Antimicrobial Nanomaterials Battle Biofilm Infection

An innovative antibacterial gel could be the sought-after breakthrough in the fight against antibiotic-resistant biofilm formation on medical implants.

Developed by researchers at Queen’s University (Belfast, United Kingdom) and Brandeis University (Waltham, MA, USA), the new gel is composed of ultra-short cationic naphthalene-derived self-assembled peptides that form a supramolecular hydrogel at physiological pH, which rapidly kills bacteria such as Pseudomonas aeruginosa, Staphylococcus Aureus, and Escherichia coli. At the same times, the gels possess reduced cytotoxicity relative to the bacterial cells, with limited erythrocyte hemolysis.

In laboratory studies, lysine conjugated variants of the antibacterial gel displayed the greatest potency, significantly reducing the viable Staphylococcus epidermidis biofilm by 94%. Reducing the size of the R-group methylene chain resulted in an even greater reduction of antibiofilm activity. According to the researchers, the self-assembling dipeptides conjugated to naphthalene show considerable promise as nanomaterial structures, biomaterials, and drug delivery devices. The study was published ahead of print on August 7, 2014, in Biomacromolecules.

“When bacteria attach to surfaces, including medical implants such as hip replacements and catheters, they produce a jelly-like substance called biofilm. This protective layer is almost impossible for current antibiotics to penetrate,” said lead author Garry Laverty, PhD, of Queens University School of Pharmacy. “This renders bacteria deep within this protective layer resistant, as they remain unexposed to the therapy. They grow and thrive on surfaces causing difficult to treat infections. The only option often is to remove the medical implant leading to further pain and discomfort for the patient.”

The presence of biofilm bacteria, which thrive on implant surfaces, are a huge burden on healthcare budgets, as they are highly resistant to current therapeutic strategies and often result in infections that are responsible for high rates of patient mortality and morbidity.

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Queen’s University
Brandeis University