title: Structural and dynamical aspects of skin studied by multiphoton excitation fluorescence microscopy-based methods.
abstract: This mini-review reports on applications of particular multiphoton excitation microscopy-based methodologies employed in our laboratory to study skin. These approaches allow in-depth optical sectioning of the tissue, providing spatially resolved information on specific fluorescence probes' parameters. Specifically, by applying these methods, spatially resolved maps of water dipolar relaxation (generalized polarization function using the 6-lauroyl-2-(N,N-dimethylamino)naphthale probe), activity of protons (fluorescence lifetime imaging using a proton sensitive fluorescence probe--2,7-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein) and diffusion coefficients of distinct fluorescence probes (raster imaging correlation spectroscopy) can be obtained from different regions of the tissue. Comparative studies of different tissue strata, but also between equivalent regions of normal and abnormal excised skin, including applications of fluctuation correlation spectroscopy on transdermal penetration of liposomes are presented and discussed. The data from the different studies reported reveal the intrinsic heterogeneity of skin and also prove these strategies to be powerful noninvasive tools to explore structural and dynamical aspects of the tissue.
authors.affiliation: Membrane Biophysics and Biophotonics group/MEMPHYS, Center for Biomembrane Physics, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark.
authors.forename: Maria
authors.initials: M
authors.lastname: Bloksgaard
authors.forename: Jonathan
authors.initials: J
authors.lastname: Brewer
authors.forename: Luis A
authors.initials: LA
authors.lastname: Bagatolli
mesh_terms: D015081:2-Naphthylamine / Q000031:analogs & derivatives / Q000378:metabolism; D000818:Animals; D005456:Fluorescent Dyes / Q000378:metabolism; D006801:Humans; D007848:Laurates / Q000378:metabolism; D008856:Microscopy, Fluorescence / Q000379:methods*; D012867:Skin / Q000033:anatomy & histology* / Q000378:metabolism*
chemical_list: D005456:Fluorescent Dyes; D007848:Laurates; D015081:2-Naphthylamine; C065580:laurdan
keywords: 2,7-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein; 6-lauroyl-2-(N,N-dimethylamino)naphthale; ACBP; ATTO 647N Streptavidin; ATTO-647N 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine; ATTO-647N-PE; ATTO-647N-STREP; BCECF; FCS; FLIM; Fluorescence lifetime imaging; GP; LAURDAN; LAURDAN generalized polarization function; Multiphoton excitation fluorescence microscopy; RICS; Raster image correlation spectroscopy; RhB; RhB-PE; SC; SHG; TMR-DEX; acyl-coenzyme a binding protein; cc; cross correlation; fluorescence correlation spectroscopy; fluorescence lifetime imaging microscopy; generalized polarization; lissamine-rhodamine B 1,2-dihexadecanoyl-sn-glycero-3-phosphoethanolamine; raster imaging correlation spectroscopy; rhodamine B ([9-(2-carboxyphenyl)-6-diethylamino-3-xanthenylidene]-diethylammonium chloride); second harmonic generation; stratum corneum; tetramethylrhodamine dextran 3000MW