Tracking the endocytic pathway of recombinant protein toxin delivered by multiwalled carbon nanotubes.
The endocytic pathway of a recombinant protein toxin, ricin A-chain (RTA), delivered by multiwalled carbon nanotubes (MWCNTs) was tracked in HeLa cells by tagging RTA with enhanced green fluorescent protein (EGFP). EGFP-RTA was found to accumulate in the endosome and to be retrogradely transported to the endoplasmic reticulum, from which it translocated into the cytosol. Nuclear staining, Z-axis scanning with a laser scanning confocal microscope (LSCM), and transmission electron microscopy (TEM) indicated that the RTA exerted its toxic effects. Endocytosis-inhibiting tests with LSCM and flow cytometry showed that MWCNT-EGFP-RTA conjugates penetrated cells principally via clathrin-mediated endocytosis. These studies are beneficial to understanding the MWCNT-based intracellular drug delivery mechanism and provide guidelines for designing promising MWCNT-based vectors for targeting diagnostic or therapeutic compounds, not only to specific cells, but even to specific cellular compartments.
Wang
Meiyan
M
Department of Chemistry and Institutes of Biomedical Sciences, Fudan University, Shanghai, P.R. China.
Yu
Shaoning
S
Wang
Chuan
C
Kong
Jilie
J
D002470:Cell Survival; D003600:Cytosol / Q000378:metabolism; D004337:Drug Carriers / Q000737:chemistry*; D004705:Endocytosis; D004721:Endoplasmic Reticulum / Q000378:metabolism; D011992:Endosomes / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D037742:Nanotubes, Carbon / Q000737:chemistry*; D011993:Recombinant Fusion Proteins / Q000378:metabolism*; D012276:Ricin / Q000378:metabolism*
D004337:Drug Carriers; D037742:Nanotubes, Carbon; D011993:Recombinant Fusion Proteins; D012276:Ricin