Nanotechnology for Cellular Imaging - Stem-Cell Nanoengineering - page 328

Chapter 20
Nanotechnology for Cellular Imaging
Miroslaw Janowski 1-4 , P. Walczak 1,2,5 , and J.W.M. Bulte 1,2,6-8
1 Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research,
The Johns Hopkins University School of Medicine, Baltimore, MD, USA
2 Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns
Hopkins University School of Medicine, Baltimore, MD, USA
3 Department of NeuroRepair, Mossakowski Medical Research Centre, Polish Academy of Sciences,
Warsaw, Poland
4 Department of Neurosurgery, Mossakowski Medical Research Centre, Polish Academy of Sciences,
Warsaw, Poland
5 Department of Radiology, Faculty of Medical Sciences, University of Warmia and Mazury, Olsztyn, Poland
6 Department of Oncology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
7 Department of Biomedical Engineering, The Johns Hopkins University School of Medicine,
Baltimore, MD, USA
8 Department of Chemical and Biomolecular Engineering, The Johns Hopkins University School of
Medicine, Baltimore, MD, USA
Introduction
There is much enthusiasm and interest in the application of stem-cell therapy in practically
every field of medicine. However, despite the promising preclinical results, stem-cell therapy
has proven to be difficult to translate into routine clinical practice. The major problem is in the
interpretation of the outcomes of stem-cell therapy, which is due to the lack of accurate
information about the fate of the cells in vivo . In parallel, for the development of new pharma-
ceuticals, an assessment of drug kinetics has been the gold standard [1]. The outcomes of
surgery, in turn, are typically confirmed by post-operative imaging. These methods allow for a
conclusive assessment of pharmacological or surgical treatment efficacy. Due to its recent
emergence, such principles have not yet been established for stem-cell therapy. However, the
value of neuroimaging for the monitoring of transplanted cells has been recently emphasized
[2] as a strategy for more rational stem-cell therapy, but, to date, only a small number of
clinical studies have followed this recommendation [3]. This is attributable to the lack of
robust, flexible, and proven techniques for the monitoring of transplanted cells.
The advances in nanotechnology and material science have been remarkable in recent
years, with new agents and effective methods for labeling of stem cells. As a result of these
advances, stem-cell therapy for internal diseases of the liver, heart, kidney, or pancreas can
be assessed more objectively; however, the evaluation of the clinical course of neurological
disorders is much more difficult. While a meta-analysis of preclinical studies has shown
positive results of stem-cell treatment for neurological diseases [4], the mechanisms medi-
ating cell-dependent effects have yet to be fully elucidated, which precludes inferences
about the injection dose and timing, cell type, etc. [5]. It is anticipated that cellular imaging
will play an essential role in defining the mechanisms governing stem-cell therapeutics,
which is crucial for further augmentation of stem-cell treatment [6].