Clinically‐Relevant Static Magnetic Field Induces Release of Encapsulated Molecules from Magnetoliposomes

Magnetoliposomes (MLs) are known for their great potential in drug release under an alternating current (AC) magnetic field (MF). However, AC magnetic fields require specific setups that remain poorly implemented worldwide, contrary to direct currents (DC) that are present in widely used magnetic resonance imaging (MRI) devices. In this work, we evidence the feasibility of a drug release triggered by a 1.5 T constant MF, currently used in clinics. The structuration of magnetite nanoparticles (NPs) stabilized by surface adsorption of citric acid (Fe₃O₄:CA NPs), and an optional chitosan shell (Fe₃O₄:CA:CS NPs) to enhance cytocompatibility, was followed under a 1.5 T constant by small-angle X-ray scattering (SAXS), and dynamic light scattering (DLS). MLs encapsulating both Fe₃O₄:CA NPs and fluorescent carboxyfluorescein (CF), were also submitted to 1.5 T, and the CF fractional release was monitored. The effect of Fe₃O₄:CA:CS NPs addition externally to MLs in the suspension was investigated. Results evidenced that both Fe₃O₄:CA and Fe₃O₄:CA:CS NPs formed necklace-like aggregates under DC MF. Fluorescence experiments demonstrated a significant CF release from MLs, which was enhanced by the addition of external NPs, while empty liposomes exhibited negligible releases. Finally, a biological evaluation of MLs and NPs revealed an excellent cytocompatibility.