yielding uptake coefficients for the decay of the double bonds in squalene of (3...
October 17, 2016: Journal of Physical Chemistry. A
Arnav Mehta, Ketan Ghaghada, Srinivasan Mukundan
The first generation of cross-sectional brain imaging using computed tomography (CT), ultrasonography, and eventually MR imaging focused on determining structural or anatomic changes associated with brain disorders. The current state-of-the-art imaging, functional imaging, uses techniques such as CT and MR perfusion that allow determination of physiologic parameters in vivo. In parallel, tissue-based genomic, transcriptomic, and proteomic profiling of brain tumors has created several novel and exciting possibilities for molecular targeting of brain tumors...
November 2016: Magnetic Resonance Imaging Clinics of North America
Panagiotis Angelikopoulos, Lev Sarkisov, Zoe Cournia, Paraskevi Gkeka
Ligand-functionalized nanoparticles (NPs) are a promising platform for imaging and drug delivery applications. A number of recent molecular simulation and theoretical studies explored how these NPs interact with model lipid membranes. However, interactions between ligand-coated NPs leading to possible cooperative effects and association have not been investigated. In this coarse-grained molecular dynamics study, we focus on a specific case of several anionic, ligand-coated NPs embedded in a lipid membrane. Several new effects are observed...
October 14, 2016: Nanoscale
Peng Mi, Fang Wang, Nobuhiro Nishiyama, Horacio Cabral
Several imaging modalities have been widely applied for the detection of cancer and its pathological activity in combination with probes capable of improving the contrast between healthy and cancerous tissues. Biocompatible polymeric nanoassemblies have been developed for precise detection of malignant tumors by enhancing the selectivity and sensitivity of the imaging. Exploiting the compartmentalized structure of the nanoassemblies advantageously allows delivering both imaging and therapeutic agents for cancer multifunctional imaging and theranostics, i...
October 14, 2016: Macromolecular Bioscience
Avnesh S Thakor, Jessie V Jokerst, Pejman Ghanouni, Jos Campbell, Erik Mittra, Sam S Gambhir
Nanoparticles (NPs) are new class of imaging agents that can be used for both anatomic and molecular imaging due to their small size and unique properties. Nanoparticle-based imaging exploits the signal intensity, stability, and biodistribution behavior of sub-micron diameter molecular imaging agents. This review focuses on nanoparticles used in human medical imaging with an emphasis on radionuclide and magnetic resonance imaging. Newer nanoparticle platforms are also discussed in relation to theranostic and multimodal nanoparticles...
October 13, 2016: Journal of Nuclear Medicine: Official Publication, Society of Nuclear Medicine
G Veronesi, A Deniaud, T Gallon, P-H Jouneau, J Villanova, P Delangle, M Carrière, I Kieffer, P Charbonnier, E Mintz, I Michaud-Soret
Silver nanoparticles (AgNPs) can enter eukaryotic cells and exert toxic effects, most probably as a consequence of the release of Ag(+) ions. Due to the elusive nature of Ag(+) ionic species, quantitative information concerning AgNP intracellular dissolution is missing. By using a synchrotron nanoprobe, silver is visualized and quantified in hepatocytes (HepG2) exposed to AgNPs; the synergistic use of electron microscopy allows for the discrimination between nanoparticular and ionic forms of silver within a single cell...
September 29, 2016: Nanoscale
Leïla Zerkoune, Sylviane Lesieur, Jean-Luc Putaux, Luc Choisnard, Annabelle Gèze, Denis Wouessidjewe, Borislav Angelov, Corinne Vebert-Nardin, James Doutch, Angelina Angelova
Soft mesoporous hierarchically structured particles were created by the self-assembly of an amphiphilic deep cavitand cyclodextrin βCD-nC10 (degree of substitution n = 7.3), with a nanocavity grafted by multiple alkyl (C10) chains on the secondary face of the βCD macrocycle through enzymatic biotransesterification, and the nonlamellar lipid monoolein (MO). The effect of the non-ionic dispersing agent polysorbate 80 (P80) on the liquid crystalline organization of the nanocarriers and their stability was studied in the context of vesicle-to-cubosome transition...
September 13, 2016: Soft Matter
Feriel Melaine, Clothilde Coilhac, Yoann Roupioz, Arnaud Buhot
Small molecules (MW < 1000 Da) represent a large class of biomarkers of interest. Recently, a new class of biosensors has been emerging thanks to the recognition properties of aptamers, short DNA or RNA single strands, selected against such small molecular targets. Among them, an adenosine-specific aptamer has been largely described and used due to its remarkable affinity to this small target (KD = 6 μM). In this paper, we achieved the proof-of-principle of an aptasensor based on the thermodynamic follow-up of adenosine binding with engineered split-aptamer sequences...
September 29, 2016: Nanoscale
Jane Politi, Jolanda Spadavecchia, Gabriella Fiorentino, Immacolata Antonucci, Luca De Stefano
Water sources pollution by arsenic ions is a serious environmental problem all around the world. Arsenate reductase enzyme (TtArsC) from Thermus thermophilus extremophile bacterium, naturally binds arsenic ions, As(V) and As (III), in aqueous solutions. In this research, TtArsC enzyme adsorption onto hybrid polyethylene glycol-stabilized gold nanoparticles (AuNPs) was studied at different pH values as an innovative nanobiosystem for metal concentration monitoring. Characterizations were performed by UV/Vis and circular dichroism spectroscopies, TEM images and in terms of surface charge changes...
October 2016: Journal of the Royal Society, Interface
Yuan Wang, Yunqing Wang, Wenhai Wang, Kaoxiang Sun, Lingxin Chen
Reporter embedded (RE) tags are a new generation of sensitive, stable surface enhanced Raman scattering (SERS) tags with Raman reporters embedded between gold nanoparticle (NP) cores and gold (or silver) shells. Most of the reported RE tags have been designed using Au nanospheres as a seed material. Herein, we investigated the synthesis and SERS properties of AuNR/reporter/Ag tags by using gold nanorod (AuNR) seeds with anisotropic physical and optical features. Several highlighted points were discovered, including the following: 1) The cetyltrimethylammonium bromide (CTAB) layer induced the co-existence of chemically and physically adsorbed Raman reporters on AuNR...
October 3, 2016: ACS Applied Materials & Interfaces
Karen Y P S Avelino, Isaac A M Frias, Norma Lucena-Silva, Renan G Gomes, Celso P de Melo, Maria D L Oliveira, César A S Andrade
In the last ten years, conjugated polymers started to be used in the immobilization of nucleic acids via non-covalent interactions. In the present study, we describe the construction and use of an electrochemical DNA biosensor based on a nanostructured polyaniline-gold composite, specifically developed for the detection of the BCR/ABL chimeric oncogene. This chromosome translocation is used as a biomarker to confirm the clinical diagnosis of both chronic myelogenous leukemia (CML) and acute lymphocytic leukemia (ALL)...
September 22, 2016: Colloids and Surfaces. B, Biointerfaces
Soyoung Kang, Yu Wang, Nicholas P Reder, Jonathan T C Liu
Biomarker-targeted surface-enhanced Raman scattering (SERS) nanoparticles (NPs) have been explored as a viable option for targeting and imaging multiple cell-surface protein biomarkers of cancer. While it has been demonstrated that this Raman-encoded molecular imaging (REMI) technology may potentially be used to guide tumor-resection procedures, the REMI strategy would benefit from further improvements in imaging speed. Previous implementations of REMI have utilized 1024 spectral channels (camera pixels) in a commercial spectroscopic CCD to detect the spectral signals from multiplexed SERS NPs, a strategy that enables accurate demultiplexing of the relative concentration of each NP "flavor" within a mixture...
2016: PloS One
Junxin Wang, Fang Chen, Santiago J Arconada-Alvarez, James Hartanto, Li-Peng Yap, Ryan Park, Fang Wang, Ivetta Vorobyova, Grant Dagliyan, Peter S Conti, Jesse V Jokerst
Heparin anticoagulation therapy is an indispensable feature of clinical care yet has a narrow therapeutic window and is the second most common intensive care unit (ICU) medication error. The active partial thromboplastin time (aPTT) monitors heparin but suffers from long turnaround times, a variable reference range, limited utility with low molecular weight heparin, and poor correlation to dose. Here, we describe a photoacoustic imaging technique to monitor heparin concentration using methylene blue as a simple and Federal Drug Administration-approved contrast agent...
September 28, 2016: Nano Letters
Hao Yang, Peter Ercius, Peter D Nellist, Colin Ophus
The ability to image light elements in both crystalline and noncrystalline materials at near atomic resolution with an enhanced contrast is highly advantageous to understand the structure and properties of a wide range of beam sensitive materials including biological specimens and molecular hetero-structures. This requires the imaging system to have an efficient phase contrast transfer at both low and high spatial frequencies. In this work we introduce a new phase contrast imaging method in a scanning transmission electron microscope (STEM) using a pre-specimen phase plate in the probe forming aperture, combined with a fast pixelated detector to record diffraction patterns at every probe position, and phase reconstruction using ptychography...
September 14, 2016: Ultramicroscopy
Yue Hu, Yong Wang, Jianshuai Jiang, Baosan Han, Shengmin Zhang, Keshi Li, ShuXiong Ge, Yahui Liu
A folate-polyethylene glycol-chitosan derivative was synthesized and its structure was characterized. An optimal perfluorooctyl bromide nanocore template was obtained via utilizing the ultrasonic emulsification method combining with orthogonal design. The targeted nanoparticles containing targeted shell of folate-polyethylene glycol-chitosan derivative and perfluorooctyl bromide nanocore template of ultrasound imaging were prepared successfully by exploiting layer-by-layer self-assembly as contrast agent for ultrasound...
2016: BioMed Research International
Zhi Li, Xuewen He, Xucheng Luo, Li Wang, Nan Ma
Inorganic nanocrystals, such as quantum dots (QDs), hold great promise as molecular imaging contrast agents because of their superior optical properties. However, the molecular imaging sensitivity of these probes is far from optimized due to the lack of efficient and general method for molecular engineering of nanocrystal into effective bioprobes for signal-amplified imaging. Herein, we develop a strategy to boost the molecular imaging sensitivity of QDs over the limit by copolymerizing QDs and cell-binding aptamers into linear QD-aptamer polymers (QAPs) through DNA-programmed hybridization chain reaction...
October 4, 2016: Analytical Chemistry
Chiara Lico, Paola Giardullo, Mariateresa Mancuso, Eugenio Benvenuto, Luca Santi, Selene Baschieri
Self-assembling plant virus nanoparticles (pVNPs) have started to be explored as nanometre-sized objects for biomedical applications, such as vaccine or drug delivery and imaging. Plant VNPs may be ideal tools in terms of biocompatibility and biodegradability endowed with a wide diversity of symmetries and dimensions, easy chemical/biological engineering, and rapid production in plants. Recently, we defined that icosahedral Tomato bushy stunt virus (TBSV) and filamentous Potato virus X (PVX) are neither toxic nor teratogenic...
September 14, 2016: Colloids and Surfaces. B, Biointerfaces
Qianwen Ding, Qiuqiang Zhan, Xiaoming Zhou, Tao Zhang, Da Xing
Remote optical detection and imaging of specific tumor-related biomarkers and simultaneous activation of therapy according to the expression level of the biomarkers in tumor site with theranostic probes should be an effective modality for treatment of cancers. Herein, an upconversion nanobeacon (UCNPs-MB/Dox) is proposed as a new theranostic nanoprobe to ratiometrically detect and visualize the thymidine kinase 1 (TK1) mRNA that can simultaneously trigger the Dox release to activate the chemotherapy accordingly...
September 20, 2016: Small
Alshaimaa A Abdelmoez, Gudrun C Thurner, Paul Debbage
No abstract text is available yet for this article.
September 19, 2016: International Journal of Clinical Pharmacology and Therapeutics
Prabhani U Atukorale, Gil Covarrubias, Lisa Bauer, Efstathios Karathanasis
This review seeks to highlight the enormous potential of targeted nanoparticles for molecular imaging applications. Being the closest point-of-contact, circulating nanoparticles can gain direct access to targetable molecular markers of disease that appear on the endothelium. Further, nanoparticles are ideally suitable to vascular targeting due to geometrically enhanced multivalent attachment on the vascular target. This natural synergy between nanoparticles, vascular targeting and molecular imaging can provide new avenues for diagnosis and prognosis of disease with quantitative precision...
September 15, 2016: Advanced Drug Delivery Reviews
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