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Fluorescent nanoparticles

Joao Paulo Coelho, José Osío Barcina, Elena Junquera, Emilio Aicart, Gloria Tardajos, Sergio Gómez-Graña, Pablo Cruz-Gil, Cástor Salgado, Pablo Díaz-Núñez, Ovidio Peña-Rodríguez, Andrés Guerrero-Martínez
Amphiphilic nonionic ligands, synthesized with a fixed hydrophobic moiety formed by a thiolated alkyl chain and an aromatic ring, and with a hydrophilic tail composed of a variable number of oxyethylene units, were used to functionalize spherical gold nanoparticles (AuNPs) in water. Steady-state and time-resolved fluorescence measurements of the AuNPs in the presence of α-cyclodextrin (α-CD) revealed the formation of supramolecular complexes between the ligand and macrocycle at the surface of the nanocrystals...
March 16, 2018: Nanomaterials
Vaishnavi Rohitkumar Shah, Pardeep K Gupta
PURPOSE: Despite the fact that r-hGH was first approved for use by FDA in 1995 and the conventional dosage form in the market has a limitation of daily subcutaneous injections, there remains a lack of sustained delivery system in the market. Nutropin depot, a long-acting dosage form of r-hGH was approved for marketing by FDA in 1999, however, it was discontinued in 2004. Since then, unabating efforts have been made to develop biodegradable polymer based formulations for r-hGH delivery...
March 15, 2018: Pharmaceutical Research
Marc Pretze, Andreas Hien, Matthias Raedle, Ralf Schirrmacher, Carmen Wängler, Björn Wängler
Gold nanoparticles (AuNPs) have widely been used for 70 years in cancer treatment, but only in the last 15 years the focus has been on specific AuNPs with homogeneous size and shape for various areas in science. They constitute a perfect platform for multi-functionalization and therefore enable the enhancement of target affinity. Here we report on the development of tumor specific AuNPs as diagnostic tools intended for the detection of prostate cancer via fluorescence imaging and positron emission tomography (PET)...
March 15, 2018: Bioconjugate Chemistry
Jin-Wen Liu, Yu-Min Wang, Chong-Hua Zhang, Lu-Ying Duan, Zheng Li, Ru-Qin Yu, Jian-Hui Jiang
Unique physicochemical characteristics of graphitic carbon nitride (g-CN) nanosheets suit them a useful tool for two-photon fluorescence bioimaging. Current g-CN nanosheets based imaging probes typically use the "always-on" design strategies, which may suffer from increased fluorescence background and limited contrast. To advance corresponding applications, g-CN nanosheets based activatable two-photon fluorescence probes remain to be explored. For the first time, we developed an activatable two-photon fluorescence probe, constructed from a nanoassembly of g-CN nanosheets and hyaluronic acid (HA)-gold nanoparticles (HA-AuNPs), for detection and imaging of hyaluronidase (HAase) in cancer cells...
March 15, 2018: Analytical Chemistry
Wei Wang
Nanomaterials exhibit structural and functional heterogeneity among individual nanoparticles, thus requiring a capability to study single nanoparticles. While electron microscopes often provide static images of their chemical composition, morphology and structure, imaging the chemical activity of single nanoparticles is highly desirable for exploring the structure-activity relationship via a bottom-up strategy, to understand their microscopic reaction mechanisms and kinetics, and to identify a minority subpopulation with extraordinary activity...
March 15, 2018: Chemical Society Reviews
Xiaoye Yang, Xiaoqun Shi, Jianbo Ji, Guangxi Zhai
The development of imaging-guided smart drug delivery systems for combinational photodynamic/chemotherapy of the tumor has become highly demanded in oncology. Herein, redox-responsive theranostic polymeric nanoparticles (NPs) were fabricated innovatively using low molecular weight heparin (LWMH) as the backbone. Chlorin e6 (Ce6) and alpha-tocopherol succinate (TOS) were conjugated to LMWH via cystamine as the redox-sensitive linker, forming amphiphilic Ce6-LMWH-TOS (CHT) polymer, which could self-assemble into NPs in water and encapsulate paclitaxel (PTX) inside the inner core (PTX/CHT NPs)...
November 2018: Drug Delivery
Koshonna Brown, Ted Thurn, Lun Xin, William Liu, Remon Bazak, Si Chen, Barry Lai, Stefan Vogt, Chris Jacobsen, Tatjana Paunesku, Gayle E Woloschak
Titanium dioxide (TiO2 ) nanoparticles are produced for many different purposes, including development of therapeutic and diagnostic nanoparticles for cancer detection and treatment, drug delivery, induction of DNA double-strand breaks, and imaging of specific cells and subcellular structures. Currently, the use of optical microscopy, an imaging technique most accessible to biology and medical pathology, to detect TiO2 nanoparticles in cells and tissues ex vivo is limited with low detection limits, while more sensitive imaging methods (transmission electron microscopy, X-ray fluorescence microscopy, etc...
January 2018: Nano Research
Negin Sabziparvar, Yosra Saeedi, Mina Nouri, Atefeh Sadat Najafi Bozorgi, Elahe Alizadeh, Farnoosh Attar, Keivan Akhtari, Seyyedeh Elaheh Mousavi, Mojtaba Falahati
NPs have received a great attention in biological and medical applications due to their unique features. However, their induced adverse effects on the biological system are not well explored. Herein, the interaction of silicon dioxide nanoparticle (SiO2 NP) with human hemoglobin (Hb) and lymphocyte cell line was evaluated under physiological conditions by multi spectroscopic (intrinsic and synchronous fluorescence spectroscopy, and circular dichrosim (CD)), molecular docking, and cellular (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) and acridine orange/ethidium bromide (AO/EB) staining) methods...
March 14, 2018: Journal of Physical Chemistry. B
Gyo Eun Gu, Chul Soon Park, Hyun-Ju Cho, Tai Hwan Ha, Joonwon Bae, Oh Seok Kwon, Jeong-Soo Lee, Chang-Soo Lee
Fluorescent polydopamine nanoparticles (FPNPs) are prepared via the ethylenediamine (EDA)-induced degradation of as-prepared non-fluorescent polydopamine (PDA) and used for targeted bioimaging. The reductive treatment of PDA in the presence of EDA yields fluorescent precipitates, inspiring us to seek various biological approaches to preparing FPNPs with excellent optical and biocompatible properties. Moreover, we firstly found that FPNPs selectively label neuromast hair cells in the lateral line of zebrafish, their applications as a reliable fluorescent indicator to investigate the neuromast hair cells, to in turn determine the viability of hair cells, was demonstrated...
March 13, 2018: Scientific Reports
Sultana Mehbuba Hossain, Ezharul Hoque Chowdhury
Biodegradable inorganic apatite-based particle complex is popular for its pH-sensitivity at the endosomal acidic environment to facilitate drug release following cellular uptake. Despite being a powerful anticancer drug, doxorubicin shows severe off-target effects and therefore would need a carrier for the highest effectiveness. We aimed to chemically modify carbonate apatite (CA) with Krebs cycle intermediates, such as citrate and succinate in order to control the growth of the resultant particles to more efficiently carry and transport the anticancer drug into the cancer cells...
March 11, 2018: Pharmaceutics
Laxman S Walekar, Peidong Hu, Hamed Vafaei Molamahmood, Mingce Long
The integrated system of pyrene and cetyltrimethyl ammonium bromide (CTAB) capped silver nanoparticles (AgNPs) with a distance (r) of 2.78nm has been developed for the detection of Hg (II) and pyrene dimer. The interaction between pyrene and AgNPs results in the fluorescence quenching of pyrene due to the energy transfer, whose mechanism can be attributed to the Forster Resonance Energy Transfer (FRET) supported by experimental observation and theoretical calculations. The developed probe shows a highly selective and sensitive response towards Hg (II) probably due to the amalgam formation, which results in the fluorescence recovery (90%) of pyrene and color change of solution from yellowish brown to colorless...
March 7, 2018: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Daniel González-Mancebo, Ana I Becerro, T Cristina Rojas, Andrés Olivencia, Ariadna Corral, Marcin Balcerzyk, Eugenio Cantelar, Fernando Cussó, Manuel Ocaña
The singular properties of lanthanide-based inorganic nanoparticles (NPs) has raised the attention of the scientific community in biotechnological applications. In particular, those systems with two or more functionalities are especially interesting. In this work, an effective and commercially attractive procedure has been developed that renders uniform, water-dispersible Ln3+ :CeF3 (Ln = Tb, Nd) NPs with different shapes and size. The method consists of the homogeneous precipitation, in a mixture of polyol and water, of cations and anions using precursors that allow the controlled release of the latter...
March 5, 2018: Journal of Colloid and Interface Science
Sajal Shrivastava, Won-Il Lee, Nae-Eung Lee
A critical unmet need in the diagnosis of bacterial infections, which remain a major cause of human morbidity and mortality, is the detection of scarce bacterial pathogens in a variety of samples in a rapid and quantitative manner. Herein, we demonstrate smartphone-based detection of Staphylococcus aureus in a culture-free, rapid, quantitative manner from minimally processed liquid samples using aptamer-functionalized fluorescent magnetic nanoparticles. The tagged S. aureus cells were magnetically captured in a detection cassette, and then fluorescence was imaged using a smartphone camera with a light-emitting diode as the excitation source...
March 6, 2018: Biosensors & Bioelectronics
Marwa M Azab, Rédha Cherif, Aryanne L Finnie, Maha M Abou El-Alamin, Maha A Sultan, Alastair W Wark
Gold nanorods (NRs) have attracted a great deal of interest for a variety of biomedical and sensing applications. However, developing robust methods for biofunctionalizing NRs has continued to be challenging, especially for NR-DNA conjugates. This is due to the presence of cetyltrimethylammonium bromide (CTAB), which plays an essential role in controlling the anisotropic particle growth. In this article, we systematically explore the growth of a polydopamine (PDA) layer on a range of NR surfaces, comparing different polyelectrolyte and alkanethiol coatings as well as direct CTAB displacement...
March 13, 2018: Analyst
Yang Liu, Mingming Jiang, Zhenzhong Zhang, Binghui Li, Haifeng Zhao, Chongxin Shan, Dezhen Shen
The generation of hot electrons from metal nanostructures through plasmon decay provided a direct interfacial charge transfer mechanism, which no longer suffers from the barrier height restrictions observed for metal/semiconductor interfaces. Metal plasmon-mediated energy conversion with higher efficiency has been proposed as a promising alternative to construct novel optoelectronic devices, such as photodetectors, photovoltaic and photocatalytic devices, etc. However, the realization of the electrically-driven generation of hot electrons, and the application in light-emitting devices remain big challenges...
March 13, 2018: Nanoscale
Jonas Reinholz, Christopher Diesler, Susanne Schöttler, Maria Kokkinopoulou, Sandra Ritz, Katharina Landfester, Volker Mailänder
The transport of nanocarriers through barriers like the gut in a living organism involves the transcytosis of these nanocarriers through the cell layer dividing two compartments. Understanding how this process works is not only essential to further developing strategies for a more effective nanocarrier transport system but also for providing fundamental insights into the barrier function as a means of protection against micro- and nanoplastics in the food chain. We therefore set out to investigate the different uptake mechanisms, intracellular trafficking and the routes for exocytosis for small polystyrene nanoparticles (PS-NPs ca...
March 9, 2018: Acta Biomaterialia
Xiangrong Li, Kaiwei Wang, Yanru Peng
The interaction of nanoparticles (NPs) with proteins is a topic of high relevance for the medical application of nanomaterials. In the study, a comprehensive investigation was performed for the binding properties of silver nanoparticles (AgNPs) to pepsin. The results indicate that the binding of AgNPs to pepsin may be a static quenching mechanism. Thermodynamic analysis reveals that AgNPs binds to pepsin is synergistically driven by enthalpy and entropy, and the major driving forces are hydrophobic and electrostatic interactions...
March 9, 2018: Chemico-biological Interactions
Hassaan Majeed, Lihong Ma, Young Jae Lee, Mikhail Kandel, Eunjung Min, Woonggyu Jung, Catherine Best-Popescu, Gabriel Popescu
Label-free imaging of rapidly moving, sub-diffraction sized structures has important applications in both biology and material science, as it removes the limitations associated with fluorescence tagging. However, unlabeled nanoscale particles in suspension are difficult to image due to their transparency and fast Brownian motion. Here we describe a novel interferometric imaging technique referred to as Magnified Image Spatial Spectrum (MISS) microscopy, which overcomes these challenges. The MISS microscope provides quantitative phase information and enables dynamic light scattering investigations with an overall optical path length sensitivity of 0...
March 5, 2018: Optics Express
Fang He, Peng-Fei Luo, Tao Tang, Fang Zhang, He Fang, Shi-Zhao Ji, Yu Sun, Guo-Sheng Wu, Bo-Han Pan, Zhi-Bao Huo, Guang-Yi Wang, Zhao-Fan Xia
Rapid repair of vascular injury is an important prognostic factor for electrical burns. This repair is achieved mainly via stromal cell-derived factor (SDF)-1α promoting the mobilization, chemotaxis, homing, and targeted differentiation of bone marrow mesenchymal stem cells (BMSCs) into endothelial cells. Forming a concentration gradient from the site of local damage in the circulation is essential to the role of SDF-1α. In a previous study, we developed reactive oxygen species (ROS)-sensitive PPADT nanoparticles containing SDF-1α that could degrade in response to high concentration of ROS in tissue lesions, achieving the goal of targeted SDF-1α release...
2018: PloS One
Xiao-Mei Shi, Li-Ping Mei, Qian Wang, Wei-Wei Zhao, Jing-Juan Xu, Hong-Yuan Chen
We report herein the energy transfer (ET) between semiconducting polymer dots (Pdots) and gold nanoparticles (Au NPs) in a photoelectrochemical (PEC) system and its feasibility for cathodic bioanalysis application. Specifically, COOH-capped Pdots were first fabricated and then assembled onto the indium-tin oxide (ITO) surface, followed by the modification of single-strand (ss) DNA probe (pDNA). After the DNA hybridization with the Au NP-tethered complementary ssDNA (Au NP-tDNA), the Au NPs were brought into the close proximity of Pdots...
March 13, 2018: Analytical Chemistry
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