Evaluating cutaneous photoaging by use of multiphoton fluorescence and second-harmonic generation microscopy

Abstract

The photoaging process of facial skin is investigated by use of multiphoton fluorescence and second-harmonic generation (SHG) microscopy. We obtain the autofluorescence (AF) and SHG images of the superficial dermis from the facial skin of three patients aged 20, 40, and 70 years. The results show that areas of AF increase with age, whereas areas of SHG decrease with age. The results are consistent with the histological findings in which collagen is progressively replaced by elastic fibers. The AF and SHG changes in photoaging are quantified by a SHG to autofluorescence aging index of dermis (SAAID). Our results suggest that SAAID can be a good indicator of the severity of photoaging.

Endogenous Optical Biomarkers of Ovarian Cancer Evaluated with Multiphoton Microscopy

“…SHG signal. Collagen structure in younger patients seemed different from older patients consistent with age-related collagen changes observed by others (31). Quantitatively, slight differences were found between normal-high risk and normal-low risk samples in the postmenopausal group, with the normal-high risk samples notably trending toward the cancer group.…”

Differentiation of normal and cancerous lung tissues by multiphoton imaging

“…This approach has been demonstrated to be useful in the quantitative analysis of basal cell carcinoma and differently aged skin. 6,13 In short, MAFSI was determined by counting the number of pixels with MAF or SHG intensities above the chosen threshold levels. This approach was used to eliminate effects on detected signal levels due to scattering and specimen-induced spherical aberration.…”

“…Other areas such as developmental biology, neurobiology, and orthopedics have also benefited from the advantages of nonlinear optical imaging. [12][13][14][15][16] In this work, we proposed to utilize nonlinear optical microscopy to image and analyze ex vivo noncancerous and cancerous lung tissues. Structurally, normal lung tissue is composed of collagen and elastic fibers, with the epithelium of the alveolus as cells responsible for gas exchange.…”

“…On the other hand, cancers such as lung adenocarcinoma ͑LAC͒ and squamous cell carcinoma ͑SCC͒ are composed primarily of tumor masses. Since previous studies have shown that collagen fibers are effective in producing second-harmonic generation signal and elastic fibers along with cells ͓NAD͑P͒H, FAD͔ can be autofluorescent, 13 multiphoton imaging may be effective in discriminating noncancerous and cancerous lung tissues.…”

Multimodal nonlinear microscopy: A powerful label-free method for supporting standard diagnostics on biological tissues

“…In fact, TPF microscopy o®ers high-resolution imaging of NADH in living cells and of elastin within connective tissue, while SHG enables the direct imaging of collagen. Combined TPF-SHG microscopy was successfully employed for studying physiological and pathological conditions of connective tissues, especially for cutaneous photoaging 22,[85][86][87] and skin tumors. 59,67,88 Combining TPF and SHG microscopy is a powerful solution for label-free tissue imaging, however they are not able to provide functional information unless used in combination with other imaging techniques.…”