Zonios George, Dimou Aikaterini, Bassukas Ioannis, Galaris Dimitrios, Tsolakidis Argyrios, Kaxiras Efthimios
University of Ioannina, Department of Materials Science and Engineering, 45110 Ioannina, Greece.
J Biomed Opt. 2008 Jan-Feb;13(1):014017. doi: 10.1117/1.2844710.
We present a new method for studying melanin in vivo based on diffuse reflectance spectroscopy of human skin. We find that the optical absorption spectrum of in vivo melanin exhibits an exponential dependence on wavelength, consistent with, but with a higher decay slope than, in vitro results. We offer theoretical justification for this exponential dependence on the basis of a recently proposed model for the structure of eumelanin protomolecules. Moreover, we report on a new method for analysis of diffuse reflectance spectra, which identifies intrinsic differences in absorption spectra between malignant melanoma and dysplastic nevi in vivo. These preliminary results are confirmed both by analysis of our own clinical data as well as by analysis of data from three independent, previously published studies. In particular, we find evidence that the histologic transition from dysplastic nevi to melanoma in situ and then to malignant melanoma is reflected in the melanin absorption spectra. Our results are very promising for the development of techniques for the noninvasive detection of melanoma and, more generally, for the study and characterization of pigmented skin lesions. It is also a promising approach for a better understanding of the biological role, structure, and function of melanin.
我们提出了一种基于人体皮肤漫反射光谱在体内研究黑色素的新方法。我们发现，体内黑色素的光吸收光谱对波长呈指数依赖性，这与体外结果一致，但衰减斜率更高。基于最近提出的真黑素原分子结构模型，我们为这种指数依赖性提供了理论依据。此外，我们报告了一种分析漫反射光谱的新方法，该方法可识别体内恶性黑色素瘤和发育异常痣之间吸收光谱的内在差异。我们自己的临床数据分析以及对三项独立的、先前发表的研究数据的分析均证实了这些初步结果。特别是，我们发现有证据表明，从发育异常痣到原位黑色素瘤再到恶性黑色素瘤的组织学转变反映在黑色素吸收光谱中。我们的结果对于开发黑色素瘤无创检测技术，以及更广泛地用于色素沉着性皮肤病变的研究和表征非常有前景。这也是更好地理解黑色素的生物学作用、结构和功能的一种有前景的方法。
