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 antibiotic-resistant 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.