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.
Miquel 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.
Today 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!
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!
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.
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.
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.