Mitochondria targeting by a nonionic and emissive push–pull type chromophore or its polymer conjugate

Intracellular organelle targeting, especially of mitochondria, is of significant importance for drug delivery to improve therapeutic efficiency and overcome the endosomal trap. While mitochondria targeting has been achieved by mostly cationic systems, this communication reports a rare phenomenon of mitochondria targeting by water-soluble non-ionic polymers (representative substrate of interest), featuring an oligo-oxyethylene appended polymethyl-methacrylate backbone, and terminated with an amine-substituted single naphthalene-monoamide (NMI) derivative (a push-pull type chromophore). The push-pull type charge-neutral NMI chromophore facilitates both cellular uptake and crossing the mitochondrial membrane barrier, while its green emission allows for simultaneous fluorescence imaging. Considering the outstanding mitochondria targeting, cell compatibility, simultaneous imaging and wide-ranging covalent-conjugation possibilities, this simple yet versatile chromophore brings new opportunities in intracellular mitochondria targeted delivery.