Photothermal combined with intratumoral injection of annonaceous acetogenin nanoparticles for breast cancer therapy.

ACGs (annonaceous acetogenins) possess excellent antitumor activity, but their serious accompanying toxicity has prevented their application in the clinic. To address this problem, we therefore constructed an intratumoral drug delivery system integrating chemotherapy and photothermal therapy. The PEGylation of polydopamine nanoparticles (PDA-PEG NPs) possessed an excellent biocompatibility with size of 70.96 ± 2.55 nm, thus can be used as good photothermal materials in the body. Moreover, PDA-PEG NPs can kill half of cancer cells under NIR (near-infrared) laser irradiation, and the survival rate of 4T1 cells is only 1% when ACG NPs and PDA-PEG NPs are combined. In vivo distribution studies showed that the 0.1 mg/kg ACGs NPs + PDA-PEG NPs + NIR group had the highest tumor inhibition rate, which was significantly superior to that of the 0.1 mg/kg ACGs NPs intratumoral injection group (82.65% vs. 59.08%). Altogether, the combination of PDA-PEG NPs + NIR with chemotherapy drugs may provide a feasible and effective strategy for the treatment of superficial tumors.