Helping Patients Breathe Easier
Millions of Americans depend on nebulizers when they have trouble breathing. Corinne Lengsfeld, an associate professor in DU's Department of Mechanical and Materials Engineering, has made nebulizers work better and paved the way for them to deliver gene therapy in the future.
Taking medicine straight to the lungs
Nebulizers are machines that turn medication into a mist so patients can inhale it, letting their lungs directly absorb the medicine. Nebulizers are used to treat asthma, emphysema, cystic fibrosis and other lung problems.
In 2004, Lengsfeld and then-undergraduate biochemistry major Ben Filas decided to find out how effective the machines are. They measured how well different brands of nebulizer delivered an asthma drug to a model lung.
With every brand they tested, Lengsfeld and Filas found that most of the medicine stuck to the inside of the nebulizer.
The team experimented with different ways to solve the problem. They found that humidifying the vapor dramatically increases the amount of medicine delivered to the patient.
Hopefully, physicians will be able to use this discovery to adjust nebulizer treatments and make them much more effective, Lengsfeld says.
A new hope for gene therapy
Along with delivering medications, nebulizers are one potential way to deliver gene therapy. Patients would inhale DNA that would enter into their cells and change their genetic material. If researchers can make the therapy work, it could treat diseases like cancer, hemophilia and cystic fibrosis.
But gene therapy research has been stuck on a persistent problem. Because DNA "breaks" easily, Lengsfeld explains, it's very hard to deliver it into the body with any sort of therapeutic effect.
Six years ago, Lengsfeld began collaborating with Thomas Anchordoquy, an associate professor of pharmaceutical biotechnology at the University of Colorado, to explain the lost or damaged DNA and devise ways to conserve it. They eventually enlisted an army of student co-investigators to help.
The team discovered that the DNA strands were being damaged by cavitation?bubbles that were forming in the fluid medication. When the bubbles collapsed, they created a shock wave that destroyed the DNA.
Lengsfeld's group realized that shock waves with wavelengths shorter than the DNA molecules can rip the DNA to shreds. But if researchers can keep the wavelengths longer than the DNA, it can safely "surf" the surface of the shock waves.
Future technology
Lengsfeld and Anchordoquy are now building on their gene therapy research. They've applied for a patent on a process that encapsulates a gene in several small particles. This protects the fragile DNA without making it too big for patients' cells to absorb.
The impact of the team's work has reached beyond the lab into classrooms. Lengsfeld has created a new advanced fluid dynamics course that incorporates the research.
The crossdisciplinary research has been an invaluable experience for his pharmaceutical students and Lengsfeld's engineering students, Anchordoquy says. "What we're doing is on the forefront of where education needs to go."
Published on March 7, 2007