(PHILADELPHIA) - Pulmonary inflammation can cause shallow breathing and the lungs to become brittle in patients who experience multiple blood transfusions, sepsis, lung surgery and acute lung trauma. This complication can leave patients on ventilators, which can further traumatize the lungs, and often results in a mortality rate of 30 to 40 percent. To date, no medication has been successful at preventing or mitigating the damage caused by lung inflammation. Now, a multidisciplinary research team led by David Eckmann, MD, PhD, Horatio C. Wood Professor of Anesthesiology and Critical Care at the Perelman School of Medicine at the University of Pennsylvania and professor of Bioengineering in Penn's School of Engineering and Applied Science, has found that when delivered by a microscopic transporter called a nanocarrier, steroids can access the hard-to-reach lung endothelial cells that need it most and are successful at preventing inflammation in mice. This proof-of-concept study is published in PLOS One.
"This is a treatment that benefits entirely from targeted delivery or it tends not to have any significant therapeutic benefit," says Eckmann.
"That's part of the challenge with this disorder: we have been uncertain to this point whether it was the medication or its delivery mechanism that wasn't working. Our results in mouse models show beyond a shadow of a doubt that the drugs can be effective, we just needed to improve delivery," says Eckmann. Acute lung injury develops as a result of direct or indirect trauma to the lungs. It compromises the hard-to-reach pores that enable gas exchange between the epithelial and endothelial barriers in the lungs.
During the past year the team was awarded an National Science Foundation and two NIH grants to design nanocarriers for targeted drug delivery through a combination of computer modeling and laboratory experiments. This study represents the first of their experimental results.
The team used a nanogel, a specialized nanocarrier, for drug delivery made up of two molecules--dextran (a sugar) and lysozyme (a protein)--which mesh into a spaghetti-like ball that can fill with water to expand and contract. A specific lung-targeting molecule is attached to the carrier's surface and the steriod, dexamethasone, an anti-inflammatory, is loaded into the nanogel, which then binds to lung endothelial cells lining the inside wall of the blood vessels where it rapidly delivers the drug.
"This molecule on the surface of the nanocarrier has specialized preference for the lung to enhance localized and targeted drug delivery," says Eckmann.
The team next plans to try the therapy in a cohort of patients at the Hospital of the University of Pennsylvania.
Additional Penn authors include Russell J. Composto, PhD, professor of Materials Science and Engineering in Penn's School of Engineering and Applied Science; Vladimir Muzykantov, MD, PhD, professor of Pharmacology; senior research investigator Vladimir Shuvaev, PhD, and postdoctoral fellows M. Carme Coll Ferrer, PhD, and Blaine Zern, PhD.
This work is supported by NIH grant R01 EB006818.
Penn Medicine is one of the world's leading academic medical centers, dedicated to the related missions of medical education, biomedical research, and excellence in patient care. Penn Medicine consists of the Raymond and Ruth Perelman School of Medicine at the University of Pennsylvania (founded in 1765 as the nation's first medical school) and the University of Pennsylvania Health System, which together form a $4.3 billion enterprise.
The Perelman School of Medicine has been ranked among the top five medical schools in the United States for the past 17 years, according to U.S. News & World Report's survey of research-oriented medical schools. The School is consistently among the nation's top recipients of funding from the National Institutes of Health, with $392 million awarded in the 2013 fiscal year.
The University of Pennsylvania Health System's patient care facilities include: The Hospital of the University of Pennsylvania -- recognized as one of the nation's top "Honor Roll" hospitals by U.S. News & World Report; Penn Presbyterian Medical Center; Chester County Hospital; Penn Wissahickon Hospice; and Pennsylvania Hospital -- the nation's first hospital, founded in 1751. Additional affiliated inpatient care facilities and services throughout the Philadelphia region include Chestnut Hill Hospital and Good Shepherd Penn Partners, a partnership between Good Shepherd Rehabilitation Network and Penn Medicine.
Penn Medicine is committed to improving lives and health through a variety of community-based programs and activities. In fiscal year 2013, Penn Medicine provided $814 million to benefit our community.