A nanodevice composition including N-acetyl cysteine linked to a dendrimer, such as a PAMAM dendrimer or a multiarm PEG polymer, is provided. Also provided is a nanodevice for targeted delivery of a compound to a location in need of treatment. The nanodevice includes a PAMAM dendrimer or multiarm PEG polymer, linked to the compound via a disulfide bond. There is provided a nanodevice composition for localizing and delivering therapeutically active agents, the nanodevice includes a PAMAM dendrimer or multiarm PEG polymer and at least one therapeutically active agent attached to the PAMAM dendrimer or multiarm PEG polymer. A method of site-specific delivery of a therapeutically active agent, by attaching a therapeutically active agent to a PAMAM dendrimer or multiarm PEG polymer using a disulfide bond, administering the PAMAM dendrimer or multiarm PEG polymer to a patient in need of treatment, localizing the dendrimer or multiarm PEG polymer to a site in need of treatment, and releasing the therapeutically active agent at the site in need of treatment.