Organic nanotubes for drug loading and cellular delivery

Organic nanotubes made of synthetic amphiphilic molecules are novel materials that form by self-assembly. In this study, organic nanotubes with a carboxyl group (ONTs) at the surface were used as a carrier for the anticancer drug doxorubicin, which has a weak amine group. The IC50 values of ONT for cells were higher than that of conventional liposomes, suggesting that ONTs are safe. The results showed that the drug loading of ONTs was susceptible to the effect of ionic strength and H+ concentration in the medium, and drug release from ONTs was promoted at lower pH, which is favorable for the release of drugs in the endosome after cellular uptake. ONTs loaded with the drug were internalized, and the drug was released quickly in the cells, as demonstrated on transmission electron microscopy images of ONTs and the detection of a 0.05% dose of ONT chelating gadolinium in the cells. Moreover, ONT could be modified chemically with folate by simply mixing with a folate-conjugate lipid. Therefore, these novel, biodegradable organic nanotubes have the potential to be used as drug carriers for controlled and targeting drug delivery.

Transmission electron micrographs (B) and high magnification image of the cell in surrounding (asterisk in B) (C) showing uptake of ONT1 to C26 cells. N: nucleus; arrowhead: ONT1.Figure optionsDownload as PowerPoint slide