Modern techniques for stem cells in vivo imaging (Review)

Abstract

Application of existing techniques and development of novel approaches to in vivo imaging of particular cell groups for the tasks of cell regenerative medicine is one of the perspective directions in modern biomedical studies. In vivo bioimaging is traditionally employed to study migration direction, proliferation and differentiation of stem cells in experiment and in clinical environment. Currently, numerous techniques for in vivo imaging of cells and cell structures with wide choice of sensitivity, specificity, and resolution characteristics are developed allowing to select an optimal tool for the particular problem. The variety of the modalities provides the opportunity to perform anatomical, physiological pharmaceutical and molecular studies as well as their combinations. Recently the in vivo imaging systems are being continuously updated, the sensitivity of setups increases, and new molecular labels as well as labeling technologies are being developed. The present review gives an overview of the basic methods for stem cells monitoring and labeling with the discussion of their possibilities, advantages and disadvantages in experimental and clinical studies. The following classes of techniques for in vivo imaging of cell migration are considered: optical methods (including bioluminescence, fluorescence and optical coherence tomography), non-optical methods (including magnetic resonance imaging and radionuclide imaging), hybrid methods (including optoacoustic tomography) and techniques of multimodal imaging. Physical characteristics of the outlined methods are analyzed, such as sensitivity, spatial resolution, specificity, maximum imaging depth. Examples of implementation of different techniques for in vivo imaging of migration of stem cells of various origin are given. Basic types of contrasting agents used to enhance contrast, sensitivity and specificity of the discussed imaging modalities are described.