Study of pathogenesis of pain in complex body disorders

In this work, we propose to the Raman spectroscopy as a new technique for the detection of the type 2 diabetes using blood serum samples. The serum samples were obtained from 15 patients who were clinically diagnosed with type 2 diabetes mellitus and 20 healthy volunteers. The average spectra showed equally intense peaks as, 695 cm −1 , the doublet of tyrosine at 828 and 853 cm −1 , phenylalanine at 1002 and 1028 cm −1 , the phospholipid shoulder at 1300-1345 cm −1 , and proteins (amide I) at 1654 cm −1 . The major differences were found at 661 and 1404 cm −1 (glutathione), 714 (polysaccharides), 605 (Phe), 545 cm −1 (tryptophan), and the shoulder of amide III at 1230-1282 cm −1 , where seem to disappear in the diabetes spectrum. On the contrary, the region that is more highlighted due to that diabetes peaks are clearly more intense was 897-955 cm −1 . Principal component analysis and linear discriminate analysis were employed for developing discrimination method. The first three principal components provided a classification of the samples from healthy and diabetes patients with high sensitivity and specificity. In addition, when the first principal component was plotted as a function of the Raman shift, it revealed these shifts accounted for the greatest differences between control and diabetes samples, which coincided with the shifts of spectral differences shown by mean spectra. Our results demonstrated that serum sample Raman spectroscopy promises to become a non-invasive support tool of the currently applied techniques for type 2 diabetes detection, decreasing the false-positive cases.

Lasers in Medical Science, 2018

The aim of this study was to identify biochemical changes in sciatic nerve (SN) after crush injury and low-level laser therapy (LLLT) with 660 nm and 808 nm by Raman spectroscopy (RS) analysis. A number of 32 Wistar rats were used, divided into four groups (control 1, control 2, LASER 660 nm, and LASER 808 nm). All animals underwent surgical procedure of the SN and groups control 2, LASER 660 nm, and LASER 808 nm were submitted to SN crush damage (axonotmesis). The LLLT in the groups LASER 660 nm and LASER 808 nm was applied daily for 21 consecutive days (100 mW, 30 s, 133 J/cm 2 fluence). The hind paw was removed and the SN was dissected and positioned on an aluminum support to collect dispersive Raman spectra (830 nm excitation, 30 s accumulation). To estimate the biochemical changes in the SN associated with LLLT, the principal component analysis (PCA) was applied. The Raman spectra of the sciatic nerve fragments showed peaks of the major biochemical components of the nerve, especially sphingolipids, phospholipids, glycoproteins, and collagen. The spectral features identified in some of the principal component loading vectors are referred to the biochemical elements present on the SN and were increased in the groups treated with LLLT, mainly lipids (sphingo and phospholipids) and proteins (collagen)-constituents of the myelin sheath. The RS was effective in identifying the biochemical differences in the SN after the crush injury, and LASER 660 nm was more efficient than the LASER 808 nm in cell proliferation and repair of the injured SN.

Photomedicine and Laser Surgery, 2015

Objective: This work aimed to investigate the biochemical changes associated with low-level laser therapy (LLLT) using 660 and 780 nm, on a well-established experimental model of osteoarthritis (OA) in the knees of rats with induced collagenase, using histomorphometry and Raman spectroscopy. Materials and methods: Thirty-six Wistar rats were divided into four groups: control (GCON, n = 9), collagenase without treatment (GCOL, n = 9), collagenase with LLLT 660 nm treatment (G660, n = 8), and collagenase with LLLT 780 nm treatment (G780, n = 10). LLLT protocol was: 30 mW power output, 10 sec irradiation time, 0.04 cm 2 spot size, 0.3 J energy, 0.75 W/cm 2 irradiance, and 7.5 J/cm 2 fluence per session per day, during 14 days. Then, knees were withdrawn and submitted to histomorphometry and Raman spectroscopy analysis. Principal components analysis (PCA) and Mahalanobis distance were employed to characterize the spectral findings. Results: Histomorphometry revealed a significant increase in the amount of collagen III for the group irradiated with 660 nm. The Raman bands at 1247, 1273, and 1453 cm-1 (from principal component score PC2), attributed to collagen type II, and 1460 cm-1 (from PC3), attributed to collagen type III, suggested that the LLLT causes acceleration in cellular activity, especially on the cells that repair cartilage, accelerating the breakdown of cartilage destroyed by collagenase and stimulating the fibroblast to synthesize repairing collagen III. Conclusions: LLLT accelerated the initial breakdown of cartilage destroyed by collagenase and stimulated the fibroblast to synthesize the repairing collagen III, suggesting a beneficial effect of LLLT on OA.

Journal of Raman Spectroscopy, 2013

Gout is a disease process where the nucleation and growth of crystals in the synovial fluid of joints elicit painful arthritis-like symptoms. Raman spectroscopy is evolving as a potential diagnostic tool in identifying such crystals; however, attainment of sufficient Raman signal while overcoming the background fluorescence remains as a major challenge. The current study focused on assessing whether excitation in 532-700 nm range will provide greater signal intensity than the standard 785 nm while not being impeded by background fluorescence. We characterized the fluorescence spectra, absorption spectra and Raman spectra of synovial fluid from patients who presented "gout-like symptoms" (symptomatic) and controls (asymptomatic). A digestion and filtration method was developed to isolate crystals from synovial fluid while reducing the organic burden. Spectral profile and photobleaching dynamics during Raman spectroscopy were observed under an excitation wavelength range spanning 532 to 785 nm. Absorbance and fluorescence profiles indicated the digestion and filtration worked effectively to extract crystals from symptomatic synovial fluid without introducing additional fluorescence. Raman spectral analyses at 532 nm, 660 nm, 690 nm and 785 nm indicated that both asymptomatic and symptomatic samples had significant levels of fluorescence at excitation wavelengths below 700 nm, which either hindered the collection of Raman signal or necessitated prolonged durations of photobleaching. Raman-based diagnostics were more feasible at the longest excitation wavelength of 785 nm without employing photobleaching. This study further demonstrated that a near-infrared OEM based lower-cost Raman system at 785 nm excitation has sufficient sensitivity to identify crystals isolated from the synovial fluid. In conclusion, while lower excitation wavelengths

Biopolymers, 2002

Raman spectroscopy has recently been applied ex vivo and in vivo to address various biomedical issues such as the early detection of cancers, monitoring of the effect of various agents on the skin, determination of atherosclerotic plaque composition, and rapid identification of pathogenic microorganisms. This leap in the number of applications and the number of groups active in this field has been facilitated by several technological advancements in lasers, CCD detectors, and fiber-optic probes. However, most of the studies are still at the proof of concept stage. We present a discussion on the status of the field today, as well as the problems and issues that still need to be resolved to bring this technology to hospital settings (i.e., the medical laboratory, surgical suites, or clinics). Taken from the viewpoint of clinicians and medical analysts, the potential of Raman spectroscopic techniques as new tools for biomedical applications is discussed and a path is proposed for the clinical implementation of these techniques.

Tissue Engineering Part B: Reviews, 2021

Musculoskeletal disorders are the most common reason of chronic pain and disability, representing an enormous socioeconomic burden worldwide. In this review, new biomedical application fields for Raman spectroscopy (RS) technique related to skeletal tissues are discussed, showing that it can provide a comprehensive profile of tissue composition in situ, in a rapid, label-free, and nondestructive manner. RS can be used as a tool to study tissue alterations associated to aging, pathologies, and disease treatments. The main advantage with respect to currently applied methods in clinics is its ability to provide specific information on molecular composition, which goes beyond other diagnostic tools. Being compatible with water, RS can be performed without pretreatment on unfixed, hydrated tissue samples, without any labeling and chemical fixation used in histochemical methods. This review first provides the description of the basic principles of RS as a biotechnology tool and is introduced into the field of currently available RS-based techniques, developed to enhance Raman signals. The main spectral processing, statistical tools, fingerprint identification, and available databases are mentioned. The recent literature has been analyzed for such applications of RS as tendon and ligaments, cartilage, bone, and tissue engineered constructs for regenerative medicine. Several cases of proof-of-concept preclinical studies have been described. Finally, advantages, limitations, future perspectives, and challenges for the translation of RS into clinical practice have been also discussed.

Acta Physica Polonica A, 2010

Studies of tissue such as bones and veins often are carried out by means of microscopic and ultrasonographic methods. Therefore studies of changes caused by pathological or physical factors often are limited to morphological level. Application of Raman spectroscopy permits to associate morphological changes and molecular changes. The paper presents preliminary studies of temperature and ionizing radiation effects on Raman spectra of bone and collagen. Furthermore, effects of pathological factors on Raman spectra of human veins had been studied. It was noticed that heating of bone collagen up to 110 • C gives the reversible changes in spectra. In the case of γ-irradiation, any effects were observed up to the dose of 1 MGy on mineral component of bone, whereas the influence on collagen was observed for doses higher than 100 kGy. The Raman spectra of varicose vs. normal veins permit to conclude some important changes observed for veins from chronic venous insufficiency patients.

e-mail vh kart ha malic manipal edii Vhsiracl Raman speciioscopy has been successfully applied in seveial areas of biology and medicine, including diagnosis of malignancy The .ippliiaiinii'. of Surface Enhanced Raman speciioscopy and imcro-Kaman have improved to the e?cieml of studying single molecule dynamies and .dliilai iMOLhcmisiiy icspcciively Rimiaii spectroscopy studies cairied out in our laboratory on oral cancer, osteoradionecrosis, radiation induced il,nil.ILLS in mouse models arc piescnlcd and discussed We have recorded Raman speciia of normal and malignant oial tissues and the obtained spectra uiu analysed using statistical (PCA) methods An ob)cciivc diagnosis method with high sensitivity and s]ieciricity based on Muhalanohis distance and >|Kiii.iI icNidual IS developed foi oral inalignaiuy The study of radiation induced damage in mouse brain and muscle tissue suggests that ladiaiion .Kinaicil chemical cascade is similar to those in stress, but it persists foi longei periods Radiulioii treatment on bone leads to immediate structural Juni'is III the mmcial part of the bone K nuords Raman spcclioscojiy, SERS, oral cancer, PC.'A analysis, radiation induced damage. ORN bone r v r s Nos 7K ^0 Am. S7 M) H|. S7 b4 .le I. Iiifroductiori riic discovery ofRiurian elTcd in the year 1928 dcinonslraled iliai (lie analysis of inelastieally scattered light from the simplest mnlLci-ilc H ,0, can provide unique finger print of molecular siiiiciurc 11, 2|. In the last 75 years, popularity and versatility of Riiiium scatlering spectroscopy have increased in many ways iiul a diverse fai)iily ol Raman-based techniques has been ilcvciopcd. More and more sensitive experimental approaches ^'Miiiiuic to be developed to explore the molecular mechanisms ''I u>mplcx biological phenomena. Raman spectroscopy has also 'ven idenlilied as a reliable diagnostic technique [3-5). A larger luimhcr of biological molecules can be probed by using Raman ^"'V tioscopy. Several studies show the potential of near-infrared kiiMian spectroscopy for the detection ol cancer and pre-cancer 'll 1 itro/in vivo, as a new tool [3-5]. Resonance Raman scattering selectively increases the uicring signal from the ground stale vibration modes that arc ^'4i|)led U) excited vibronic levels (6J. This large enhancement Raman scattering cross section of specific molecular ^'hiation modes, offers great advantages over non-resonancê ^"'(spondmg AutKor Raman scattering. Research findings show that UVRR spectroscopy can be used to characterize normal and diseased colon tissue by selectively enhancing spectra of aromatic amino acids, and parameterizing their contribution to the colon spectrum That means, UV RR spectroscopy can provide complete biochemical characterization of the tissue under study as well as it can describe the pathological change [6|. Micro-Raman spectroscopy is a powerful tool for study of the structural variations in samples of sizes down to sub microns [7, 8]. In the Raman microanalysis, a laser beam is focused onto a very small area with a microscope objective and Raman scattered light from the area is collected by the same objective, dispersed by a monochiomalor and spectra recorded. Raman microscopy has potential utility in structural studies in situ. Recent advances in lasers, detectors, and spectrograph and filter technologies have made it possible to detect even very weak Raman signals from a single living cell [7, 8]. Ultrasensitive Raman detection based on surface enhanced Raman scattering is now well established [9, 10]. Surfaceenhanced Raman spectroscopy (SERS) is a phenomenon resulting in strongly increased Raman signals of molecules that ©20031ACS

1998

There is a vast demand for in vivo methods for the detection of skin cancer, one of the most dangerous skin lesions. Use of near infrared Fourier transform (NIR-FT)-Raman spectroscopy virtually eliminates the fluorescence of the normal cell constituents and provides a signal to noise ratio, r SN , large enough to successfully evaluate the spectra using chemometric methods. A novel fiber optic probe for NIR-FT-Raman spectroscopy was used, which allows sterilization and the prevention of hazards due to laser radiation and makes in vivo measurements possible. The Raman spectra of normal skin are dominated by the connective tissue, mainly collagen type I. The Raman spectra of skin with inflammatory diseases show an increased lipid and water content. Kaposi sarcomas show typical features of tumors mainly in the amide III and the protein backbone range. A clear separation of Raman spectra of normal skin from those of benign and malignant neoplasms can be achieved by cluster analysis. However, the unequivocal diagnosis of skin cancer needs investigation of a larger number of more defined skin samples, taking into consideration the concurrent appearance of different skin symptoms like coloring and inflammation. cal fibers are used in Raman endoscopes [14] for measurement.

2008