gold – Inorganic Nanoparticles Group

Size-Dependent Protein–Nanoparticle Interactions in Citrate-Stabilized Gold Nanoparticles: The Emergence of the Protein Corona. Published in Bioconjugate Chemistry

Editor — Fri, 28 Sep 2018 13:05:06 +0000

Surface modifications of highly monodisperse citrate-stabilized gold nanoparticles (AuNPs) with sizes ranging from 3.5 to 150 nm after their exposure to cell culture media supplemented with fetal bovine serum were studied and characterized by the combined use of UV−vis spectroscopy, dynamic light scattering, and zeta potential measurements. In all the tested AuNPs, a dynamic process of protein adsorption was observed, evolving toward the formation of an irreversible hard protein coating known as Protein Corona. Interestingly, the thickness and density of this protein coating were strongly dependent on the particle size, making it possible to identify different transition regimes as the size of the particles increased: (i) NP-protein complexes (or incomplete corona), (ii) the formation of a near-single dense protein corona layer, and (iii) the formation of a multilayer corona. In addition, the different temporal patterns in the evolution of the protein coating came about more quickly for small particles than for the larger ones, further revealing the significant role that size plays in the kinetics of this process. Since the biological identity of the NPs is ultimately determined by the protein corona and different NP−biological interactions take place at different time scales, these results are relevant to biological and toxicological studies.

Size-Dependent Protein–Nanoparticle Interactions in Citrate-Stabilized Gold Nanoparticles: The Emergence of the Protein Corona.

Jordi Piella, Neus G. Bastus, and Víctor Puntes Bioconjugate Chem., 2017, 28 (1), pp 88–97

Probing the surface reactivity of nanocrystals by the catalytic degradation of organic dyes: the effect of size, surface chemistry and composition. Published in Journal of Materials Chemistry A

Editor — Fri, 28 Sep 2018 10:00:57 +0000

We herein present a comprehensive study on how the catalytic performance and reusability of Au nanocrystals (NCs) are affected by systematic variations of crystal size, surface coating and composition. The reductions of different organic dyes (4-nitrophenol, rhodamine B and methylene blue) by borohydride ions were used as model catalytic reactions. The catalytic performance of the Au NCs ranged between 3.6 to 110 nm was found to be dependent on crystal size, indicating that Au surface atoms have a distinct size-dependent reactivity in this reaction. Similarly, the catalytic performance was found to be strongly dependent on the nature of the coating molecule, obtaining lower catalytic activities for molecules strongly bound to the Au surface. Finally, the catalytic performance was found to be dependent on the chemical composition of the NC (Au, Ag, Pt) and the model dye used as a testing system, with the highest degradation rate found for methylene blue, followed by 4-nitrophenol and rhodamine B. We believe that this study provides a better understanding of the catalytic performance of Au NCs upon controlled modifications of the structural and morphological parameters, and a working environment that can be used to facilitate the selection of the optimum NC size, coating molecule and evaluation system for a particular study of interest.

Probing the surface reactivity of nanocrystals by the catalytic degradation of organic dyes: the effect of size, surface chemistry and composition

New Paper on the Size-Controlled Synthesis of Sub-10-nanometer Citrate-Stabilized Gold Nanoparticles Published in Chemistry of Materials.

Editor — Sat, 11 Mar 2017 16:42:59 +0000

The development of synthetic strategies for the controlled production of small Au nanoparticles (Au NPs) with accessible surface is of crucial important for the design of the final selectivity, activity and compatibility of Au NPs, especially in those (bio)applications where size is a critical parameter . In this work, we report a new synthetic method for the production of highly monodisperse, biocompatible and functionalizable sub-10-nm citrate-stabilized gold nanoparticles following a kinetically controlled seeded-growth strategy. We found how the use of traces of tannic acid together with an excess of sodium citrate during nucleation is fundamental in the formation of a high number of small ∼3.5 nm Au seeds. These seeds can be further grown, with nanometric resolution, to produce Au NPs with a precise control over their sizes between 3.5 and 10 nm. These samples allow studying the size-dependent optical properties in the small transition size regime lying between clusters and nanoparticles. The work has now been published in Chemistry of Materials under the title “Size-Controlled Synthesis of Sub-10-nanometer Citrate-Stabilized Gold Nanoparticles and Related Optical Properties.“

Premiere of Gold Light – the first jewel with gold nanoparticles

Editor — Sun, 02 Dec 2012 16:41:45 +0000

The premiere of Luz de Oro (Gold Light) will take place on December 12, 2012, at 7pm at the Hotel Mercer (Carrer dels Lledó, 7) in Barcelona city.

Gold Light is an exciting new jewellery product based on gold nanoparticles, the fruit of a collaboration between our group and the entrepreneurs Roberto Caligari and Joan Peris, artisanal jewellers who work in Barcelona’s Gothic Quarter. The team has sought to exploit the fascinating behaviour of nanoparticles of noble metals (gold, platinum, silver, etc.) for jewellery, especially the way they interact with light. This has lead to the creation of a series of jewels where the precious metals take a new shape, resulting in unexpected light and color presentations.

You can read more on Gold Light at its project website: http://www.goldlightjewels.com/

Update (01/02/2013): Check out also this news article from Oro y Hora, a publication specialized in jewellery.

Using nanoparticles for drug delivery in cancer treatment: our major results published in PLoS ONE

Editor — Fri, 02 Nov 2012 20:11:37 +0000

One of the main works of Joan Comenge’s doctorate in our group has focused on the study of drug delivery using nanoparticles as carriers, specifically for cancer treatment. The work started up on the patent previously developed by Víctor Puntes and collaborators, to refine and test gold nanoparticles where the chosen anti-cancer drug (cisplatin) is linked to them by a pH-sensitive link resulting from a careful multi-step bioconjugation protocol.

Developed through a long interdisciplinary collaboration with research groups from the Santiago de Compostela University, the University of Valencia and the Sant Pau Hospital, the results on the analysis of this drug delivery system, including in vitro and in vivo (mice) bio-distribution studies, has recently been published in PLoS ONE: “Detoxifying Antitumoral Drugs via Nanoconjugation: The Case of Gold Nanoparticles and Cisplatin”.

The paper presents the success of the specially designed nanocarriers in decreasing the treatment toxicity, essentially by driving the drug more efficiently to its target, the tumor, and thus avoiding undesired side effects. But it is also geared to present and advance the field of nanocarriers for delivering platinum-based drugs more broadly. For example, an editorial published almost simultaneously, “Nanoparticles: the future for platinum drugs or a research red herring?” (by N. Wheate, Nanomedicine), did a great job in summarizing the hopes and challenges that lie in this type of cancer treatment approach. And notably, our work on delivering cisplatin with gold nanoparticles addresses all the points raised, framing the strategy and its results on a more general, and more useful, pharmacological perspective.

J. Comenge, C. Sotelo, F. Romero, O. Gallego, A. Barnadas, T. García-Caballero Parada, F. Domingues and V. Puntes (2012). Detoxifying Antitumoral Drugs via Nanoconjugation: The Case of Gold Nanoparticles and Cisplatin, PLoS ONE 7(10): e47562

http://www.plosone.org/article/info:doi/10.1371/journal.pone.0047562?imageURI=info:doi/10.1371

(open access article)

Our research on nanoparticles for drug delivery featured in newspaper Ara

Editor — Mon, 08 Oct 2012 22:55:26 +0000

The work on drug delivery carried out by our group and collaborators, led by Víctor Puntes, has been featured in an article by the Catalan newspaper Ara. The article explains our project of using gold nanoparticles to improve the delivery of anti-cancer drugs (biodistribution and release). The article by Mònica Ferrado, “Gold to fight cancer”, was published on September 30, 2012.

Link to article (in Catalan, access by subscription)

New paper on enzime immobilization published in Langmuir

Editor — Mon, 28 May 2012 17:01:52 +0000

The group’s recent work on bioconjugation for enzime immobilization, carried out by Joan Comenge and Víctor Puntes, has been published in a Langmuir paper in collaboration with the group of Prof. Gregorio Álvaro at the Chemical Engineering Department of UAB. Congratulations Joan!

Rational Nanoconjugation Improves Biocatalytic Performance of Enzymes: Aldol Addition Catalyzed by Immobilized Rhamnulose-1-Phosphate Aldolase. Langmuir 28 (15), pp 6461–6467 (2012):

http://pubs.acs.org/doi/abs/10.1021/la3003993

Víctor Puntes featured in newspaper La Vanguardia for nanobiomedicine entrepreneurship

Editor — Sat, 05 May 2012 20:19:41 +0000

Prof. Víctor Puntes has been featured in an article in La Vanguardia, a local newspaper, in relation to our research on bioconjugated nanoparticles for drug delivery. For several years, Víctor and several members of our group, together with collaborators, have been carrying on a project on bioconjugation of gold nanoparticles for delivery of cisplatin, an anti-cancer drug. This work has led to a patent that has been now licensed to the Swiss company Nanonica, to create the start-up Nanotargeting as joint venture between Nanonica, ICN, and Ferrer Group.

This story, being an excellent example of technology transfer and entrepreneurship in the biotechnological field, was fully covered by the local newspaper La Vanguardia in the article “Gold in nanotechnology”, by Rosa Salvador, published on May 2, 2012.

Read the full article here (in Spanish)

New paper on the protein corona formation on bioconjugated gold nanoparticles

Editor — Mon, 02 Apr 2012 18:16:51 +0000

A new paper is out on the study of the protein corona formation and the thermal denaturalization in bioconjugated gold nanoparticles. The work was led by the Colloids and Polymers Physics Group from the Universidad de Santiago de Compostela (USC), and resulted from a collaboration between Eudald Casals, Víctor Puntes, and Sonia Goy, who is currently a visiting researcher from USC at our group in Barcelona. Congratulations on this joint work!

Physicochemical Characteristics of Protein–NP Bioconjugates: The Role of Particle Curvature and Solution Conditions on Human Serum Albumin Conformation and Fibrillogenesis Inhibition. S. Goy-López, J. Juárez, M. Alatorre-Meda, E. Casals, V.F. Puntes, P. Taboada, V. Mosquera. Langmuir (DOI 10.1021/la300402w), 2012:

http://pubs.acs.org/doi/full/10.1021/la300402w

The group has published an ACS Nano paper on using nanoparticles for environmental remediation

Editor — Sat, 25 Feb 2012 14:06:51 +0000

A new paper is out on nanoremediation to clean up mercury from water with gold nanoparticles, also in collaboration with Prof. Jordi Arbiol of ICMAB. Congratulations Isaac and all!

Citrate-Coated Gold Nanoparticles As Smart Scavengers for Mercury(II) Removal from Polluted Waters, ACS Nano. Isaac Ojea Jiménez, Xicoténcaltl López, Jordi Arbiol and Víctor Puntes:

http://pubs.acs.org/doi/abs/10.1021/nn204313a