Researchers have developed a biopolymer microthread technology that could deliver these hMSCs directly to damaged heart tissue.
- The microthreads are made of fibrin, which is a protein that assists in blood clotting and can be engineered to acquire different tensile strengths and to dissolve at various rates once implanted;
- This makes it easier to adjust the threads for several different uses as published in the Journal of Biomedical Materials Research;
- Injecting human mesenchymal stem cells (hMSCs), which come from adult bone marrow, into the heart muscle or bloodstream resulted poorly, with 15% or less of the cells actually attaching to heart muscle or even surviving;
- Many of the injected hMSCs are washed away by the bloodstream.
Glenn Gaudette, lead author of the study and assistant professor of biomedical engineering at WPI, along with George Pins, associate professor of biomedical engineering at WPI, and a team of researchers used small bundles of the fibrin microthreads to seed hMSCs, where the stem cells would attach to the threads.
- Once attached, the hMSCs were cultured for 5 days;
- According to the study, the stem cells started multiplying and eventually covered the two-centimeter-long threads completely;
- There were approximately 10,000 hMSCs on each one;
- Once the seeding and growing process was complete, the microthreads were attached to a surgical needle and drawn through a collagen gel;
- This gel stimulated the human tissue, keeping the stem cells both alive and attached to the threads;
- This result suggests that the cells could be sutured into human tissue.
In addition to repairing damaged hearts, stem cells still had the ability to grow into other kinds of cells. To do this, they took the stem cells off of the threads using established protocols to culture them and prompt them to differentiate into bone cells and fat cells. As it turns out, the cells were able to differentiate into both.