Tag: magnetic

Hot off the press: published paper on Nanoscale!

The paper entitled “Nanoclusters of crystallographically aligned nanoparticles for magnetic thermotherapy: aqueous ferrofluid, agarose phantoms and ex vivo melanoma tumour assessment” has recently been published on the Nanoscale Journal. We congratulate Anna Roig and our collaborator Marcela Fernández for being authors of this nice study!

 

Abstract: Magnetic hyperthermia is an oncological therapy where magnetic nanostructures, under a radiofrequency field, act as heat transducers increasing tumour temperature and killing cancerous cells. Nanostructure heating efficiency depends both on the field conditions and on the nanostructure properties and mobility inside the tumour. Such nanostructures are often incorrectly bench-marketed in the colloidal state and using field settings far off from the recommended therapeutic values. Here, we prepared nanoclusters composed of iron oxide magnetite nanoparticles crystallographically aligned and their specific absorption rate (SAR) values were calorimetrically determined in physiological fluids, agarose-gel-phantoms and ex vivo tumours extracted from mice challenged with B16-F0 melanoma cells. A portable, multipurpose applicator using medical field settings; 100 kHz and 9.3 kA m−1, was developed and the results were fully analysed in terms of nanoclusters’ structural and magnetic properties. A careful evaluation of the nanoclusters’ heating capacity in the three milieus clearly indicates that the SAR values of fluid suspensions or agarose-gel-phantoms are not adequate to predict the real tissue temperature increase or the dosage needed to heat a tumour. Our results show that besides nanostructure mobility, perfusion and local thermoregulation, the nanostructure distribution inside the tumour plays a key role in effective heating. A suppression of the magnetic material effective heating efficiency appears in tumour tissue. In fact, dosage had to be increased considerably, from the SAR values predicted from fluid or agarose, to achieve the desired temperature increase. These results represent an important contribution towards the design of more efficient nanostructures and towards the clinical translation of hyperthermia.

Good news! Miquel Torras has secured a Severo Ochoa Grant for his Master’s Research at ICMAB within the N&N Group!

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Miquel Torras, Master Student, coursing “MSc. Applied Materials Chemistry” at Universitat de Barcelona, has secured one of the competitive Severo Ochoa Grants to conduct his research at the ICMAB-CSIC, within the N&N Group

Miquel will work on magneto-plasmonic nanostructures, following the work of his Bachelor’s degree, under the supervision of Anna Roig.

We are very happy for him! Congratulations Miquel!

More info about the Severo Ochoa Grant call and resolution: https://sede.csic.gob.es/becas-severo-ochoa-icmab

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Miquel Torras is back with us to do his MSc Thesis in magnetic plasmonic nanotriangles

Miquel Torras in the labMiquel Torras, who was in the N&N Group during last semester to do his Degree’s Final Project, is back with us this year. He has started a MSc in Applied Materials Chemistry at Universitat de Barcelona (UB) and will do his MSc Thesis in the group, under the supervision of Anna Roig. He will be working on the synthesis and characterization of magnetic and plasmonic gold nanotriangles

Welcome back!

Hot off the press: new article in small! Alignment under magnetic field of mixed iron oxide/silica colloidal mesoporous particles induced by shape anisotropy

Scheme of the preparation of the mixed iron oxide/silica rod-like colloidal particles.

A new paper entitled “Alignment under magnetic field of mixed Fe2O3/SiOcolloidal mesoporous particles induced by shape anisotropy” (Jheng-Guang Li, Giulia Fornasieri, Anne Bleuzen, Martí Gich, Alexander Gloter, Frédéric Bouquet, Marianne Impéror-Clerc, DOI: 10.1002/smll.201602272) has been publised in small this last September 14, 2016. Congratulations Martí!

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Farewell to Iván and Seminar of Esther Dalfo on biomedical applications of C. elegans

Iván GómezToday during the group meeting we said goodbye to Iván, who is leaving to continue his Ph.D. thesis in Colombia. Iván is a great chemist, who works with magnetic graphene for water decontamination. We wish him a lot of success in his thesis and in his future endeavours!

Esther Dalfo

On the other hand, Esther Dalfo gave us a nice talk on biomedical applications of C. elegans “Investigating neurodegeneration by using the nematode Caenorhabditis elegans”. Esther is an Associate Researcher at the Institute of Neuroscience of the UAB, specialized in neurodegeneration and human genetics. Thank you! 

Group Meeting

 

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 Chem. Commun.

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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.

Paper Accepted in ACS Biomaterials Science and Engineering

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

Siming Yu,a   Jordan A. Hachtel,bc   Matthew F. Chisholm,c  Sokrates T. Pantelides,bc   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
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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.

 

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ACCEPTED PAPER! Encapsulation of VEGF165 in magnetic PLGA nanocapsules

 

Encapsulation of VEGF165 in magnetic PLGA nanocapsules for potential local delivery and bioactivity into human brain endothelial cells

 

Elisa Carenza, Olivier Jordan, Pablo San Segundo Martínez, Radovan Jiřík, Zenon Starčuk jr., Gerrit Borchard, Anna Rosell* and Anna Roig*  

 

 J. Mater. Chem. B, 2015, 

 Accepted Manuscript 
 DOI: 10.1039/C4TB01895H
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New drug delivery systems based on biodegradable magnetic nanocapsules for targeted delivery of pro-angiogenic proteins, potentially useful in therapeutic angiogenesis

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