Brave New Fiber
Tissue engineering enters a new era.
The National Institutes of Health define tissue engineering as the process by which scientists combine cells, scaffolds and biologically active molecules to “assemble functional constructs that restore, maintain, or improve damaged tissues or whole organs.”
Few doubt that tissue engineering will one day revolutionize treatments for a wide array of injuries and illnesses. But thus far much of its potential has been unrealized. One barrier involves constraints surrounding the construction of the aforementioned “scaffolds,” those extra-cellular matrices that allow cells to form themselves into tissue.
Scaffolds are often successfully constructed using “nonwoven fibers” created by a process called electrospinning. It works, but is limited in scope. The reason, says Elizabeth Loboa, dean of MU’s College of Engineering, is that electrospinning tissue scaffolding, especially on the scale needed to advance real-world therapies, is far too time-consuming and expensive. For those with circulation disorders, athletes and others in need of cartilage repair, or women seeking to replace breast tissue lost to mastectomies, this is very bad news indeed.
Thankfully, Loboa and a team of researchers recently announced that they are closing in on the development of an effective alternative to electrospinning, one that deploys techniques common in textile manufacturing to create cheaper, better scaffolding. “Electrospinning produces weak fibers, scaffolds that are not consistent and have pores that are too small,” Loboa says. “We can run our system for hours and create about a ten-inch diameter of scaffold material.”
The goal, she adds, is to use textile techniques to “scale up” production of polylactic acid (PLA) scaffolds, an FDA-approved material that is seeded with human stem cells. Ultimately they aim to produce “hundreds of meters of materials that look the same, have the same properties, and can be used in clinical settings.”
Loboa worked with Stephen A. Tuin, a recent doctoral graduate at her lab who works with the Joint Department of Biomedical Engineering at the University of North Carolina and North Carolina State University, and Behnam Pourdeyhimi of the North Carolina State College of Textiles. The group published a pair of papers that used three common textile-creation methods to learn whether these techniques would create the materials needed to mimic native tissue. Results showed all three performed as least as well as electrospinning, and sometimes better.
“These alternative methods are more cost-effective than electrospinning,” says Loboa. “A small sample of electrospun material could cost between two and five dollars. The cost for these three manufacturing methods is between 30 cents and three dollars. These methods proved to be effective and efficient. Next steps include testing how the different scaffolds created in the three methods perform once implanted in animals.” Loboa, Tuin and Pourdeyhimi’s research appeared in the journals Biomedical Materials and Acta Biomaterialia.