Nanolabeling and X-ray synchrotron radiation for research in cardiology, oncology, muscular dystrophy and for blood vessel 3D visualization

Fiori F., Giuliani A., Komlev V., Manescu A., Renghini C., Rustichelli F.

Department S.A.I.F.E.T. – Section of Physical Sciences, Polytechnic University of Marche, Ancona, Italy
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Материалы конференции «Нанотехнологии в онкологии 2009»

(a) Cardiology

The recent introduction of stem cells in cardiology provides new tools in understanding the regenerative processes of the normal and pathologic heart and has opened the search of new therapeutic strategies. Recent published reports have contributed to identify the possible approaches of cellular therapy to generate new myocardium involving transcoronary and intramyocardial injection of progenitor cells. The possibility to rebuild muscle, arteries and capillaries is the necessary requirement to obtain successful approaches in cardiac regeneration. However, one of the limiting factors in the overall interpretation of clinical results obtained by cell therapy is represented by the lack of in vivo visualization of the injected cells and of their fate within the myocardium. Thus, we advanced the hypothesis that X-ray computed microtomography may offers the unique possibility to detect with high definition and resolution the 3D visualization of spatial distribution of rat cardiac progenitor cells (CPCs, labeled with magnetic nanoparticles) inside the infarcted rat heart early after injection. The obtained 3D images constituted a very innovative progress as compared to the experimental 2D histological images, which do not provide the correct position of the rat clonogenic cells within the heart. Through microCT, we were able to observe in 3D the migration of these cells within damaged cardiac tissue, with important structural details undetectable by the conventional bidimensional imaging techniques. In fact identification and localization of the injected cells is presently unfeasible in clinical setting and is usually carried out by immunohistochemistry and other morphometric methods on 2D samples. This new 3D imaging approach appears to be an exclusive way to investigate the cellular events involved in cardiac regeneration and represent a promising tool for future clinical applications [1]

(b) Oncology

A highly vascularized colon cancer xenograft model in immunocompromised mice (SCID) was developed by Ludwig Boltzmann Institute for Cancer Research Vienna, which can be compared to local tumour growth. The highly reproducible transplant system uses human colon cancer SW480 cells for tumour growth and metastatic spread over time. The SW480 xenograft transplant causes terminally diseased mice with tumour growth in multiple organs after 12 days post injection. Results are presented concerning ex-vivo X-ray micro-CT experiments, by which the metastatic spread in different organs, at different post-injection times, was evaluated after injecting SW480 cells labeled by Endorem nanoparticles [2].

(c) Duchenne Muscular Distrophy

Recent work supports the idea that stem cells can reach the site of muscle regeneration through systemic routes, thus contributing to muscle repair more efficiently than canonical myogenic progenitors. Human circulating stem cells, expressing the CD133 antigen, were recently shown to take part in muscle regeneration, when delivered intra-arterially into skeletal muscle tissues of scid-mdx mice. The results of ex-vivo [3] and in-vivo [4] X-ray micro-CT experiments are presented, aiming to determine the fate of CD133 cells (labeled by Endorem nanoparticles) and their distribution in the muscular tissue at different times after injection in the mice.

(d) Blood vessel 3D visualization

Standard X-ray micro-computed tomography is a technique that allows a good visualization of the structure of mineralized tissues and biomaterials, but it fails to finely discern soft tissues. The X-ray synchrotron radiation pseudo-holotomography was used to visualize, at three-dimensional (3D) level, microvascular networks for the first time with no need for contrast agents, and to extract quantitative structural data in a bone-engineered construct. The pseudo-holotomography is an innovative technique that offers a promising powerful tool to investigate angio and microvasculogenesis in advanced biomedical research areas such as regenerative medicine and antiangiogenic cancer therapies [5].

References

1. Frati C, Rossini A, Giuliani A, Komlev V, Costanza L, Savi M, Capogrossi MC, Quaini F, Manescu A, Rustichelli F. High-resolution X-ray microtomography for three-dimensional visualization of Cardiac Progenitor Cells Homing in infarcted rat hearts. To be published.
2. Fiori F, Manescu A, Girardin E, Moriggl R, Nirvathi H, Rustichelli F. To be published.
3. Torrente Y, Belicchi M, Gavina M, Fiori F, Komlev V, Rustichelli F. FEBS Letters, 580, 2006; 24: 5759-5764.
4. Torrente Y, Farini A, Villa C, Fiori F, Manescu A, Rustichelli F. To be published.
5. Komlev VS, Mastrogiacomo M, Peyrin F, Cancedda R and Rustichelli F. X-Ray Synchrotron Radiation Pseudo-Holotomography as a New Imaging Technique to Investigate Angio- and Microvasculogenesis with No Usage of Contrast Agents. Tissue Engineering Part C: Methods September, 2009; 15: 3: 425-430.