Nitric Oxide Activatable Photodynamic Therapy Agents Based on BODIPY-Copper Complexes

Theoretical Insights into the Impact of Pyrrole and Imidazole Substituents on the BODIPY Chromophore

This paper concerns the in silico studies of the influence of heterocyclic substituents as well as their protonated and deprotonated forms on the spectral characteristics of BODIPY (4,4-difluoro-4-bora-3a,4a-diaza-s-indacene) dyes. Computational studies were carried out in order to reveal the most effective method of modeling of the spectral features of fluorescent BODIPY dyes. To perform these studies, the pyrrole and imidazole derivatives of BODIPY dyes were selected, and their spectral features were investigated with DFT and TD-DFT calculations. The calculations showed that the deprotonation of the substituents leads to a bathochromic shift of the calculated absorption wavelength, while the protonation (imidazole derivative) brings about a hypsochromic shift with respect to the neutral form of the dye. The calculated spectral characteristics, considering the influence of the solvent polarity (PCM model), were correlated with the ETN solvatochromic parameter. These correlations show that the increase in the solvent polarity causes a hypsochromic shift of the calculated absorption and emission wavelengths, whereas the bathochromic shift of the wavelengths is observed for the protonated form.

Reconfigurable logic operations for fluorescent sensing of drug resistant and/or hypoxic cancer cells

Precision diagnosis is of great importance and can be achievable through information processing sensors. A distyryl pyridinium BODIPY decorated with nitroreductase and esterase enzyme responsive modules is shown to display configurable fluorescence read out upon enzyme-catalysed elimination reaction creating pyridine distyryl BODIPYs. Discrimination of the cellular profile, i.e. drug resistance and hypoxic microenvironment, is achieved with a single molecule through reconfigurable molecular logic gate operations.