Thin film functionalized PLGA nanoparticles were modified to release nitric oxide from an s-nitrosothiol donor. The nitric oxide modified nanoparticles were bacteriostatic against Escherichia coli. The nitric oxide modified nanoparticles increased the effectiveness of tetracycline against Escherichia coli. The modified nitric oxide nanoparticles did not exhibit cytotoxic effects against fibroblasts.