Wednesday, June 30, 2010
Regenerating lung tissue !!!
In a breakthrough which could pave the way for regenerating human lungs, scientists claim to have successfully implanted laboratory-cultivated cells into a rat's lungs.
Lung tissue is difficult to regenerate as it does not generally repair or regenerate beyond the microscopic level. The only current way to replace damaged adult lung tissue is to perform lung transplantation, which is highly susceptible to organ rejection and infection.
Now, a team at Yale University successfully implanted tissue-engineered lungs, cultured in vitro, which could serve the lung's primary function of exchanging oxygen and carbon dioxide, the 'Science Express' reported.
The scientists took adult rat lungs and first removed their existing cellular components, preserving the extracellular matrix and hierarchical branching structures of the airways and vascular system to use later as scaffolds for the growth of new lung cells.
They then cultured a combination of lung-specific cells on the extracellular matrix, using a novel bioreactor designed to mimic some aspects of the fetal lung environment.
Under the fetal-like conditions of the bioreactor, the cells repopulated the decellularised matrix with functional lung cells. When implanted into rats for short intervals of time (45-120 minutes), the engineered lungs exchanged oxygen and carbon dioxide similarly to natural lungs.
Lead scientist Laura Niklason said: "We succeeded in engineering an implantable lung in our rat model that could efficiently exchange oxygen and carbon dioxide, and could oxygenate hemoglobin in the blood. This is an early step in the regeneration of entire lungs for larger animals and, eventually, for humans."