Iron-oxide-nanoparticle-tagged Mesenchymal Stem Cell Exosomes in Therapeutics

Abstract Purpose of Review Mesenchymal Stromal/Stem Cells (MSCs) include a population of cells that are predominantly stromal cells with a small fraction of mesenchymal stem cells that demonstrate stem-cell like properties. MSCs have great therapeutic potential but are not used frequently in clinical settings because of methodological challenges posed at pre-transplantation stages, issues during post-transplantation detection, and the accompanying risks of tumorigenicity, immunogenicity and toxicity. Labelling MSCs with iron-oxide nanoparticles (IONPs) has shown promising results but it is not problem-free. This article highlights the utility of IONP-tagged MSC-derived exosomes in facilitating MSC therapeutics. Recent Findings To circumvent the issues associated with cell-based therapy, researchers have contemplated using a cell-free approach. MSC-derived exosomes are nanovesicles that contain beneficial biomolecules, and transplantation with these exosomes offers several procedural and physiological advantages over transplantation with parent MSCs. Notably, tagging these MSC-exosomes with IONPs leads to better guidance of these exosomes, and therefore, their therapeutic factors towards target cells, increased ability of exosomes to carry large amounts of therapeutic biomolecules, increased accumulation of exosomes at target site, increased expression of endogenous growth factors and increased therapeutic efficacy. Administration of IONP-tagged MSC-exosomes into animal models of spinal cord injury, ischemic stroke, myocardial infarction, and cancer has shown promising results such as enhanced angiogenesis, and reduction in inflammation, cell apoptosis, fibrosis, toxicity and/or tumour growth. Summary IONP-tagged MSC-derived exosomes show potential for disease amelioration. Further investigation is needed to address the challenges posed by this approach, including hemocompatibility issues to ensure patient safety and treatment efficacy.