Synthesis of ZnFe2O4@SiO2 nanoparticles as a pH-sensitive drug release system and good nano carrier for CT-DNA binding

In the present research, the synthesis process of ZnFe2O4@SiO2 nanoparticles is expressed and its properties have been evaluated with XRD, SEM, EDS, VSM and FT-IR techniques. The decrease in saturation magnetization from 75.44 to 33.38 emug(-1) is attributed to the formation of a silica layer around the ZnFe2O4 nanoparticles. The efficiency of ZnFe2O4@SiO2 nanoparticles as drug delivery carrier was evaluated by loading and releasing of doxorubicin as a model drug. The drug release results showed that the drug release amounts is higher at low pH, which means that the nanoparticles have a pH-sensitive release behavior. The in vitro interaction of ZnFe2O4@SiO2-DOX nanoparticles with calf thymus DNA (CT-DNA) was investigated by UV-Vis and fluorescence spectroscopy. Observation of the hypochromic effect (34%) in UV-Vis spectroscopy studies and data of competitive fluorescence assay with Hoechst 33258 and ethidium bromide probes confirms the intercalation binding mode between CT-DNA and ZnFe2O4@SiO2-DOX nanoparticles. Thermodynamic data recommend that the foremost forces involved in the interaction are of the electrostatic type. The obtained data show the importance of the nanoparticles as carriers for targeted and controlled drug delivery and DNA intercalator, so that better magnetic carriers can be designed using the nanoparticles. (C) 2021 Elsevier B.V. All rights reserved.