Low Band Gap Donor-Acceptor Conjugated Polymer Nanoparticles and their NIR-mediated Thermal Ablation of Cancer Cells

Low band gap D-A conjugated PNs consisting of 2-ethylhexyl cyclopentadithiophene co-polymerized with 2,1,3-benzothiadiazole (for nano-PCPDTBT) or 2,1,3-benzoselenadiazole (for nano-PCPDTBSe) have been developed. The PNs are stable in aqueous media and showed no significant toxicity up to 1 mg center dot mL-1. Upon exposure to 808?nm light, the PNs generated temperatures above 50 degrees C. Photothermal ablation studies of the PNs with RKO and HCT116 colorectal cancer cells were performed. At concentrations above 100 mu g center dot mL-1 for nano-PCPDTBSe, cell viability was less than 20%, while at concentrations above 62 mu g center dot mL-1 for nano-PCPDTBT, cell viability was less than 10%. The results of this work demonstrate that low band gap D-A conjugated polymers 1) can be formed into nanoparticles that are stable in aqueous media; 2) are non-toxic until stimulated by IR light and 3) have a high photothermal efficiency.