Figure 3.

Schematic representation of the primary strategies for engineering exosomes displaying targeting ligands. Exosomes have the potential to serve as drug carriers engineered by different methods. Exosome modification mainly involves two methods: active approaches and passive approaches. The former includes methods of incorporating target substances in the process of exosomal biogenesis, such as transferring target peptide-expressing plasmids into cells to generate exosomes with target ligands. The latter includes methods of loading or combining exogenous substances after exosome secretion, such as electroporation or chemical conjugation.