Regenerative medicine was widely discussed at CCC 2012, and Heart Institute researchers continue to innovate in harnessing the body’s own stem cells to fix or replace damaged cardiac tissue.
Two Heart Institute graduate students presented research nominated for the Trainee Research Award in basic science. Nicholas Latham, working in the Cardiac Translational Research Laboratory, compared the ability of cardiac stem cells (CSCs), which produce heart muscle cells, and circulating angiogenic cells (CACs), which promote the growth of new blood vessels, to encourage tissue healing in cell culture and in mice.
His group found that, in cell culture, a combination of the two stem cell types boosted the release of growth factors that encourage tissue healing and more effectively promoted blood-vessel growth. In a mouse model of heart attack, the CSCs and CACs together better prevented scar tissue formation and improved heart function compared with either cell type alone.
Drew Kuraitis, working in the Cardiovascular Tissue Engineering Laboratory, presented research into the feasibility of using frozen and re-cultured stem cells in regenerative techniques. If frozen cells work as well as fresh stem cells in assisting tissue repair, healthy stem cells could be banked for later use.
Two Heart Institute graduate students presented research nominated for the Trainee Research Award in basic science.
The researchers tested both mature CACs and their precursor cells from which they can be cultured. After freezing, both cell types retained their ability to migrate and to adhere to damaged tissue. In a mouse model of heart damage, no difference was seen between fresh cells, cells frozen for one day and cells frozen for four weeks in their ability to improve recovery of heart function.
Other Heart Institute research focused on ways to improve the retention and survival of stem cells in therapy. Rashmi Tiwari-Pandey presented work on keeping stem cells alive and healthy for longer after transplantation. She described an injectable acellular biologic scaffold designed to hold and protect stem cells in the heart to increase healing. In a mouse model of heart attack, mice that received the scaffold with or without CACs had a reduction in damaged tissue and better preservation of heart function than mice receiving CACs alone.
Tanja Sofrenovic presented research using a collagen-based supportive matrix, called sLex. In another mouse model of heart attack, injection of the matrix improved heart function. Mice receiving sLex had more recruitment of stem cells to the heart, more expression of proteins associated with healing, and fewer dying cells and more dividing cells in the heart.
Everad Tilokee discussed a related tech-nology: the encapsulation of CSCs to enhance their survival after their injection into the body. He and his colleagues found that CSCs encapsulated with supportive proteins had an improved ability to survive and divide. Further research into the specific components of the capsules could lead to the development of a timed-release mechanism for stem cell delivery, explained Tilokee.