Using Combination Therapy to Target Biofilm Infections

Bacteria are single-celled microorganisms that are found in every habitat on Earth. Most bacteria are harmless, but if pathogenic bacteria enter the body, they can cause infection. Most bacterial infections can be cured by antibiotics, however, not infections caused by biofilms. Biofilm infections occur when bacteria infecting a host attach onto a surface and proliferate, producing extracellular polymeric substances (EPS). These EPS form a 3D matrix that serves as extra protection for the bacteria against antimicrobials and host immune response. Most biofilm infections develop a chronic state because biofilms are resistant to antibiotics and lack an effective cure. Combination therapy has recently become an advantageous means to treat antibiotic-resistant infections by decreasing the dosage of antibiotics necessary while utilizing another therapeutic agent. Polymeric nanoparticles have emerged to be potential novel antimicrobials to combat biofilm infections. In this work, engineered polymeric nanoparticles, poly(oxanorbornene-imide)-based polymers (PONI-C11-TMA), have been explored for combination therapy with antibiotics to revive the use of antibiotics against drug-resistant biofilm infections and target biofilm infections more effectively. Preliminary results have shown that the presence of PONI-C11-TMA was able to restore the efficacy of otherwise ineffective antibiotics due to acquired resistance in a planktonic bacteria setting.