CONJUGATED POLYMERIC NANOSTRUCTURES AS POTENCIAL TOOLS IN DNA NANOTECHNOLOGY: INTERACTIONS WITH THE DOUBLE-HELIX.

We synthesized two types of conjugated polymeric nanoparticles (CPNs), made with MEH-PPV (Poly[2-methoxy-5-(2-ethylhexyloxy)-1,4- phenylenevinylene]) and PFD (Poly(9,9- di-n-dodecyl fluorenyl-2,7-diyl)), that significantly interact with double-stranded DNA. The binding between these nanostructures and the biopolymer was characterized via single molecule force spectroscopy assays performed by optical tweezers and by direct visualization via atomic force microscopy imaging. The results found show that both types of CPNs bind cooperatively by outside the double-helix, inducing bendings, and with a considerably high equilibrium association constant - on the order of 10⁶ M⁻¹. These findings open the door for the use of CPNs to construct supramolecular assemblies with nucleic acids for various purposes, such as in the design of DNA-based nanodevices and in the development of new drug carriers based on functionalized nanoparticles for cancer chemotherapies, to cite a few.