%0 Journal Article
%T Nona-Arginine Facilitates Delivery of Quantum Dots into Cells via Multiple Pathways
%A Yi Xu
%A Betty Revon Liu
%A Han-Jung Lee
%A Katie B. Shannon
%A Jeffrey G. Winiarz
%A Tien-Chun Wang
%A Huey-Jenn Chiang
%A Yue-wern Huang
%J Journal of Biomedicine and Biotechnology
%D 2010
%I Hindawi Publishing Corporation
%R 10.1155/2010/948543
%X 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.
%U http://www.hindawi.com/journals/biomed/2010/948543/