Investigation on interaction and sonodynamic damage of fluorescein derivants to bovine serum albumin (BSA) under ultrasonic irradiation

• Fluorescein derivants were used to study the interaction and damage to BSA.
• Sonodynamic and sonocatalytic activities of fluorescein derivants were studied at first.
• Some quenchers were used to determine the kind of the generated ROS.

The fluorescein derivants (Fluorescein: (2-(6-Hydroxy-3-oxo-(3H)-xanthen-9-yl) benzoic acid), Fluorescein-DA: (Bis [N,N-bis (carboxymethyl) aminomethyl] fluorescein) and Fluorescein-DAFe(III): (Bis [N,N-bis (carboxymethyl) aminomethyl] fluoresceinFerrous(III)) with a tricyclic plane structure were used to study the interaction and sonodynamic damage to bovine serum albumin (BSA) under ultrasonic irradiation through fluorospectrometry and UV–vis spectrophotometry. Besides, because of the existence of Fe(III) ion in Fluorescein-DAFe(III), under ultrasonic irradiation the sonocatalytic activity in the damage of BSA molecules was also found. Three-dimensional fluorescence spectra and three-dimensional fluorescence contour profile spectra were mentioned to determine the fluorescence quenching and the conformation change of BSA in the absence and presence of these fluorescein derivants. As judged from the experimental results, the fluorescence quenching of BSA in aqueous solution caused by these fluorescein derivants were all attributed to static quenching process. The damage degree and mode were related to some factors such as ultrasonic irradiation time, fluorescein derivant concentration and ionic strength. Finally, several quenchers were used to determine the amount and kind of generated reactive oxygen species (ROS) during sonodynamic and sonocatalytic reaction processes. It suggests that these fluorescein derivants induce protein damage via various ROS, at least, including singlet oxygen (1O2) and hydroxyl radicals (OH). Perhaps, this paper may offer some important subjects for broadening the application of these fluorescein derivants in sonodynamic therapy (SDT) and sonocatalytic therapy (SCT) technologies for tumor treatment.

The fluorescein derivants (Fluorescein: (2-(6-Hydroxy-3-oxo-(3H)-xanthen-9-yl) benzoic acid), Fluorescein-DA: (Bis [N,N-bis (carboxymethyl) aminomethyl] fluorescein), Fluorescein-DAFe(III): (Bis [N,N-bis (carboxymethyl) aminomethyl] fluoresceinFerrous(III)) were used to study the interaction and the sonodynamic damage to bovine serum albumin (BSA) under ultrasonic irradiation through fluorospectrometry and UV-vis spectrophotometry. Besides, because of the existence of Fe(III) ion in Fluorescein-DAFe(III): the sonocatalytic damage of BSA molecules was also found. The damage degree and mode were related to such factors as ultrasonic irradiation time, fluorescein derivant concentration and ionic strength. Finally, some quenchers were used to determine the kind of generated reactive oxygen species (ROS) during sonodynamic and sonocatalytic reaction processes, suggesting that fluorescein derivants induced protein damage via various ROS.Figure optionsDownload as PowerPoint slide