Protein polymer-gold nanoparticles, compositions comprising protein polymer-gold nanoparticles, and uses of protein polymer-gold nanoparticles. A protein polymer-gold nanoparticle comprises a gold core and a plurality of protein polymer molecules coordinated to the gold core via a poly-histidine tag present on each protein polymer molecule. A protein polymer molecule comprises one or more elastin-like polypeptide domain and a coiled-coil region of Cartilage Oligomeric Matrix Protein domain or a variant thereof. For example, the protein polymer-gold nanoparticles can be used in methods of small molecule delivery to an individual.