Small molecule AIEgens for illuminating sub-cellular endoplasmic reticulum, mitochondria and lysosomes

Abstract

Organelles are the working hubs of the cells. Hence, visualizing these organelles inside the cells is highly important for understanding their roles in pathological states and development of therapeutic strategies. Herein, we report the development of a novel highly substituted oxazoles with modular scaffolds (AIE-ER, AIE-Mito and AIE-Lyso) which can home into endoplasmic reticulum (ER), mitochondria and lysosomes inside the cells. These oxazoles showed remarkable aggregation-induced emission (AIE) property in water and in solid state due to dual intramolecular H-bonding which was confirmed by the pH and temperature dependent fluorescence studies followed by molecular dynamics (MD) simulations and density functional theory (DFT) calculations. Confocal laser scanning microscopy studies revealed that AIE-ER, AIE-Mito and AIE-Lyso efficiently homed into ER, mitochondria and lysosomes respectively in the HeLa cervical cancer cells and non-cancerous human retinal pigment epithelial RPE-1 cells within 3h without showing any toxicity to the cells with high sub-cellular photostability. To the best of our knowledge, this is the first report of highly substituted oxazole-based small molecule AIEgens for organelle imaging. We anticipate these novel AIEgens have promise to image sub-cellular organelles in different diseased states as well as understanding the inter-organelle interactions towards the development of novel therapeutics.