The invention provides amphiphilic biocompatible copolymers which have a hydrophilic backbone and pendant hydrophobic groups. The polymers form nanoscale molecular aggregates in aqueous environments, which have hydrophobic interiors within which anticancer drugs may be solubilized. The polymers optionally feature attached antibodies, receptor ligands, and other targeting moieties which mediate adherence of the drug-carrying aggregates to targeted cancer cells.
