University of Helsinki researchers report tree resin killed highly resistant bacteria in the lab.
Scientists have found a new compound made from tree resin can kill 99% of drug-resistant bacteria without harming healthy tissue. The nanocellulose might be “used as a wound dressing or as a protective surface on medical implants,” they reported, publishing their findings in Applied Bio Materials.
“It was like a wonder,” Ghada Hassan, Faculty of Pharmacy, University of Helsinki, said. “The material is biocompatible and found to be devoid of significant toxicity towards human blood cells. Therefore, bacteria cell dies but the human cell doesn’t which makes it both effective and safe. This material can potentially be used for biomedical applications for example as integral parts of advanced biomaterials for human health including prosthetic implants or vascular stents or in wound dressings.”
Infection by methicillin-resistant Staphylococcus aureus (MRSA) can put pressure on ulcers and wounds from prosthetic, plastic, and reconstructive surgery. In search of a solution against resistant bacteria, Hassan noticed small wound treatments made from the resin of conifers and recalled “references to resin as a wound dressing date back 500 years in Finland, and there are many favorable anecdotal reports,” she said. It’s a well-known fact that trees produce the resin when wounded to protect themselves from infection.
Of course, “for implants you cannot open the patient and pour in some resin there and then close the patient and hope it will be well,” she said. So, using dehydroabietic acid derivatives, Hassan and her team created a film that could be used instead. They applied MRSA directly to sheets of the modified nanocellulose and found that almost all the bacteria were killed.
Then, the team concocted an artificial dermis containing horse plasma and applied a film made up of the nanocellulose, finding it was equally as effective in killing the bacteria. In more rounds of testing, the researchers discovered the nanocellulose could kill multiple strains of S. aureus, as well as Escherichia coli.
“The novel compound seems to damage bacteria through multiple mechanisms, making it more difficult for the organisms to evolve resistance,” Hassan said.
“The research suggests a lot of potential for the new compound,” agreed Aaron Glatt, MD, a professor of medicine at the Icahn School of Medicine at Mount Sinai in New York City and a spokesperson for the Infectious Diseases Society of America. “But it must undergo clinical trials before it can realize that potential. This paper is certainly no indication that it will become the definitive answer. What looks good in a laboratory, what looks good in a test tube, let’s put it to the test in real life.”
Barry Kreiswirth, PhD, adjunct faculty member of the department of medicine at New York University, added, “Even if it passes muster in clinical trials, it will have to show cost-effectiveness. As an example, we know that using copper bed rails and other copper products in a hospital setting reduces infections, but no one is willing to pay the extra cost to copperize a hospital bed.”
“The modified nanocellulose is less expensive and less toxic than copper and silver, which are also being tested as a coating for implants,” Hassan responded. “Cellulose is the most abundant polymer on Earth. And unlike some other material under consideration, its bacteria-killing ingredients don’t leach out into the environment, so it may stay effective for a longer time.”