Hot off the press: New article accepted in Acta Biomaterialia!

Written by Anna May on July 20, 2016. Posted in New publications, News.

The article “Bio-identity and fate of albumin-coated SPIONs evaluated in cells and by the C. elegans model” (Si-Ming Yu, Laura González-Moragas, Maria Milla, Androniki Kolovou, Rachel Santarella-Mellwig, Yannick Schwab, Anna Laromaine, Anna Roig) is now published online in Acta Biomaterialia at:
http://www.sciencedirect.com/science/article/pii/S174270611630349X.
doi:10.1016/j.actbio.2016.07.024.

Abstract: Nanoparticles, whose surface adsorbs proteins in an uncontrolled and non-reproducible manner will have limited uses as nanomedicinal products. A promising approach to avoid nanoparticle non-specific interactions with proteins is to design bio-hybrids by purposely pre-forming a protein corona around the inorganic cores. Here, we investigate, in vitro and in vivo, the newly acquired bio-identity of superparamagnetic iron oxide nanoparticles (SPIONs) upon their functionalization with a pre-formed and well-defined bovine serum albumin (BSA) corona. Cellular uptake, intracellular particle distribution and cytotoxicity were studied in two cell lines: adherent and non-adherent cells. BSA decreases nanoparticle internalization in both cell lines and protects the iron core once they have been internalized. The physiological response to the nanoparticles is then in vivo evaluated by oral administration to Caenorhabditis elegans, which was selected as a model of a functional intestinal barrier. Nanoparticle biodistribution, at single particle resolution, is studied by transmission electron microscopy. The analysis reveals that the acidic intestinal environment partially digests uncoated SPIONs but does not affect BSA-coated ones. It also discloses that some particles could enter the nematode’s enterocytes, likely by endocytosis which is a different pathway than the one described for the worm nutrients.

Keywords: Iron oxide nanoparticles; Protein corona; Cytotoxicity; C. elegans; Biodistribution.

Congratulations to all the authors!

Hot off the press at Nanoscale!

Written by Anna Roig on May 25, 2016. Posted in New publications, News.

Albumin-coated SPIONs: An experimental and theoretical evaluation of protein conformation, binding affinity, and competition with serum proteins, by 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.

Among 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.

Hot off the press: accepted manuscript in Chem. Commun.

Written by Anna May on March 11, 2016. Posted in New publications, News.

Today is the big day: second manuscript accepted!

The manuscript “A silica-based magnetic platform decorated with mixed ligand gold nanoparticles: A recyclable catalyst for esterification reactions” (Elif Ertem, Nerea Murillo-Cremaes, Randy Patrick Carney, Anna Laromaine, Emma-Rose Janeček, Anna Roig* and Francesco Stellaccia*; DOI: 10.1039/C6CC01146B) has been accepted in Chemical Communications.

This paper describes a novel and convenient synthetic strategy for the preparation of magnetically responsive silica nanospheres decorated with mixed ligand protected gold nanoparticles. Gold nanoparticles are attached to the silica surface via stable amide bond formation. The hierarchical nanospheres show promising results as a reusable and efficient catalyst for esterification reactions and they can be recovered through a simple magnetic separation.

Congratulations!

Figure: Schematic illustration of: (a) the partial ligand exchange of 3-mercapto-1-propanesulfonate (MPSA):1-octanethiol(OT) covered gold nanoparticles, (b) the synthesis of core-shell magnetic silica and (c) the synthesis of the magnetic silica decorated with gold nanoparticles hierarchical nanospheres.

Hot off the press: accepted manuscript in Faraday Discussions!

Written by Anna May on March 11, 2016. Posted in New publications, News.

We 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.

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).

New paper accepted in Microchimica Acta

Written by Anna Roig on November 13, 2015. Posted in New publications, News.

The work has resulted from a collaboration between the ICMAB, the CNM and the company Dropsens.

Screen-printed electrodes made of a bismuth nanoparticle porous carbon nanocomposite material applied to the detection of heavy metals (Pengfei Niu, César Fernández-Sánchez,* Martí Gich,* Carla Navarro-Hernández, Pablo Fanjul-Bolado, and Anna Roig, Microchimica Acta, February 2016, Volume 183, Issue 2, pp 617-623).

This work reports on the simplified fabrication and on the characterization of bismuth-based screen-printed electrodes (SPEs) for use in heavy metal detection.
A nanocomposite consisting of bismuth nanoparticles and amorphous carbon was synthesized by a combined one-step sol-gel and pyrolysis process and milled down to a specific particle size distribution as required for the preparation of an ink formulation to be used in screen printing. The resulting electrochemical devices were applied to the detection of Pb(II) and Cd(II) ions in water samples.
The porous structure of carbon and the high surface area of the bismuth nanoparticles allow for the detection of Pb(II) and Cd(II) at concentration levels below 4 ppb. The application of the SPEs was demonstrated by quantifying these ions in tap drinking water and wastewater collected from an influent of an urban wastewater treatment plant.

Paper in collaboration with ICN2 in RSC Advances

Written by Anna Roig on October 23, 2015. Posted in New publications, News.

Dual T1/T2 MRI contrast agent based on hybrid SPION@coordination polymer nanoparticles

The study by M. Borges, S. Yu, A. Laromaine, A. Roig, S. Súarez-García, J. Lorenzo,D. Ruiz-Molina and F. Novio* has just been published in RSC Advances 2015, 5, 86779–86783.

The paper reports a novel hybrid T1/T2 dual MRI contrast agent by the encapsulation of SPIONs (T2 contrast agent) into an iron-based coordination polymer with T1-weighted signal. This new hybrid material presents improved relaxometry and low cytotoxicity, which make it suitable for its use as contrast agent for MRI.

Paper Accepted in ACS Biomaterials Science and Engineering

Written by Anna Roig on September 29, 2015. Posted in New publications.

Protective effects of Bovine Serum Albumin on superparamagnetic iron oxide nanoparticles evaluated in the nematode Caenorhabditis elegans

Laura Gonzalez-Moragas, Si-Ming Yu, Elisa Carenza, Anna Laromaine*, Anna Roig

Nanomaterials have unique biological reactivity that need to be thoroughly investigated. In this context, the use of simple in vivo models to biologically evaluate nanoparticles is currently in increasing demand as they offer low-cost and information-rich experiments. In this work, we evaluated how surface modification (citrate and protein-coated) of superparamagnetic iron oxide nanoparticles induces changes in their toxicological profile and biodistribution using the animal model Caenorhabditis elegans and combining techniques from materials science and biochemistry.

Publication at Nanoscale: Magnetic gold nanotriangles by microwave-assisted polyol synthesis

Written by Anna Roig on September 14, 2015. Posted in New publications, News.

Siming Yu,^a Jordan A. Hachtel,^b^c Matthew F. Chisholm,^c Sokrates T. Pantelides,^b^c Anna Laromaine*^a and Anna Roig*^a

Nanoscale, 2015,7, 14039-14046, DOI: 10.1039/C5NR03113C
Received 12 May 2015, Accepted 16 Jul 2015, First published online 21 Jul 2015

Simple approaches to synthesize hybrid nanoparticles with magnetic and plasmonic functionalities, with high control of their shape and avoiding cytotoxic reactants, to target biomedical applications remain a huge challenge. Here, we report a facile, fast and bio-friendly microwave-assisted polyol route for the synthesis of a complex multi-material consisting of monodisperse gold nanotriangles around 280 nm in size uniformly decorated by superparamagnetic iron oxide nanoparticles of 5 nm. These nanotriangles are readily dispersible in water, display a strong magnetic response (10 wt% magnetic fraction) and exhibit a localized surface plasmon resonance band in the NIR region (800 nm). Moreover, these hybrid particles can be easily self-assembled at the liquid–airinterfaces.

Paper accepted in Chem. Eng. J.

Written by Anna Roig on June 13, 2015. Posted in New publications, News.

We want to congratulate to Laura and Siming for the acceptance of the paper “Scale-up synthesis of iron oxide nanoparticles by microwave-assisted thermal decomposition” in Chemical Engineering Journal by Laura González-Moragas, SiMing Yu (equal contributors), Nerea Murillo, Anna Laromaine, Anna Roig.

N&N Group and Grup de Transductors Químics (CNM) Collaboration: new paper on heavy metals detection

Written by JAGS on March 19, 2015. Posted in New publications, News.

Electroanalytical Assessment of Heavy Metals in Waters with Bismuth Nanoparticle-Porous Carbon Paste Electrodes

The final version of the paper in Electrochimica Acta is on-line . It will be published in the journal in May. You can download it from the link. http://authors.elsevier.com/a/1QjGc_JcNCuYR The journal provides free access to the article for almost two months and the article can also be shared during this time.

Highlights

•A bismuth carbon nanocomposite material prepared by a one-pot sol-gel process.
•Application to the fabrication of a sensor for heavy metal detection in waters.
•Cd, Pb and Ni were measured at concentration levels below the MAC-EQS set by the EU.
•Thorough assessment of the sensor performance in water samples of different origin.