Published online May 26, 2020. doi: 10.4252/wjsc.v12.i5.381
Peer-review started: January 23, 2020
First decision: April 1, 2020
Revised: April 2, 2020
Accepted: April 23, 2020
Article in press: April 23, 2020
Published online: May 26, 2020
Stroke survivors commonly suffer from disabilities requiring temporary or lifelong assistance, resulting in a substantial economic burden for poststroke care and stem cell (SC) therapeutics appear to be a promising alternative for intervention in stroke therapy. However, the efficacy of SC therapy depends on the SC homing ability and engraftment into the injury site over a long period of time.
The analysis of the homing and tracking SC processes is a pivotal strategy for utilizing preclinical results to increase translational knowledge to improve stroke care at the bedside.
In this systematic review, we aim to evaluate SC migration homing, tracking and therapeutic efficacy in the treatment of stroke using nanoparticles.
A systematic literature search was performed to identify articles published prior to November 2019 that were indexed in PubMed and Scopus. The following inclusion criteria were used: (1) Studies that used in vivo models of stroke or ischemic brain lesions; (2) Studies of SCs labeled with some type of contrast agent for cell migration detection; and (3) Studies that involved in vivo cellular homing and tracking analysis.
A total of 82 articles were identified by indexing in Scopus and PubMed. After the inclusion criteria were applied, 35 studies were selected, and the articles were assessed for eligibility; ultimately, only 25 studies were included. Most of the selected studies used SCs from human and mouse bone marrow labeled with magnetic nanoparticles alone or combined with fluorophore dyes. These cells were administered in the stroke model (to treat middle cerebral artery occlusion in 74% of studies and for photothrombotic induction in 26% of studies). Fifty-three percent of studies used xenogeneic grafts for cell therapy, and the migration homing and tracking evaluation was performed by magnetic resonance imaging as well as other techniques, such as near-infrared fluorescence imaging (12%) or bioluminescence assays (12%).
Our systematic review provides a comprehensive, up-to-date evaluation of the SC migration and efficacy of cellular therapy for brain injury. Cellular therapy demonstrated considerable efficacy with regard to the functional and structural evaluation, as well as the differentiation of the cells in the late stage of evaluation (after 7 d of cell implantation), using protein molecular and other tests.
In summary, a long clinical follow-up is necessary in combination with the use of the homing imaging technique as the gold standard to address the gap between the clinical application and the preclinical cellular therapy outcome. Thus, the prescription of SCs labeled with SPION according to this review may help improve future clinical trials.