A Noninvasive Method for Assessing Interior Skin Damage Caused by Chronological Aging and Photoaging Based on Near-Infrared Diffuse Reflection Spectroscopy

Abstract

This paper reports a noninvasive method for evaluating skin aging based on near-infrared diffuse reflectance (NIR-DR) spectroscopy. Skin aging can be attributed to photoaging and chronological aging. Both types of aging are heavily involved in the skin changes that occur as we get older, for example, wrinkles or sagging skin. Our goal is to develop a noninvasive way to assess changes taking place inside the skin for each type of aging by using NIR-DR spectroscopy. Interior skin damages caused by photoaging and chronological aging were studied for an ultraviolet-B (UVB)-irradiated hairless mouse group (24 mice) and a non-irradiated group (29 mice) by using NIR-DR spectroscopy and principal component analysis (PCA). The results suggested the possibility of monitoring the contribution and the quantitative assessment of both types of aging taking place inside the skin by using the 5990-5490 cm(-1) and 5000-4480 cm(-1) regions of NIR-DR spectra. For the photoaging, structural changes in proteins are most clearly reflected by a shift of the band near 4880 cm(-1) due to a combination of amide A and amide II modes. On the other hand, the chronological aging is associated with a change in collagen quantity as is seen in the intensity changes in NIR bands assigned to collagen. NIR-DR spectroscopy and PCA may allow us to noninvasively assess the degree of photoaging and chronological aging as the degeneration of elasticity in collagen protein and the degradation of protein quantity, respectively.

Quantitative analysis on collagen morphology in aging skin based on multiphoton microscopy

“…[1][2][3][4][5] Cutaneous aging is a complicated biological process affecting different constituents of skin, which can be divided into two types: chronological aging and photoaging. 2,3 Recently, various optical methods, such as multiphoton microscopy (MPM) 6,7 serving as two photon excited fluorescence and second harmonic generation (SHG) microscopy, optical coherence tomography, 8,9 confocal laser scanning, 9,10 and diffuse spectroscopy 11 have been developed for use in some medical applications and in dermatology. [8][9][10][11][12][13][14][15][16] Since MPM is a label-free noninvasive approach with high-resolution, it has been successfully used as an effective technique in dermatology, including aging skin.…”

“…2,3 Recently, various optical methods, such as multiphoton microscopy (MPM) 6,7 serving as two photon excited fluorescence and second harmonic generation (SHG) microscopy, optical coherence tomography, 8,9 confocal laser scanning, 9,10 and diffuse spectroscopy 11 have been developed for use in some medical applications and in dermatology. [8][9][10][11][12][13][14][15][16] Since MPM is a label-free noninvasive approach with high-resolution, it has been successfully used as an effective technique in dermatology, including aging skin. [14][15][16] However, the effects of the above two cutaneous aging processes are often overlapped including changes in epithelium and dermis.…”

Principal component model of multispectral data for near real-time skin chromophore mapping

“…Blood volume and oxygenation are especially of interest for skin-lesion treatment follow-up as a parameter of the angeogenic process and metabolic state of a tumor. Previous work of assessing these parameters in healthy and diseased skin [1][2][3][4][5][6][7][8][9] included fitting the acquired intensity data to an analytical model of photon migration in diffuse media. Reconstructed concentration maps are therefore based on the wavelengthdependent absorption coefficient and require an accurate model.…”

“…[1][2][3][4][5][6][7] Assessment of the metabolic state of skin surface lesions is often desired in clinical routines as a measure for treatment outcome. Near-infrared diffuse multispectral imaging of the skin combined with an analytical, numerical, or stochastic skin model can provide this information by producing spatial maps of skin chromophore concentrations.…”

Evaluation and assessment of photoaging

“…A third study proposed a near-infrared diffuse reflectance (NIR-DR) spectroscopy method for the non-invasive evaluation of changes [44,45]. This was first validated in mice, and most recently reported in human skin [44,45].…”