APTES modified magnetite nanoparticles as a theranostic nanocarrier: a study of loading and sustained release of daunorubicin

In recent decades, iron oxide nanoparticles have been recognized as effective magnetic resonance imaging (MRI) contrast agents and efficient nanocarriers in various drug delivery systems. In this study, APTES-modified iron oxide nanoparticles (APTES@MNPs) were synthesized using a co-precipitation method. This was followed by the implementation of a modified refluxometric method to investigate the loading and sustained release of the chemotherapeutic drug, daunorubicin. Additionally, the T₂ contrasting ability was examined to elucidate the theranostic properties of drug-loaded nanoparticles. The fabricated nanoparticles were characterized using DLS, FTIR, PXRD, FESEM, TEM, XPS, VSM, TGA, and Raman spectroscopy techniques. The nanoparticles exhibited a high T₂ contrast behavior with r₂/r₁ = 16.5. The kinetic study of drug loading showed that the adsorption model followed pseudo-second-order kinetics with a pseudo-second-order rate constant (k₂) of 0.00134 mg g⁻¹ min⁻¹ at pH ∼ 10. The drug release study showed a result of 72% desorption at pH ∼ 5.2, whereas at pH ∼ 7.4, it was only 12.6%. In addition, adsorption experiments were performed at pH ∼ 10. Furthermore, the adsorption of daunorubicin onto the nanoparticles was supported by computational results. Overall, APTES@MNPs acted as a potent and biocompatible sustained-release drug carrier with good diagnostic properties for anticancer theranostic applications.