Vibrational Spectroscopy as a Tool for Studying Drug-Cell Interaction: Could High Throughput Vibrational Spectroscopic Screening Improve Drug Development

Vibrational spectroscopy is currently widely explored as a tool in biomedical applications. An area at the forefront of this field is the use of vibrational spectroscopy for disease diagnosis, ultimately aiming towards spectral pathology. However, while this field shows promising results, moving this technique into the clinic faces the challenges of widespread clinical trials and legislative approval. While spectral pathology has received a lot of attention, there are many other biomedical applications of vibrational spectroscopy, which could potentially be translated to applications with greater ease. A particularly promising application is the use of vibrational spectroscopic techniques to study the interaction of drugs with cells. Many studies have demonstrated the ability to detect biochemical changes in cells in response to drug application, using both infrared and Raman spectroscopy. This has shown potential for use in high throughput screening (HTS) applications, for screening of efficacy and mode of action of potential drug candidates, to speed up the drug discovery process. HTS is still a relatively new and growing area of research and, therefore, there is more potential for new techniques to move into and shape this field. Vibrational spectroscopic techniques come with many benefits over the techniques used currently in HTS, primarily based on fluorescence assays to detect specific binding interactions or phenotypes. They are label free, and an infrared or Raman spectrum provides a wealth of biochemical information, and therefore could reveal not only information about a specific interaction, but about how the overall biochemistry of a cell changes in response to application of a drug candidate. Therefore, drug mode of action could be elucidated. This review will investigate the potential for vibrational spectroscopy, particularly FTIR and Raman spectroscopy, to benefit the field of HTS and improve the drug development process. In addition to FTIR and Raman spectroscopy, surface enhanced Raman spectroscopy (SERS), coherent anti-Stokes Raman spectroscopy (CARS) and stimulated Raman spectroscopy (SRS), will be investigated as an alternative tool in the HTS process

Legacy and social media respectively influence risk perceptions and protective behaviors during emerging health threats: A multi-wave analysis of communications on Zika virus cases.

ObjectiveBoth legacy media, such as television and newspapers, and online social media are potentially important but incompletely understood sources of information in the face of emerging public health risks. This research aimed to understand media effects on risk perceptions and behaviors concerning the Zika virus in the United States.MethodsWe analyzed a multi-wave nationally representative survey (N = 29,062) and the volume of communications in social and legacy media (i.e., legacy media data from news sources and databases, N = 2,660 and social media data from Twitter, N = 1,605,752) in the United States between April and October 2016, dates coinciding with the early cases of local transmission of Zika in the United States (i.e., 25 weeks). The present study conducted econometric analyses (i.e., Granger causality tests) to assess the associations of legacy and social media coverage with risk perceptions and protective behaviors in the total sample and specific groups separated by pregnancy status/intent, geographic region, income, education level, age, and ethnicity.ResultsThe results from the overall sample suggested that changes in the volume of information in legacy and social media (i.e., Twitter) were followed by different changes in community risk perceptions and protective behaviors. Specifically, social media coverage correlated with the level of risk perceptions, whereas the legacy media coverage correlated with the level of protective behaviors. Analyses across different subpopulations, including those of different pregnancy status/intent, geographic Zika risk, income, education level, age, and ethnicity, replicated the social media associations with risk perceptions in most cases. However, legacy media and protective behaviors were linked only in some vulnerable subpopulations (e.g., the less-educated populations).ConclusionUnderstanding how media coverage relates to Zika risk perceptions and protective behaviors will help to facilitate effective risk communications by healthcare professionals and providers, particularly when a health risk emerges

The RNA-dependent RNA polymerase of the hepatitis A virus

SIGLEAvailable from British Library Document Supply Centre-DSC:DXN024358 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Competency-Based Assessment for Clinical Supervisors: Design-Based Research on a Web-Delivered Program

Background: Clinicians need to be supported by universities to use credible and defensible assessment practices during student placements. Web-based delivery of clinical education in student assessment offers professional development regardless of the geographical location of placement sites. Objective: This paper explores the potential for a video-based constructivist Web-based program to support site supervisors in their assessments of student dietitians during clinical placements. Methods: This project was undertaken as design-based research in two stages. Stage 1 describes the research consultation, development of the prototype, and formative feedback. In Stage 2, the program was pilot-tested and evaluated by a purposeful sample of nine clinical supervisors. Data generated as a result of user participation during the pilot test is reported. Users’ experiences with the program were also explored via interviews (six in a focus group and three individually). The interviews were transcribed verbatim and thematic analysis conducted from a pedagogical perspective using van Manen’s highlighting approach. Results: This research succeeded in developing a Web-based program, “Feed our Future”, that increased supervisors’ confidence with their competency-based assessments of students on clinical placements. Three pedagogical themes emerged: constructivist design supports transformative Web-based learning; videos make abstract concepts tangible; and accessibility, usability, and pedagogy are interdependent. Conclusions: Web-based programs, such as Feed our Future, offer a viable means for universities to support clinical supervisors in their assessment practices during clinical placements. A design-based research approach offers a practical process for such Web-based tool development, highlighting pedagogical barriers for planning purposes.Full Tex

Raman spectroscopy investigation of biochemical changes in tumour spheroids with ageing and after treatment with staurosporine

There has been increasing use of in vitro cell culture models that more realistically replicate the three dimensional (3D) environment found in vivo. Multicellular tumour spheroids (MTS) using cell lines or patient-derived organoids have become an important in vitro drug development tool, where cells are grown in a 3D 'sphere' that exhibits many of the characteristics found in vivo. Significantly, MTS develop gradients in nutrients and oxygen, commonly found in tumours, that contribute to therapy resistance. While MTS show promise as a more realistic in vitro culture model, there is a massive need to improve imaging technologies for assessing biochemical characteristics and drug response in such models to maximize their translation into useful applications such as high throughput screening (HTS). In this study we investigate the potential for Raman spectroscopy to unveil biochemical information in MTS and have investigated how spheroid age influences drug response, shedding light on increased therapy resistance in developing tumours. The wealth of molecular level information delivered by Raman spectroscopy in a noninvasive manner, could aid translation of these 3D models into HTS applications.PostprintPeer reviewe

Bioanalytical measurements enabled by surface-enhanced Raman scattering (SERS) probes

Since its discovery in 1974, surface-enhanced Raman scattering (SERS) has gained momentum as an important tool in analytical chemistry. SERS is used widely for analysis of biological samples, ranging from in vitro cell culture models, ex vivo tissue and blood samples, and direct in vivo application. New insights have been gained into biochemistry, with an emphasis on biomolecule detection, from small molecules such as glucose and amino acids to larger biomolecules such as DNA, proteins, and lipids. These measurements have increased our understanding of biological systems, and significantly, they have improved diagnostic capabilities. SERS probes display unique advantages in their detection sensitivity and multiplexing capability. We highlight key considerations that are required when performing bioanalytical SERS measurements, including sample preparation, probe selection, instrumental configuration, and data analysis. Some of the key bioanalytical measurements enabled by SERS probes with application to in vitro, ex vivo, and in vivo biological environments are discussed

Through tissue imaging of a live breast cancer tumour model using handheld surface enhanced spatially offset Resonance Raman Spectroscopy

In order to improve patient survival and reduce the amount of unnecessary and traumatic biopsies, non-invasive detection of cancerous tumours is of imperative and urgent need. Multicellular tumour spheroids (MTS) can be used as an ex vivo cancer tumour model, to model in vivo nanoparticle (NP) uptake by the enhanced permeability and retention (EPR) effect. Surface enhanced spatially offset Raman spectroscopy (SESORS) combines both surface enhanced Raman spectroscopy (SERS) and spatially offset Raman spectroscopy (SORS) to yield enhanced Raman signals at much greater sub-surface levels. By utilizing a reporter that has an electronic transition in resonance with the laser frequency, surface enhanced resonance Raman scattering (SERRS) yields even greater enhancement in Raman signal. Using a handheld SORS spectrometer with back scattering optics, we demonstrate the detection of live breast cancer 3D multicellular tumour spheroids (MTS) containing SERRS active NPs through 15 mm of porcine tissue. False color 2D heat intensity maps were used to determine tumour model location. In addition, we demonstrate the tracking of SERRS-active NPs through porcine tissue to depths of up to 25 mm. This unprecedented performance is due to the use of red-shifted chalcogenpyrylium-based Raman reporters to demonstrate the novel technique of surface enhanced spatially offset resonance Raman spectroscopy (SESORRS) for the first time. Our results demonstrate a significant step forward in the ability to detect vibrational fingerprints from a tumour model at depth through tissue. Such an approach offers significant promise for the translation of NPs into clinical applications for non-invasive disease diagnostics based on this new chemical principle of measurement

Surface-enhanced Raman spectroscopy for in vivo biosensing

Surface-enhanced Raman scattering (SERS) is of interest for biomedical analysis and imaging because of its sensitivity, specificity and multiplexing capabilities. The successful application of SERS for in vivo biosensing requires probes to be biocompatible and procedures to be minimally invasive, challenges that have respectively been met by developing new nanoprobes and instrumentation. This Review presents recent developments in these areas, describing case studies in which sensors have been implemented, as well as outlining shortcomings that must be addressed before SERS sees clinical use

Ratiometric analysis using Raman spectroscopy as a powerful predictor of structural properties of fatty acids

Raman spectroscopy has been used extensively for analysis of biological samples in vitro, ex vivo and in vivo. While important progress has been made towards using this analytical technique in clinical applications, there is a limit to how much chemically specific information can be extracted from a spectrum of a biological sample, which consists of multiple overlapping peaks from a large number of species in any particular sample. In an attempt to elucidate more specific information regarding individual biochemical species, as opposed to very broad assignments by species class, we propose a bottom up approach beginning with detailed analysis of pure biochemical components. Here we demonstrate a simple ratiometric approach applied to fatty acids, a subsection of the lipid class, to allow the key structural features, in particular degree of saturation and chain length, to be predicted. This is proposed as a starting point for allowing more chemically and species specific information to be elucidated from the highly multiplexed spectrum of multiple overlapping signals found in a real biological sample. The power of simple ratiometric analysis is also demonstrated by comparing the prediction of degree of unsaturation in food oil samples using ratiometric and multivariate analysis techniques which could be used for food oil authentication