Imaging of Cell Migration Mediated Exocytosis with Gold Nanoprobes

Insight into the exocytosis process of diagnostical nanomaterials is critical for their clinical transformation. However, it is unclear whether nanomaterials will be eliminated during cell migration. Herein, gold nanoparticles (AuNPs) were utilized as plasmonic imaging probes and dark-field microscopy was applied to examine the movement as well as exocytosis of AuNPs during cell migration. The results showed that internalized AuNPs could localize into the retraction fibers. The mobility of nanoparticles reduced with the increased distance from the cell body. When the retraction fibers disconnected from the cell body, AuNPs were left outside the cell. This study demonstrated the migracytosis of nanomaterials, which could benefit the future design of safer and more efficient nanomaterials for diagnostics.