CCRM has been known to hire its graduates, consult with its esteemed professors, review disclosures from its faculty, collaborate on projects, and our Chief Scientific Officer, Dr. Peter Zandstra, is one of its respected professors. All of this to disclose that CCRM has very strong ties to the Institute of Biomaterials and Biomedical Engineering (IBBME) at the University of Toronto (U of T).
Nonetheless, IBBME produces high-calibre research and I’m pleased to include some of it here.
Signals has featured U of T faculty and discoveries in the past, but never in the format to follow. With thanks to our partners at IBBME and U of T, please enjoy these research summaries from work that was published in 2016.
Novel MRI approach gives heart failure patients new hope
Professor Hai-Ling Margaret Cheng and her collaborators developed a novel magnetic resonance imaging (MRI) method that will help shed new light on the effectiveness of stem cell therapy for heart failure patients.
Despite their great promise, only a small proportion of stem cells are able to survive implantation and start regenerating damaged organs, such as hearts or lungs. The ability to track which stem cells are living and which are dying or where they are located in the body could help scientists adjust therapeutic strategies to maximize their effectiveness in fighting certain diseases.
Working with University of Toronto Scarborough chemistry professor Xiao-an Zhang, Professor Craig Simmons, and undergraduate summer research student Said Loai, they developed a unique contrast agent that can be injected into cells to track them using MRI. (You can read an interview with Craig Simmons here.) While conventional contrast agents only last a few days, their compound is designed specifically to stay within these cells throughout their lifespan, allowing researchers to conduct longer-term analysis and monitoring of stem cell therapy effectiveness, such as where they are going in the body or if they integrate into the appropriate host tissue over time. Their contrast agent was demonstrated to be able to stay within embryonic stem cells, the precursor of full cardiac cells, and were successfully grown into mature heart cells.
The team’s study appeared in the Journal of Magnetic Resonance Imaging and can be found here.
Stem cell therapy reverses age-related osteoporosis in mice
Osteoporosis affects over 200 million people worldwide and is responsible for an estimated 8.9 million fractures per year. Fractures of the hip – one of the most common breaks for those suffering from age-related osteoporosis – lead to a significant lack of mobility and, for some, can be deadly.
Having previously demonstrated a casual effect between mice that developed age-related osteoporosis and low or defective mesenchymal stem cells (MSCs) in these animals, University of Ottawa professor William Stanford (cross-appointed in IBBME) partnered with Professor John E. Davies and post-doctoral fellow Jeffrey Kiernan (IBBME PhD) to see if the introduction of healthy stem cells could prevent or treat this type of osteoporosis. (You can read more about Dr. Davies work with MSCs here.)
To test that theory, the researchers injected osteoporotic mice with MSCs from healthy mice. Stem cells are “progenitor” cells, capable of dividing and changing into all the different cell types in the body. Able to become bone cells, MSCs have a second unique feature, ideal for the development of human therapies: these stem cells can be transplanted from one person to another without the need for matching (needed for blood transfusions, for instance) and without being rejected.
After six months post-injection, a quarter of the life span of these animals, the osteoporotic bone had astonishingly given way to healthy, functional bone.
You can find the work published in the journal Stem Cells Translational Medicine.
‘Organ-on-a-chip’ – lab grown heart and liver tissue for drug testing and more
Professor Milica Radisic and PhD candidate Boyang Zhang led the development of AngioChip, a lab-grown human tissue platform for discovering and testing new drugs that could eventually be used to repair or replace damaged organs. (Read an earlier profile of Dr. Radisic’s work, and a reference to the AngioChip, here.)
Radisic, Zhang and their collaborators created a fully three-dimensional structure with blood vessels and a lattice for other cells to attach and grow. Zhang built the scaffold out of POMaC, a polymer that is both biodegradable and biocompatible. The scaffold is made from a series of thin layers, stamped with a pattern of channels that are each about 50 to 100 micrometres wide.
The layers, which resemble computer microchips, are then stacked into a 3D structure of synthetic blood vessels and cross-linked using UV light. When the structure is finished, it is bathed in a liquid containing living cells, which quickly colonize the channels and begin growing just as they would in the human body.
Their work, performed in partnership with University Professor Michael Sefton, Professor Aaron Wheeler (read more about him here) and their lab groups, as well as researchers from the University Health Network, can be found in the journal Nature Materials.
With files from the University of Toronto.
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