Novel nanofiber dressing infused with vitamin D stimulates the body's natural defenses and may reduce dependence on compounds that produce drug resistance.
A new approach to wound dressings shows promising results to reduce surgical site infections (SSIs)—which jack up the cost of healthcare by $10 billion annually—by enhancing the body's natural immune responses, rather than using conventional antimicrobial drugs.
A study published July 4 in Nanomedicine found that electrospun nanofiber-based wound dressings loaded with a bioactive form of vitamin D spur production of an antimicrobial peptide that fights infection naturally.
This development, which is at least a few years away from a commercially viable product, provides a compelling combination of solutions to address SSIs. It uses a new material, not currently employed for wound dressings, as well as the application of vitamin D in a unique manner that promotes healing and may address the issue of drug-resistant microorganisms. Researchers at Oregon State University, Corvallis, and University of Nebraska Medical Center, Omaha, are working with other scientists to study this solution.
SSI: A Costly Challenge
SSIs have an enormous impact on patient care and outcomes, costing the U.S. healthcare system billions of dollars annually. According to the study:
- SSIs are the most common healthcare-associated infection and result in widespread human suffering and economic loss.
- Each year more than 290,000 surgical patients in the United State develop an infection within 30 days of their operation.
- SSIs account for an estimated $10 billion in additional healthcare costs and more than 13,000 of those people die.
- Postsurgical infections increase the length of postoperative hospital stays by 7–10 days, as well as rates of readmission to the hospital, expense and rates of death.
Further information about the financial impact of surgical site infections on hospitals is available in a 2013 article published in JAMA.
New Dressing Material Delivers Advantages
Currently, "there is a paucity of dressings that can simultaneously prevent or treat infections and promote wound healing," the study says.
To develop the experimental dressing material, the scientists employ electrospinning, a simple, cost-effective and reproducible technique, to produce nanofibers made of biocompatible and biodegradable polymers.
The fibers "range from several nanometers to tens of microns," says Jingwei Xie, PhD, assistant professor, department of surgery-transplant and Mary & Dick Holland Regenerative Medicine Program, University of Nebraska Medical Center.
These fibers are made into wound dressings, which "offer significant advantages over hydrogels or sponges for local drug delivery," Xie says. For example, it is easier to incorporate certain types of drugs into electrospun nanofibers.
"Compared with traditional wound dressings, nanofiber-based wound dressings provide several functional and structural advantages including hemostasis, high filtration, semipermeability, conformability and scar-free healing," according to the study. "Hydrogels are capable of soft-tissue-like compliance, but are difficult to suture and are often too weak to support physiologic loads."
Bioactive Vitamin D Stimulates Body's Natural Defenses
Beyond the material in the dressing, one of the key advantages appears to be the use of a bioactive form of vitamin D, which is encapsulated into the fibers. The vitamin stimulates the body's natural defenses to fight infections.
In earlier experiments, one of the study's authors, Adrian Gombart, PhD, professor of biochemistry and biophysics at the Linus Pauling Institute, Oregon State University College of Science, found that vitamin D "actually does turn on one antimicrobial peptide gene [in the body.]"
The dressings the researchers created proved capable of delivering vitamin D on a sustained basis over four weeks, and they significantly induced production of a peptide that kills microbes by disrupting their membranes.
Besides its antimicrobial properties, this form of vitamin D has anti-inflammatory properties and may also play a "role in a wound healing itself," says Gombart, due to its anti-inflammatory properties and its ability to help form new blood vessels.
Navigating Drug Resistance
Today, it is common practice to deliver antibiotics via wound dressings.
"When you encapsulate an antibiotic—and we know antibiotics work—you also develop antibiotic resistance pathogens," Gombart. This happens because the antibiotic uses a single molecule to target one aspect of a microorganism. It's fairly simple for the pathogen to evolve and find a way around the antibiotic, creating drug resistance.
"Our idea is to use compounds that modulate an immune response in the [human] host," says Gombart. "That makes it much more difficult for [the pathogens] to evolve resistance because they would have to make multiple changes."
Because the dressings work by enhancing innate immune responses, rather than by containing conventional, single-target antimicrobial compounds, they are less likely to contribute to drug resistance.
Research is still in the early stages and must undergo further studies before the dressings can be tested in humans.
Mandy Roth is the innovations editor at HealthLeaders.