Raman spectroscopic analysis of human skin tissue sectionsex-vivo: evaluation of the effects of tissue processing and dewaxing

Raman spectroscopic mapping for the analysis of solar radiation induced skin damage

“…The results are compared to cytotoxicological evaluation of the reduced viability of the tissue model as a result of exposure. The data analysis protocol was in accordance with previous work which demonstrated that K-means means cluster analysis (KMCA) of Raman spatial profiles of unprocessed and formalin fixed paraffin processed (FFPP) skin tissue sections successfully discriminated the structural layers of skin while principal components analysis differentiated the identified clusters based on their dominant characteristic biochemical constituents 17 . Using similar analysis, the spectral profiles of model tissue sections clearly differentiate the superficial, epidermal, and dermal regions, which compare well with the spectral profiles of human skin sections as well as the morphology revealed by histological staining of the sections.…”

“…Thus they offer additional information, potentially valuable for diagnosis, that is not provided by X-ray or MRI techniques 16 . Raman spectroscopy has been demonstrated to have higher spatial and spectral resolution than IR spectroscopy, however 17 . It has been furthermore demonstrated that some of the experimental difficulties associated with the measurement of chemical and physical inhomogeneity can be surmounted 18,19 .…”

“…It has been furthermore demonstrated that some of the experimental difficulties associated with the measurement of chemical and physical inhomogeneity can be surmounted 18,19 . However, the study of human skin necessarily involves huge variations related to the origin of the samples 17 . Many parameters can influence the experimental observations and these have to be taken into account.…”

Spectral pre and post processing for infrared and Raman spectroscopy of biological tissues and cells

“…A good example of KMCA in Raman spectroscopy is shown in the study by Dorney et al [12], in which it was used to identify regions in the Raman dataset which correspond to polystyrene nanoparticles, and differentiate them from neighbouring cytoplasm, as well as the nucleus and nucleolus ( Figure 5). Many other examples of KMCA as a spectroscopic imaging reconstruction technique can be found in the investigation of a wide range of samples including tissue sections [78], cells [12,79,80] and in the analysis of human skin [26,81]. While this method has been shown to be useful in partitioning spectra into clusters, it is important to highlight that the method is not without certain pitfalls.…”

“…Establishing the relative impact of the spectral distortions associated with the EFSW effect compared to the target intrinsic biochemical variations may be critical in reaching a decision over clinical applications of IR absorption for spectral histopathology. In terms of sample presentation, fresh frozen sections are recommended as the tissue architecture and biochemistry is kept largely intact and, notably, the lipidic information can be accessed [26]. Furthermore, they are more amenable to combining immunohistochemistry, proteomics, and biospectroscopy.…”