It's quite likely that whether you visit your doctor for back pain, anxiety or an ingrown toenail, you won't leave without a prescription of some kind. Cold and flu symptoms are among the most common reasons why people visit their doctors and, often, antibiotics are the go-to remedy. Repeatedly taking antibiotics causes major problems, however, as overuse of this type of medication, both in the health care setting and in industrial agriculture, has resulted in increased resistance.
In fact, every time you take antibiotics, your body builds resistance, they become less and less effective and, worse, any bacterium that survives the medication also builds resistance. One of the worst aspects of drug-resistant bacteria, or superbugs, is that an alarming number are found on the biofilm — a thin slimy surface substance — that forms on medical devices, including implants.
In one study, Mohan Jacob, head of Electrical and Electronics Engineering at James Cook University (JCU) in Queensland, Australia and his team of Ph.D. associates used nanotechnology to harness the power of antimicrobial molecules from plants to create antibacterial coatings. Their findings were recently published in Polymers.1 Jacob cites a recent study published in Microbial Biotechnology, which reported that approximately 17 million new biofilm infections are reported every year, leading to 550,000 fatalities.
In addition, about 80 percent of the surgery-associated infections worldwide may be associated with biofilm formation.2 That's why more doctors are turning to natural agents with antibacterial properties, such as tea tree oil, as studies show it may help prevent millions of infections every year. Tea tree oil (Melaleuca alternifolia) is an essential oil that creates a bioactive coating to keep harmful bacteria from adhering to medical devices.
How a Bioactive Surface Is Made From an Essential Oil
In regard to the scientists' search for a way to turn plant compounds into bioactive coatings for medical devices to avoid having to rely on antibiotics, they used plant secondary metabolites, aka PSMs, of tea tree oil and its most important component, terpene-4-ol. Derived from essential oils and herb extracts, with relatively powerful broad-spectrum antibacterial activities, they're termed "secondary" as they're not vital to the plant's survival or function.
Jacob described them as a "low-cost renewable resource available in commercial quantities, with limited toxicity and, potentially, different mechanisms for fighting bacteria than synthetic antibiotics."3 But the biggest challenge Jacob and his team faced in developing antibacterial coatings from PSMs was converting the liquid state of the compounds into a solid without losing any of their antibacterial nature.
Medical News Today notes that scientists have used nanotechnology for this purpose for several years. Kateryna Bazaka, an adjunct senior research fellow at JCU and the study's coauthor, explained the scientists' procedure in creating polymers is somewhat like naturally occurring rubber and cellulose to make a resistant, "chain-like structure," in this case converting the PSMs of tea tree oil. She noted:
"We used plasma-enhanced techniques within a reactor containing the essential oil vapors. When the vapors are exposed to a glow discharge, they are transformed and settle on the surface of an implant as a solid biologically active coating."4
Essential Oils for Medical Device Polymers and Beyond
Plasma polymerization of this sort has been in use to create biological activity on surfaces for about 20 years. In the 2010 version of the "Handbook of Deposition Technologies for Films and Coatings," one scientist explained that plasma is the "fourth state of matter, consisting largely of ionized gas which maintains overall electrical neutrality."5
One reason the plasma technique is so effective for this kind of plant conversion is that it's environmentally friendly; no potentially harmful chemicals or solvents are used in the process that might remain in the coating or damage surfaces the coating is applied to. The upshot is that if tea tree oil can be converted to protect the surfaces of medical devices, millions of infections may be prevented every year.
According to Jacob, after publishing more than 70 research articles and six Ph.D. theses on the topic, the scientists involved in the project are bona fide pioneers in the world's development of bioactive polymers from plant compounds. But the concept has been extended. Because the thin polymer coatings are visually transparent, they're being tapped for coating contact lenses, as well as for optical windows in aquatic sensors.
Specifically, Jacob and his team are targeting biofilm growth on failing aquatic sensors due to marine organisms, working with Peter Mulvey and associate professor Jeff Warner at the JCU-based Australian Institute of Tropical Health and Medicine. Controlled Environments notes:
"Even though synthetic antibiotics have been the best weapon for eradicating microbial infections since the arrival of penicillin, the overuse of these medications is gradually rendering them ineffective. Scientists think that if new strategies are not developed soon, medical treatments could retreat to the era where slight injuries and common infections develop into serious medical problems."6