BODIPY-Based Photosensitizers as Potential Anticancer and Antibacterial Agents: Role of the Positive Charge and the Heavy Atom Effect

Boron-dipyrromethene derivatives, including cationic and iodinated analogs, were obtained and subjected to physicochemical and in vitro photodynamic activity studies. Iodinated derivatives revealed a substantial heavy atom effect manifested by a bathochromic shift of the absorption band by about 30 nm and fluorescence intensity reduced by about 30-35 times, compared to that obtained for non-iodinated ones. In consequence, singlet oxygen generation significantly increased with phi(Delta)values in the range 0.69-0.97. The in vitro photodynamic activity was evaluated on Gram-positiveStaphylococcus aureus, Gram-negativeEscherichia coli, and on human androgen-sensitive prostate adenocarcinoma cells (LNCaP). The novel cationic, iodinated BODIPY, demonstrated the highest activity toward all studied cells. An excellent cytotoxic effect was found against LNCaP cells with an IC(50)value of 19.3 nM, whereas the viability ofS. aureuswas reduced by >5.6 log(10)at 0.25 mu M concentration and by >5.3 log(10)in the case ofE. coliat 5 mu M. Thus, this analog seems to be a very promising candidate for the application in both anticancer and antimicrobial photodynamic therapy.

Automated summary

Boron-dipyrromethene derivatives, especially the novel cationic, iodinated BODIPY, showed enhanced photodynamic activity in vitro, with promising potential for applications in both anticancer and antimicrobial therapy.