This technology employs drug nanocarriers made up of metal nanoparticles (NPs) that are less than 10nm in diameter. The metal NPs have amphiphilic organic outer shells that are capable of adsorbing large amounts of hydrophobic therapeutic agents (50 or more per nanoparticle). Therapeutic agents such as peptides or proteins can also be covalently linked to the NPs. The NPs are attached to the antibodies through bioconjugation at the hinge region so as to not disrupt the natural pharmacokinetics or bio-distribution of the antibody. Upon targeting to specific cells, the antibody drug nanocarriers are endocytosed, and the therapeutic agents are released into the cytosol.