One of the major areas of research in nanomedicine is the design of drug delivery systems with remotely controllable release of the drug. Despite the progress in the field, this aspect still poses a challenge, in terms of selectivity and possible harmful interactions with biological components other than the target. We report an innovative approach for the controlled release of DNA, based on clusters of core–shell magnetic nanoparticles [1]. The coating of magnetic nanoparticles with an external inert shell, such as gold, has been proposed in order to add further properties to the nanoparticles. Moreover, gold provides a platform for the attachment of thiolated biomolecules.
The versatility of DNA as a block molecule for nanotechnologies lies in the unique recognition selectivity and thermal responsitivity, which can be coupled to the properties of inorganic nanomaterials.
We have accomplished the conjugation of Au@Fe3O4 with a thiolated oligonucleotide, whose pairing with a half-complementary strand in solution induces clusterization. The application of a low frequency (6 KHz) alternating magnetic field induces DNA melting with the release of the single strand, based on the hyperthermic heating of clusters [2].
The possibility of steering and localizing the magnetic nanoparticles, and magnetically actuating the DNA release discloses new perspectives in the field of nucleic-acid based therapy.
[1] M. Bonini, D. Berti, P. Baglioni, Nanostructures for magnetically triggered release of drugs and biomolecules, CURRENT OPINION IN COLLOID & INTERFACE SCIENCE, 2013, 18, 5, 459-467.
[2] M. Banchelli, S. Nappini, C. Montis, M. Bonini, P. Canton, D. Berti and P. Baglioni, Magnetic nanoparticle clusters as actuators of ssDNA release, Phys. Chem. Chem. Phys., 2014, in press.
salvatore@csgi.unifi.it
