Scientists are now able to directly compare the different kinds of injury that mechanical ventilation causes to cells in the lungs.
In a new study, using a ventilator-on-a-chip model developed at The Ohio State University, researchers found that shear stress from the collapse and reopening of the air sacs is the most injurious type of damage.
This miniature “organ-on-a-chip” model simulates not only lung injury during mechanical ventilation, but also repair and recovery, in human-derived cells in real time, said co-lead author Samir Ghadiali, PhD, professor and chair of biomedical engineering at Ohio State.
“The initial damage is purely physical, but the processes after that are biological in nature – and what we’re doing with this device is coupling the two,” Ghadiali said.
The team hopes the device will also help in the hunt for therapies to address ventilator-induced lung injury.
The research was published recently in the journal Lab on a Chip.
Of particular value is the ventilator-on-a chip’s measurement of real-time changes to cells that affect the integrity of that barrier, enabled by an innovative approach: growing human lung cells on a synthetic nanofiber membrane mimicking the complex lung matrix. It’s closer to the authentic ventilated lung microenvironment than any similar lung chip systems to date, the researchers say.
The device measures the effects of three types of mechanical stress on the integrity of the barrier: lung cell stretch from overinflation, increased pressure on lung cells, and cyclical collapse and reopening of air sacs.
Experiments showed that overinflation with a high volume of air and cyclic collapse and reopening of air sacs both led the barrier to become leaky, but the cells could recover more quickly from overinflation than from the repetitive opening and closing of air sacs.
