Abstract
Methotrexate successful therapy encounters various challenges in chemotherapy, such as poor oral bioavailability, low specificity, side effects and the development of drug resistances. In this study, we propose a dual-targeted nanocarrier comprising magnetite/chitosan nanoparticles for an efficient Methotrexate delivery. The synthesis of the particles was confirmed through morphological analysis using electron microscopy and elemental mappings via energy dispersive X-ray spectroscopy. These nanoparticles exhibited a size of ≈ 270 nm, a zeta potential of ≈ 24 mV, and magnetic responsiveness, as demonstrated by hysteresis cycle analysis and visual observations under a magnetic field. In addition, these core/shell particles displayed high stability, as evidenced by size and surface electric charge measurements, during storage at both 4 ºC and 25 ºC for at least 30 days. Electrophoretic properties were examined in relation to pH and ionic strength, confirming the stability. The nanoparticles demonstrated a pH-responsive drug release as observed by a sustained Methotrexate release over the next 90 h under pH ≈ 7.4, while complete release occurred within 3 h under acidic conditions (pH ≈ 5.5). In the ex vivo biocompatibility assessment, the magnetite/chitosan particles showed excellent hemocompatibility and no cytotoxic effects on normal MCF-10A and cancer MCF-7 cells. Furthermore, the Methotrexate-loaded nanoparticles significantly enhanced the antitumor activity reducing the half-maximal inhibitory concentration by ≈ 2.7-fold less compared to the free chemotherapeutic.