Micro‐Raman spectroscopy used to identify and grade human skin pilomatrixoma

Abstract

Raman microspectroscopy was applied to analyze the changes in structural conformation and chemical composition of the mass of human skin pilomatrixoma (PMX). The normal skin dermis, collagen type I, and hydroxyapatite (HA) were used as control. The excised specimens from two patients diagnosed as a typical PMX were detected, in which one specimen was a soft mass, but the other was a hard mass with somewhat calcified deposits via histopathological examination. The Raman spectrum of normal skin dermis was found to be similar to the Raman spectrum of collagen type I, confirming that the collagen type I was a predominant component in normal skin dermis. The differences of Raman peak intensity between normal skin dermis and soft or hard PMX mass were obvious at 1,622-1,558, 1,400-1,230, 1,128, 1,000-850, 749, and 509 cm(-1). In particular, the peak at 1,665 cm(-1) assigned to amide I band shifted to 1,655 cm(-1) and the peak at 1,246 cm(-1) corresponding to amide III band was reduced in its intensity in hard PMX mass. The significant changes in collagen content and its structural conformation, the higher content of tryptophan, and disulfide formation in PMX masses were markedly evidenced. In addition, the shoulder and weak peak at 960 cm(-1) assigned to the stretching vibration of PO(4) (3-) of HA also appeared respectively in the Raman spectra of soft and hard PMX masses, suggesting the occurrence of calcification of HA in the PMX tissue, particularly in the hard PMX mass. The result indicates that the micro-Raman spectroscopy may provide a highly sensitive and specific method for identifying normal skin dermis and how it differs in chemical composition from different PMX tissues.

Investigating the effects of Pentoxifylline on human breast cancer cells using Raman spectroscopy

“…A linear increase with drug dosage was observed for the bands around 1280 cm À1 (¼ CH bending of lipids) and 1305 cm À1 (CH 3 /CH 2 bending of phospholipids) suggesting changes in lipid pro¯le upon PTX exposure. [44][45][46][47] This is in concordance with already mentioned reports on PTX affecting membrane°uidity by altering lipids. [9][10][11] Minor changes in free amino acids indicated by the bands around 950 cm À1 (proline), phenylalanine (1008 cm À1 ), 1620 cm À1 (tryptophan), suggesting changes in overall protein content after drug treatment were also observed.…”

In situ chemical analysis of modern organic tattooing inks and pigments by micro‐Raman spectroscopy

“…Specifically, these pigments lay within phagosomes or intracellular storage vacuoles, which in turn would be surrounded by a vast dermal array of collagen. 45 The use of a laser wavelength in the visible region, known to cause strong native background fluorescence when analysing biological matrices, was not found to be a problem. Two characteristic peaks synonymous to collagen Type I (1650 cm 1 (C O) Amide I and 1444 cm 1 υ CH 2 /CH 3 , respectively) 46 were not detected in any of our spectra.…”

Infrared microspectroscopic imaging as a probing tool to fast distinguish chemical compositions in calcified deposits of prostatic calculi and calcific tendonitis

“…In the traditional FT-IR analysis without microscopy, this technique allows identifying any organic or inorganic molecules in the calcified samples by grinding the sample with KBr powder or sealing the sample within two KBr pellets for spectral determination after compression [6,8,11]. In our previous studies, several human calcified tissues, such as calcinosis cutis, skin pilomatrixoma, cornea, senile cataractous lens, vitreous asteroid bodies, sclera and superior vesical artery had been investigated using this powerful and convenient vibrational microspectroscopic technique [7][8][9][10][11]23,27,28]. However, the main drawback of this technique is that the manual singlepoint random determination at microscopic level cannot really reflect the spatial distribution of all the components in the mixture, leading to possibly inaccurate diagnose of the complicated components in the calcified mixture.…”