Abstract

In vivo multiphoton tomography with a wavelength-tunable femtosecond laser has been performed to investigate the autofluorescence intensity of major endogenous fluorophores of human skin in dependence on the excitation wavelength. In high-resolution multiphoton images of different skin layers, clear trends were found for fluorophores like keratin, NAD(P)H, melanin as well as for the elastin and collagen networks. The analysis of the measurements is supplemented by additional measurements of fluorescence lifetime imaging and signal-decay curves by time-correlated single-photon counting.

© 2010 OSA

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    [CrossRef] [PubMed]
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    [CrossRef] [PubMed]
  3. P. T. So, C. Y. Dong, B. R. Masters, and K. M. Berland, “Two-photon excitation fluorescence microscopy,” Annu. Rev. Biomed. Eng. 2(1), 399–429 (2000).
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    [CrossRef] [PubMed]
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    [CrossRef] [PubMed]
  24. W. Becker, A. Bergmann, M. A. Hink, K. König, K. Benndorf, and C. Biskup, “Fluorescence lifetime imaging by time-correlated single-photon counting,” Microsc. Res. Tech. 63(1), 58–66 (2004).
    [CrossRef]
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    [CrossRef] [PubMed]
  27. K. Teuchner, W. Freyer, D. Leupold, A. Volkmer, D. J. Birch, P. Altmeyer, M. Stücker, and K. Hoffmann, “Femtosecond two-photon excited fluorescence of melanin,” Photochem. Photobiol. 70(2), 146–151 (1999).
    [PubMed]
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    [CrossRef] [PubMed]
  29. A. Ehlers, I. Riemann, M. Stark, and K. König, “Multiphoton fluorescence lifetime imaging of human hair,” Microsc. Res. Tech. 70(2), 154–161 (2007).
    [CrossRef]

2009 (4)

E. Dimitrow, I. Riemann, A. Ehlers, M. J. Koehler, J. Norgauer, P. Elsner, K. König, and M. Kaatz, “Spectral fluorescence lifetime detection and selective melanin imaging by multiphoton laser tomography for melanoma diagnosis,” Exp. Dermatol. 18(6), 509–515 (2009).
[CrossRef] [PubMed]

E. Dimitrow, M. Ziemer, M. J. Koehler, J. Norgauer, K. König, P. Elsner, and M. Kaatz, “Sensitivity and specificity of multiphoton laser tomography for in vivo and ex vivo diagnosis of malignant melanoma,” J. Invest. Dermatol. 129(7), 1752–1758 (2009).
[CrossRef] [PubMed]

M. J. Koehler, A. Preller, N. Kindler, P. Elsner, K. König, R. Bückle, and M. Kaatz, “Intrinsic, solar and sunbed-induced skin aging measured in vivo by multiphoton laser tomography and biophysical methods,” Skin Res. Technol. 15(3), 357–363 (2009).
[CrossRef] [PubMed]

K. M. Hanson and C. J. Bardeen, “Application of nonlinear optical microscopy for imaging skin,” Photochem. Photobiol. 85(1), 33–44 (2009).
[CrossRef] [PubMed]

2008 (2)

K. König, “Clinical multiphoton tomography,” J Biophotonics 1(1), 13–23 (2008).
[CrossRef]

M. S. Roberts, M. J. Roberts, T. A. Robertson, W. Sanchez, C. Thorling, Y. H. Zou, X. Zhao, W. Becker, and A. V. Zvyagin, “In vitro and in vivo imaging of xenobiotic transport in human skin and in the rat liver,” J. Biophoton. 1(6), 478–493 (2008).
[CrossRef]

2007 (3)

S. E. Cross, B. Innes, M. S. Roberts, T. Tsuzuki, T. A. Robertson, and P. McCormick, “Human skin penetration of sunscreen nanoparticles: in-vitro assessment of a novel micronized zinc oxide formulation,” Skin Pharmacol. Physiol. 20(3), 148–154 (2007).
[CrossRef] [PubMed]

A. Ehlers, I. Riemann, M. Stark, and K. König, “Multiphoton fluorescence lifetime imaging of human hair,” Microsc. Res. Tech. 70(2), 154–161 (2007).
[CrossRef]

J. A. Palero, H. S. de Bruijn, A. van der Ploeg van den Heuvel, H. J. Sterenborg, and H. C. Gerritsen, “Spectrally resolved multiphoton imaging of in vivo and excised mouse skin tissues,” Biophys. J. 93(3), 992–1007 (2007).
[CrossRef] [PubMed]

2006 (5)

K. Schenke-Layland, I. Riemann, O. Damour, U. A. Stock, and K. König, “Two-photon microscopes and in vivo multiphoton tomographs--powerful diagnostic tools for tissue engineering and drug delivery,” Adv. Drug Deliv. Rev. 58(7), 878–896 (2006).
[CrossRef] [PubMed]

F. Stracke, B. Weiss, C. M. Lehr, K. König, U. F. Schaefer, and M. Schneider, “Multiphoton microscopy for the investigation of dermal penetration of nanoparticle-borne drugs,” J. Invest. Dermatol. 126(10), 2224–2233 (2006).
[CrossRef] [PubMed]

K. König, A. Ehlers, F. Stracke, and I. Riemann, “In vivo drug screening in human skin using femtosecond laser multiphoton tomography,” Skin Pharmacol. Physiol. 19(2), 78–88 (2006).
[CrossRef] [PubMed]

J. Chen, S. Zhuo, T. Luo, X. Jiang, and J. Zhao, “Spectral characteristics of autofluorescence and second harmonic generation from ex vivo human skin induced by femtosecond laser and visible lasers,” Scanning 28(6), 319–326 (2006).
[CrossRef] [PubMed]

M. J. Koehler, K. König, P. Elsner, R. Bückle, and M. Kaatz, “In vivo assessment of human skin aging by multiphoton laser scanning tomography,” Opt. Lett. 31(19), 2879–2881 (2006).
[CrossRef] [PubMed]

2005 (3)

A. Pena, M. Strupler, T. Boulesteix, and M. Schanne-Klein, “Spectroscopic analysis of keratin endogenous signal for skin multiphoton microscopy,” Opt. Express 13(16), 6268–6274 (2005).
[CrossRef] [PubMed]

L. H. Laiho, S. Pelet, T. M. Hancewicz, P. D. Kaplan, and P. T. So, “Two-photon 3-D mapping of ex vivo human skin endogenous fluorescence species based on fluorescence emission spectra,” J. Biomed. Opt. 10(2), 024016 (2005).
[CrossRef] [PubMed]

R. M. Williams, W. R. Zipfel, and W. W. Webb, “Interpreting second-harmonic generation images of collagen I fibrils,” Biophys. J. 88(2), 1377–1386 (2005).
[CrossRef]

2004 (2)

A. Zoumi, X. Lu, G. S. Kassab, and B. J. Tromberg, “Imaging coronary artery microstructure using second-harmonic and two-photon fluorescence microscopy,” Biophys. J. 87(4), 2778–2786 (2004).
[CrossRef] [PubMed]

W. Becker, A. Bergmann, M. A. Hink, K. König, K. Benndorf, and C. Biskup, “Fluorescence lifetime imaging by time-correlated single-photon counting,” Microsc. Res. Tech. 63(1), 58–66 (2004).
[CrossRef]

2003 (2)

W. R. Zipfel, R. M. Williams, R. Christie, A. Y. Nikitin, B. T. Hyman, and W. W. Webb, “Live tissue intrinsic emission microscopy using multiphoton-excited native fluorescence and second harmonic generation,” Proc. Natl. Acad. Sci. U.S.A. 100(12), 7075–7080 (2003).
[CrossRef] [PubMed]

K. König and I. Riemann, “High-resolution multiphoton tomography of human skin with subcellular spatial resolution and picosecond time resolution,” J. Biomed. Opt. 8(3), 432–439 (2003).
[CrossRef] [PubMed]

2002 (2)

S. Huang, A. A. Heikal, and W. W. Webb, “Two-photon fluorescence spectroscopy and microscopy of NAD(P)H and flavoprotein,” Biophys. J. 82(5), 2811–2825 (2002).
[CrossRef] [PubMed]

A. Zoumi, A. Yeh, and B. J. Tromberg, “Imaging cells and extracellular matrix in vivo by using second-harmonic generation and two-photon excited fluorescence,” Proc. Natl. Acad. Sci. U.S.A. 99(17), 11014–11019 (2002).
[CrossRef] [PubMed]

2000 (1)

P. T. So, C. Y. Dong, B. R. Masters, and K. M. Berland, “Two-photon excitation fluorescence microscopy,” Annu. Rev. Biomed. Eng. 2(1), 399–429 (2000).
[CrossRef]

1999 (1)

K. Teuchner, W. Freyer, D. Leupold, A. Volkmer, D. J. Birch, P. Altmeyer, M. Stücker, and K. Hoffmann, “Femtosecond two-photon excited fluorescence of melanin,” Photochem. Photobiol. 70(2), 146–151 (1999).
[PubMed]

1997 (1)

B. R. Masters, P. T. So, and E. Gratton, “Multiphoton excitation fluorescence microscopy and spectroscopy of in vivo human skin,” Biophys. J. 72(6), 2405–2412 (1997).
[CrossRef] [PubMed]

1996 (1)

C. Xu, W. Zipfel, J. B. Shear, R. M. Williams, and W. W. Webb, “Multiphoton fluorescence excitation: new spectral windows for biological nonlinear microscopy,” Proc. Natl. Acad. Sci. U.S.A. 93(20), 10763–10768 (1996).
[CrossRef] [PubMed]

1990 (1)

W. Denk, J. H. Strickler, and W. W. Webb, “Two-photon laser scanning fluorescence microscopy,” Science 248(4951), 73–76 (1990).
[CrossRef] [PubMed]

Altmeyer, P.

K. Teuchner, W. Freyer, D. Leupold, A. Volkmer, D. J. Birch, P. Altmeyer, M. Stücker, and K. Hoffmann, “Femtosecond two-photon excited fluorescence of melanin,” Photochem. Photobiol. 70(2), 146–151 (1999).
[PubMed]

Bardeen, C. J.

K. M. Hanson and C. J. Bardeen, “Application of nonlinear optical microscopy for imaging skin,” Photochem. Photobiol. 85(1), 33–44 (2009).
[CrossRef] [PubMed]

Becker, W.

M. S. Roberts, M. J. Roberts, T. A. Robertson, W. Sanchez, C. Thorling, Y. H. Zou, X. Zhao, W. Becker, and A. V. Zvyagin, “In vitro and in vivo imaging of xenobiotic transport in human skin and in the rat liver,” J. Biophoton. 1(6), 478–493 (2008).
[CrossRef]

W. Becker, A. Bergmann, M. A. Hink, K. König, K. Benndorf, and C. Biskup, “Fluorescence lifetime imaging by time-correlated single-photon counting,” Microsc. Res. Tech. 63(1), 58–66 (2004).
[CrossRef]

Benndorf, K.

W. Becker, A. Bergmann, M. A. Hink, K. König, K. Benndorf, and C. Biskup, “Fluorescence lifetime imaging by time-correlated single-photon counting,” Microsc. Res. Tech. 63(1), 58–66 (2004).
[CrossRef]

Bergmann, A.

W. Becker, A. Bergmann, M. A. Hink, K. König, K. Benndorf, and C. Biskup, “Fluorescence lifetime imaging by time-correlated single-photon counting,” Microsc. Res. Tech. 63(1), 58–66 (2004).
[CrossRef]

Berland, K. M.

P. T. So, C. Y. Dong, B. R. Masters, and K. M. Berland, “Two-photon excitation fluorescence microscopy,” Annu. Rev. Biomed. Eng. 2(1), 399–429 (2000).
[CrossRef]

Birch, D. J.

K. Teuchner, W. Freyer, D. Leupold, A. Volkmer, D. J. Birch, P. Altmeyer, M. Stücker, and K. Hoffmann, “Femtosecond two-photon excited fluorescence of melanin,” Photochem. Photobiol. 70(2), 146–151 (1999).
[PubMed]

Biskup, C.

W. Becker, A. Bergmann, M. A. Hink, K. König, K. Benndorf, and C. Biskup, “Fluorescence lifetime imaging by time-correlated single-photon counting,” Microsc. Res. Tech. 63(1), 58–66 (2004).
[CrossRef]

Boulesteix, T.

Bückle, R.

M. J. Koehler, A. Preller, N. Kindler, P. Elsner, K. König, R. Bückle, and M. Kaatz, “Intrinsic, solar and sunbed-induced skin aging measured in vivo by multiphoton laser tomography and biophysical methods,” Skin Res. Technol. 15(3), 357–363 (2009).
[CrossRef] [PubMed]

M. J. Koehler, K. König, P. Elsner, R. Bückle, and M. Kaatz, “In vivo assessment of human skin aging by multiphoton laser scanning tomography,” Opt. Lett. 31(19), 2879–2881 (2006).
[CrossRef] [PubMed]

Chen, J.

J. Chen, S. Zhuo, T. Luo, X. Jiang, and J. Zhao, “Spectral characteristics of autofluorescence and second harmonic generation from ex vivo human skin induced by femtosecond laser and visible lasers,” Scanning 28(6), 319–326 (2006).
[CrossRef] [PubMed]

Christie, R.

W. R. Zipfel, R. M. Williams, R. Christie, A. Y. Nikitin, B. T. Hyman, and W. W. Webb, “Live tissue intrinsic emission microscopy using multiphoton-excited native fluorescence and second harmonic generation,” Proc. Natl. Acad. Sci. U.S.A. 100(12), 7075–7080 (2003).
[CrossRef] [PubMed]

Cross, S. E.

S. E. Cross, B. Innes, M. S. Roberts, T. Tsuzuki, T. A. Robertson, and P. McCormick, “Human skin penetration of sunscreen nanoparticles: in-vitro assessment of a novel micronized zinc oxide formulation,” Skin Pharmacol. Physiol. 20(3), 148–154 (2007).
[CrossRef] [PubMed]

Damour, O.

K. Schenke-Layland, I. Riemann, O. Damour, U. A. Stock, and K. König, “Two-photon microscopes and in vivo multiphoton tomographs--powerful diagnostic tools for tissue engineering and drug delivery,” Adv. Drug Deliv. Rev. 58(7), 878–896 (2006).
[CrossRef] [PubMed]

de Bruijn, H. S.

J. A. Palero, H. S. de Bruijn, A. van der Ploeg van den Heuvel, H. J. Sterenborg, and H. C. Gerritsen, “Spectrally resolved multiphoton imaging of in vivo and excised mouse skin tissues,” Biophys. J. 93(3), 992–1007 (2007).
[CrossRef] [PubMed]

Denk, W.

W. Denk, J. H. Strickler, and W. W. Webb, “Two-photon laser scanning fluorescence microscopy,” Science 248(4951), 73–76 (1990).
[CrossRef] [PubMed]

Dimitrow, E.

E. Dimitrow, M. Ziemer, M. J. Koehler, J. Norgauer, K. König, P. Elsner, and M. Kaatz, “Sensitivity and specificity of multiphoton laser tomography for in vivo and ex vivo diagnosis of malignant melanoma,” J. Invest. Dermatol. 129(7), 1752–1758 (2009).
[CrossRef] [PubMed]

E. Dimitrow, I. Riemann, A. Ehlers, M. J. Koehler, J. Norgauer, P. Elsner, K. König, and M. Kaatz, “Spectral fluorescence lifetime detection and selective melanin imaging by multiphoton laser tomography for melanoma diagnosis,” Exp. Dermatol. 18(6), 509–515 (2009).
[CrossRef] [PubMed]

Dong, C. Y.

P. T. So, C. Y. Dong, B. R. Masters, and K. M. Berland, “Two-photon excitation fluorescence microscopy,” Annu. Rev. Biomed. Eng. 2(1), 399–429 (2000).
[CrossRef]

Ehlers, A.

E. Dimitrow, I. Riemann, A. Ehlers, M. J. Koehler, J. Norgauer, P. Elsner, K. König, and M. Kaatz, “Spectral fluorescence lifetime detection and selective melanin imaging by multiphoton laser tomography for melanoma diagnosis,” Exp. Dermatol. 18(6), 509–515 (2009).
[CrossRef] [PubMed]

A. Ehlers, I. Riemann, M. Stark, and K. König, “Multiphoton fluorescence lifetime imaging of human hair,” Microsc. Res. Tech. 70(2), 154–161 (2007).
[CrossRef]

K. König, A. Ehlers, F. Stracke, and I. Riemann, “In vivo drug screening in human skin using femtosecond laser multiphoton tomography,” Skin Pharmacol. Physiol. 19(2), 78–88 (2006).
[CrossRef] [PubMed]

Elsner, P.

M. J. Koehler, A. Preller, N. Kindler, P. Elsner, K. König, R. Bückle, and M. Kaatz, “Intrinsic, solar and sunbed-induced skin aging measured in vivo by multiphoton laser tomography and biophysical methods,” Skin Res. Technol. 15(3), 357–363 (2009).
[CrossRef] [PubMed]

E. Dimitrow, M. Ziemer, M. J. Koehler, J. Norgauer, K. König, P. Elsner, and M. Kaatz, “Sensitivity and specificity of multiphoton laser tomography for in vivo and ex vivo diagnosis of malignant melanoma,” J. Invest. Dermatol. 129(7), 1752–1758 (2009).
[CrossRef] [PubMed]

E. Dimitrow, I. Riemann, A. Ehlers, M. J. Koehler, J. Norgauer, P. Elsner, K. König, and M. Kaatz, “Spectral fluorescence lifetime detection and selective melanin imaging by multiphoton laser tomography for melanoma diagnosis,” Exp. Dermatol. 18(6), 509–515 (2009).
[CrossRef] [PubMed]

M. J. Koehler, K. König, P. Elsner, R. Bückle, and M. Kaatz, “In vivo assessment of human skin aging by multiphoton laser scanning tomography,” Opt. Lett. 31(19), 2879–2881 (2006).
[CrossRef] [PubMed]

Freyer, W.

K. Teuchner, W. Freyer, D. Leupold, A. Volkmer, D. J. Birch, P. Altmeyer, M. Stücker, and K. Hoffmann, “Femtosecond two-photon excited fluorescence of melanin,” Photochem. Photobiol. 70(2), 146–151 (1999).
[PubMed]

Gerritsen, H. C.

J. A. Palero, H. S. de Bruijn, A. van der Ploeg van den Heuvel, H. J. Sterenborg, and H. C. Gerritsen, “Spectrally resolved multiphoton imaging of in vivo and excised mouse skin tissues,” Biophys. J. 93(3), 992–1007 (2007).
[CrossRef] [PubMed]

Gratton, E.

B. R. Masters, P. T. So, and E. Gratton, “Multiphoton excitation fluorescence microscopy and spectroscopy of in vivo human skin,” Biophys. J. 72(6), 2405–2412 (1997).
[CrossRef] [PubMed]

Hancewicz, T. M.

L. H. Laiho, S. Pelet, T. M. Hancewicz, P. D. Kaplan, and P. T. So, “Two-photon 3-D mapping of ex vivo human skin endogenous fluorescence species based on fluorescence emission spectra,” J. Biomed. Opt. 10(2), 024016 (2005).
[CrossRef] [PubMed]

Hanson, K. M.

K. M. Hanson and C. J. Bardeen, “Application of nonlinear optical microscopy for imaging skin,” Photochem. Photobiol. 85(1), 33–44 (2009).
[CrossRef] [PubMed]

Heikal, A. A.

S. Huang, A. A. Heikal, and W. W. Webb, “Two-photon fluorescence spectroscopy and microscopy of NAD(P)H and flavoprotein,” Biophys. J. 82(5), 2811–2825 (2002).
[CrossRef] [PubMed]

Hink, M. A.

W. Becker, A. Bergmann, M. A. Hink, K. König, K. Benndorf, and C. Biskup, “Fluorescence lifetime imaging by time-correlated single-photon counting,” Microsc. Res. Tech. 63(1), 58–66 (2004).
[CrossRef]

Hoffmann, K.

K. Teuchner, W. Freyer, D. Leupold, A. Volkmer, D. J. Birch, P. Altmeyer, M. Stücker, and K. Hoffmann, “Femtosecond two-photon excited fluorescence of melanin,” Photochem. Photobiol. 70(2), 146–151 (1999).
[PubMed]

Huang, S.

S. Huang, A. A. Heikal, and W. W. Webb, “Two-photon fluorescence spectroscopy and microscopy of NAD(P)H and flavoprotein,” Biophys. J. 82(5), 2811–2825 (2002).
[CrossRef] [PubMed]

Hyman, B. T.

W. R. Zipfel, R. M. Williams, R. Christie, A. Y. Nikitin, B. T. Hyman, and W. W. Webb, “Live tissue intrinsic emission microscopy using multiphoton-excited native fluorescence and second harmonic generation,” Proc. Natl. Acad. Sci. U.S.A. 100(12), 7075–7080 (2003).
[CrossRef] [PubMed]

Innes, B.

S. E. Cross, B. Innes, M. S. Roberts, T. Tsuzuki, T. A. Robertson, and P. McCormick, “Human skin penetration of sunscreen nanoparticles: in-vitro assessment of a novel micronized zinc oxide formulation,” Skin Pharmacol. Physiol. 20(3), 148–154 (2007).
[CrossRef] [PubMed]

Jiang, X.

J. Chen, S. Zhuo, T. Luo, X. Jiang, and J. Zhao, “Spectral characteristics of autofluorescence and second harmonic generation from ex vivo human skin induced by femtosecond laser and visible lasers,” Scanning 28(6), 319–326 (2006).
[CrossRef] [PubMed]

Kaatz, M.

E. Dimitrow, I. Riemann, A. Ehlers, M. J. Koehler, J. Norgauer, P. Elsner, K. König, and M. Kaatz, “Spectral fluorescence lifetime detection and selective melanin imaging by multiphoton laser tomography for melanoma diagnosis,” Exp. Dermatol. 18(6), 509–515 (2009).
[CrossRef] [PubMed]

E. Dimitrow, M. Ziemer, M. J. Koehler, J. Norgauer, K. König, P. Elsner, and M. Kaatz, “Sensitivity and specificity of multiphoton laser tomography for in vivo and ex vivo diagnosis of malignant melanoma,” J. Invest. Dermatol. 129(7), 1752–1758 (2009).
[CrossRef] [PubMed]

M. J. Koehler, A. Preller, N. Kindler, P. Elsner, K. König, R. Bückle, and M. Kaatz, “Intrinsic, solar and sunbed-induced skin aging measured in vivo by multiphoton laser tomography and biophysical methods,” Skin Res. Technol. 15(3), 357–363 (2009).
[CrossRef] [PubMed]

M. J. Koehler, K. König, P. Elsner, R. Bückle, and M. Kaatz, “In vivo assessment of human skin aging by multiphoton laser scanning tomography,” Opt. Lett. 31(19), 2879–2881 (2006).
[CrossRef] [PubMed]

Kaplan, P. D.

L. H. Laiho, S. Pelet, T. M. Hancewicz, P. D. Kaplan, and P. T. So, “Two-photon 3-D mapping of ex vivo human skin endogenous fluorescence species based on fluorescence emission spectra,” J. Biomed. Opt. 10(2), 024016 (2005).
[CrossRef] [PubMed]

Kassab, G. S.

A. Zoumi, X. Lu, G. S. Kassab, and B. J. Tromberg, “Imaging coronary artery microstructure using second-harmonic and two-photon fluorescence microscopy,” Biophys. J. 87(4), 2778–2786 (2004).
[CrossRef] [PubMed]

Kindler, N.

M. J. Koehler, A. Preller, N. Kindler, P. Elsner, K. König, R. Bückle, and M. Kaatz, “Intrinsic, solar and sunbed-induced skin aging measured in vivo by multiphoton laser tomography and biophysical methods,” Skin Res. Technol. 15(3), 357–363 (2009).
[CrossRef] [PubMed]

Koehler, M. J.

M. J. Koehler, A. Preller, N. Kindler, P. Elsner, K. König, R. Bückle, and M. Kaatz, “Intrinsic, solar and sunbed-induced skin aging measured in vivo by multiphoton laser tomography and biophysical methods,” Skin Res. Technol. 15(3), 357–363 (2009).
[CrossRef] [PubMed]

E. Dimitrow, I. Riemann, A. Ehlers, M. J. Koehler, J. Norgauer, P. Elsner, K. König, and M. Kaatz, “Spectral fluorescence lifetime detection and selective melanin imaging by multiphoton laser tomography for melanoma diagnosis,” Exp. Dermatol. 18(6), 509–515 (2009).
[CrossRef] [PubMed]

E. Dimitrow, M. Ziemer, M. J. Koehler, J. Norgauer, K. König, P. Elsner, and M. Kaatz, “Sensitivity and specificity of multiphoton laser tomography for in vivo and ex vivo diagnosis of malignant melanoma,” J. Invest. Dermatol. 129(7), 1752–1758 (2009).
[CrossRef] [PubMed]

M. J. Koehler, K. König, P. Elsner, R. Bückle, and M. Kaatz, “In vivo assessment of human skin aging by multiphoton laser scanning tomography,” Opt. Lett. 31(19), 2879–2881 (2006).
[CrossRef] [PubMed]

König, K.

E. Dimitrow, I. Riemann, A. Ehlers, M. J. Koehler, J. Norgauer, P. Elsner, K. König, and M. Kaatz, “Spectral fluorescence lifetime detection and selective melanin imaging by multiphoton laser tomography for melanoma diagnosis,” Exp. Dermatol. 18(6), 509–515 (2009).
[CrossRef] [PubMed]

E. Dimitrow, M. Ziemer, M. J. Koehler, J. Norgauer, K. König, P. Elsner, and M. Kaatz, “Sensitivity and specificity of multiphoton laser tomography for in vivo and ex vivo diagnosis of malignant melanoma,” J. Invest. Dermatol. 129(7), 1752–1758 (2009).
[CrossRef] [PubMed]

M. J. Koehler, A. Preller, N. Kindler, P. Elsner, K. König, R. Bückle, and M. Kaatz, “Intrinsic, solar and sunbed-induced skin aging measured in vivo by multiphoton laser tomography and biophysical methods,” Skin Res. Technol. 15(3), 357–363 (2009).
[CrossRef] [PubMed]

K. König, “Clinical multiphoton tomography,” J Biophotonics 1(1), 13–23 (2008).
[CrossRef]

A. Ehlers, I. Riemann, M. Stark, and K. König, “Multiphoton fluorescence lifetime imaging of human hair,” Microsc. Res. Tech. 70(2), 154–161 (2007).
[CrossRef]

K. Schenke-Layland, I. Riemann, O. Damour, U. A. Stock, and K. König, “Two-photon microscopes and in vivo multiphoton tomographs--powerful diagnostic tools for tissue engineering and drug delivery,” Adv. Drug Deliv. Rev. 58(7), 878–896 (2006).
[CrossRef] [PubMed]

F. Stracke, B. Weiss, C. M. Lehr, K. König, U. F. Schaefer, and M. Schneider, “Multiphoton microscopy for the investigation of dermal penetration of nanoparticle-borne drugs,” J. Invest. Dermatol. 126(10), 2224–2233 (2006).
[CrossRef] [PubMed]

M. J. Koehler, K. König, P. Elsner, R. Bückle, and M. Kaatz, “In vivo assessment of human skin aging by multiphoton laser scanning tomography,” Opt. Lett. 31(19), 2879–2881 (2006).
[CrossRef] [PubMed]

K. König, A. Ehlers, F. Stracke, and I. Riemann, “In vivo drug screening in human skin using femtosecond laser multiphoton tomography,” Skin Pharmacol. Physiol. 19(2), 78–88 (2006).
[CrossRef] [PubMed]

W. Becker, A. Bergmann, M. A. Hink, K. König, K. Benndorf, and C. Biskup, “Fluorescence lifetime imaging by time-correlated single-photon counting,” Microsc. Res. Tech. 63(1), 58–66 (2004).
[CrossRef]

K. König and I. Riemann, “High-resolution multiphoton tomography of human skin with subcellular spatial resolution and picosecond time resolution,” J. Biomed. Opt. 8(3), 432–439 (2003).
[CrossRef] [PubMed]

Laiho, L. H.

L. H. Laiho, S. Pelet, T. M. Hancewicz, P. D. Kaplan, and P. T. So, “Two-photon 3-D mapping of ex vivo human skin endogenous fluorescence species based on fluorescence emission spectra,” J. Biomed. Opt. 10(2), 024016 (2005).
[CrossRef] [PubMed]

Lehr, C. M.

F. Stracke, B. Weiss, C. M. Lehr, K. König, U. F. Schaefer, and M. Schneider, “Multiphoton microscopy for the investigation of dermal penetration of nanoparticle-borne drugs,” J. Invest. Dermatol. 126(10), 2224–2233 (2006).
[CrossRef] [PubMed]

Leupold, D.

K. Teuchner, W. Freyer, D. Leupold, A. Volkmer, D. J. Birch, P. Altmeyer, M. Stücker, and K. Hoffmann, “Femtosecond two-photon excited fluorescence of melanin,” Photochem. Photobiol. 70(2), 146–151 (1999).
[PubMed]

Lu, X.

A. Zoumi, X. Lu, G. S. Kassab, and B. J. Tromberg, “Imaging coronary artery microstructure using second-harmonic and two-photon fluorescence microscopy,” Biophys. J. 87(4), 2778–2786 (2004).
[CrossRef] [PubMed]

Luo, T.

J. Chen, S. Zhuo, T. Luo, X. Jiang, and J. Zhao, “Spectral characteristics of autofluorescence and second harmonic generation from ex vivo human skin induced by femtosecond laser and visible lasers,” Scanning 28(6), 319–326 (2006).
[CrossRef] [PubMed]

Masters, B. R.

P. T. So, C. Y. Dong, B. R. Masters, and K. M. Berland, “Two-photon excitation fluorescence microscopy,” Annu. Rev. Biomed. Eng. 2(1), 399–429 (2000).
[CrossRef]

B. R. Masters, P. T. So, and E. Gratton, “Multiphoton excitation fluorescence microscopy and spectroscopy of in vivo human skin,” Biophys. J. 72(6), 2405–2412 (1997).
[CrossRef] [PubMed]

McCormick, P.

S. E. Cross, B. Innes, M. S. Roberts, T. Tsuzuki, T. A. Robertson, and P. McCormick, “Human skin penetration of sunscreen nanoparticles: in-vitro assessment of a novel micronized zinc oxide formulation,” Skin Pharmacol. Physiol. 20(3), 148–154 (2007).
[CrossRef] [PubMed]

Nikitin, A. Y.

W. R. Zipfel, R. M. Williams, R. Christie, A. Y. Nikitin, B. T. Hyman, and W. W. Webb, “Live tissue intrinsic emission microscopy using multiphoton-excited native fluorescence and second harmonic generation,” Proc. Natl. Acad. Sci. U.S.A. 100(12), 7075–7080 (2003).
[CrossRef] [PubMed]

Norgauer, J.

E. Dimitrow, I. Riemann, A. Ehlers, M. J. Koehler, J. Norgauer, P. Elsner, K. König, and M. Kaatz, “Spectral fluorescence lifetime detection and selective melanin imaging by multiphoton laser tomography for melanoma diagnosis,” Exp. Dermatol. 18(6), 509–515 (2009).
[CrossRef] [PubMed]

E. Dimitrow, M. Ziemer, M. J. Koehler, J. Norgauer, K. König, P. Elsner, and M. Kaatz, “Sensitivity and specificity of multiphoton laser tomography for in vivo and ex vivo diagnosis of malignant melanoma,” J. Invest. Dermatol. 129(7), 1752–1758 (2009).
[CrossRef] [PubMed]

Palero, J. A.

J. A. Palero, H. S. de Bruijn, A. van der Ploeg van den Heuvel, H. J. Sterenborg, and H. C. Gerritsen, “Spectrally resolved multiphoton imaging of in vivo and excised mouse skin tissues,” Biophys. J. 93(3), 992–1007 (2007).
[CrossRef] [PubMed]

Pelet, S.

L. H. Laiho, S. Pelet, T. M. Hancewicz, P. D. Kaplan, and P. T. So, “Two-photon 3-D mapping of ex vivo human skin endogenous fluorescence species based on fluorescence emission spectra,” J. Biomed. Opt. 10(2), 024016 (2005).
[CrossRef] [PubMed]

Pena, A.

Preller, A.

M. J. Koehler, A. Preller, N. Kindler, P. Elsner, K. König, R. Bückle, and M. Kaatz, “Intrinsic, solar and sunbed-induced skin aging measured in vivo by multiphoton laser tomography and biophysical methods,” Skin Res. Technol. 15(3), 357–363 (2009).
[CrossRef] [PubMed]

Riemann, I.

E. Dimitrow, I. Riemann, A. Ehlers, M. J. Koehler, J. Norgauer, P. Elsner, K. König, and M. Kaatz, “Spectral fluorescence lifetime detection and selective melanin imaging by multiphoton laser tomography for melanoma diagnosis,” Exp. Dermatol. 18(6), 509–515 (2009).
[CrossRef] [PubMed]

A. Ehlers, I. Riemann, M. Stark, and K. König, “Multiphoton fluorescence lifetime imaging of human hair,” Microsc. Res. Tech. 70(2), 154–161 (2007).
[CrossRef]

K. Schenke-Layland, I. Riemann, O. Damour, U. A. Stock, and K. König, “Two-photon microscopes and in vivo multiphoton tomographs--powerful diagnostic tools for tissue engineering and drug delivery,” Adv. Drug Deliv. Rev. 58(7), 878–896 (2006).
[CrossRef] [PubMed]

K. König, A. Ehlers, F. Stracke, and I. Riemann, “In vivo drug screening in human skin using femtosecond laser multiphoton tomography,” Skin Pharmacol. Physiol. 19(2), 78–88 (2006).
[CrossRef] [PubMed]

K. König and I. Riemann, “High-resolution multiphoton tomography of human skin with subcellular spatial resolution and picosecond time resolution,” J. Biomed. Opt. 8(3), 432–439 (2003).
[CrossRef] [PubMed]

Roberts, M. J.

M. S. Roberts, M. J. Roberts, T. A. Robertson, W. Sanchez, C. Thorling, Y. H. Zou, X. Zhao, W. Becker, and A. V. Zvyagin, “In vitro and in vivo imaging of xenobiotic transport in human skin and in the rat liver,” J. Biophoton. 1(6), 478–493 (2008).
[CrossRef]

Roberts, M. S.

M. S. Roberts, M. J. Roberts, T. A. Robertson, W. Sanchez, C. Thorling, Y. H. Zou, X. Zhao, W. Becker, and A. V. Zvyagin, “In vitro and in vivo imaging of xenobiotic transport in human skin and in the rat liver,” J. Biophoton. 1(6), 478–493 (2008).
[CrossRef]

S. E. Cross, B. Innes, M. S. Roberts, T. Tsuzuki, T. A. Robertson, and P. McCormick, “Human skin penetration of sunscreen nanoparticles: in-vitro assessment of a novel micronized zinc oxide formulation,” Skin Pharmacol. Physiol. 20(3), 148–154 (2007).
[CrossRef] [PubMed]

Robertson, T. A.

M. S. Roberts, M. J. Roberts, T. A. Robertson, W. Sanchez, C. Thorling, Y. H. Zou, X. Zhao, W. Becker, and A. V. Zvyagin, “In vitro and in vivo imaging of xenobiotic transport in human skin and in the rat liver,” J. Biophoton. 1(6), 478–493 (2008).
[CrossRef]

S. E. Cross, B. Innes, M. S. Roberts, T. Tsuzuki, T. A. Robertson, and P. McCormick, “Human skin penetration of sunscreen nanoparticles: in-vitro assessment of a novel micronized zinc oxide formulation,” Skin Pharmacol. Physiol. 20(3), 148–154 (2007).
[CrossRef] [PubMed]

Sanchez, W.

M. S. Roberts, M. J. Roberts, T. A. Robertson, W. Sanchez, C. Thorling, Y. H. Zou, X. Zhao, W. Becker, and A. V. Zvyagin, “In vitro and in vivo imaging of xenobiotic transport in human skin and in the rat liver,” J. Biophoton. 1(6), 478–493 (2008).
[CrossRef]

Schaefer, U. F.

F. Stracke, B. Weiss, C. M. Lehr, K. König, U. F. Schaefer, and M. Schneider, “Multiphoton microscopy for the investigation of dermal penetration of nanoparticle-borne drugs,” J. Invest. Dermatol. 126(10), 2224–2233 (2006).
[CrossRef] [PubMed]

Schanne-Klein, M.

Schenke-Layland, K.

K. Schenke-Layland, I. Riemann, O. Damour, U. A. Stock, and K. König, “Two-photon microscopes and in vivo multiphoton tomographs--powerful diagnostic tools for tissue engineering and drug delivery,” Adv. Drug Deliv. Rev. 58(7), 878–896 (2006).
[CrossRef] [PubMed]

Schneider, M.

F. Stracke, B. Weiss, C. M. Lehr, K. König, U. F. Schaefer, and M. Schneider, “Multiphoton microscopy for the investigation of dermal penetration of nanoparticle-borne drugs,” J. Invest. Dermatol. 126(10), 2224–2233 (2006).
[CrossRef] [PubMed]

Shear, J. B.

C. Xu, W. Zipfel, J. B. Shear, R. M. Williams, and W. W. Webb, “Multiphoton fluorescence excitation: new spectral windows for biological nonlinear microscopy,” Proc. Natl. Acad. Sci. U.S.A. 93(20), 10763–10768 (1996).
[CrossRef] [PubMed]

So, P. T.

L. H. Laiho, S. Pelet, T. M. Hancewicz, P. D. Kaplan, and P. T. So, “Two-photon 3-D mapping of ex vivo human skin endogenous fluorescence species based on fluorescence emission spectra,” J. Biomed. Opt. 10(2), 024016 (2005).
[CrossRef] [PubMed]

P. T. So, C. Y. Dong, B. R. Masters, and K. M. Berland, “Two-photon excitation fluorescence microscopy,” Annu. Rev. Biomed. Eng. 2(1), 399–429 (2000).
[CrossRef]

B. R. Masters, P. T. So, and E. Gratton, “Multiphoton excitation fluorescence microscopy and spectroscopy of in vivo human skin,” Biophys. J. 72(6), 2405–2412 (1997).
[CrossRef] [PubMed]

Stark, M.

A. Ehlers, I. Riemann, M. Stark, and K. König, “Multiphoton fluorescence lifetime imaging of human hair,” Microsc. Res. Tech. 70(2), 154–161 (2007).
[CrossRef]

Sterenborg, H. J.

J. A. Palero, H. S. de Bruijn, A. van der Ploeg van den Heuvel, H. J. Sterenborg, and H. C. Gerritsen, “Spectrally resolved multiphoton imaging of in vivo and excised mouse skin tissues,” Biophys. J. 93(3), 992–1007 (2007).
[CrossRef] [PubMed]

Stock, U. A.

K. Schenke-Layland, I. Riemann, O. Damour, U. A. Stock, and K. König, “Two-photon microscopes and in vivo multiphoton tomographs--powerful diagnostic tools for tissue engineering and drug delivery,” Adv. Drug Deliv. Rev. 58(7), 878–896 (2006).
[CrossRef] [PubMed]

Stracke, F.

F. Stracke, B. Weiss, C. M. Lehr, K. König, U. F. Schaefer, and M. Schneider, “Multiphoton microscopy for the investigation of dermal penetration of nanoparticle-borne drugs,” J. Invest. Dermatol. 126(10), 2224–2233 (2006).
[CrossRef] [PubMed]

K. König, A. Ehlers, F. Stracke, and I. Riemann, “In vivo drug screening in human skin using femtosecond laser multiphoton tomography,” Skin Pharmacol. Physiol. 19(2), 78–88 (2006).
[CrossRef] [PubMed]

Strickler, J. H.

W. Denk, J. H. Strickler, and W. W. Webb, “Two-photon laser scanning fluorescence microscopy,” Science 248(4951), 73–76 (1990).
[CrossRef] [PubMed]

Strupler, M.

Stücker, M.

K. Teuchner, W. Freyer, D. Leupold, A. Volkmer, D. J. Birch, P. Altmeyer, M. Stücker, and K. Hoffmann, “Femtosecond two-photon excited fluorescence of melanin,” Photochem. Photobiol. 70(2), 146–151 (1999).
[PubMed]

Teuchner, K.

K. Teuchner, W. Freyer, D. Leupold, A. Volkmer, D. J. Birch, P. Altmeyer, M. Stücker, and K. Hoffmann, “Femtosecond two-photon excited fluorescence of melanin,” Photochem. Photobiol. 70(2), 146–151 (1999).
[PubMed]

Thorling, C.

M. S. Roberts, M. J. Roberts, T. A. Robertson, W. Sanchez, C. Thorling, Y. H. Zou, X. Zhao, W. Becker, and A. V. Zvyagin, “In vitro and in vivo imaging of xenobiotic transport in human skin and in the rat liver,” J. Biophoton. 1(6), 478–493 (2008).
[CrossRef]

Tromberg, B. J.

A. Zoumi, X. Lu, G. S. Kassab, and B. J. Tromberg, “Imaging coronary artery microstructure using second-harmonic and two-photon fluorescence microscopy,” Biophys. J. 87(4), 2778–2786 (2004).
[CrossRef] [PubMed]

A. Zoumi, A. Yeh, and B. J. Tromberg, “Imaging cells and extracellular matrix in vivo by using second-harmonic generation and two-photon excited fluorescence,” Proc. Natl. Acad. Sci. U.S.A. 99(17), 11014–11019 (2002).
[CrossRef] [PubMed]

Tsuzuki, T.

S. E. Cross, B. Innes, M. S. Roberts, T. Tsuzuki, T. A. Robertson, and P. McCormick, “Human skin penetration of sunscreen nanoparticles: in-vitro assessment of a novel micronized zinc oxide formulation,” Skin Pharmacol. Physiol. 20(3), 148–154 (2007).
[CrossRef] [PubMed]

van der Ploeg van den Heuvel, A.

J. A. Palero, H. S. de Bruijn, A. van der Ploeg van den Heuvel, H. J. Sterenborg, and H. C. Gerritsen, “Spectrally resolved multiphoton imaging of in vivo and excised mouse skin tissues,” Biophys. J. 93(3), 992–1007 (2007).
[CrossRef] [PubMed]

Volkmer, A.

K. Teuchner, W. Freyer, D. Leupold, A. Volkmer, D. J. Birch, P. Altmeyer, M. Stücker, and K. Hoffmann, “Femtosecond two-photon excited fluorescence of melanin,” Photochem. Photobiol. 70(2), 146–151 (1999).
[PubMed]

Webb, W. W.

R. M. Williams, W. R. Zipfel, and W. W. Webb, “Interpreting second-harmonic generation images of collagen I fibrils,” Biophys. J. 88(2), 1377–1386 (2005).
[CrossRef]

W. R. Zipfel, R. M. Williams, R. Christie, A. Y. Nikitin, B. T. Hyman, and W. W. Webb, “Live tissue intrinsic emission microscopy using multiphoton-excited native fluorescence and second harmonic generation,” Proc. Natl. Acad. Sci. U.S.A. 100(12), 7075–7080 (2003).
[CrossRef] [PubMed]

S. Huang, A. A. Heikal, and W. W. Webb, “Two-photon fluorescence spectroscopy and microscopy of NAD(P)H and flavoprotein,” Biophys. J. 82(5), 2811–2825 (2002).
[CrossRef] [PubMed]

C. Xu, W. Zipfel, J. B. Shear, R. M. Williams, and W. W. Webb, “Multiphoton fluorescence excitation: new spectral windows for biological nonlinear microscopy,” Proc. Natl. Acad. Sci. U.S.A. 93(20), 10763–10768 (1996).
[CrossRef] [PubMed]

W. Denk, J. H. Strickler, and W. W. Webb, “Two-photon laser scanning fluorescence microscopy,” Science 248(4951), 73–76 (1990).
[CrossRef] [PubMed]

Weiss, B.

F. Stracke, B. Weiss, C. M. Lehr, K. König, U. F. Schaefer, and M. Schneider, “Multiphoton microscopy for the investigation of dermal penetration of nanoparticle-borne drugs,” J. Invest. Dermatol. 126(10), 2224–2233 (2006).
[CrossRef] [PubMed]

Williams, R. M.

R. M. Williams, W. R. Zipfel, and W. W. Webb, “Interpreting second-harmonic generation images of collagen I fibrils,” Biophys. J. 88(2), 1377–1386 (2005).
[CrossRef]

W. R. Zipfel, R. M. Williams, R. Christie, A. Y. Nikitin, B. T. Hyman, and W. W. Webb, “Live tissue intrinsic emission microscopy using multiphoton-excited native fluorescence and second harmonic generation,” Proc. Natl. Acad. Sci. U.S.A. 100(12), 7075–7080 (2003).
[CrossRef] [PubMed]

C. Xu, W. Zipfel, J. B. Shear, R. M. Williams, and W. W. Webb, “Multiphoton fluorescence excitation: new spectral windows for biological nonlinear microscopy,” Proc. Natl. Acad. Sci. U.S.A. 93(20), 10763–10768 (1996).
[CrossRef] [PubMed]

Xu, C.

C. Xu, W. Zipfel, J. B. Shear, R. M. Williams, and W. W. Webb, “Multiphoton fluorescence excitation: new spectral windows for biological nonlinear microscopy,” Proc. Natl. Acad. Sci. U.S.A. 93(20), 10763–10768 (1996).
[CrossRef] [PubMed]

Yeh, A.

A. Zoumi, A. Yeh, and B. J. Tromberg, “Imaging cells and extracellular matrix in vivo by using second-harmonic generation and two-photon excited fluorescence,” Proc. Natl. Acad. Sci. U.S.A. 99(17), 11014–11019 (2002).
[CrossRef] [PubMed]

Zhao, J.

J. Chen, S. Zhuo, T. Luo, X. Jiang, and J. Zhao, “Spectral characteristics of autofluorescence and second harmonic generation from ex vivo human skin induced by femtosecond laser and visible lasers,” Scanning 28(6), 319–326 (2006).
[CrossRef] [PubMed]

Zhao, X.

M. S. Roberts, M. J. Roberts, T. A. Robertson, W. Sanchez, C. Thorling, Y. H. Zou, X. Zhao, W. Becker, and A. V. Zvyagin, “In vitro and in vivo imaging of xenobiotic transport in human skin and in the rat liver,” J. Biophoton. 1(6), 478–493 (2008).
[CrossRef]

Zhuo, S.

J. Chen, S. Zhuo, T. Luo, X. Jiang, and J. Zhao, “Spectral characteristics of autofluorescence and second harmonic generation from ex vivo human skin induced by femtosecond laser and visible lasers,” Scanning 28(6), 319–326 (2006).
[CrossRef] [PubMed]

Ziemer, M.

E. Dimitrow, M. Ziemer, M. J. Koehler, J. Norgauer, K. König, P. Elsner, and M. Kaatz, “Sensitivity and specificity of multiphoton laser tomography for in vivo and ex vivo diagnosis of malignant melanoma,” J. Invest. Dermatol. 129(7), 1752–1758 (2009).
[CrossRef] [PubMed]

Zipfel, W.

C. Xu, W. Zipfel, J. B. Shear, R. M. Williams, and W. W. Webb, “Multiphoton fluorescence excitation: new spectral windows for biological nonlinear microscopy,” Proc. Natl. Acad. Sci. U.S.A. 93(20), 10763–10768 (1996).
[CrossRef] [PubMed]

Zipfel, W. R.

R. M. Williams, W. R. Zipfel, and W. W. Webb, “Interpreting second-harmonic generation images of collagen I fibrils,” Biophys. J. 88(2), 1377–1386 (2005).
[CrossRef]

W. R. Zipfel, R. M. Williams, R. Christie, A. Y. Nikitin, B. T. Hyman, and W. W. Webb, “Live tissue intrinsic emission microscopy using multiphoton-excited native fluorescence and second harmonic generation,” Proc. Natl. Acad. Sci. U.S.A. 100(12), 7075–7080 (2003).
[CrossRef] [PubMed]

Zou, Y. H.

M. S. Roberts, M. J. Roberts, T. A. Robertson, W. Sanchez, C. Thorling, Y. H. Zou, X. Zhao, W. Becker, and A. V. Zvyagin, “In vitro and in vivo imaging of xenobiotic transport in human skin and in the rat liver,” J. Biophoton. 1(6), 478–493 (2008).
[CrossRef]

Zoumi, A.

A. Zoumi, X. Lu, G. S. Kassab, and B. J. Tromberg, “Imaging coronary artery microstructure using second-harmonic and two-photon fluorescence microscopy,” Biophys. J. 87(4), 2778–2786 (2004).
[CrossRef] [PubMed]

A. Zoumi, A. Yeh, and B. J. Tromberg, “Imaging cells and extracellular matrix in vivo by using second-harmonic generation and two-photon excited fluorescence,” Proc. Natl. Acad. Sci. U.S.A. 99(17), 11014–11019 (2002).
[CrossRef] [PubMed]

Zvyagin, A. V.

M. S. Roberts, M. J. Roberts, T. A. Robertson, W. Sanchez, C. Thorling, Y. H. Zou, X. Zhao, W. Becker, and A. V. Zvyagin, “In vitro and in vivo imaging of xenobiotic transport in human skin and in the rat liver,” J. Biophoton. 1(6), 478–493 (2008).
[CrossRef]

Adv. Drug Deliv. Rev. (1)

K. Schenke-Layland, I. Riemann, O. Damour, U. A. Stock, and K. König, “Two-photon microscopes and in vivo multiphoton tomographs--powerful diagnostic tools for tissue engineering and drug delivery,” Adv. Drug Deliv. Rev. 58(7), 878–896 (2006).
[CrossRef] [PubMed]

Annu. Rev. Biomed. Eng. (1)

P. T. So, C. Y. Dong, B. R. Masters, and K. M. Berland, “Two-photon excitation fluorescence microscopy,” Annu. Rev. Biomed. Eng. 2(1), 399–429 (2000).
[CrossRef]

Biophys. J. (5)

B. R. Masters, P. T. So, and E. Gratton, “Multiphoton excitation fluorescence microscopy and spectroscopy of in vivo human skin,” Biophys. J. 72(6), 2405–2412 (1997).
[CrossRef] [PubMed]

R. M. Williams, W. R. Zipfel, and W. W. Webb, “Interpreting second-harmonic generation images of collagen I fibrils,” Biophys. J. 88(2), 1377–1386 (2005).
[CrossRef]

J. A. Palero, H. S. de Bruijn, A. van der Ploeg van den Heuvel, H. J. Sterenborg, and H. C. Gerritsen, “Spectrally resolved multiphoton imaging of in vivo and excised mouse skin tissues,” Biophys. J. 93(3), 992–1007 (2007).
[CrossRef] [PubMed]

S. Huang, A. A. Heikal, and W. W. Webb, “Two-photon fluorescence spectroscopy and microscopy of NAD(P)H and flavoprotein,” Biophys. J. 82(5), 2811–2825 (2002).
[CrossRef] [PubMed]

A. Zoumi, X. Lu, G. S. Kassab, and B. J. Tromberg, “Imaging coronary artery microstructure using second-harmonic and two-photon fluorescence microscopy,” Biophys. J. 87(4), 2778–2786 (2004).
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Exp. Dermatol. (1)

E. Dimitrow, I. Riemann, A. Ehlers, M. J. Koehler, J. Norgauer, P. Elsner, K. König, and M. Kaatz, “Spectral fluorescence lifetime detection and selective melanin imaging by multiphoton laser tomography for melanoma diagnosis,” Exp. Dermatol. 18(6), 509–515 (2009).
[CrossRef] [PubMed]

J Biophotonics (1)

K. König, “Clinical multiphoton tomography,” J Biophotonics 1(1), 13–23 (2008).
[CrossRef]

J. Biomed. Opt. (2)

L. H. Laiho, S. Pelet, T. M. Hancewicz, P. D. Kaplan, and P. T. So, “Two-photon 3-D mapping of ex vivo human skin endogenous fluorescence species based on fluorescence emission spectra,” J. Biomed. Opt. 10(2), 024016 (2005).
[CrossRef] [PubMed]

K. König and I. Riemann, “High-resolution multiphoton tomography of human skin with subcellular spatial resolution and picosecond time resolution,” J. Biomed. Opt. 8(3), 432–439 (2003).
[CrossRef] [PubMed]

J. Biophoton. (1)

M. S. Roberts, M. J. Roberts, T. A. Robertson, W. Sanchez, C. Thorling, Y. H. Zou, X. Zhao, W. Becker, and A. V. Zvyagin, “In vitro and in vivo imaging of xenobiotic transport in human skin and in the rat liver,” J. Biophoton. 1(6), 478–493 (2008).
[CrossRef]

J. Invest. Dermatol. (2)

F. Stracke, B. Weiss, C. M. Lehr, K. König, U. F. Schaefer, and M. Schneider, “Multiphoton microscopy for the investigation of dermal penetration of nanoparticle-borne drugs,” J. Invest. Dermatol. 126(10), 2224–2233 (2006).
[CrossRef] [PubMed]

E. Dimitrow, M. Ziemer, M. J. Koehler, J. Norgauer, K. König, P. Elsner, and M. Kaatz, “Sensitivity and specificity of multiphoton laser tomography for in vivo and ex vivo diagnosis of malignant melanoma,” J. Invest. Dermatol. 129(7), 1752–1758 (2009).
[CrossRef] [PubMed]

Microsc. Res. Tech. (2)

A. Ehlers, I. Riemann, M. Stark, and K. König, “Multiphoton fluorescence lifetime imaging of human hair,” Microsc. Res. Tech. 70(2), 154–161 (2007).
[CrossRef]

W. Becker, A. Bergmann, M. A. Hink, K. König, K. Benndorf, and C. Biskup, “Fluorescence lifetime imaging by time-correlated single-photon counting,” Microsc. Res. Tech. 63(1), 58–66 (2004).
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Opt. Express (1)

Opt. Lett. (1)

Photochem. Photobiol. (2)

K. Teuchner, W. Freyer, D. Leupold, A. Volkmer, D. J. Birch, P. Altmeyer, M. Stücker, and K. Hoffmann, “Femtosecond two-photon excited fluorescence of melanin,” Photochem. Photobiol. 70(2), 146–151 (1999).
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Proc. Natl. Acad. Sci. U.S.A. (3)

W. R. Zipfel, R. M. Williams, R. Christie, A. Y. Nikitin, B. T. Hyman, and W. W. Webb, “Live tissue intrinsic emission microscopy using multiphoton-excited native fluorescence and second harmonic generation,” Proc. Natl. Acad. Sci. U.S.A. 100(12), 7075–7080 (2003).
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C. Xu, W. Zipfel, J. B. Shear, R. M. Williams, and W. W. Webb, “Multiphoton fluorescence excitation: new spectral windows for biological nonlinear microscopy,” Proc. Natl. Acad. Sci. U.S.A. 93(20), 10763–10768 (1996).
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Scanning (1)

J. Chen, S. Zhuo, T. Luo, X. Jiang, and J. Zhao, “Spectral characteristics of autofluorescence and second harmonic generation from ex vivo human skin induced by femtosecond laser and visible lasers,” Scanning 28(6), 319–326 (2006).
[CrossRef] [PubMed]

Science (1)

W. Denk, J. H. Strickler, and W. W. Webb, “Two-photon laser scanning fluorescence microscopy,” Science 248(4951), 73–76 (1990).
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Skin Pharmacol. Physiol. (2)

S. E. Cross, B. Innes, M. S. Roberts, T. Tsuzuki, T. A. Robertson, and P. McCormick, “Human skin penetration of sunscreen nanoparticles: in-vitro assessment of a novel micronized zinc oxide formulation,” Skin Pharmacol. Physiol. 20(3), 148–154 (2007).
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K. König, A. Ehlers, F. Stracke, and I. Riemann, “In vivo drug screening in human skin using femtosecond laser multiphoton tomography,” Skin Pharmacol. Physiol. 19(2), 78–88 (2006).
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Skin Res. Technol. (1)

M. J. Koehler, A. Preller, N. Kindler, P. Elsner, K. König, R. Bückle, and M. Kaatz, “Intrinsic, solar and sunbed-induced skin aging measured in vivo by multiphoton laser tomography and biophysical methods,” Skin Res. Technol. 15(3), 357–363 (2009).
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Other (1)

P. T. C. S. Barry R. Masters, ed., Handbook of Biomedical Nonlinear Optical Microscopy (Oxford University Press, Inc., 2008).

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Figures (14)

Fig. 7
Fig. 7

Left: Multiphoton image for λ = 720 nm recorded at a depth of 116 μm. The black line represents the ROI for the evaluation of the signal dependence on excitation wavelength (Fig. 8). Right: Series of multiphoton images for λ = 720 nm, 740 nm 760 nm, 780 nm, 800 nm, 820 nm, 840 nm, 860 nm, 880 nm (from left to right, top to bottom).

Fig. 9
Fig. 9

Multiphoton images of collagen / elastin structures (depth 130 μm) with different excitation wavelengths (a-c: λ = 800 nm, d: λ = 820 nm) and different filters (BG 39: color-glass filter; BP 395/11, BP 460/60: bandpass filters. a) and d) show both detected SHG and autofluorescence, b) only shows detected SHG, c) only shows autofluorescence (50 mW excitation power 50 mW).

Fig. 1
Fig. 1

Normalized transmission of the signal pathway of the DermaInspect with (dotted line) and without (solid line) color glass filter BG 39. The dashed line shows the spectral sensitivity of the PMT.

Fig. 2
Fig. 2

Minimum pulse durations derived from autocorrelation measurements with low (circles) and normal (squares) dispersion option of the DeepSee unit.

Fig. 3
Fig. 3

Left: Multiphoton image for λ = 720 nm recorded at the skin surface. The black line represents the ROI for the evaluation of the signal dependence on excitation wavelength (Fig. 8). Right: Series of multiphoton images for λ = 720 nm, 740 nm 760 nm, 780 nm, 800 nm, 820 nm, 840 nm, 860 nm, 880 nm (from left to right, top to bottom).

Fig. 4
Fig. 4

Left: Multiphoton image for λ = 720 nm recorded at a depth of 22 μm. The black line represents the ROI for the evaluation of the signal dependence on excitation wavelength (Fig. 8). Right: Series of multiphoton images for λ = 720 nm, 740 nm 760 nm, 780 nm, 800 nm, 820 nm, 840 nm, 860 nm, 880 nm (from left to right, top to bottom).

Fig. 5
Fig. 5

Left: Multiphoton image for λ = 720 nm recorded at a depth of 55 μm. The black line represents the ROI for the evaluation of the signal dependence on excitation wavelength (Fig. 8). Right: Series of multiphoton images for λ = 720 nm, 740 nm 760 nm, 780 nm, 800 nm, 820 nm, 840 nm, 860 nm, 880 nm (from left to right, top to bottom).

Fig. 6
Fig. 6

Left: Multiphoton image for λ = 720 nm recorded at a depth of 90 μm. The black line represents the ROI for the evaluation of the signal dependence on excitation wavelength (Fig. 8). Right: Series of multiphoton images for λ = 720 nm, 740 nm 760 nm, 780 nm, 800 nm, 820 nm, 840 nm, 860 nm, 880 nm (from left to right, top to bottom).

Fig. 8
Fig. 8

Signal intensities of main fluorophores of human skin in dependence of excitation wavelength derived from Fig. 3 - Fig. 6.

Fig. 10
Fig. 10

Spectral dependence of the ROI intensity of Fig. 7 of the overall signal (squares) and SHG light blocked with (circles, triangle).

Fig. 11
Fig. 11

Left row: FLIM images of the same region as in Fig. 9 (depth 130 μm) with an excitation wavelength of λ = 800 nm and with BG 39 color-glass filter (left) and a 430-490 nm bandpass filter (right). The square diamond shapes indicate the pixels whose decay curves are shown in Fig. 12.

Fig. 12
Fig. 12

Typical decay curves from the FLIM images in Fig. 11.

Fig. 13
Fig. 13

In vivo FLIM images of a layer of the stratum papillare with excitation wavelength λ = 710 nm and λ = 800 nm. The signal decay times τ1 and τ2 are false-color coded.

Fig. 14
Fig. 14

Distribution of the decay times from images from Fig. 13.

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