Butyrylcholinesterase Responsive Supramolecular Prodrug with Targeted Near‐infrared Cellular Imaging Property

Abstract An enzyme responsive supramolecular prodrug with near‐infrared targeted cell imaging property is constructed from organic dye (4‐(3‐(benzo[d]thiazol‐2‐yl)‐2‐hydroxy‐5‐methylstyryl)‐1‐methylpyridin‐1‐ium) (G), anti‐cancer drug chlorambucil (Cbl−G), water‐soluble cucurbit[7]uril (CB[7]) and biocompatible hyaluronic acid (HA). It is very interesting that CB[7] can not only associate Cbl−G to form supramolecular nanofibers, but also further assemble with targeter HA to form supramolecular nanoparticles with a diameter of about 200 nm. The loading efficiency of Cbl−G in the assembly is calculated to be as high as 98.2%. Cell experiments using HeLa and A549 cancer cells indicated that the prodrug nanoparticles are easily internalized into cancer cells via receptor‐mediated endocytosis, and disassembled under the action of butyrylcholinesterase by cutting the ester bond of prodrug, exhibiting a controlled drug release behavior as well as a simultaneous near‐infrared (NIR) fluorscence imaging in cancer cells. The present research might provide a feasible strategy for in situ monitoring drug delivery and NIR cellular imaging.