Jakub Surmacki

Raman imaging at biological interfaces: applications in breast cancer diagnosis

BackgroundOne of the most important areas of Raman medical diagnostics is identification and characterization of cancerous and noncancerous tissues. The methods based on Raman scattering has shown significant potential for probing human breast tissue to provide valuable information for early diagnosis of breast cancer. A vibrational fingerprint from the biological tissue provides information which can be used to identify, characterize and discriminate structures in breast tissue, both in the normal and cancerous environment.ResultsThe paper reviews recent progress in understanding structure and interactions at biological interfaces of the human tissue by using confocal Raman imaging and IR spectroscopy. The important differences between the noncancerous and cancerous human breast tissues were found in regions characteristic for vibrations of carotenoids, fatty acids, proteins, and interfacial water. Particular attention was paid to the role played by unsaturated fatty acids and their derivatives as well as carotenoids and interfacial water.ConclusionsWe demonstrate that Raman imaging has reached a clinically relevant level in regard to breast cancer diagnosis applications. The results presented in the paper may have serious implications on understanding mechanisms of interactions in living cells under realistically crowded conditions of biological tissue.

Label-free monitoring of tissue biochemistry following traumatic brain injury using Raman spectroscopy

Acute tissue biochemical response to traumatic brain injury is revealed using Raman spectroscopy.

Surface-Enhanced Raman Spectroscopy Analysis of Human Breast Cancer via Silver Nanoparticles: An Examination of Fabrication Methods

Breast cancer in a traditional way is diagnosed using mammography, computer tomography, ultrasounds, biopsy, and finally, histopathological analysis. Histopathological analysis is a gold standard in breast cancer diagnostics; however, it is time consuming and prone to the human interpretations. That is why new methods based on optical properties of analyzed human tissue samples are needed to be introduced to the clinical practice objective, costless and fast diagnostic protocols. Nowadays, Raman spectroscopy-based methods are gaining more and more importance. Raman spectroscopy and imaging allow to characterize human tissue samples using an electromagnetic radiation from a safe range, and simultaneously, a minimal sample preparation is required. During measurements, a natural differentiation in tissues components’ scattering cross sections is used to build 2D and 3D maps of the chemical component distribution. The paper presents the application of SERS (surface-enhanced Raman spectroscopy) measurements for analysis of human breast cancer (adenocarcinoma). The advantages of SERS application in cancer diagnostics are also discussed. Moreover, the detailed chemical composition of human breast cancer tissue based on Raman bands of DNA/RNA, amino acids, lipids, and proteins which are significantly enhanced is presented. Three different methods of NP preparation are presented, and the effectiveness of Raman signal enhancement of Ag nanoparticles synthetized by these methods is compared. The enhancement effect of NPs synthetized by reduction of silver nitrate with sodium borohydride (method no. 1) and silver nitrate-hydroxylamine hydrochloride reduction (method no. 2) was stronger when compared with the polyol method (method no. 3). Presented SERS results confirmed that the clearly resolved and high-intensity Raman spectra of cancer human breast tissue can be recorded using integration times of the order of fractional seconds and one milliwatt of the excitation laser power.

Raman micro-spectroscopy for accurate identification of primary human bronchial epithelial cells

Live cell Raman micro-spectroscopy is emerging as a promising bioanalytical technique for label-free discrimination of a range of different cell types (e.g. cancer cells and fibroblasts) and behaviors (e.g. apoptosis). The aim of this study was to determine whether confocal Raman micro-spectroscopy shows sufficient sensitivity and specificity for identification of primary human bronchial epithelial cells (HBECs) to be used for live cell biological studies in vitro. We first compared cell preparation substrates and media, considering their influence on lung cell proliferation and Raman spectra, as well as methods for data acquisition, using different wavelengths (488 nm, 785 nm) and scan protocols (line, area). Evaluating these parameters using human lung cancer (A549) and fibroblast (MRC5) cell lines confirmed that line-scan data acquisition at 785 nm using complete cell media on a quartz substrate gave optimal performance. We then applied our protocol to acquisition of data from primary human bronchial epithelial cells (HBEC) derived from three independent sources, revealing an average sensitivity for different cell types of 96.3% and specificity of 95.2%. These results suggest that Raman micro-spectroscopy is suitable for delineating primary HBEC cell cultures, which in future could be used for identifying different lung cell types within co-cultures and studying the process of early carcinogenesis in lung cell culture.

Application of confocal Raman micro-spectroscopy for label-free monitoring of oxidative stress in living bronchial cells

Oxidative stress in cancer is implicated in tumor progression, being associated with increased therapy resistance and metastasis. Conventional approaches for monitoring oxidative stress in tissue such as high-performance liquid chromatography and immunohistochemistry are bulk measurements and destroy the sample, meaning that longitudinal monitoring of cancer cell heterogeneity remains elusive. Raman spectroscopy has the potential to overcome this challenge, providing a chemically specific, label free readout from single living cells. Here, we applied a standardized protocol for label-free confocal Raman micro-spectroscopy in living cells to monitor oxidative stress in bronchial cells. We used a quartz substrate in a commercial cell chamber contained within a microscope incubator providing culture media for cell maintenance. We studied the effect of a potent reactive oxygen species inducer, tert-butyl hydroperoxide (TBHP), and antioxidant, N-acetyl-L-cysteine (NAC) on living cells from a human bronchial epithelial cells (HBEC). We found that the Raman bands corresponding to nucleic acids, proteins and lipids were significantly different (p<0.05) for control, TBHP, and NAC. Encouragingly, partial least squares discriminant analysis applied to our data showed high sensitivity and specificity for identification of control (87.3%, 71.7%), NAC (92.3%, 85.1%) and TBHP (86.9%, 92.9%). These results suggest that confocal Raman micro-spectroscopy may be able to monitor the biological impact of oxidative and reductive processes in cells, hence enabling longitudinal studies of oxidative stress in therapy resistance and metastasis at the single cell level.

Current and Emerging Technologies for Probing Molecular Signatures of Traumatic Brain Injury

Traumatic brain injury (TBI) is understood as an interplay between the initial injury, subsequent secondary injuries, and a complex host response all of which are highly heterogeneous. An understanding of the underlying biology suggests a number of windows where mechanistically inspired interventions could be targeted. Unfortunately, biologically plausible therapies have to-date failed to translate into clinical practice. While a number of stereotypical pathways are now understood to be involved, current clinical characterization is too crude for it to be possible to characterize the biological phenotype in a truly mechanistically meaningful way. In this review, we examine current and emerging technologies for fuller biochemical characterization by the simultaneous measurement of multiple, diverse biomarkers. We describe how clinically available techniques such as cerebral microdialysis can be leveraged to give mechanistic insights into TBI pathobiology and how multiplex proteomic and metabolomic techniques can give a more complete description of the underlying biology. We also describe spatially resolved label-free multiplex techniques capable of probing structural differences in chemical signatures. Finally, we touch on the bioinformatics challenges that result from the acquisition of such large amounts of chemical data in the search for a more mechanistically complete description of the TBI phenotype.

From breast tissue diagnosis by Raman spectroscopy to femtosecond dynamics at the phospholipid membrane-water interface

In this paper we present our recent results on normal, malignant, and benign breast tissue by Raman spectroscopy for 100 patients and compare them with the results of histopathological analysis to estimate the sensitivity and specificity of the method. The typical Raman spectra and microscope picture of the sample prepared for histopatological analysis of the normal and pathological tissues are presented in Fig. 1.