Cellular Metabolism of Fluorescent Nanoprobes Formed by Self-Assembly of Amphiphiles: Dynamic Trafficking from the Golgi Apparatus to the Lysosome

Dynamic trafficking of foreign substances (organic molecules) in eukaryotic cells is closely correlated to the metabolism of cells; however, it is to date not fully understood due to the lack of suitable probes. In the present study, we employed an amphiphilic probe (i.e., TPE-11) with aggregation induced emission properties to study the trafficking, and through cutting the feed of TPE-11 after a certain culturing time, we confirmed that the trafficking and aggregation of the amphiphilic dye molecules are not controlled by the entropy-driven diffusion but mainly determined by the biological activities of the cells. In addition, the trafficking of the nanoprobes formed by TPE-11 was analyzed by colocalizing the fluorescent signals of GM130/calnexin (anchoring proteins of the Golgi apparatus (GOL) and endoplasmic reticulum (ER), respectively) and TPE-11. In the first 5 h (after removal of the dyes), the fluorescent signals of the nanoemitters were mainly localized at GOL rather than ER, and in the second 6 h, the signals migrated to the lysosome. Moreover, suppression of the protein transporting function led to a random distribution of nanoprobes all over the cells. We assume that GOL should be a main organelle for aggregation of TPE-11. Thereafter, the aggregates were then transferred to the lysosome for further processing.