title: Two-photon microscopes and in vivo multiphoton tomographs--powerful diagnostic tools for tissue engineering and drug delivery.
abstract: Near-infrared multiphoton microscopes and in vivo femtosecond laser tomographs are novel powerful diagnostic tools for intra-tissue drug screening and high-resolution structural imaging applicable to many areas of biomedical research. Deep tissue cells and extracellular matrix (ECM) compartments can be visualized in situ with submicron resolution without the need for tissue processing. In particular, the reduced fluorescent coenzyme NAD(P)H, flavoproteins, keratin, melanin, and elastin are detected by two-photon excited autofluorescence, whereas myosin, tubulin and the ECM protein collagen can be imaged additionally by second harmonic generation (SHG). Therefore, these innovative multiphoton technologies have been used to probe architecture and state of a variety of native tissues, as well as of tissue-engineered constructs, giving insights on the interaction between scaffolds and seeded cells in vitro prior implantation. Moreover, non-invasive 4-D multiphoton tomographs are employed in clinical studies to examine the diffusion behavior, the intra-tissue accumulation of topically applied cosmetic and pharmaceutical components, and their interaction with skin cells.
authors.affiliation: Cardiovascular Research Laboratory, University of California Los Angeles (UCLA), 675 Charles E. Young Drive South, MRL 3-579, Los Angeles, CA 90095-1760, USA. kschenkelayland@mednet.ucla.edu
authors.forename: Katja
authors.initials: K
authors.lastname: Schenke-Layland
authors.forename: Iris
authors.initials: I
authors.lastname: Riemann
authors.forename: Odile
authors.initials: O
authors.lastname: Damour
authors.forename: Ulrich A
authors.initials: UA
authors.lastname: Stock
authors.forename: Karsten
authors.initials: K
authors.lastname: König
mesh_terms: D000818:Animals; D016903:Drug Monitoring; D006801:Humans; D036641:Microscopy, Fluorescence, Multiphoton; D023822:Tissue Engineering; D014054:Tomography