Applications of condensed matter understanding to medical tissues and disease progression: Elemental analysis and structural integrity of tissue scaffolds D.A. Bradley a , M.J. Farquharson b , O. Gundogdu a , Alia Al-Ebraheem b , Elna Che Ismail a , W. Kaabar a,Ã , O. Bunk c , F. Pfeiffer c,d , G. Falkenberg e , M. Bailey f a Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford GU2 7XH, UK b Department of Radiography, School of Community and Health Sciences, City University, London, UK c Paul Scherrer Institute, CH-5232 Villigen, Switzerland d Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne, Switzerland e Hamburger Synchrotronstrahlungslabor HASYLAB at Deutsches Elektronensynchrotron DESY, Notkestr. 85, D-22603 Hamburg, Germany f Surrey Ion Beam Centre, Advanced Technology Institute, University of Surrey, Guildford GU2 7XH, UK article info Article history: Received 9 December 2008 Accepted 15 December 2008 Keywords: Cartilage Breast tissue Elemental analysis Structural integrity Tissue scaffolds abstract The investigations reported herein link tissue structure and elemental presence with issues of environmental health and disease, exemplified by uptake and storage of potentially toxic elements in the body, the osteoarthritic condition and malignancy in the breast and other soft tissues. Focus is placed on application of state-of-the-art ionizing radiation techniques, including, micro-synchrotron X-ray fluorescence (m-SXRF) and particle-induced X-ray emission/Rutherford backscattering mapping (m-PIXE/RBS), coherent small-angle X-ray scattering (cSAXS) and X-ray phase-contrast imaging, providing information on elemental make-up, the large-scale organisation of collagen and anatomical features of moderate and low atomic number media. For the particular situations under investigation, use of such facilities is allowing information to be obtained at an unprecedented level of detail, yielding new understanding of the affected tissues and the progression of disease. & 2009 Elsevier Ltd. All rights reserved. 1. Introduction Recent years have seen rapid developments in a number of techniques, the objective of which is to obtain micrometer spatial resolution imaging of elemental concentration, down to levels of sub-parts per million, together with complementary information on the large-scale (mm 2 ) organisation of the various tissues of interest, examining spacings up to in excess of 100nm. For trace elements (typically at the parts-per-million, ppm, level), minor elements (at somewhat higher levels typically in the 1000 ppm range) and major elements, two of the most widely used methods are microbeam particle-induced X-ray emission (m-PIXE) and Rutherford backscattering (RBS) analysis, otherwise referred to as nuclear microprobe analysis or ion beam analysis, and microbeam synchrotron X-ray fluorescence (m-SXRF). Micro X-ray fluores- cence and m-PIXE/RBS techniques and their applications have now been rather extensively reviewed, respective examples of such reviews being found in Adams et al. (1998) and Llabador and Moretto (1996). As such, no detailed account of these techniques themselves will be included in this article. It should also be mentioned that, while spatial resolution at the sub-micrometer level is possible, in practice, the beam size will more practically depend on the demands of the application and the capabilities of the facility, typically being limited by the flux on the target, and the extent of the mapping. Both the ion beam and m-SXRF techniques offer the advantage of multi-element detection and 2D mapping, significant sensitivity and the feasibility of absolute quantification, provided appropriate standards can be established. In their review of the use of X-ray or gamma-ray techniques Theodorakou and Farquharson (2008) have provided an extensive discussion of studies of tissue organisation, made possible by diffraction techniques, including the use of wide-angle X-ray scattering (WAXS) and small-angle X-ray scattering (SAXS), the former typically giving information concerning intra-molecular correlations and the latter concerning inter-molecular correla- tions, in particular preferential orientations. Present work focuses on use of the latter. In the studies presented herein, focus is first placed upon biomedical applications of m-SXRF and m-PIXE/RBS facilities, ARTICLE IN PRESS Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/radphyschem Radiation Physics and Chemistry 0969-806X/$ - see front matter & 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.radphyschem.2008.12.007 Ã Corresponding author. E-mail addresses: d.a.bradley@surrey.ac.uk (D.A. Bradley), w.kaabar@surrey.ac.uk (W. Kaabar). Radiation Physics and Chemistry 79 (2010) 162–175