Cell uptake and intracellular visualization using quantum dots or nuclear localization signal-modified quantum dots with gold nanoparticles as quenchers.
Understanding and controlling the interactions between nanoscale objects and living cells is of great importance for diagnostic imaging and therapeutic applications. Quantum dots (QDs) have remarkable optical characteristics, such as uniquely feature bright, photostable, tunable and narrow fluorescence emissions, as well as broad absorption spectra. Here we report a platform of using quantum dots to investigate the cell uptake and the interactions between nanoscale objects and cells. QDs are uptaken by BHK cells easily through endocytosis. We could clearly differentiate the QDs outside the cell or inside the cell by quenching the QDs with similar sized gold nanoparticles and reduce the noise of fluorescent image. Microscopic images show that QDs are homogeneously distributed within the whole cell except the nucleus. However, unmodified QDs could not penetrate the nuclear membrane and move into the nucleus. Coupling QDs with Nuclear Localization Signal (NLS, CGGGPKKKRKVGG) can significantly enhance the translocation amount of QDs into the cell and cell nucleus. This method combined with microscopy imaging system can visualize the particle delivery routes and provide valuable information in the drug/gene delivery and tumor diagnosis.
Institute of Biomedical Engineering, College of Medicine, College of Engineering, National Taiwan University, 100, Taiwan.
Kai-Wei
KW
Kuo
Te-Hsuen
TH
Chen
Wei-Ti
WT
Kuo
Hong-Yi
HY
Huang
Hsien-Yi
HY
Lo
Yi-You
YY
Huang
D000595:Amino Acid Sequence; D000818:Animals; D002467:Cell Nucleus / Q000737:chemistry*; D002478:Cells, Cultured; D006224:Cricetinae; D006046:Gold; D053768:Metal Nanoparticles; D008969:Molecular Sequence Data; D019913:Nuclear Localization Signals; D045663:Quantum Dots
D019913:Nuclear Localization Signals; D006046:Gold