Self-Reporting Aggregation-Induced Emission Gene Transfection System via Multivalent Tetrazole-Amine Complexation

Gene transfection visualization provides intuitive and direct evidence of gene function and cellular signaling pathways through dynamic, real-time tracking of gene delivery and expression. In this work, we synthesized two tetraphenylethylene-backboned AIE (aggregation-induced emission) fluorophores with acidic tetrazole moieties, which were subsequently integrated with branched polyethylenimine (BPEI) gene carriers via electrostatic interactions to construct a fluorescent gene delivery complex system. This self-reporting gene delivery platform combines responsive AIE fluorescence properties with good biocompatibility while maintaining the vector's binding competence to the host cell in living systems. By employing GFP (green fluorescence protein)-tagged plasmid DNA in a proof-of-concept study, the system enables real-time spatiotemporal tracking and precise localization of gene transporting processes into HeLa cells. Quantitative flow cytometric analysis revealed enhanced transfection efficiency for the TPE-4TA/BPEI/DNA complexes (52.7%) compared to conventional BPEI vectors (47.9%). This study not only contributes to a better understanding of the gene transfection process but also provides valuable concepts and methods for the design and development of gene transfection systems.