Quantum dots encapsulated in phospholipid micelles for imaging and quantification of tumors in the near-infrared region

Near-infrared (NIR) whole-body imaging is a powerful noninvasive method for the visualization of complex biological phenomena such as tumor and tumor vasculature and for whole-body studies. In this study we introduced a new NIR contrast agent in poly(ethylene glycol)-phospholipid micelle-encapsulated quantum dots (QD-Ms). QD-Ms maximally accumulated in the tumor area within 1 hour as compared to 4 hours for the commercially available PEGylated quantum dots (QD-PEGs) and allowed for the visualization of both tumor and internal organs. QD-Ms showed a signal-to-noise ratio of 15 that allowed the quantification of the micelles' biodistribution using image analysis. The signal obtained with the QD-Ms was higher than with the commercial formulation at half the QD dose. Overall, the QD-Ms seem to be a powerful and rapidly acting nanosized imaging agent that allows for effective visualization of tumors using NIR imaging.