Near-infrared AIEgen-functionalized and diselenide-linked oligo-ethylenimine with self-sufficing ROS to exert spatiotemporal responsibility for promoted gene delivery

Abstract

Reversible stabilities are required for therapeutic (e.g. DNA) delivery systems to afford adequate stability in the journey to therapeutic targets but make the systems susceptible to structural disassembly and the liberation of their therapeutic payloads. For this purpose, we attempted to synthesize an oligo-ethyleneimine (OEI)-crosslinked polycation, characterized with self-sufficing reactive oxygen species (ROS) by virtue of a functional aggregation-induced emissive (AIE) component (with good near-infrared imaging functions) and an ROS-labile diselenide linkage. The strategic AIE component was capable of exerting facile ROS production upon convenient daylight irradiation (unprecedented ROS-producing efficiency of 80.14%), consequently helping to activate an endosomal escape functionality and the fragmentation of the OEI-crosslinked polycation into low molecular weight OEI products. Consequently, the engineered capabilities enabled the spatiotemporal control of the stabilities of the electrostatic-based DNA self-assembled formation so that it was adequately stable in the gene transportation journey to the targets but could reverse the stabilities to liberate pDNA to execute the subsequent biological processes, evidenced by the disassociation of the near-infrared emission of AIEgen and Cy5-pDNA. Therefore, our devised strategies provided tempting design implications for utilizing daylight as an impetus for the intracellular delivery of functional molecules, and thus could be developed further to find broad utilities in the transportation of a variety of biological substances in therapeutic applications.