Jun 30 2009
Combat-related injuries have long plagued the military in part because of multidrug-resistant bacteria. Imagine being able to spray a compound fracture with microcapsules that deliver a drug to bolster the immune system, stopping infection before it starts.
That technology might be around the corner, says Bingyun Li, Ph.D., of the West Virginia University Department of Orthopaedics and director of the WVU Biomaterials, Bioengineering & Nanotechnology Laboratory. Li’s team has developed a drug-delivery technology involving microcapsules – and a second technique, nanocoating – that have been shown to work in animal studies.
Results of the team’s research involving the drug interleukin-12, a drug currently in anti-cancer clinical trials, has been published in the May issue of the journal Biomaterials. A deeper explanation of the approach, which could develop into an alternative to antibiotic therapy, is scheduled to be published in an upcoming issue of the Journal of Orthopaedic Research.
“These pioneering techniques could be important to the United States because of the wars in Iraq and Afghanistan,” Li says. “The treatment of battlefield casualties is expensive, and the infection rate runs from 2 percent to 15 percent. In some cases, because the organisms have developed resistance, antibiotics don’t work.”
Outside the arena of warfare, millions of people could potentially be helped by the technology because infections can result whenever a biomedical device is implanted.
Li’s team developed two ways to deliver interleukin-12.
The first is in microcapsules that can be injected or, potentially, delivered in a fine-mist spray directly to the site of an injury. The second is a nanocoating of interleukin-12 applied directly to stents, pacemakers, pain pumps, artificial limbs – virtually any biomedical device – before implantation. The coating is measured on the nano scale; one nanometer is one billionth of a meter.
“Interleukin-12 will maximize the body’s natural response to an extent where infections can be prevented without the risk of the offending bacteria developing resistance to the treatment, as is becoming more of a problem with antibiotic therapy alone. With nanocoating, the drug is right where it needs to be – at the interface of the implant and your tissue,” Li said. “With the microcapsule, the drug can be injected or sprayed where desired, and the nanocoating and microcapsule prolong the half-life of interleukin-12.”
In both methods, because the interleukin-12 is delivered locally rather than spread throughout the body, as in antibiotic therapy, side effects are minimal, Li explained.
Li drew his team from the WVU Department of Orthopaedics, the WVU School of Pharmacy, the National Institute for Occupational Health and Safety (NIOSH), and the WVU Department of Microbiology, Immunology and Cell Biology.
Li, who is also a guest researcher with NIOSH, is giving a presentation on the technology later this summer to officials from the Naval Medical Research Center in Silver Spring, Maryland. He is also working with Christopher Kolanko, Ph.D., a Department of Defense consultant for the WVU Research Corporation, and program managers with the Department of Defense, to discuss further research possibilities and possible military applications.
Li’s team has spent the past four years developing the technology, funded in part by the WVU Research Corporation, the National Science Foundation and the Osteosynthesis and Trauma Care Foundation.