Label-free imaging of in vivo skin: longitudinal studies capturing cell dynamics

This study presents recent advances in an imaging platform developed by our lab, the fast large area multiphoton exoscope (FLAME), a microscope designed for clinical skin imaging. Its dual-scanning modality enables reliable, cellular-scale imaging of the same skin locations over extended time periods across areas up to 1 cm 2 . Enabling fluorescence lifetime imaging microscopy, this device, for the first time in vivo , allows detailed longitudinal tracking of cellular dynamics in human skin, such as responses to injury, significantly advancing the capabilities of dermatological research. By overcoming previous limitations in large-area, high-resolution skin imaging, FLAME opens new opportunities for monitoring therapy responses, tracking cellular dynamics, and understanding skin biology at the cellular level.