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Mitri E.,CNR Institute of Materials | Mitri E.,University of Trieste | Birarda G.,Lawrence Berkeley National Laboratory | Vaccari L.,Elettra Synchrotron Light Laboratory | And 4 more authors.
Lab on a Chip - Miniaturisation for Chemistry and Biology | Year: 2014

Here we present a new bonding protocol for SU-8 negative tone photoresist that exploits the chemical modifications induced in the resin by exposure to 254 nm (UVC) light. Fourier Transform Infrared microspectroscopy (μ-FTIR) was used to carry out a thorough study on the chemical processes and modifications occurring within the epoxy resin by exposure to 365 nm and 254 nm light. In particular, we established that UVC light promotes the opening of the epoxy rings bypassing the post-exposure bake. The possibility to promote a further activation of the resin, already patterned with standard UV lithography, was exploited to produce closed microfluidic devices. Specifically, we were able to fabricate fluidic chips, characterized by broadband transparency from mid-IR to UV and long term stability in continuous flow conditions. CaF2 was used as substrate, coated by sputtering with a nanometric silicon film, in order to make surface properties of this material more suitable for standard fabrication processes with respect to the original substrate. The fabricated microfluidic chips were used to study by μ-FTIR the biochemical response of live breast cancer MCF-7 cells to osmotic stress and their subsequent lysis induced by the injection of deionized water in the device. μ-FTIR analyses detected fast changes in protein, lipid and nucleic acid content as well as cytosol acidification. This journal is © 2014 The Royal Society of Chemistry. Source

Loutherback K.,Lawrence Berkeley National Laboratory | Birarda G.,Lawrence Berkeley National Laboratory | Birarda G.,Elettra Synchrotron Light Laboratory | Chen L.,Lawrence Berkeley National Laboratory | Holman H.-Y.N.,Lawrence Berkeley National Laboratory
Protein and Peptide Letters | Year: 2016

A long-standing desire in biological and biomedical sciences is to be able to probe cellular chemistry as biological processes are happening inside living cells. Synchrotron radiation-based Fourier transform infrared (SR-FTIR) spectral microscopy is a label-free and nondestructive analytical technique that can provide spatiotemporal distributions and relative abundances of biomolecules of a specimen by their characteristic vibrational modes. Despite great progress in recent years, SR-FTIR imaging of living biological systems remains challenging because of the demanding requirements on environmental control and strong infrared absorption of water. To meet this challenge, microfluidic devices have emerged as a method to control the water thickness while providing a hospitable environment to measure cellular processes and responses over many hours or days. This paper will provide an overview of microfluidic device development for SR-FTIR imaging of living biological systems, provide contrast between the various techniques including closed and open-channel designs, and discuss future directions of development within this area. Even as the fundamental science and technological demonstrations develop, other ongoing issues must be addressed; for example, choosing applications whose experimental requirements closely match device capabilities, and developing strategies to efficiently complete the cycle of development. These will require imagination, ingenuity and collaboration. © 2016 Bentham Science Publishers. Source

Flower K.R.,University of Manchester | Khalifa I.,University of Manchester | Bassan P.,University of Manchester | Demoulin D.,University of Manchester | And 6 more authors.
Analyst | Year: 2011

Recently a new di-gold(i) organometallic complex [1,3-(Ph 3PAu)2-C6H4] (KF0101) has been synthesised and found to exhibit cytotoxic activity in vitro. Subsequently it has been demonstrated that KF0101 shows little or no cross-resistance against a number of the cisplatin resistant ovarian cancer cell lines in vitro suggesting a different mode of action for the drug. In this study, syncrotron radiation infrared microspectroscopy (SR-IRMS) has been used on drug treated single A2780 cells in order to determine if this different mode of action can be identified spectroscopically. The aim of the study was to establish: (i) if single cell SR-IRMS could be used to give insight into the cellular response on treatment with different cytotoxic agents relative to non-treated cells (control) and (ii) that if the cytotoxic drugs elicit a different biochemical response these responses could be distinguished from each other. The most striking features obtained after Principal Componants Analysis (PCA) of Resonant Mie Scattering (RMieS) corrected single cell spectra of drug treated ovarian A2780 cells are: (i) The spectra obtained for the control are quite heterogeneous and several hundred spectra are required to adequately define the nature of the control; (ii) after drug treatment at the IC50 level for 24 h with cisplatin, KF0101, methotrexate, paclitaxel or 5-fluorouracil the cell spectra, as represented on a PCA scores plot, generally concentrate in certain well defined areas of the control, there are however a small number of spectra that fall outside of the area defined by the control; and (iii) a differentiation between cell spectra obtained on treatment with different drugs is observed which fits well with different in vitro cell culture behaviour and a flow cytometry cell cycle analysis of the contol and drug treated cells. Inspection of the loading plots shows that PC1 is essentially the same for all plots and reflects changes in cell biochemistry related to the cell cycle. PC2, however, on comparison of the control versus cisplatin or cisplatin versus KF0101 is indicative of differences induced by drug treatment and has been termed as cell cycle-plus behaviour. These data are shown to be consistent with that obtained using bench-top IRMS by averaging a number of single cell spectra and carrying out a PCA, but SR-IRMS offers more insight into how the drug is affecting the cell population. More importantly, this approach enables the influence of the cell cycle on both the control and drug treated samples to be taken into consideration when evaluating the drug-cell interaction. © 2011 The Royal Society of Chemistry. Source

Vaccari L.,Elettra Synchrotron Light Laboratory | Birarda G.,Elettra Synchrotron Light Laboratory | Birarda G.,CNR Institute of Materials | Businaro L.,CNR Institute for Photonics and Nanotechnologies | And 2 more authors.
Analytical Chemistry | Year: 2012

Until nowadays most infrared microspectroscopy (IRMS) experiments on biological specimens (i.e., tissues or cells) have been routinely carried out on fixed or dried samples in order to circumvent water absorption problems. In this paper, we demonstrate the possibility to widen the range of in-vitro IRMS experiments to vibrational analysis of live cellular samples, thanks to the development of novel biocompatible IR-visible transparent microfluidic devices (MD). In order to highlight the biological relevance of IRMS in MD (MD-IRMS), we performed a systematic exploration of the biochemical alterations induced by different fixation protocols, ethanol 70% and formaldehyde solution 4%, as well as air-drying on U937 leukemic monocytes by comparing their IR vibrational features with the live U937 counterpart. Both fixation and air-drying procedures affected lipid composition and order as well as protein structure at a different extent while they both induced structural alterations in nucleic acids. Therefore, only IRMS of live cells can provide reliable information on both DNA and RNA structure and on their cellular dynamic. In summary, we show that MD-IRMS of live cells is feasible, reliable, and biologically relevant to be recognized as a label-free cell-based assay. © 2012 American Chemical Society. Source

D'amico F.,Elettra Synchrotron Light Laboratory | Saito M.,Elettra Synchrotron Light Laboratory | Bencivenga F.,Elettra Synchrotron Light Laboratory | Marsi M.,University Paris - Sud | And 10 more authors.
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | Year: 2013

We present a newly developed resonant Raman scattering instrument working in the UV spectral range. This set-up, which exploits the UV synchrotron radiation source available at Elettra (Trieste, Italy), results in an innovative spectroscopic facility to be used for addressing a large array of open problems, ranging from the electronic properties of nanostructures and strongly correlated materials to biochemistry. © 2012 Elsevier B.V. Source

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