Acidic Nanoparticles Are Trafficked to Lysosomes and Restore an Acidic Lysosomal pH and Degradative Function to Compromised ARPE-19 Cells (original) (raw)
Figure 1
Acid nanoparticles are delivered to lysosomes of ARPE-19 cells.
A-D. Live cell images of colocalized nanoparticles with ARPE-19 lysosomes after a 24 hour incubation with NP2R A. ARPE-19 cell lysosomes as visualized with the dye LysoTracker Green. Images taken at 40x magnification with a Zeiss confocal microscope. LysoTracker detected at 488/500 nm (excitation/emission). B. ARPE-19 ingestion of Nile Red stained nanoparticle NP2R. Cells were incubated for 24 hours in full culture medium with 1 mg/ml concentration of NPs. Nanoparticles were detected at 540/580 (excitation/emission). Before incubation, the nanoparticle suspension was passed through a 0.8 µM syringe filter to remove clumped particles. After incubation period, cells were washed thoroughly with isotonic solution in an attempt to further remove clumps and any extracellular NPs. C. DIC image of the ARPE-19 cells and nanoparticles. With this image the morphology of the ARPE-19 cells are clearly visible. D. Composite image of the LysoTracker Green (lysosomes), Nile Red (nanoparticles), and DIC exposures. This image demonstrates the colocalization of the ingested nanoparticles with the ARPE-19 lysosomes. E. Concentration dependence of lysosomal delivery. The degree of colocalization of NP1R, NP2R, and NP3R with lysotracker green as a function of concentration. Each point is the mean +/− SEM of a calculated Pearson’s coefficient within one area of interest (AOI) in one microscope field; n = 3 fields. Inserts indicate overlap of NP1R and NP3R. In 1E, NP2R were incubated for 1 hr. before colocalization was determined.