Gallate-induced nanoparticle uptake by tumor cells: Structure-activity relationships.

•Co-incubation of gallates and MNPs enhanced MNP internalization by tumor cells.•The galloyl moiety may be the pharmacophore of MNP-cell interaction enhancement.•Two adjacent hydroxyl groups on the benzene ring are crucial for the enhancement.•Methyl gallate and gallamide exerted most potent effects among derivatives studied.•Magnetic force and gallates exerted a synergetic effect on cellular uptake of MNPs.