Novel BODIPYs with dimethylamine substituents and their cationic and iodinated derivatives for anticancer and antibacterial photodynamic therapy

Photodynamic therapy (PDT) is a minimally invasive modality, clinically approved for treating several localized cancer and noncancer lesions and also perspective modality to treat microbial induced pathologies. It utilizes a photosensitizer activated with a light of a specific wavelength to produce reactive oxygen species responsible for the cytotoxic effect.

Boron-dipyrromethene (BODIPY) derivatives are organic chromophores possessing diverse applications, including fluorescent imaging probes, labeling reagents, chemosensors, and laser dyes. In addition, BODIPYs gain increasing attention as photosensitizers due to their distinctive photophysical properties attractive for PDT.

Novel BODIPYs with dimethylaminopropoxyphenyl substituents and their cationic and iodinated derivatives were synthesized and then characterized using mass spectrometry, UV-Vis spectrophotometry, and various NMR techniques. Subsequent photochemical studies allowed to evaluate their absorption and emission properties and the singlet oxygen generation ability. In vitro photodynamic activity studies were performed on human androgen-sensitive prostate adenocarcinoma cells (LNCaP) and two bacterial strains (Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli). Also, the impact of the presence of quaternary ammonium cation and iodine atoms in the structure of BODIPYs on physicochemical and photochemical properties as well as photodynamic activity was assessed. BODIPY derivative possessing both a positive charge and iodine atoms revealed the highest activity towards all studied cells. This compound seems to be a very promising photosensitizer for the application in photodynamic therapy of cancer and bacterial cells.