Nanoconjugates of peptide nucleic acids with magnetic iron oxide nanoparticles for DNA targeting

Reliable, general and flexible synthetic methodologies have been set up to prepare Peptide Nucleic Acids (PNA) nanoconjugates. Two different synthetic strategies have been used. Following the “one step” procedure, naked magnetic nanoparticles (MNP) have been directly functionalized with properly modified PNA. Following the “two step” procedure, the MNP is previously coated with appropriate linkers bearing amine and azide functions, which are suitable to give covalent bonds with the homothymine PNA decamers expressly tailored to provide them with free carboxyl and acetylene functions to be reacted with the functionalized nanoparticles. Hybridization with matched and mismatched DNA has been put in evidence in a new way through the measure of T2 relaxation time.