TOPICAL REVIEW: Prospects for in vivo Raman spectroscopy (original) (raw)

Clinical utility of Raman spectroscopy: current applications and ongoing developments

Advanced health care technologies, 2016

Availability of fast, noninvasive/minimally invasive, and accurate diagnostic tests can maximize the benefit of patient care. The application of Raman spectroscopy (RS) in biological and biomedical applications has surged recently as a result of technological advancements in instrumentation and spectral data handling techniques. With maturation, the potential of RS in clinical diagnosis of various diseases, in particular, early cancer, has been widely explored and reported. This paper provides an introduction to the Raman theory and technology behind RS for nonspecialists interested in its clinical uses. Latest achievements in oncological, cardiovascular, and neurological applications of RS along with its clinical implementations are discussed.

Medical applications of Raman spectroscopy: From proof of principle to clinical implementation

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.

In-vivo Raman spectroscopy: from basics to applications

Journal of Biomedical Optics, 2018

For more than two decades, Raman spectroscopy has found widespread use in biological and medical applications. The instrumentation and the statistical evaluation procedures have matured, enabling the lengthy transition from ex-vivo demonstration to in-vivo examinations. This transition goes hand-in-hand with many technological developments and tightly bound requirements for a successful implementation in a clinical environment, which are often difficult to assess for novice scientists in the field. This review outlines the required instrumentation and instrumentation parameters, designs, and developments of fiber optic probes for the in-vivo applications in a clinical setting. It aims at providing an overview of contemporary technology and clinical trials and attempts to identify future developments necessary to bring the emerging technology to the clinical end users. A comprehensive overview of in-vivo applications of fiber optic Raman probes to characterize different tissue and disease types is also given.

Raman Spectroscopy in Clinical Investigations

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

Histochemical analysis of biological tissues using Raman spectroscopy

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 1996

This paper reviews the application of the Raman spectroscopic technique for analysis of biological tissue. The advantages and disadvantages of visible, near-IR and UV excitations are described, and the problems and prospects of using these methodologies for disease diagnosis are addressed. In situ analysis of tissue proteins, lens, cornea, blood constituents, biological stones and several hard tissues is reviewed, and the potentials for diagnosing arterial disease, and cancer in gynecological tissues, soft tissues, breast, colon, bladder and brain are also presented. Recent technological advances in instrumentation allow the use of Raman spectroscopy for real time histochemical analysis of tissues. The capability of Raman microspectroscopy for providing spatial information about the distribution of biochemical constituents in tissues has been demonstrated. The work reviewed indicates the promise of Raman spectroscopy for endoscopic imaging and real-time quantitation of biochemical constituents in clinical situations.

Advances in the clinical application of Raman spectroscopy for cancer diagnostics

Photodiagnosis and Photodynamic Therapy, 2013

Light interacts with tissue in a number of ways including, elastic and inelastic scattering, reflection and absorption, leading to fluorescence and phosphorescence. These interactions can be used to measure abnormal changes in tissue. Initial optical biopsy systems have potential to be used as an adjunct to current investigative techniques to improve the targeting of blind biopsy. Future prospects with molecular-specific techniques may enable objective optical detection providing a real-time, highly sensitive and specific measurement of the histological state of the tissue. Raman spectroscopy has the potential to identify markers associated with malignant change and could be used as diagnostic tool for the early detection of precancerous and cancerous lesions in vivo. The clinical requirements for an objective, noninvasive, real-time probe for the accurate and repeatable measurement of pathological state of the tissue are overwhelming. This paper discusses some of the recent advances in the field.

Assessing Variability of In Vivo Tissue Raman Spectra

Raman spectroscopy (RS) has received increasing attention as a potential tool for clinical diagnostics. However, the unknown comparability of multiple tissue RS systems remains a major issue for technique standardization and future multisystem trials. In this study, we evaluated potential factors affecting data collection and interpretation, utilizing the skin as an example tissue. The effects of contact pressure and probe angle were characterized as potential user-induced variability sources. Similarly, instrumentation-induced variability sources of system stability and system-dependent response were also analyzed on skin and a nonvolatile biological tissue analog. Physiologically induced variations were studied on multiple tissue locations and patients. The effect of variability sources on spectral line shape and dispersion was analyzed with analysis-ofvariance methods, and a new metric for comparing spectral dispersion was defined. In this study, in vivo measurements were made on multiple sites of skin from five healthy volunteers, with four stand-alone fiber optic probe-based tissue RS systems. System stability and controlled userinduced variables had no effects on obtained spectra. By contrast, instrumentation and anatomical location of measurement were significant sources of variability. These findings establish the comparability of tissue Raman spectra obtained by unique systems. Furthermore, we suggest steps for further procedural and instrumentation standardization prior to broad clinical applications of the technique.

Raman Spectroscopy Applied to Health Sciences

Raman Spectroscopy, 2018

Raman spectroscopy has remarkable analytical abilities to scientists who want to study biological samples. The use of Raman spectroscopy within biologic samples has been increasing in the last years because it can provide biochemical information, allows discrimination between two or more sample groups, and, contrary to what happens with other spectroscopic techniques, water has no interference in the spectra. Biological samples typically do not require extensive preparation, and biochemical and structural information extracted from spectroscopic data can be used to characterize different groups. This chapter presents the general features of Raman spectroscopy and Raman spectroscopic tools relevant to the application in health sciences. In order to emphasize the potential of Raman in this research field, examples of its application in oncology, in bacterial identification and in dementia diagnosis are given.