Functionalization of cationic poly(p-phenylene ethynylene) with dendritic polyethylene enables efficient DNAzyme delivery for imaging Pb2+ in living cells
We report here an effective Pb2+-dependent DNAzyme (8-17 DNAzyme) delivery system based on the water-soluble dendritic polyethylene–cationic poly(p-phenylene ethynylene) for successfully imaging Pb2+ in living cells. For utilizing the 8-17 DNAzyme and its unique ability to catalyze a phosphodiester bond cleavage reaction in the presence of Pb2+, the distinctive conjugated polymer-based polyvalent nanocarrier design manages to load and transport 8-17 DNAzyme across cell membranes, and to realize the fluorescence imaging of Pb2+ in living cells. As shown by the confocal microscopy and flow cytometry observations, the fluorescence of Cy5.5 is obviously activated under the conditions of incubation with Pb2+, compared with the absence of Pb2+. Taken together, the study demonstrates the combination of the molecular-wire effect with “dendrimer effects” on their effective DNAzyme delivery and their cellular imaging Pb2+.