Researchers from the Institute of Materials Science in Juazeiro, Brazil have reported on the antibacterial properties of usnic acid, a strong lichen metabolite, encapsulated in electrospun fibers. The team’s work was published in Recent Patents on Nanotechnology.
Usnic acid has been used in commercial products, such as creams, toothpastes and sunscreen, due to their antiviral, animicrobial and anti-inflammatory properties. To optimize the use of this compound as an alternative to antibiotics, the team of researchers sought to identify a way to encapsulate the compound and release it in a controlled manner at varying levels of acid concentration.
The team proposed that the usnic acid be encapsulated in electrospun fibers of poly (vinyl pyroolidone) and Eudragit L-100. Electrospun fibers minimize the aggregation level and provide reasonable amounts of surface area for the material to diffuse along the fiber walls. The process also produces a massive amount of active available surface. The loaded enteric electrospun fibers also favor the development of pH-controlled antibacterial materials, according to the team.
The researchers tested the material’s antibacterial properties against Staphylococcus aureus in a time dependent controlled diffusion process. The usnic acid released in a controlled rate from the polymeric matrix at a high pH (high levels of acid concentration) and the team could observe antibacterial activity after 10 minutes of interaction with the media.
“The strong biological activity of usnic acid-loaded electrospun fibers provides a promising application for corresponding material as a bactericidal agent for wound healing treatment.” the team wrote.