Disclosed herein are embodiments of a composition comprising a drug in a polymer nanoparticle. The nanoparticles may have a size and/or a surface potential selected to facilitate lymph node uptake and/or dissemination throughout the lymphatic system. The nanoparticle may be a polyethyleneglycol-block-poly(ε-caprolactone) (PEG-PCL) nanoparticle. Also disclosed are embodiments of a method of using the composition. The composition may be administered subcutaneously. The drug-loaded nanoparticles are useful for treating certain cancers and/or decreasing the number of melanocytes in lymph nodes that are proximal to, distal to or both proximal and distal to a site of administration.
