A non-cytotoxic dendrimer with innate and potent anticancer and anti-metastatic activities.

The structural perfection and multivalency of dendrimers have made them useful for biodelivery and bioactivity via peripheral functionalization and the modulation of core-forming structures and dendrimer generations. Yet only few dendrimers have shown inherent therapeutic activity arising from their inner repeating units. Here, we report the synthesis and characterization of a polyacylthiourea dendrimer with inherent potent anticancer activity and the absence of cytotoxicity in mice. The poly(ethylene glycol)-functionalized fourth generation of the dendrimer, which can be efficiently synthesized from sequential click reactions of orthogonal monomers, displays low in vivo acute and subacute toxicities yet potently inhibits tumour growth and metastasis. The dendrimer's in vivo anticancer activity arises from the depletion of bioavailable copper and the subsequent inhibition of angiogenesis and cellular proliferation. When compared with some clinically used cytotoxin drugs, the dendrimer exerts inherent anticancer activity via non-cytotoxic pathways and leads to higher therapeutic efficacy, yet without cytotoxin-induced side effects.