Non-invasive stem cell tracking using novel nanomaterials : in vitro and ex vivo studies

• Main Author: Sweeney, Sean Kenneth
• Other Authors: Assouline, Jose G.
• Format: Others
• Language: English
• Published: University of Iowa 2012
• Subjects: computed tomography; contrast agents; magnetic resonance imaging; mesenchymal stem cells; nanomaterials; stem cell tracking; Biomedical Engineering and Bioengineering
• Online Access: https://ir.uiowa.edu/etd/2282; https://ir.uiowa.edu/cgi/viewcontent.cgi?article=6763&context=etd

As research and clinical use of stem cell therapies progresses, it is becoming more evident that being able to visualize the stem cell transplant in vivo is of great benefit to the researcher or clinician. As a result, researchers are working to address this need. Our lab is collaborating to develop novel, multimodal nanomaterials, one with a core of mesoporous silica, and the other with a core of gadolinium oxide. Varying modifications have been made as needs arose. Human mesenchymal stem cells (MSCs) were isolated from bone marrow aspirates and confirmed to be positive for STRO-1, a common MSC marker. These cells were labeled with 125 μg/mL of varying nanoparticle types: gadolinium oxide, doped with 0.5%, 5%, or 10% europium for magnetic resonance imaging (MRI) and luminescence microscopy, and mesoporous silica nanoparticles (MSN), loaded with fluorescein for fluorescent microscopy and capped with either iron oxide or gold for MRI and computed tomography (CT), respectively. We studied the kinetics of MSN uptake by MSCs for 10 days using fluorescent microscopy. In ex vivo studies, we used the 4.7 Tesla Varian® small animal MRI scanner to detect 5*10⁴ cells labeled with ferrite-capped MSN particles and injected into the brain, lung, and heart of a perfusion-fixed mouse. Micro-CT was used to detect 1.7*10⁶ cells labeled with gold-capped MSN and delivered to the lungs via the trachea in a perfusion-fixed mouse. The results of this research are preliminary to in vivo testing using animal models as a proof-of-concept for these potentially marketable particles.