Doktoratskolleg MEIBio - Molecular and Elemental Imaging in Bioscience
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christina.streli(a)tuwien.ac.at

PhD Fellow #7

Trace element Distribution in Human Osteoporotic and Non-Osteoporotic Bone using Synchrotron Micro X-Ray Fluorescence Imaging

Faculty: Christina Streli

Micro-X-ray Spectrometry (m-XRS) using synchrotron radiation as excitation source is a multielement method to determine 2D and 3D (confocal m-XRS) elemental distributions with spatial resolutions down to 100 nm using most advanced X-ray optics. The advantage is the trace element capability and the information depth of some 100 mm depending on matrix and element, but quantification is still a challenge even at some mm spatial resolution due to the inhomogenous distribution and the influence of the matrix due to absorption.

Osteoporosis is characterized by a low bone mass and a micro-architectural deterioration of bone tissue with a consequent increase in bone fragility and susceptibility to fracture. As the population continues to age, the effects of osteoporosis will become increasingly prevalent.

A recent study (1) hypothesizes that manganese (Mn) is an essential mineral for calcium fixation (or incorporation) into bones. This theory is based on the finding that a decrease in Mn content in antlers causes a 27% reduction in the required impact energy to break antler bone material. Elimination of Mn from the diet of chicks caused an increase in the incidence and severity of bone abnormalities and a depressed growth rate (2) while Mn supplementation was successfully used to prevent bone loss after ovariectomy in rats (3).

The aim of this study is to test this hypothesis by determining Mn concentration and distribution in osteoporotic and non-osteoporotic human bone. The knowledge of the Mn quantification and distribution in the samples will provide an insight into the fixation (or incorporation) of Ca in bone. For quantification the results from other elemental imaging methods like LA-ICP-MS and TOF-SIMS are essential to establish quantification models even at higher spatial resolution elemental maps.

1. Landete-Castillejos, T., et al. 2012. Alternative hypothesis for the origin of osteoporosis: The role of Mn. Frontiersin Bioscience E 4: 1385-1390. 2. Leach, R. M., and Muenster, A.-M. 196
2. Studies on the role of manganese in bone formation I. Effect upon the mucopolysaccharide content of chick bone. J Nútr 78(1): 51-56.
3. Rico, H., et al. 2000. Effects on bone loss of manganese alone or with copper supplement in ovariectomized rats: A morphometric and densitomeric study. Eur J Obstet Gyn R B 90(1): 97-101.

Collaborations:

 

  • For establishing the quantification models for trace element analysis for 3D imaging an intense cooperation with LA-ICPMS, A. Limbeck (TU Vienna) and TOF-SIMS, H. Hutter (TU Vienna) is planned.
  • The integration of molecular imaging, M. Marchetti-Deschmann (TU Vienna) might be of interest to identify collagens in the bone matrix.
  • National cooperation partners outside the DK: Ludwig Boltzmann-Institut for Osteology ( Prof. K.Klaushofer, Doz.P.Roschger) Vienna, providing human bone samples and sample preparation as well as QBEI analysis.
  • International coop partner: As there are no synchrotron radiation sources available in Austria cooperations with Synchrotron radiation facilities (DESY Hamburg, BESSY Berlin, ANKA Karlsruhe, ESRF Grenoble) and SSRL (Stanford, California- X-ray microscope with nm resolution) are necessary which will allow the candidate to gain experience by performing experiments at international large scale facilities.
  • T. Landete-Castillejos providing Antler samples