摘要
This paper presents a multimodal approach that combines time-resolved fluorescence microscopy and spatial light interference microscopy into a single complex allowing for a concurrent comprehensive analysis of cell samples in vitro.The combined application of quantitative phase imaging using partially coherent radiation with timeresolved fluorescence imaging of endogenic coenzymes NADH and FAD,as well as Radachlorin photosensitizer,allowed for evaluation of a set of morphological and physiological parameters of cells of the two lines,HeLa and A549,in the course of photodynamic treatment.Besides comparison of cells of the two lines in terms of volume,height,dry mass,projected area,and redox ratio,we analysed the mechanisms and rate of Radachlorin accumulation.Using the developed multimodal approach,we demonstrated that in both the cell lines,Radachlorin was taken up in complexes with serum albumin,transported by endocytosis,and accumulated primarily in lysosomes.The Radachlorin transportation through the cellular membrane to lysosomes was accompanied by a decrease in its fluorescence lifetime,which was apparently owing to a gradual increase in endosome acidity.The different contributions of the fast and slow components of time-resolved fluorescence signals of nicotinamide adenine dinucleotide(NADH)and flavin adenine dinucleotide(FAD)enabled us to demonstrate the difference in the redox ratios of cells of the two lines.The average concentration of the accumulated Radachlorin photosensitizer in cells of the two lines and their resistivity to photodynamic treatment also differed:HeLa cells tended to accumulate more Radachlorin and demonstrated lower resistivity to photodynamic treatment.
基金
financial support provided by the Russian Science Foundation under grant No.21–72-10044.
