Overcoming blood-brain barrier (BBB) and targeting
tumor cells are two key steps for
glioma chemotherapy. By taking advantage of the specific expression of Na+-coupled
carnitine transporter 2 (OCTN2) on both brain capillary endothelial cells and
glioma cells, l-
carnitine conjugated
poly(lactic-co-glycolic acid) nanoparticles (LC-PLGA NPs) were prepared to enable enhanced BBB permeation and
glioma-cell targeting. Conjugation of
l-carnitine significantly enhanced the uptake of PLGA nanoparticles in the BBB endothelial cell line hCMEC/D3 and the
glioma cell line T98G. The uptake was dependent on Na+ and inhibited by the excessive free
l-carnitine, suggesting involvement of OCTN2 in the process. In vivo mouse studies showed that LC-PLGA NPs resulted in high accumulation in the brain as indicated by the biodistribution and imaging assays. Furthermore, compared to
Taxol and
paclitaxel-loaded unmodified PLGA NPs, the drug-loaded LC-PLGA NPs showed improved anti-
glioma efficacy in both 2D-cell and 3D-spheroid models. The PEG spacer length of the
ligand attached to the nanoparticles was optimized, and the formulation with PEG1000 (LC-1000-PLGA NPs) showed the maximum targeting efficiency. We conclude that
l-carnitine-mediated cellular recognition and internalization via OCTN2 significantly facilitate the transcytosis of nanoparticles across BBB and the uptake of nanoparticles in
glioma cells, resulting in improved anti-
glioma efficacy.