Point-wise laser effect on NIH/3T3 cells impregnated with photosensitizer-loaded porous calcium carbonate microparticles

The development of novel carriers for the targeted photosensitizer delivery is a significant problem in a modern photodynamic therapy. Such a nanomedicine research is aimed to reduce the sides effects connected with insufficient selectivity of action for the applied dye. Porous calcium carbonate (CaCO₃) particles were proposed as matrices for the photosensitizer “Photosens” encapsulation. Cellular uptake and phototoxicity of the carriers were investigated using NIH/3T3 cells. The local concentration of the dye inside of the cell was increased by the usage of Photosens-loaded CaCO₃ particles in comparison with the “free” Photosens solution, due to the fact, that the particles trapped by cells provided the dye localization inside. Cellular experiments demonstrated high penetration of containers into the cells within 24h. The point-wise laser (670 nm, 3 mW, 5 min) effect on cells was investigated by confocal laser scanning microscopy. Significant phototoxic effect was shown for Photosens-loaded CaCO₃ particles allowing controlled consequential cell destroying by the laser. The demonstrated effect hold out the prospect for the application of proposed system in anticancer PDT.