Hafnium-doped nano-magnetite/poly(N-vinylcaprolactam) composites for doxorubicin release

Abstract

In this work, thermo-responsive nanocomposites based on hafnium-dope magnetite (Hf0.6Fe2.4O4) nanoparticles and poly(vinylcaprolactam) (PNVCL) were prepared for the targeted delivery of doxorubicin (DOX). First, the hafnium-doped magnetite nanoparticles were synthesized by the inverse chemical co-precipitation method and then functionalized with vinyltrimethoxysilane (VTMS) to endow with vinyl groups which are susceptible to free radical polymerization. Then the “grafting from” approach was used to graft PNVCL onto VTMS-functionalized Hf0.6Fe2.4O4. These nanocomposites were characterized by X-ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), vibrating sample magnetometry (VSM), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). DOX molecules were loaded onto the nanocomposites and the DOX release studies were carried out at different temperature (25 and 37 °C) in phosphate buffer solution 5.8. The XRD and XPS results demonstrated the incorporation of hafnium into the structure of magnetite. TEM images showed semi-spherical Hf0.6Fe2.4O4 nanoparticles surrounded by a layer of PNVCL while the XPS studies demonstrated the covalent interaction between the nanoparticles and the polymer. Finally, the PNVCL-modified Hf0.6Fe2.4O4 nanoparticles showed a sustained release of this drug during the first 24 h at 37 °C reaching up to 70% of cumulative drug release which make them suitable as drug delivery systems.