Magnetic nano composites for gallic acid delivery

A new magnetic layered double hydroxide (MLDH) composed of Fe, Mg, and Al was designed to improve gallic acid delivery to breast tumors. The metals formed the octahedrons within the layers, while the gallate ions were dissolved in the aqueous interlayer space. The drug loading was 30 %, determined with UV/Vis spectrophotometry. The material exhibited superparamagnetic behavior with a saturated magnetization of 5.5 emu/gr. This magnetic property enables the compound to be directed towards the therapeutic target using an external magnetic field, while the superparamagnetic attribute prevents the material from remaining magnetized in the body after the external magnetic field is removed. The diameter of the composites, measured from TEM images, was 110 nm: small enough for systemic circulation. For comparison, a conventional layered double hydroxide composed of Mg and Al was loaded with gallic acid and impregnated with Fe3O4 magnetic nanoparticles (LDHNP). The drug loading was slightly lower (23 %), and the material demonstrated a combination of superparamagnetic and ferromagnetic behavior. However, the saturated magnetization was higher, 15 emu/gr for the superparamagnetic-like component and 13 emu/gr for the ferromagnetic-like component. From TEM images, the diameter of the composites was 57 nm. Drug release was studied with Franz diffusion cells. Both systems showed fast release at the lysosomal pH (4.8), but the MLDH avoids the release at the blood pH (7.4) more than the LDHNP. Lastly, the systems were tested against breast cancer cells. After 48 h, the new composite demonstrated a 77 % reduction in cell viability, while the conventional composite impregnated with NPs showed a 66 % reduction. The designed Fe/Mg/Al magnetic nano composite loaded with gallic acid is easier to manufacture and holds promise for breast cancer treatments.