Synthesis and cellular uptake mechanism of Tat decorated Au/Au2S nanoparticles  

To realize an efficient and targeted cancer therapy by the drug/gene carrier， cell penetrating peptide Tat decorated Au-Au₂S nanoparticles were prepared by a redox method. Transmission electron microscopy (TEM)， surface enhanced Raman scattering (SERS) and UV-vis spectrometer were used for characterizing Tat/Au-Au₂S nanoparticles，  and confocal laser scanning microscope (CLSM) and flow cytometer (FACS) were used to investigate the mechanism of cellular uptake. The chemicophysical results indicate that Tat peptide could be conjugated onto Au Au2S nanoparticles via Au—S bonds， and Tat/Au-Au₂S nanoparticles present as 50 nm-diameter sphericities with NIR sensitivity. Co-location and endocytosis inhibition experiments suggest that Tat/Au-Au₂S nanoparticles may enter Hela cells via a lipid raft mediated endocytosis pathway，  whereas via a combined endocytosis pathway of lipid raft-dependent and receptor-dependent into bone marrow stromal cells (BMSCs).