Lung regeneration comes closer to reality
Researchers have now reported their development of new methods and techniques for engineering lungs for patients with COPD and pulmonary fibrosis.
University of Vermont Professor of Medicine Daniel Weiss, M.D., Ph.D., and his team's work focuses on lung tissue bioengineering, which involves the use of a scaffold - or framework - of lungs from human cadavers to engineer new lungs for patients with end-stage disease.
Weiss said that it's expensive and difficult to repopulate an entire human lung at one time, and, unlike in mouse models, this doesn't readily allow the study of multiple conditions, such as cell types, growth factors, and environmental influences like mechanical stretch - normal breathing motions - that will all affect successful lung recellularization.
To address this, Wagner developed a technique to dissect out and recellularize multiple, small segments in a biological/physiological manner that would take into consideration the appropriate three-dimensional interaction of blood vessels with the lung's airways and air sacs.
Working with biomaterials scientist Rachel Oldinski, Ph.D., UVM assistant professor of engineering, they further developed a new method using a nontoxic, natural polymer derived from seaweed to use as a coating for each lung segment prior to recellularization.
This process allowed the team to selectively inject new stem cells into the small decellularized lung segments while preserving vascular and airway channels. Use of this technique, which resulted in a higher retention of human stem cells in both porcine (pig) and human scaffolds, allows the small lung segments to be ventilated for use in the study of stretch effects on stem cell differentiation.
Through another novel technique - thermography or thermal imaging - Wagner and colleagues developed a non-invasive and non-destructive means for monitoring the lung scaffolds' integrity and physiologic attributes in real-time during the decellularization process.
The articles have been published in journal Biomaterials.
(Posted on 09-03-2014)