Biomedical Spectroscopy and Imaging - Volume 1, issue 4

Authors: López-Luke, Tzarara | Wheeler, Damon A. | de la Rosa, Elder | Torres-Castro, Alejandro | Adams, Staci A. | Zavodivker, Liat S. | Zhang, Jin Z.

Article Type: Research Article

Abstract: Hollow gold–silica double-shell (HGSDS) and hollow gold–silica composite (HGSC) nanostructures have been synthesized and their structural, optical, and surface-enhanced Raman scattering (SERS) properties have been characterized. The structure of the HGSDS and HGSC was determined by scanning transmission electron microscopy (STEM) and high-resolution transmission electron microscopy (HRTEM). STEM images of the HGSDS reveal a reasonably uniform diameter of approximately 500–1000 nm with SiO2 deposited, using a modified Stöber method, onto aggregated structures of hollow gold nanospheres (HGNs). The HGSC structures were determined to be 30 nm in size by HRTEM. The broad surface plasmon resonance (SPR) absorption of both …the HGSDS and HGSC structures is dominated by gold but concomitantly influenced by the silica, with the peak position blue-shifted by ~100 nm relative to that of the starting HGNs. The broad and tunable SPR band can be useful for applications such as SERS. As a preliminary demonstration, SERS studies of Rhodamine 6G (R6G) and β-glucose have been carried out. The results show reproducible detection with limits as low as 0.9 and 5 mM, respectively. Glucose has traditionally been difficult to detect with SERS due to its small Raman cross-section and low SERS signal arising from weak interaction with the metal substrate. Compared to HGNs, the SERS signal of β-glucose using HGSDS and HGSC is enhanced, which is attributed to the relatively strong interaction between the glucose and the SiO2 surface. These results demonstrate that the silica-modified HGN structures are both interesting and useful as a result of their unique structural and optical properties. Show more

Keywords: SERS, HGNs, silica shell, glucose

DOI: 10.3233/BSI-2012-0024

Citation: Biomedical Spectroscopy and Imaging, vol. 1, no. 4, pp. 275-291, 2012

Authors: Akhoondi, Maryam | Oldenhof, Harriëtte | Sieme, Harald | Wolkers, Willem F.

Article Type: Research Article

Abstract: The aim of this study was to investigate the driving forces causing freezing-induced gel phase formation in cellular membranes. Fourier transform infrared spectroscopy (FTIR) was used to study subzero membrane phase behavior of mouse embryonic fibroblast (3T3) cells under dehydrating and non-dehydrating freezing conditions, in the absence and presence of dimethylsulfoxide (DMSO). In addition, suprazero membrane phase behavior and the effects of salt stress and air-drying on lipid disorder were studied. FTIR studies showed that freezing induces a fluid-to-gel membrane phase transition, both in the absence and presence of DMSO, which is reversible upon thawing. With DMSO the phase transition …occurs more gradual over a greater temperature range. At suprazero temperatures, membrane conformational disorder was found to be decreased when cells were exposed to high concentrations of NaCl. This effect, however, is minor compared to the effects of freezing on membrane phase state. Membrane conformational disorder at −30°C in the case of freezing-induced dehydration was lower compared to that of air-dried cells. When cells are air-dried in the presence of 3 M NaCl, however, membrane conformational disorder drastically decreases. This indicates that the freezing-induced removal of water from the phospholipid head groups results from osmotic forces. Show more

Keywords: Cryopreservation, drying, Fourier transform infrared spectroscopy, freezing, membrane phase behavior

DOI: 10.3233/BSI-120027

Citation: Biomedical Spectroscopy and Imaging, vol. 1, no. 4, pp. 293-302, 2012

Authors: Turker, Sevgi

Article Type: Review Article

Abstract: Infrared (IR) spectroscopy, as one the most common spectroscopic techniques, has been developed in terms of both instrumentation and analysis methods. This allows the wide applications of infrared spectroscopy in all branches of basic and applied research. Especially, its ability for direct identification of chemical changes without the addition of contrast agents enables the examination of a large variety of biological samples, including biological fluids, isolated cells, tissues, and sections. This review focuses on in vitro and in vivo applications of Fourier transform infrared (FTIR) spectroscopy and Fourier transform infrared microspectroscopy (FTIRM) to analyze the biochemical and structural changes associated …with neurological diseases such as Alzheimer's disease, Parkinson's disease, transmissible spongiform encephalopathies, multiple sclerosis, as well as epilepsy. With the application of FTIR and FTIRM, successful discrimination of pathological states of these diseases could be achieved. Hence, the high capacity of these methods offers insight into disease-induced alterations underlying pathogenesis of the diseases, which provides early diagnostic information and the improvement of therapeutic approaches. Show more

Keywords: FTIR, FTIRM, Alzheimer's disease, Parkinson's disease, transmissible spongiform encephalopathies, multiple sclerosis, epilepsy, protein secondary structure, diagnosis

DOI: 10.3233/BSI-120023

Citation: Biomedical Spectroscopy and Imaging, vol. 1, no. 4, pp. 303-323, 2012

Authors: Ausili, Alessio | Berglin, Mattias | Elwing, Hans | Corbalán-García, Senena | Gómez-Fernández, Juan C.

Article Type: Research Article

Abstract: QCM-D technique is based on the physical phenomenon that generates an acoustic shear wave with an oscillating resonance in quartz resulting in an evanescent wave that arises at the interface of the quartz and the solution. The amplitude of the acoustic wave is influenced by the deposition of material onto the quartz surface and from the subsequent decrease of the frequency the bound mass can be calculated. The dissipation shift which arises inform about viscoelasticity and flexibility of the adsorbed material. QCM-D can be applied for real-time studies of several biological systems since it is a simple, fast, low-cost and …sensitive technique without having to label any sample. Common applications in biological field include measurements on adsorption of lipids, proteins, DNA and cells directly onto the surface of the sensor, which generally are chemically modified by self-assembled monolayer (SAM) technique or by spin-coated polymers. QCM-D can also be used to study molecular interactions between macromolecules and adsorbed materials. Three examples of the use of this technique are presented, namely the docking orientation of the C2 domain of PKCε on phospholipid membranes, the conformational changes of fibrinogen adsorbed to model acrylic polymers and the attachment of endothelial cells to carboxylated polymers of different configuration. Show more

Keywords: QCM-D, proteins at interfaces, cell at interfaces

DOI: 10.3233/BSI-2012-0025

Citation: Biomedical Spectroscopy and Imaging, vol. 1, no. 4, pp. 325-338, 2012

Authors: Chow, Kam Kong | Short, Michael | Zeng, Haishan

Article Type: Research Article

Abstract: The analysis of human breath has been driven to new heights and has great potential to impact our society in the area of medical science. Breath analysis is promising as non-invasive, simple and point-of-care clinical measurements to reduce the medical burden caused by invasive, time-consuming and expensive clinical devices. Spectroscopic techniques for breath analysis can offer information to correlate its signals to exhaled substances for molecular identification and quantification to provide the pathophysiological status of the body. In this review paper, techniques such as mass spectrometry-based (gas chromatography-mass spectrometry, proton transfer reaction-mass spectrometry, selected ion flow tube-mass spectrometry), laser absorption …spectroscopy-based (cavity ring down spectroscopy and tunable diode laser absorption spectroscopy) and other spectroscopic techniques for breath analysis applications are compared in terms of its advantages/disadvantages, versatilities and plausibility to be transformed in clinical applications. Show more

Keywords: Breath analysis, volatile organic compounds (VOCs), exhaled substances, spectroscopy, mass spectrometry, laser spectroscopy

DOI: 10.3233/BSI-120029

Citation: Biomedical Spectroscopy and Imaging, vol. 1, no. 4, pp. 339-353, 2012

Authors: Cascio, C. | Mulla, A. | Vanker, R. | Feldmann, J. | Meharg, A.A. | Jenkins, R.O. | Haris, P.I.

Article Type: Research Article

Abstract: Inductively Coupled Plasma – Mass Spectroscopy (ICP-MS) was used to monitor urinary selenium, copper and zinc in a group of Bangladeshi (n=54), Indian (n=25), Pakistani (n=21), and White Caucasian (n=23) volunteers living in the UK. The most striking findings were far higher urinary copper levels (P<0.001) in the Bangladeshi group (median: 30.2 μg Cu/l) compared to other ethnicities (15.6 μg Cu/l, Pakistani; 14.8 μg Cu/l, Indian; 10.5 μg Cu/l, Caucasians) and to reference values reported for the UK population. Although no significant difference was found for Zn (P=0.22; medians: 430 μg Zn/l for Bangladeshis, 377 μg Zn/l for Pakistani, 350 …μg Zn/l for Caucasians, 355 μg Zn/l for Indians), a significantly (P<0.001) higher Cu:Zn ratio was found for the Bangladeshis. Urinary Se of Bangladeshis (17.6 μg Se/l) was significantly (P<0.001) higher compared to Indians (13.8 μg Se/l) and Pakistani (4.1 μg Se/l), although urinary selenium was generally within the reported reference values reported for the UK population. Exposure to copper via ethnic food consumption or altered copper metabolism may contribute to higher levels of Cu and Cu:Zn ratio in the Bangladeshi group. Previous studies have correlated high serum copper levels to cardiovascular diseases (CVD), liver cirrhosis, chronic hepatitis and hepatocellular carcinoma (HCC). Bangladeshis have higher than UK average mortality from HCC and a disproportionately higher incidence of CVD. The high urinary Cu levels and Cu:Zn ratio detected in UK Bangladeshis may therefore reflect early onset of disease process, and may ultimately result in these conditions for members of the Bangladeshi community. Show more

Keywords: Urine, copper, selenium, zinc, ICP-MS, baseline, ethnicity

DOI: 10.3233/BSI-120026

Citation: Biomedical Spectroscopy and Imaging, vol. 1, no. 4, pp. 355-364, 2012

Authors: Al-Rmalli, Shaban W. | Jenkins, Richard O. | Watts, Michael J. | Haris, Parvez I.

Article Type: Research Article

Abstract: Hundreds of millions of people world-wide are exposed to high concentrations of the toxic element arsenic (As) through drinking water and consumption of certain foods, especially rice. In this study Inductively Coupled Plasma Mass Spectroscopy (ICP-MS) was used to analyse rice from the greater Sylhet region of Bangladesh which has relatively lower groundwater As concentrations. Different varieties of rice were analysed for inorganic-As (i-As) and other elements (Cd, Mn, Pb, Se and Zn) in order to identify rice with low As content and higher essential element (Zn and Se) content. Sylheti non-aromatic rice showed lower As concentration (27.1–174.1 μg/kg) compared …to non-aromatic rice from other regions of Bangladesh. Furthermore, aromatic rice from Sylhet had the lowest As content (10.1 μg/kg) and the highest Se content (341 μg/kg) compared to non-aromatic rice. Approximately 70% of the total As in Sylheti rice was i-As and parboiled rice contained the highest i-As (90%) compared to other rice varieties. Aromatic rice generally contained lower concentrations of toxic elements (As, Cd, Pb) and higher concentrations of essential elements (Se, Zn) compared to non-aromatic rice. For someone consuming 500 g of non-aromatic or aromatic rice from Sylhet, the daily intake of As from consumption of rice would be reduced by approximately 48% and 69%, respectively, compared to non-aromatic rice from other parts of Bangladesh thus far investigated. Also the daily intake of As from consumption of aromatic rice is 40% lower compared to non-aromatic rice sourced from the Sylhet region. The daily intake of Se and Zn from consumption of rice would be increased by 46% and 23%, respectively, for someone consuming aromatic rice instead of non-aromatic rice from Sylhet. This study reveals that consuming certain types of aromatic rice can potentially not only reduce exposure to As but also increase the daily intake of Se and Zn in Bangladeshis. This type of rice could also be used in infant foods instead of rice with higher As concentration. Show more

Keywords: Rice, aromatic rice, Bangladesh, arsenic, cadmium, lead, selenium, zinc

DOI: 10.3233/BSI-120028

Citation: Biomedical Spectroscopy and Imaging, vol. 1, no. 4, pp. 365-381, 2012

Authors: Dochow, Sebastian | Bergner, Norbert | Matthäus, Christian | Praveen, Bavishna B. | Ashok, Praveen C. | Mazilu, Michael | Krafft, Christoph | Dholakia, Kishan | Popp, Jürgen

Article Type: Research Article

Abstract: We demonstrate that wavelength modulation overcomes frequent obstacles for in-situ and in-vivo implementations of Raman spectroscopy, namely autofluorescence, removal of the system transmission function including etaloning as well as compensation of ambient light. It is the method of choice for Raman measurements of samples with high background under ambient light conditions such as real-time assessment of tissues in the operating theatre.

Keywords: Raman spectroscopy, shifted excitation, autofluorescence suppression

DOI: 10.3233/BSI-120031

Citation: Biomedical Spectroscopy and Imaging, vol. 1, no. 4, pp. 383-389, 2012

Article Type: Other

Citation: Biomedical Spectroscopy and Imaging, vol. 1, no. 4, pp. 391-394, 2012

Article Type: Other

Citation: Biomedical Spectroscopy and Imaging, vol. 1, no. 4, pp. 395-396, 2012