ANTIBIOTIC resistance, a topic reviewed in one of EMG’s latest blog posts, is an issue of growing concern. As bacterial resistance extends to even the most potent of antibiotics, researchers and medics alike search for new, alternative treatments to halt this advance and maybe even start a counter offensive.
Phage therapy allows targeted antibacterial agents to be administered to attack invading pathogens while avoiding any ‘self’ cells and resident ‘healthy’ bacteria. Critically, this modality does not contribute to multidrug resistance and could offer a new option in the ever-dwindling arsenal of effective agents against antibiotic-resistant bacteria. Despite clear benefits, phage therapy is limited by its delivery mechanism, with the lungs being a particularly difficult treatment site. However, work carried out at the Georgia Institute of Technology, Atlanta, Georgia, USA, offers a new strategy.
Previous phage delivery methodologies have included the use of a nebuliser to deliver wet phage mixtures to the lungs, often resulting in inefficient outcomes. Study lead, Prof Andrés García, George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, stated: “We set out to engineer a biomaterial carrier that would keep the phage active while delivering them deep into the lungs in a uniform fashion.” A delicate balancing act had to be managed to achieve this, creating a carrier that was heavy enough to avoid rapid clearance while being light enough to reach every corner of the lung. The microcarrier used to transport the bacteriophages was ultimately produced from the same material used in degradable stitches. The phages were incubated on the particles and introduced into a mouse pneumonia model through inhalation of a dry powder. The results showed that the coated phages attacked the bacteria and cleared the infection, while the untreated control mice died.
There is still work to be done to develop the technique and ensure its safety for human use, but study co-author Prof Nael McCarty, Emory University and Children’s Healthcare of Atlanta, Atlanta, Georgia, USA, highlighted the importance of this therapy, particularly for cystic fibrosis patients who experience chronic lung infections. He positively concluded: “Phage therapy could complement existing therapies without worsening antibiotic resistance.”