Figure 2. Labeling and surface modification strategies for biodistribution analysis and targeted drug delivery.

Targeting of exosomes to specific organs or cells can be achieved through engineering the exosomal membrane to express certain molecules such as targeting peptides conjugated with exosomal membrane-associated domains like lysosome-associated membrane glycoprotein 2b (Lamp2b) or the C1C2 domain of lactadherin (LA). Labeling of exosomes for tracking and imaging purposes is achieved via fluorescence, bioluminescence, and radiolabeling approaches.