[1] R. Schulz et al., "Modeling of drug diffusion based on concentration profiles in healthy and damaged human skin," Biophys. J. 117, 998–1008 (2019).
[2] M. K. Matta et al., "Effect of sunscreen application under maximal use conditions on plasma concentration of sunscreen active ingredients: A randomized clinical trial," JAMA 321, 2082–2091 (2019).
[3] C. Choe, J. Lademann, M. E. Darvin, "Analysis of human and porcine skin in vivo/ex vivo for penetration of selected oils by confocal Raman microscopy," Skin Pharmacol. Physiol. 28, 318–330 (2015).
[4] C. Kra?t, J. Popp, "The many facets of Raman spectroscopy for biomedical analysis," Anal. Bioanal. Chem. 407, 699–717 (2015).
[5] S. Osseiran et al., "Characterizing stratum corneum structure, barrier function, and chemical content of human skin with coherent Raman scattering imaging," Biomed. Opt. Express 9, 6425–6443 (2018).
[6] L. Zhang et al., "Resolving water, proteins, and lipids from in vivo confocal Raman spectra of stratum corneum through a chemometric approach," J. Vis. Exp. 2019(151), e60186 (2019).
[7] R. Vyumvuhore et al., "Raman spectroscopy: In vivo quick response code of skin physiological status," J. Biomed. Opt. 19(11), 111603 (2014).
[8] K. V. Berezin et al., "Optical clearing of human skin using some monosaccharides in vivo," Opt. Spectrosc. 127, 352–358 (2019).
[9] J. Gallwas et al., "Effect of optical clearing agents on optical coherence tomography images of cervical epithelium," Lasers Med. Sci. 30, 517–525 (2015).
[10] M. E. Shvachkina, D. D. Yakovlev, E. N. Lazareva, A. B. Pravdin, D. A. Yakovlev, "Monitoring of the process of immersion optical clearing of collagen bundles using optical coherence tomography," Opt. Spectrosc. 127, 359–367 (2019).
[11] M. Balu, H. Mikami, J. Hou, E. O. Potma, B. J. Tromberg, "Rapid mesoscale multiphoton microscopy of human skin," Biomed. Opt. Express 7, 4375–4387 (2016).
[12] K. Koenig, 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).
[13] E. A. Shirshin et al., "In vivo optical imaging of the viable epidermis around the nailfold capillaries for the assessment of heart failure severity in humans," J. Biophotonics 11(9), e201800066 (2018).
[14] E. A. Shirshin et al., "Two-photon autofluorescence lifetime imaging of human skin papillary dermis in vivo: Assessment of blood capillaries and structural proteins localization," Sci. Rep. 7, 1171 (2017).
[15] M. Rajadhyaksha, M. Grossman, D. Esterowitz, R. H. Webb, R. R. Anderson, "In vivo confocal scanning laser microscopy of human skin: Melanin provides strong contrast," J. Invest. Dermatol. 104, 946–952 (1995).
[16] V. H. Maciel, W. R. Correr, C. Kurachi, V. S. Bagnato, C. da Silva Souza, "Fluorescence spectroscopy as a tool to in vivo discrimination of distinctive skin disorders," Photodiagnosis Photodyn. Ther. 19, 45–50 (2017).
[17] I. Ferulova, A. Lihachev, J. Spigulis, "Photobleaching effects on in vivo skin auto- fluorescence lifetime," J. Biomed. Opt. 20(5), 051031 (2015).
[18] D. I. Ramos-Soto, A. K. Singh, E. Saucedo-Casas, E. Castro-Camus, M. Alfaro-Gomez, "Visualization of moisturizer effects in stratum corneum in vitro using THz spectroscopic imaging," Appl. Opt. 58, 6581–6585 (2019).
[19] K. I. Zaytsev et al., "The progress and perspectives of terahertz technology for diagnosis of neoplasms: A review," J. Opt. (United Kingdom) 22, 013001 (2020).
[20] C. Merle, C. Laugel, P. Chaminade, A. Baillet- Gu?roy, "Quantitative study of the stratum corneum lipid classes by normal phase liquid chromatography: Comparison between two universal detectors," J. Liq. Chromatogr. Relat. Technol. 33, 629–644 (2010).
[21] V. Kalchenko, I. Meglinski, A. Sdobnov, Y. Kuznetsov, A. Harmelin, "Combined laser speckle imaging and fluorescent intravital microscopy for monitoring acute vascular permeability reaction," J. Biomed. Opt. 24(6), 060501 (2019).
[22] B. Gotter, W. Faubel, R. H. H. Neubert, "Optical methods for measurements of skin penetration," Skin Pharmacol. Physiol. 21, 156–165 (2008).
[23] C. V. Raman, K. S. Krishnan, "A new type of secondary radiation," Nature 121, 501–502 (1928).
[24] A. Quatela, L. Miloudi, A. Tfayli, A. Baillet- Gu?roy, "In vivo Raman microspectroscopy: Intraand intersubject variability of stratum corneum spectral markers," Skin Pharmacol. Physiol. 29, 102–109 (2016).
[25] D. Huang et al., "Optical clearing of porcine skin tissue in vitro studied by Raman microspectroscopy," J. Biomed. Opt. 17, 015004 (2012).
[26] V. V. Tuchin, Tissue Optics: Light Scattering Methods and Instruments for Medical Diagnosis, SPIE Press, Bellingham (2015).
[27] E. Gratton, "Deeper tissue imaging with total detection," Science 331, 1016–1017 (2011).
[28] B. E. Bouma, G. J. Tearney, Handbook of Optical Coherence Tomography, Marcel Dekker, New York (2002).
[29] A. Y. Sdobnov et al., "Recent progress in tissue optical clearing for spectroscopic application," Spectrochim. Acta A, Mol. Biomol. Spectrosc. 197, 216–229 (2018).
[30] D. A. Boas, "A fundamental limitation of linearized algorithms for diffuse optical tomography," Opt. Express 1, 404–413 (1997).
[31] C. L. Smithpeter, A. K. Dunn, A. J. Welch, R. Richards-Kortum, "Penetration depth limits of in vivo confocal reflectance imaging," Appl. Opt. 37, 2749–2754 (1998).
[32] V. V. Tuchin, "Light propagation in tissues with controlled optical properties," J. Biomed. Opt. 2, 401–417 (1997).
[33] E. A. Genina, A. N. Bashkatov, V. V. Tuchin, "Tissue optical immersion clearing," Expert Rev. Med. Devices 7, 825–842 (2010).
[34] V. V. Tuchin, X. Xu, R. K. Wang, "Dynamic optical coherence tomography in studies of optical clearing, sedimentation, and aggregation of immersed blood," Appl. Opt. 41, 258–271 (2002).
[35] D. K. Tuchina et al., "Ex vivo optical measurements of glucose diffusion kinetics in native and diabetic mouse skin," J. Biophotonics 8, 332–346 (2015).
[36] K. V. Larin et al., "Optical clearing for OCT image enhancement and in-depth monitoring of molecular diffusion," IEEE J. Sel. Top. Quantum Electron. 18, 1244–1259 (2012).
[37] H. Hama et al., "Scale: A chemical approach for fluorescence imaging and reconstruction of transparent mouse brain," Nat. Neurosci. 14, 1481–1488 (2011).
[38] H. Hama et al., "ScaleS: An optical clearing palette for biological imaging," Nat. Neurosci. 18, 1518– 1529 (2015).
[39] D. Zhu, K. V. Larin, Q. Luo, V. V. Tuchin, "Recent progress in tissue optical clearing," Laser Photonics Rev. 7, 732–757 (2013).
[40] A. K. Bui et al., "Revisiting optical clearing with dimethyl sulfoxide DMSO," Lasers Surg. Med. 41, 142–148 (2009).
[41] V. V. Tuchin, "A clear vision for laser diagnostics (review)," IEEE J. Sel. Top. Quantum Electron. 13, 1621–1628 (2007).
[42] X. Weny, Z. Maoy, Z. Han, V. V. Tuchin, D. Zhu, "In vivo skin optical clearing by glycerol solutions: Mechanism," J. Biophotonics 3, 44–52 (2010).
[43] J. Hirshburg, B. Choi, J. S. Nelson, A. T. Yeh, "Collagen solubility correlates with skin optical clearing," J. Biomed. Opt. 11, 040501 (2006).
[44] J. Hirshburg, B. Choi, J. S. Nelson, A. T. Yeh, "Correlation between collagen solubility and skin optical clearing using sugars," Lasers Surg. Med. 39, 140–144 (2007).
[45] J. M. Hirshburg, K. M. Ravikumar, W. Hwang, A. T. Yeh, "Molecular basis for optical clearing of collagenous tissues," J. Biomed. Opt. 15, 055002 (2010).
[46] A. T. Yeh, B. Choi, J. S. Nelson, B. J. Tromberg, "Reversible dissociation of collagen in tissues," J. Invest. Dermatol. 121, 1332–1335 (2003).
[47] L. M. C. Oliveira and V. V. Tuchin, The Optical Clearing Method: A New Tool for Clinical Practice and Biomedical Engineering, Springer International Publishing, Switzerland (2019).
[48] X. Wen, S. L. Jacques, V. V. Tuchin, D. Zhu, "Enhanced optical clearing of skin in vivo and optical coherence tomography in-depth imaging," J. Biomed. Opt. 17, 066022 (2012).
[49] Y. Y. Fu, S. C. Tang, "Optical clearing facilitates integrated 3D visualization of mouse ileal microstructure and vascular network with high definition," Microvasc. Res. 80, 512–521 (2010).
[50] O. Nadiarnykh, P. J. Campagnola, "Retention of polarization signatures in SHG microscopy of scattering tissues through optical clearing," Opt. Express 17, 5794–5806 (2009).
[51] M. V. Schulmerich et al., "Optical clearing in transcutaneous Raman spectroscopy of murine cortical bone tissue," J. Biomed. Opt. 13, 021108 (2008).
[52] Q. Lin, E. N. Lazareva, V. I. Kochubey, Y. Duan, V. V. Tuchin, "Kinetics of optical clearing of human skin studied in vivo using portable Raman spectroscopy," Laser Phys. Lett. 17, 105601 (2020).
[53] P. Liu et al., "Discrimination of dimethyl sulphoxide diffusion coefficient in the process of optical clearing by confocal micro-Raman spectroscopy," J. Biomed. Opt. 18, 020507 (2013).
[54] A. Y. Sdobnov, M. E. Darvin, J. Schleusener, J. Lademann, V. V. Tuchin, "Hydrogen bound water profiles in the skin influenced by optical clearing molecular agents — Quantitative analysis using confocal Raman microscopy," J. Biophotonics 12(5), e201800283 (2019), doi: 10.1002/ jbio.201800283.
[55] K. V. Larin, V. V. Tuchin, "Functional imaging and assessment of the glucose diffusion rate in epithelial tissues in optical coherence tomography," Quantum Electron. 38, 551–556 (2008).
[56] J. Jiang, M. Boese, P. Turner, R. K. Wang, "Penetration kinetics of dimethyl sulphoxide and glycerol in dynamic optical clearing of porcine skin tissue in vitro studied by Fourier transform infrared spectroscopic imaging," J. Biomed. Opt. 13, 021105 (2008).
[57] N. J. Yang, M. J. Hinner, "Getting across the cell membrane: An overview for small molecules, peptides, and proteins," Methods Mol. Biol. 1266, 29– 53 (2015).
[58] S. R. Utz, V. V. Tuchin, E. M. Galkina, "The dynamics of some human skin biophysical parameters in the process of optical clearing after hyperosmotic solutions topical application," Vestn. Dermatol. Venerol. 91(4), 60–68 (2015).
[59] P. J. Caspers et al., "Monitoring the penetration enhancer dimethyl sulfoxide in human stratum corneum in vivo by confocal Raman spectroscopy," Pharm. Res. 19, 1577–1580 (2002).
[60] M. H. Khan et al., "Optical clearing of in vivo human skin: Implications for light-based diagnostic imaging and therapeutics," Lasers Surg. Med. 34, 83–85 (2004).
[61] V. Genin et al., "Ex vivo investigation of glycerol diffusion in skin tissue," J. Biomed. Photonics Eng. 2, 010303-1–010303-5 (2016).
[62] A. Sdobnov, M. E. Darvin, J. Lademann, V. V. Tuchin, "A comparative study of ex vivo skin optical clearing using two-photon microscopy," J. Biophotonics 10, 1115–1123 (2017).
[63] S. Debeer et al., "Comparative histology and immunohistochemistry of porcine versus human skin," Eur. J. Dermatol. 23, 456–466 (2013).
[64] S. Mangelsdorf, T. Vergou, W. Sterry, J. Lademann, A. Patzelt, "Comparative study of hair follicle morphology in eight mammalian species and humans," Ski. Res. Technol. 20, 147–154 (2014).
[65] M. E. Darvin et al., "Comparison of in vivo and ex vivo laser scanning microscopy and multiphoton tomography application for human and porcine skin imaging," Quantum Electron. 44, 646– 651 (2014).
[66] T. Sullivan, W. H. Eaglstein, S. C. Davis, P. Mertz, "The pig as a model for human wound healing," Wound Repair Regen. 9, 66–76 (2001).
[67] C. S. Choe, J. Schleusener, J. Lademann, M. E. Darvin, "Human skin in vivo has a higher skin barrier function than porcine skin ex vivo — Comprehensive Raman microscopic study of the stratum corneum," J. Biophotonics 11, e201700355 (2018).
[68] V. V. Tuchin et al., "Optical clearing of skin using flashlamp-induced enhancement of epidermal permeability," Lasers Surg. Med. 38, 824–836 (2006).
[69] J. Schleusener, J. Lademann, M. E. Darvin, "Depthdependent autofluorescence photobleaching using 325, 473, 633, and 785 nm of porcine ear skin ex vivo," J. Biomed. Opt. 22, 091503 (2017).
[70] F. Menges, "Spectragryph: Optical spectroscopy software: Description," https://www.e?emm2.de/ spectragryph/about descr.html (2020).
[71] A. Y. Sdobnov, V. V. Tuchin, J. Lademann, M. E. Darvin, "Confocal Raman microscopy supported by optical clearing treatment of the skin— influence on collagen hydration," J. Phys. D, Appl. Phys. 50, 285401 (2017).
[72] R. Na, I. M. Stender, M. Henriksen, H. C. Wulf, "Autofluorescence of human skin is age-related after correction for skin pigmentation and redness," J. Invest. Dermatol. 116, 536–540 (2001).
[73] T. Dai, B. M. Pikkula, L. V. Wang, B. Anvari, "Comparison of human skin opto-thermal response to near-infrared and visible laser irradiations: A theoretical investigation," Phys. Med. Biol. 49, 4861–4877 (2004).
[74] E. Guillard, A. Tfayli, M. Manfait, A. Baillet- Gu?roy, "Thermal dependence of Raman descriptors of ceramides — Part II: Effect of chains lengths and head group structures," Anal. Bioanal. Chem. 399, 1201–1213 (2011).
[75] P. J. Caspers, G. W. Lucassen, E. A. Carter, H. A. Bruining, G. J. Puppels, "In vivo confocal Raman microspectroscopy of the skin: Noninvasive determination of molecular concentration profiles," J. Invest. Dermatol. 116, 434–442 (2001).
[76] N. Nakagawa, M. Matsumoto, S. Sakai, "In vivo measurement of the water content in the dermis by confocal Raman spectroscopy," Skin Res. Technol. 16, 137–141 (2010).
[77] T. T.Nguyen et al., "Characterization of type I and IV collagens by Raman microspectroscopy: Identification of spectral markers of the dermo-epidermal junction," J. Spectrosc. (New York) 27, 686183 (2012).
[78] B. G. Frushour, J. L. Koenig, "Raman scattering of collagen, gelatin, and elastin," Biopolymers 14, 379– 391 (1975).
[79] A. Nijssen et al., "Discriminating basal cell carcinoma from its surrounding tissue by Raman spectroscopy," J. Invest. Dermatol. 119, 64–69 (2002).
[80] M. Gniadecka, H. C. Wulf, O. F. Nielsen, D. H. Christensen, J. Hercogova, "Distinctive molecular abnormalities in benign and malignant skin lesions: Studies by Raman spectroscopy," Photochem. Photobiol. 66, 418–423 (1997).
[81] B. H. Hokr, V. V. Yakovlev, "Raman signal enhancement via elastic light scattering," Opt. Express 21, 11757 (2013).
[82] P. Matousek, "Raman signal enhancement in deep spectroscopy of turbid media," Appl. Spectrosc. 61, 845–854 (2007).
[83] D. Oelkrug, B. Boldrini, K. Rebner, "Comparative Raman study of transparent and turbid materials: Models and experiments in the remote sensing mode," Anal. Bioanal. Chem. 409, 673–681 (2017).
[84] J. Jiang, R. K. Wang, "Comparing the synergistic effects of oleic acid and dimethyl sulfoxide as vehicles for optical clearing of skin tissue in vitro," Phys. Med. Biol. 49, 5283–5294 (2004).
[85] A. Liopo, R. Su, D. A. Tsyboulski, A. A. Oraevsky, "Optical clearing of skin enhanced with hyaluronic acid for increased contrast of optoacoustic imaging," J. Biomed. Opt. 21, 081208 (2016).