Increasing Dna Binding Affinity of Doxorubicin by Loading on Fe3o4 Nanoparticles: A Multi-Spectroscopic Study Publisher Pubmed



Mirzaeikalar Z^{1, 2} ; Yavari A³ ; Jouyban A^{4, 5}
Source: Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy Published:2020

Abstract

Magnetic Fe3O4 nanoparticles were synthesized successfully by co-precipitation method and characterized using XRD, SEM and EDS analyses. Then doxorubicin (DOX, a known anticancer drug) was loaded onto nanoparticles. In vitro DNA interaction of free DOX and loaded DOX onto Fe3O4 nanoparticles (DOX-Fe3O4) was investigated by DNA-viscosity measurements, UV–visible and fluorescence spectroscopies. The obtained values for binding constant of DOX and DOX-Fe3O4 compounds from UV–visible spectroscopies were 0.04 × 105 and 0.68 × 105 L mol− 1, respectively, which confirms DOX-Fe3O4 compound have a stronger interaction with CT-DNA compared to DOX. Considerable changes on viscosity of the compounds recommended that their binding mode with CT-DNA is intercalative binding. Fluorescence intensity of DOX and DOX-Fe3O4 was quenched via static process by regular addition of CT-DNA. Thermodynamic parameters suggest that Van der Waals forces and hydrogen bonding for DOX and electrostatic forces for DOX-Fe3O4 are predominantly responsible for interaction with CT-DNA. Competition fluorescence studies were done by Hoechst 33258 as a well-known groove binder and ethidium bromide (EtBr) as a known intercalator probe. Percentage of displacement for EtBr-DNA complex with DOX and DOX-Fe3O4 was 39% and 61%, and for Hoechst-DNA complex was 9% and 5%, respectively. These results confirmed that both compounds are intercalator binders, although DOX-Fe3O4 with a further 22% displacement is a stronger intercalator binder than DOX. The stronger interaction of DOX-Fe3O4 compared to DOX suggests that the current system can be used as a new and effective way to targeted therapy of anticancer drugs. © 2019