Adsorption of Doxorubicin onto Citrate-Stabilized Magnetic Nanoparticles

We have synthesized citric-acid-stabilized magnetic nanoparticles with very good magnetization behavior and relatively low contribution from shape and surface magnetic anisotropies. In this work, we report also on a simple adsorption of doxorubicin onto the surface of these nanoferrites that can provide a facile preparation process for potential drug carriers. To estimate the amount of adsorbed doxorubicin, we propose a novel method utilizing a ternary system for the determination of interactions between drug and citric-acid-stabilized nanoparticles. The Gibbs free enthalpy of adsorption was determined from Henry's isotherm that represents the drug adsorption profile within the studied concentration range. The estimated value seems to be promising for the preparation of drug-loaded nanoparticles solely by means of the adsorption process. Additional encapsulation of doxorubicin-loaded nanoparticles in an inert polypyrrole microvessel might provide a protective surrounding for drug molecules. In our opinion, understanding the physical interactions between doxorubicin and nanoparticles might be a key factor governing drug release and overall pharmacodynamics.