Study On The Biochemical Features Of Squamous Cell Carcinoma Using Raman Spectroscopy

Raman spectroscopy is an efficient and nondestructive testing method which can represent the vibration information of the molecules.The composition and structural information of matter can be analyzed by studying the position,number and intensity of featured Raman peaks.Thus,it has wide applications in the aspect of biomedicine.Confocal Raman microspectral imaging(CRMI)is a kind of spectral imaging methodology based on Raman spectroscopy and confocal optical configurations,which has the advantages,such as high-spatial resolution,high-sensitivity,high-imaging efficiency as well as the capability of microsamples analysis.In this work,the principle of Raman spectroscopy is explained from the view of classical and quantum theory respectively.In addition,it gives a brief introduction of CRMI technology principles,advantages,and application progresses.The most important achievement in this work is the analysis of pathological features during squamous cell carcinoma(SCC)by CRMI method.After obtaining the featured Raman spectra of normal skin tissue,its biochemical composition and structural characteristics were analyzed by both Univariate and Multi-Variate(K-mean Cluster Analysis,KCA)methods.According to the spectral analysis of normal human skin tissue,it was found that the dermis layer could be visualized by the reconstruction of reticular collagen Raman peaks at 855,940 and 1248 cm-1.The reconstructed images of ceramide lipid bands at 1064,1106,1126,1300 cm-1 were able to describe the organizational morphological characteristics of stratum corneum.Moreover,the aggregation model of melanin in the epidermis can be realized by Raman images of1375 and 1580 cm-1.By the analysis of the distributions of different compositions in the hair follicles,especially melanin,it was proved that the hair follicles descend from the epidermis sinking to the dermis,and the hair follicles contain a large amount of melanin.The spectra characteristics of two SCC cases were studied by CRMI.By the reference of H&E staining microscopic image,the pathological mechanism of SCC was investigated in detail,including the diffusion patterns of SCC cells,as well as the transformation law of collagen,lipids and DNA etc.during the tumor metastasis.Experimental results showed that both primary and secondary SCC,the intensities of collagen peaks(853,936 and 1248 cm-1)had a rapid decrease in the cancerous area.On the contrary,the intensities of peaks belonging to DNA(720 and 1327 cm-1)and lipids(1305 cm-1)had a obvious increase,which illustrated that DNA and lipids aggregated in the process of SCC cells metastasize from epidermis to dermis.Due to the different inflammatory response of primary SCC and secondary SCC,the changing situation of phenylalanine(1002 cm-1)related to the inflammatory differed a lot in the two cases of sample.In the conclusion,the micro-structure and material distribution information of biological tissues can be explained adequately by CRMI,as well as,the changes of different components can also be measured qualitatively,quantificationally and positionally.All of the achievements in this work illustrated that CRMI technology has a wide application prospect in the research of molecular biological mechanism of pathological changes of tissues.