Scientists from the Massachusetts Institute of Technology are using nanoparticles to tackle drug-resistant bacteria, according to a study published in Advanced Materials.
Gram-negative bacteria are particularly difficult to treat, since they are protected by two cell membranes. But the team of Cambridge-based researchers reported that antimicrobial peptides inside of a silicon nanoparticle effectively reduced the number of bacteria in mice infected with Pseudomonas aeruginosa – a Gram-negative bacterium that can cause pneumonia.
The team likened their technique to the strategies used to get drugs into cancerous tissues.
“There are a lot of similarities in the delivery challenges. In infection, as in cancer, the name of the game is selectively killing something, using a drug that has potential side effects,” senior author Sangeeta Bhatia said in prepared remarks.
Antimicrobial peptides are naturally-occurring proteins that can kill bacteria. Bhatia and her team observed that by combining an antimicrobial peptide with another peptide to help ferry the drug across bacterial membranes, they could boost the effectiveness of each individual peptide.
After combining the peptides, the scientists packed them into silicon nanoparticles to ensure that they got to the right location at the right time. In the mouse study, the team administered the nanoparticles directly to the trachea, but they plan to design an inhaled formulation for human studies.
The team reported that mice treated with the nanoparticles had one-millionth the number of bacteria in their lungs as untreated mice. They also lived longer than their untreated counterparts.
Importantly, the researchers found that the synergistic peptides could kill strains of drug-resistant Pseudomonas taken from patients and cultured in the lab.
The team said they plan to work with another peptide that would help target antimicrobial peptides to the proper place within the body.