Nona-arginine facilitates delivery of quantum dots into cells via multiple pathways.
Semiconductor quantum dots (QDs) have recently been used to deliver and monitor biomolecules, such as drugs and proteins. However, QDs alone have a low efficiency of transport across the plasma membrane. In order to increase the efficiency, we used synthetic nona-arginine (SR9), a cell-penetrating peptide, to facilitate uptake. We found that SR9 increased the cellular uptake of QDs in a noncovalent binding manner between QDs and SR9. Further, we investigated mechanisms of QD/SR9 cellular internalization. Low temperature and metabolic inhibitors markedly inhibited the uptake of QD/SR9, indicating that internalization is an energy-dependent process. Results from both the pathway inhibitors and the RNA interference (RNAi) technique suggest that cellular uptake of QD/SR9 is predominantly a lipid raft-dependent process mediated by macropinocytosis. However, involvement of clathrin and caveolin-1 proteins in transducing QD/SR9 across the membrane cannot be completely ruled out.
Department of Biological Sciences, Missouri University of Science and Technology, Rolla, MO 65409, USA.
Yi
Y
Xu
Betty Revon
BR
Liu
Han-Jung
HJ
Lee
Katie B
KB
Shannon
Jeffrey G
JG
Winiarz
Tien-Chun
TC
Wang
Huey-Jenn
HJ
Chiang
Yue-wern
YW
Huang
D001692:Biological Transport; D015153:Blotting, Western; D019187:Cadmium Compounds / Q000008:administration & dosage / Q000493:pharmacokinetics; D022461:Caveolins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D033922:Clathrin Heavy Chains / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D016503:Drug Delivery Systems / Q000379:methods*; D006801:Humans; D008856:Microscopy, Fluorescence; D009842:Oligopeptides / Q000008:administration & dosage* / Q000493:pharmacokinetics; D010873:Pinocytosis; D045663:Quantum Dots; D034741:RNA, Small Interfering / Q000235:genetics; D018036:Selenium Compounds / Q000008:administration & dosage / Q000493:pharmacokinetics; D013440:Sulfides / Q000008:administration & dosage / Q000493:pharmacokinetics; D017967:Zinc Compounds / Q000008:administration & dosage / Q000493:pharmacokinetics
D019187:Cadmium Compounds; D022461:Caveolins; D009842:Oligopeptides; D034741:RNA, Small Interfering; D018036:Selenium Compounds; D013440:Sulfides; D017967:Zinc Compounds; C491427:nonaarginine; D033922:Clathrin Heavy Chains; C058667:cadmium selenide; C031238:zinc sulfide