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.
Department of Chemistry and Institutes of Biomedical Sciences, Fudan University, Shanghai, P.R. China.
Meiyan
M
Wang
Shaoning
S
Yu
Chuan
C
Wang
Jilie
J
Kong
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