The airway between the voice box and the lungs is the trachea, more commonly known as the windpipe. Damage to or loss of tracheal tissue, which can arise from injury resulting in constriction or resection to address a tumor, can be life-threatening or lead to a significantly reduced quality of life.

Unfortunately, doctors have limited solutions for patients with damaged tracheas; surgical joining of damaged ends, for instance, is only possible in adults if less than half of the tube is damaged. For children, the damage level needs to be less than 30 percent. Although it’s possible to clear away obstructive tissue or to implant a stent, this is a temporary solution: The repaired tube tends to close off again after about a year.

Recent tissue-engineering methods that approach the problem through cell scaffolding have also been met with a variety of challenges. But biomedical engineers at Case Western Reserve University (CWRU) are avoiding the reliance on current scaffolding strategies by assembling cells into a tube structure and coaxing them to form three distinct tissue types. These self-assembled modules become a “living” windpipe structure that is highly elastic.

"The unique approach we are taking to this problem of trachea damage or loss is forming tissue modules using a patient's cells and assembling them like childhood toy Legos into a more complex tissue," said research leader Eben Alsberg, a professor of biomedical engineering and orthopaedic surgery who also serves as director of the Alsberg Stem Cell & Engineered Novel Therapeutics (ASCENT) Lab at Case.

"The hope is that a surgeon could implant the tissue tube into the body and it will grow and incorporate into the existing tissue," said Alsberg. "We're excited about this approach, as it may have broad applicability to bottom-up engineering of many other complex tissues and organs."

The research, published in the journal Advanced Science, was supported by a $1.9 million grant from the National Institute of Biomedical Imaging and Bioengineering, part of the National Institutes of Health (NIH) based in Bethesda, Maryland.