The rapidly diminishing number of effective antibiotics that can be used to treat infectious diseases and associated complications in a physician's arsenal is having a drastic impact on human health today. This study explored the development and optimization of a polymersome nanocarrier formed from a biodegradable diblock copolymer to overcome bacterial antibiotic resistance. Here, polymersomes were synthesized containing silver nanoparticles embedded in the hydrophobic compartment, and ampicillin in the hydrophilic compartment. Results showed for the first time that these silver nanoparticle-embedded polymersomes (AgPs) inhibited the growth of Escherichia coli transformed with a gene for ampicillin resistance (bla) in a dose-dependent fashion. Free ampicillin, AgPs without ampicillin, and ampicillin polymersomes without silver nanoparticles had no effect on bacterial growth. The relationship between the silver nanoparticles and ampicillin was determined to be synergistic and produced complete growth inhibition at a silver-to-ampicillin ratio of 1 : 0.64. In this manner, this study introduces a novel nanomaterial that can effectively treat problematic, antibiotic-resistant infections in an improved capacity which should be further examined for a wide range of medical applications.

Bacterial genetic resistance to antibiotics is a massive threat to global and US health care today. Infections caused by antibiotic-resistant bacteria are becoming increasingly prevalent and difficult to treat. This study explored the development and optimization of a polymersome nanocarrier formed from an amphiphilic diblock copolymer designed to overcome this resistance. Silver nanoparticles were embedded in the hydrophobic membrane of polymersomes while the antibiotic was encapsulated in the particle's aqueous core, providing a dual-mechanism, long lasting, time release treatment. Here, these silver nanoparticle-embedded polymersomes (AgPs) were loaded with ampicillin and subsequently tested for bactericidal function against Escherichia coli that had been transformed with a gene for ampicillin resistance (ampR). The AgPs killed the antibioticresistant bacteria, whereas free antibiotic, encapsulated antibiotic without the addition of the silver nanoparticles, and AgPs without the addition of ampicillin did not kill the bacteria.