Intracellular uptake of and sensing with SERS-active hybrid exosomes: insight into a role of metal nanoparticles.

Aim: Exosomes, known as novel biocompatible vesicles, have attracted much interest. This makes it urgent to observe exosomes at the visually cellular or subcellular levels. Methods: Herein, we constructed a new kind of exosome/metal nanohybrid and employed a surface-enhanced Raman scattering technique to study the intracellular behaviors of hybrid exosomes. Results: Experimental results revealed that hybrid exosomes were internalized mainly through clathrin-mediated endocytosis and thereafter transported to lysosomes. The metal nanoparticles in the hybrid were demonstrated to have little effect on exosomal characteristics while serving as surface-enhanced Raman scattering generators. Conclusion: This study is significant for removing the barrier in designing programmable exosome/metal nanohybrids, which will greatly improve the utility of exosomal nanohybrids for therapeutics, such as multifunctional drug-delivery systems.