Quantum Dot-Based Designed Nanoprobe for Imaging Lipid Droplet

Lipid droplet is a dynamic subcellular organelle, and its imaging is important for understanding its functional role toward the cellular-scale origin of many diseases. However, currently available imaging probes are inefficient in monitoring their activity for longer time scale. Here we designed a quantum dot-based fluorescent nanoprobe that can be used to image a lipid droplet for a longer time. The nanoprobe has a quantum dot core, a polymer shell with a zwitterionic surface charge, and optimum lipophilic functionality. The nanoprobe has a 30–40 nm hydrodynamic size with near-zero surface charge at physiological pH and modular interaction with the cell membrane and enters into the cell via predominate lipid-raft endocytosis and label lipid droplets. The presented nanoprobe can be used for understanding the functional role of a lipid droplet toward various cellular functions.