CHRONIC HEPATITIS-C; RAT-LIVER; FIBROSIS; LIBS; FEASIBILITY; IDENTIFICATION; BACTERIAL; SAMPLES

Hepatic cirrhosis is a major cause of morbidity and mortality worldwide due to hepatitis C, alcoholism and fatty liver disease associated with obesity. Assessment of hepatic fibrosis relies in qualitative histological evaluation of biopsy samples. This method is time-consuming and depends on the histopathologists' interpretation. In the last decades, non-invasive techniques were developed to detect and monitor hepatic fibrosis. Laser-induced breakdownspectroscopy (LIBS) is a good candidate for a real-time, independent and fast technique to diagnose hepatic fibrosis. In this work LIBS was employed to characterize rat liver tissues with different stages of fibrosis. Depth profiling measurements were carried out by using a nanosecond Nd:YAG laser operated at the fundamental wavelength and an echelle spectrometer coupled with an ICCD camera. Due to the soft nature of the samples, plasma conditions largely change between consecutives shots. Thus, a theoretically supported procedure to correct the spectral line intensities was implemented. This procedure allows the reduction of the intensities' dispersion from 67% to 12%. After the correction, the LIBS signal shows an enhancement in calcium intensity by a factor of three as the fibrosis progressed. Calcium is known to increase crosslinking of extracellular matrix proteins in the fibrous septa. Therefore, our result singles it out as a key participant in the hepatic fibrosis. (C) 2017 Optical Society of America

hyperspectral imaging; laser-induced breakdown spectroscopy; biomedical application;

Hyperspectral imaging (HSI) can be used to quickly and non-invasively monitor both physical and morphological characteristics as well as intrinsic chemical and molecular information about tissue pathology. Laser-induced breakdown spectroscopy (LIBS) is an elemental analysis technique that is based on atomic emission spectroscopy and laser plasma emission spectroscopy. In this paper, we use both HIS and LIBS to quantitatively distinguish the organs of mice including brain, heart, liver, lung, kidney and spleen from their different reflectance spectra and LIBS spectra, respectively. The two approaches presented here provide complementary functional information and may have potential biomedical applications for early disease detection and diagnosis.