24 February 2014. Biomedical engineers at Michigan Technological University in Houghton and Duke University in Durham, North Carolina developed a process for creating a framework needed to turn stem cells into engineered regenerative tissue. The research team led by Michigan Tech professor Feng Zhao published its findings online in a recent issue of the journal Advanced Functional Materials (paid subscription required).
Healthy human cells create their own framework structures that organize and build the cells into human tissue. For regenerative medicine, however, that support structure needs to be built separately for cells to populate and grow into new tissue to heal wounds or replace damaged tissue, such as cartilage. Any replacement tissue must also be compatible with the host to reduce the risk of rejection by the body’s immune system.
The problem addressed by the Michigan Tech researchers was to create an organized matrix to support tissue cell growth in the lab with similar properties to natural tissue. Up to now, those structures were based largely on synthetic, not natural, materials or animal substances.
Zhao’s team devised a process for growing fibroblasts — the connective tissue in this supportive matrix — in a controlled lab environment, on a grated surface, some 130 nanometers in depth. The fibroblasts derived from human skin cells were grown as nanoscale fibers, about 80 nanometers in diameter, highly uniform in size and in close alignment, over 8 weeks.
The researchers also were able to seed the resulting matrix with adult stem cells derived from bone marrow that can be transformed into a range of human tissues including muscle, bone, tendon, and cartilage. Since the synthetic fibroblasts were grown originally from human skin tissue, they retained the same supporting complex molecular functions, in addition to providing a place for the cells to grow.
Zhao and colleagues tested the scaffolding for potential rejection by the host if transplanted into a patient. The researchers exposed the lab-generated scaffold to immune system cells associated with inflammation, and compared the response to fibroblast fibers on their own and not in a scaffold. The tests show the scaffold generated significantly fewer inflammatory proteins than the unaligned and unorganized fibroblasts.
“The material they made is quite uniform, and of course it is completely biological,” says Zhao in a university statement. “I think we could use this to engineer softer tissues, like skin, blood vessels and muscle.”
Read more:
- Calif Stem Cell, UC Irvine Partner on Eye Transplant Tissue
- University, Biotech Develop Heart Tissue Repair Patch
- Synthetic Tissue Created with Water, Lipids, 3-D Printing
- New Company Formed to Create Engineered Corneal Tissue
- Stem Cells Induced to Become Blood Vessel Tissue Cells
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