title: A simple way to track single gold-loaded alginate microcapsules using x-ray CT in small animal longitudinal studies.
abstract: The use of alginate based microcapsules to deliver drugs and cells with a minimal host interaction is increasingly being proposed. A proficient method to track the position of the microcapsules during such therapies, particularly if they are amenable to commonly used instrumentation, would greatly help the development of such treatments. Here we propose to label the microcapsules with gold nanoparticles to provide a bright contrast on small animal x-ray micro-CT systems enabling single microcapsule detection. The microcapsules preparation is based on a simple protocol using inexpensive compounds. This, combined with the widespread availability of micro-CT apparatus, renders our method more accessible compared with other methods. Our labeled microcapsules showed good mechanical stability and low cytotoxicity in-vitro. Our post-mortem rodent model data strongly suggest that the high signal intensity generated by the labeled microcapsules permits the use of a reduced radiation dose yielding a method fully compatible with longitudinal in-vivo studies.
  
  
  BACKGROUND
  The authors of this study report the development of a micro-CT based tracking method of alginate-based microcapsules by incorporating gold nanoparticles in the microcapsules. They demonstrate the feasibility of this system in rodent models, where due to the high signal intensity, even reduced radiation dose is sufficient to track these particles, providing a simple and effective method to track these commonly used microcapsules and allowing longitudinal studies.
authors: Swiss Light Source, 5232 Villigen, PSI, Switzerland; Australian Synchrotron, Imaging and Medical Beam Line (IMBL), Clayton, Victoria, Australia. Electronic address: alberto.astolfo@psi.ch.
authors: Alberto
authors: A
authors: Astolfo
authors: Beijing Key Lab of Bioprocess, Beijing University of Chemical Technology, Beijing, PR China; CSIRO Materials Science and Engineering, Clayton, Victoria, Australia.
authors: Fengxiang
authors: F
authors: Qie
authors: Australian Synchrotron, Imaging and Medical Beam Line (IMBL), Clayton, Victoria, Australia; Grenoble Institut des Neurosciences, Grenoble, France.
authors: Astrid
authors: A
authors: Kibleur
authors: CSIRO Materials Science and Engineering, Clayton, Victoria, Australia.
authors: Xiaojuan
authors: X
authors: Hao
authors: Elettra-Sincrotrone Trieste S.C.p.A., Trieste, Italy; Istituto Nazionale di Fisica Nucleare-Sezione di Trieste, Trieste, Italy.
authors: Ralf Hendrik
authors: RH
authors: Menk
authors: Istituto Nazionale di Fisica Nucleare-Sezione di Trieste, Trieste, Italy; Department of Physics, University of Trieste, Trieste, Italy.
authors: Fulvia
authors: F
authors: Arfelli
authors: Istituto Nazionale di Fisica Nucleare-Sezione di Trieste, Trieste, Italy; Department of Physics, University of Trieste, Trieste, Italy.
authors: Luigi
authors: L
authors: Rigon
authors: CSIRO Animal, Food and Health Sciences, Geelong, Victoria, Australia.
authors: Tracey M
authors: TM
authors: Hinton
authors: CSIRO Materials Science and Engineering, Clayton, Victoria, Australia.
authors: Malsha
authors: M
authors: Wickramaratna
authors: Beijing Key Lab of Bioprocess, Beijing University of Chemical Technology, Beijing, PR China.
authors: Tianwei
authors: T
authors: Tan
authors: CSIRO Materials Science and Engineering, Clayton, Victoria, Australia. Electronic address: tim.hughes@csiro.au.
authors: Timothy C
authors: TC
authors: Hughes
mesh_terms: D000464:Alginates / Q000737:chemistry*; D000818:Animals; D002214:Capsules / Q000737:chemistry*; D020723:Glucuronic Acid / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D006603:Hexuronic Acids / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D014057:Tomography, X-Ray Computed
chemical_list: D000464:Alginates; D002214:Capsules; D006603:Hexuronic Acids; D006046:Gold; D020723:Glucuronic Acid
keywords: Alginate microcapsules; Computed tomography; Gold nanoparticles; Reversible Addition–Fragmentation chain Transfer (RAFT) polymerization; X-ray imaging