- Existing tissue engineering platforms to mend damaged or injured hearts involve invasive open heart surgery to implant regenerative cells or tissues.
- Current research team has developed lab grown biocompatible tissue that can be injected, and unfolds into a patch within the body to repair damaged tissues and organs.
or diseased heart or other organs could be fixed by injectable lab engineered
tissue, overcoming the need for painful, invasive open surgery, according to a
biomedical engineering research team at the University of Toronto
Faculty of Applied Science & Engineering.
Injectable Lab Grown Tissue Patch - Game Changer In Tissue Repair Technology
The last couple of decades have seen a huge expansion in stem cell and tissue engineering research and development.
Generally lab generated tissue used for repair and regeneration of injured or damaged organs (eg: heart attack ) has involved implantation of the tissue at the site of injury through an invasive surgical procedure such as open heart surgery and required general anesthesia.
Biomedical engineering Professor Milica Radisic at the University of Toronto Faculty of Applied Science & Engineering and her colleagues are experts in developing polymer scaffolds on which realistic 3D tissue resembling native tissue can be grown in the lab setting. AngioChip, one of their innovations, is a tiny patch of heart tissue having its own blood supply. These heart cells are able to beat with a regular rhythm. Yet another of their novel creation snaps together like sheets of Velcro.
The team hoped to translate their expertise in the field of polymer science to create an injectable biocompatible material that could be used to repair injured tissues and organs.
Developing An Injectable Biocompatible Material - A Herculean Task
- Miles Montgomery, a PhD candidate in Radisic's lab, spent nearly three years just experimenting in order to produce a tissue patch that could be injected, rather than implanted.
- After several gut wrenching failures, Montgomery finally managed to produce what he was looking for - a scaffold material that matched the mechanical properties of the target tissue and possessed the necessary shape-memory behaviour. Thus, the patch would unfold itself into a bandage-like shape as it is delivered into the target area in vivo.
According to Radisic, the shape-memory effect depends on physical properties, not chemical ones. This essentially means that the unfolding process does not further injections, and local tissue reactions or conditions will not affect the process.
Testing The Lab Grown Injectable Tissue Patch
- The next step was growing (seeding) heart cells on the above scaffold, and the created tissue was injected into rats and pigs.
- The injected tissue unfolded into a postage stamp sized patch (nearly the same size as implanted tissue) as it emerged from the needle. The heart thankfully withstood the procedure very well
- The scaffold made of biodegradable material would disintegrate over time leaving behind only the heart tissue
- It was found that following the procedure, the heart function also improved and the ventricles were able to pump better than before injection of the patch.
Plans For Future Research
- Whether the improved cardiac function is sustained over a long period of time.
- The team has also applied for patents on the invention and are planning to test the use of the patch in other organs, such as the liver.
- Prof Radisic opines that this platform could be customized as per requirements by, for instance the addition of growth factors to encourage tissue regeneration.
- Materials Science and Tissue Engineering: Repairing the Heart - (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3786696/)