MaNaTwee Influence of magnetic nanoparticle heating over individual biomolecules determined by optical tweezers”

Drs. J. Ricardo Arias and Gorka Salas

Funding :

MINECO MAT2015-71806-R

Duration: 2016 - 2018

36 months

The aim of this project is to measure, at the single structure level, the temperature profile of a single magnetic nanoparticle (NP) or of a single aggregate with activity in the cell interior considering the typical parameters that rule their excitation by remote, alternate Laser Position Detector magnetic fields (HAC-fields). In addition, to determine the influence of magnetic NPs at the molecular level inside the cell, we will use a simple biomolecule model and measure the influence of magnetic NPs over an individual DNA molecule. Experiments will be performed in vitro by means of optical tweezers and microfluidics technology which, together, will provide an unprecedented analysis. This proposal encompasses progress in the study of nanostructures as local actuators in the fields of nanomedicine and functional nanomaterials. Considering that magnetic fields (H-fields) have a high penetration depth in biological tissues and a low physiological influence, we believe that our measurements will allow magnetic NPs to be proposed as nanoswitches that operate between the folded and denatured states of biological molecules, such as DNA and proteins. This progress may facilitate the access to highlyspecific therapies based on physical action, rather than the traditional biochemical approach based on the use of drugs, with off-target effects. In addition, we expect that our results with magnetic nanostructures will pave the way to the design of active materials based on the combination of magnetic NPs and biological molecules.

Main essay in the MaNaTwee: a DNA chain doped with iron oxide magnetic NPs is subjected to an alternate magnetic field through a chemically-etched Fe-Co microwire, thus exciting heat from the NPs that triggers the DNA melting. The force at which melting is produced is measured by the optical trap, which further allows an experiment at the single-molecule level.