Adsorption of paclitaxel onto magnetic nanoparticles for potential application in the treatment of triple-negative breast cancer.

The chemotherapeutic agent paclitaxel is used in the treatment of triple-negative breast cancer. However, its formulation (Taxol^®) exhibits high toxicity and poor targeting. A novel solution involves nanostructured systems based on magnetic iron oxide nanoparticles (IONPs) combined with chemotherapeutic agents. These systems show increased targeting and inhibitory action toward cancer cells, proving to be favorable for developing formulations with anticancer activity. For this reason, in this work, a system based on paclitaxel adsorbed onto chitosan-coated iron oxide nanoparticles was obtained for the treatment of triple-negative breast cancer. IONPs were synthesized via the Massart coprecipitation method and functionalized with chitosan using in-situ and post-synthesis methods. They were characterized by XRD, FTIR, TEM, SEM, TGA, DLS, and ζ-Potential. The cell viability of the different systems was studied at various time intervals. The obtained nanoparticles exhibited a diffraction pattern corresponding to magnetite. The presence of chitosan was corroborated by infrared spectroscopy. It was determined that the system obtained via the in-situ method was the most appropriate for paclitaxel immobilization and subsequent administration, according to DLS, ζ-Potential, and cell viability profiles. The adsorption kinetics of paclitaxel were studied. The optimal adsorption time was found to be between 2 and 4 hours. The kinetic data fitted the pseudo-second-order model. The drug adsorption isotherm fitted the Freundlich model, evidencing a heterogeneous adsorbent surface with exponentially distributed active site energies.