One-step synthesized immunostimulatory oligonucleotides-functionalized quantum dots for simultaneous enhanced...

Unmethylated cytosine-phosphate-guanine (CpG) dinucleotides, normally occur in natural bacterial and viral genomes, show strong immunostimulatory activities to invading pathogens and have found widespread applications in both basic research and clinical trials. For the first time, we design a simple one-step synthesis of CpG-functionalized quantum dots (QDs), combining fascinating features of enhanced immunogenicity and cell imaging. The induction of QDs can greatly increase CpG uptake ability by TLR9-positive cells and elevate CpG stability against nuclease degradation. What is more, the outstanding optical properties also suggest that the CpG-QDs can serve as promising optical probes for the evaluation of the cellular uptake efficiency of the CpG motifs. To our best knowledge, this is the first report to use a facile one-pot synthesis strategy that allows the CpG-functionalized QDs to be prepared, which are able to serve as both the potent platform for immunotherapy and the fluorescent probes for intracellular imaging.