Tag: superparamagnetic

Hot off the press at Nanoscale!

Albumin-coated SPIONs: An experimental and theoretical evaluation of protein conformation, binding affinity, and competition with serum proteinsby Siming Yu, Alex Perálvarez-Marín, Caterina Minelli, Jordi Faraudo, Anna Roig* and Anna Laromaine*, has just been accepted for publication in Nanoscale, DOI: 10.1039/C6NR01732K.

nanoscale-hotAmong inorganic nanoparticles, superparamagnetic iron oxide nanoparticles (SPIONs) show great promise for medicine. In this work, we study in detail the formation, composition, and structure of a monolayer of bovine serum albumin (BSA) on SPIONs. We determine, both by molecular simulations and experimentally, that ten molecules of BSA form a monolayer of BSA around  the SPIONs and their binding strength to the SPIONs is about 3.5×10–4 M, ten times higher than the adsorption of fetal bovine serum (FBS) on the same SPIONs. We elucidate a strong electrostatic interaction between BSA and the SPIONs, although the secondary structure of the protein is not affected. We present data that supports the strong binding of the BSA layer on SPIONs and the properties of the BSA layer as a protein-resistant coating. We believe that a complete understanding of the behavior and morphology of BSA-SPIONs and how the protein interacts with SPIONs is crucial for improving NP surface design and expanding the potential applications of SPIONs in nanomedicine.

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Hot off the press: accepted manuscript in Faraday Discussions!

FARADAY_Forthcoming-publcation-198x300We are very happy to announce that the manuscript Gold nanotriangles decorated with superparamagnetic iron oxide nanoparticles: a compositional and microstructural study (J.A. Hachtela, S. Yuc , A.R. Lupini, S.T. Pantelidesa, M. Gich, A. Laromaine, A. Roig, DOI: 10.1039/C6FD00028B) has been accepted by the Faraday Discussions journal.

The manuscript will be presented and discussed at a forthcoming Faraday Discussions meeting, this next summer. During the meeting, all delegates will be able to contribute to the debate, which will be included in the final volume. This will be a great opportunity to discuss the formation mechanism of the magnetic gold nanotriangles with some experts on this field. 

The combination of iron oxide and gold in a single nanoparticle results in both magnetic and plasmonic properties that can stimulate novel applications in bio-sensing, medical imaging, or therapeutics. Microwave heating method allows the fabrication of multi-component, multi-functional nanostructures by promoting selective heating at desired sites. Recently, we reported a microwave-assisted polyol route yielding gold nanotriangles decorated with iron oxide nanoparticles (1). Here, we present an in-depth microstructural and compositional characterization of the system by using scanning transmission electron microscopy (STEM) and electron energy loss (EELS) spectroscopy. A method to remove the iron oxide nanoparticles from the gold nanocrystals and some insights on crystal nucleation and growth mechanisms are also provided.

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Figure: (a) Schematic representation of the synthesis route. (b) HRTEM image of a Au NH-SPIONs and a Au NT-SPIONs. Characterization of the heterostructures: (c) UV-Vis-NIR spectra. (d) Hydrodynamic diameter of the Au-SPIONS measured by DLS. (e) Magnetization curve up to 6 T at 5K.

(1) Magnetic gold nanotriangles by microwave polyol synthesis (S.M. Yu, J.A. Hachtel, M.F. Chisholm, S.T. Pantelides, A. Laromaine, A. Roig; Nanoscale 2015, 7, 14039-14046. DOI: 10.1039/C5NR03113C). 

Paper Accepted in ACS Biomaterials Science and Engineering