Review of optical methods for non-invasive imaging of skin fibroblasts - from in vitro to ex vivo and in vivo visualization.

Fibroblasts are among the most common cell types in the stroma responsible for creating and maintaining the structural organization of the extracellular matrix (ECM) in the dermis, skin regeneration, and a range of immune responses. Until now, the processes of fibroblast adaptation and functioning in a varying environment have not been fully understood. Modern laser microscopes are capable of studying fibroblasts in vitro and ex vivo. One-photon- and two-photon-excited fluorescence microscopy, Raman spectroscopy/micro-spectroscopy are well-suited non-invasive optical methods for fibroblast imaging in vitro and ex vivo. In vivo staining-free fibroblast imaging is not still implemented. The exception is fibroblast imaging in tattooed skin. Although in vivo non-invasive staining-free imaging of fibroblasts in the skin has not yet been implemented, it is expected in the future. This review summarizes the state of the art in fibroblast visualization using optical methods and discusses the advantages, limitations, and prospects for future non-invasive imaging. This article is protected by copyright. All rights reserved.