M5 - Assessing chemical differences in mice hair exposed to gamma rays or x-rays via Raman Spectroscopy

Showing differences in hair from X- or gamma-ray exposed mice by Raman spectroscopy and chemometrics.

Abstract Text:

The exposure of radiation continues to be a growing concern among the general population. In the event of a nuclear fallout, it would be useful to estimate the dose of exposure experienced to determine follow-up care and prognosis. Ionizing radiation such as gamma rays, x-rays, and particle bombardment (such as alpha, beta, etc.) can cause harmful effects to the human body, such as DNA damage, lipids damage, and mutations. Hair is a sample that can be collected non-invasively and has shown promise for retrospective biodosimetry. This experiment examines the difference of ionizing radiation (gamma rays and x-rays) on murine hairs exposed to 0 Gy, 1 Gy, and 4 Gy radiation at 7,14 and 25 days following exposure by investigating the melanin Raman signals. To better understand the differences of ionizing radiation, 25 mice (5 control, 10 gamma and 10 x-rays) had their hair collected after being exposed to ionizing radiation. Raman spectroscopy is the inelastic scattering of light that measures the vibrational modes of molecules. It is useful for biological samples such as mouse hair because Raman spectroscopy is non-destructive, molecularly specific, and insensitive to water. The Raman signal from the hair samples was collected. The melanin response is similar to carbonaceous materials consisting of a disordered and graphite band at 1380 and 1580 cm^-1, respectively.  Partial least squares discriminant analysis (PLS-DA), and principal component analysis (PCA) was analyzed and process using the raw data collected. Total body exposure to radiation can lead to radiation sickness, organ failure and even death at prominent levels of radiations.  This work hopes to identify significant differences between x-ray and gamma ray irradiated hairs with results demonstrating these changes in a dose dependent manner.