Biomedical applications of AzaBODIPYs and their gold nanoparticle conjugates: The <i>in vitro</i> inhibition of Michigan Cancer Foundation-7 breast cancer cells

Two 2,6-iodinated azaBODIPY dyes with methylthiophenyl groups at the 1,7 positions and phenyl (1) and thien-3-yl (2) rings at the 3,5-positions are reported. 1 and 2 have singlet-oxygen quantum yields in dimethylsulfoxide (DMSO) of 0.82 and 0.17, respectively. Nanomedicine formulations were prepared by conjugating the dyes to gold nanoparticles (AuNPs). The photophysical activities of the dyes and their respective AuNP conjugates (1@AuNPs and 2@AuNPs) were investigated. The AuNPs were spherical, and their nanoconjugates had desirable diameters of ca. 8 nm. The in vitro activity of the dyes and their respective conjugates was investigated with Thorlabs M730L4 (1.0 mW cm[Formula: see text] and M660L3 (1.7 mW cm[Formula: see text] LEDs. The dyes alone exhibited significant activity against MCF–7 human breast cancer cells with IC[Formula: see text] values of 11.0 ± 0.78 and 12.8 ± 0.96 [Formula: see text] M for 1 and 2, respectively. In contrast, the IC[Formula: see text] values of the nanoconjugates were 3.60 ± 0.07 and 10.0 ± 0.05 [Formula: see text] M for 1@AuNPs and 2@AuNPs. 1 and 1@AuNPs thus exhibited excellent potential as photodynamic therapy (PDT) agents at moderate light doses and short irradiation times.