Phalloidin-Functionalized Hyperbranched Conjugated Polyelectrolyte for Filamentous Actin Imaging in Living Hela Cells

A phalloidin-functionalized hyperbranched conjugated polyelectrolyte (HCPE-phalloidin) is synthesized and used for direct filamentous actin (F-actin) imaging in living Hela cells. Different from commercially available organic dye-phalloidin conjugates, which require sophisticated techniques to be delivered into living cells, simple incubation of living cells with HCPE-phalloidin leads to efficient internalization of the probe and clear visualization of F-actin due to high brightness of HCPE and good specificity between phalloidin and actin. In addition, HCPE-phalloidin possesses improved photostability as compared to that for commercially available Alexa Fluor 488-phalloidin conjugates, suggesting that the new probe is promising for long-term F-actin imaging in living cells. Further fine-tuning the fluorescent property and targeting ability of HCPE-based probes could lead to more complicated imaging applications and subcellular target detection.