Shirkavand Afshan, Farivar Shirin, Mohajerani Ezeddin, Ataie-Fashtami Leila, Ghazimoradi Mohammad H
POMP Lab, Photonics Department, Laser and Plasma Research Institute, Shahid Beheshti University, Tehran, 1983969411, Iran.
Genetics, Stem Cells, Department of Cell and Molecular Biology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, 1983963113, Iran.
Lasers Surg Med. 2019 Oct;51(8):742-750. doi: 10.1002/lsm.23095. Epub 2019 May 15.
Optical reflectance spectroscopy is a non-invasive technique for optical characterization of biological samples. Any alteration in a cell from normal or carcinogenic causes will change its refractive index. The aim of this study is to develop a computerized program for extraction of a refractive index of normal and cancerous skin cell lines, including melanoma, fibroblast, and adipose cells, using visible near-infrared reflectance spectra and the Kramers-Kronig (K-K) relations.
A fiber optic reflectance spectrometer in visible near-infrared wavelength was used for spectrum acquisition in an in vitro study. Human skin cell lines for melanoma (A375), fibroblast, and adipose sample were cultured for optical spectroscopy. Following data acquisition, an analytical MATLAB code was developed to run the K-K relations. The program was validated for three biological samples using an Abbe refractometer.
The validation error (below 5%) and determination of changes in the refractive index of melanoma, normal fibroblasts, and adipose skin cells was carried out at wavelengths of 450-950 nm. The refractive index of melanoma was 1.59270 ± 0.0550 at 450 nm, the minimum amount of 1.27790 ± 0.0550 to 1.321 ± 0.0550 at 620 nm, and rose sharply to 1.44321 ± 0.0550 at 935 nm. The respective results for fibroblast and adipose tissue cells were 1.33282 ± 0.0134 and 1.28345 ± 0.0163 at 450 nm with an increasing trend to 1.30494 ± 0.0135 and 1.26716 ± 0.0163 at 935 nm.
Refractive index characteristics show potential for cancer screening and diagnosis. The results show that optical spectroscopy is a promising, non-invasive tool for assessment of the refractive index of living biological cells in in vitro settings. Tracking changes in the refractive index allows screening of normal and abnormal cells for probable alterations in a non-invasive label-free method. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.
光学反射光谱法是一种用于对生物样品进行光学表征的非侵入性技术。细胞因正常或致癌原因发生的任何改变都会改变其折射率。本研究的目的是开发一种计算机程序，利用可见近红外反射光谱和克拉默斯-克勒尼希（K-K）关系，提取正常和癌性皮肤细胞系（包括黑色素瘤、成纤维细胞和脂肪细胞）的折射率。
在一项体外研究中，使用可见近红外波长的光纤反射光谱仪进行光谱采集。培养用于黑色素瘤（A375）、成纤维细胞和脂肪样本的人类皮肤细胞系以进行光谱学研究。在数据采集之后，开发了一个用于运行K-K关系的MATLAB分析代码。使用阿贝折射仪对三个生物样品验证该程序。
在450 - 950 nm波长下进行了验证误差（低于5%）以及黑色素瘤、正常成纤维细胞和脂肪皮肤细胞折射率变化的测定。黑色素瘤在450 nm处的折射率为1.59270 ± 0.0550，在620 nm处最小值为1.27790 ± 0.0550至1.321 ± 0.0550，并在935 nm处急剧上升至1.44321 ± 0.0550。成纤维细胞和脂肪组织细胞在450 nm处的相应结果分别为1.33282 ± 0.0134和1.28345 ± 0.0163，在935 nm处呈上升趋势，分别为1.30494 ± 0.0135和1.26716 ± 0.0163。
折射率特征显示出癌症筛查和诊断的潜力。结果表明，光谱学是一种有前景的非侵入性工具，可用于在体外环境中评估活生物细胞的折射率。追踪折射率的变化能够以非侵入性无标记方法筛查正常和异常细胞的可能改变。《激光外科学与医学》。© 2019威利期刊公司。
