Review
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Stem Cells. Jan 26, 2015; 7(1): 65-74
Published online Jan 26, 2015. doi: 10.4252/wjsc.v7.i1.65
Mesenchymal stem cell tracking in the intervertebral disc
Charles Handley, Tony Goldschlager, David Oehme, Peter Ghosh, Graham Jenkin
Charles Handley, Tony Goldschlager, David Oehme, Graham Jenkin, The Ritchie Centre, Monash Institute of Medical Research, Monash University, Clayton VIC 3168, Australia
Charles Handley, Tony Goldschlager, Department of Neurosurgery, Monash Medical Centre, Clayton VIC 3168, Australia
David Oehme, Department of Neurosurgery, St Vincent’s Hospital, Fitzroy VIC 3065, Australia
Peter Ghosh, Proteobioactives Research Laboratories, Brookvale NSW 2100, Australia
Author contributions: Handley C, Goldschlager T, Oehme D, Ghosh P and Jenkin G contributed to the research, writing, editing and final approval of the paper.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Charles Handley, MBBS, The Ritchie Centre, Monash Institute of Medical Research, Monash University, Wellington Road, Clayton VIC 3168, Australia. charles.handley@monashhealth.org
Telephone: +61-3-99024700 Fax: +61-3-95947114
Received: July 29, 2014
Peer-review started: July 31, 2014
First decision: September 16, 2014
Revised: October 6, 2014
Accepted: October 23, 2014
Article in press: December 16, 2014
Published online: January 26, 2015
Abstract

Low back pain is a common clinical problem, which leads to significant social, economic and public health costs. Intervertebral disc (IVD) degeneration is accepted as a common cause of low back pain. Initially, this is characterized by a loss of proteoglycans from the nucleus pulposus resulting in loss of tissue hydration and hydrostatic pressure. Conservative management, including analgesia and physiotherapy often fails and surgical treatment, such as spinal fusion, is required. Stem cells offer an exciting possible regenerative approach to IVD disease. Preclinical research has demonstrated promising biochemical, histological and radiological results in restoring degenerate IVDs. Cell tracking provides an opportunity to develop an in-depth understanding of stem cell survival, differentiation and migration, enabling optimization of stem cell treatment. Magnetic Resonance Imaging (MRI) is a non-invasive, non-ionizing imaging modality with high spatial resolution, ideally suited for stem cell tracking. Furthermore, novel MRI sequences have the potential to quantitatively assess IVD disease, providing an improved method to review response to biological treatment. Superparamagnetic iron oxide nanoparticles have been extensively researched for the purpose of cell tracking. These particles are biocompatible, non-toxic and act as excellent MRI contrast agents. This review will explore recent advances and issues in stem cell tracking and molecular imaging in relation to the IVD.

Keywords: Intervertebral disc, Stem cells, Cell tracking, Magnetic resonance imaging, Intervertebral disc degeneration

Core tip: Mesenchymal stem cell (MSC) transplantation shows exciting promise for the future regenerative approach to intervertebral disc (IVD) disease. Extensive preclinical research has demonstrated benefits from MSC treatment in disc degeneration. Cell tracking, with iron oxide nanoparticles and MRI, provides an opportunity to develop an in-depth understanding of stem cell survival, differentiation and migration, enabling optimization of stem cell treatment. This review summarizes the current literature relating to MSC tracking in the IVD, which is limited to short term monitoring. Medium to long-term cell tracking is required to accelerate translation of MSC treatment in the IVD to clinical practice.