Enhancing Cellular Internalization of Gold Nanoparticles with Controllable Surface Modification and Functionalization

W. Qian, M. Murakami, Y. Ichikawa, Y. Che
IMRA America, Inc., US

Keywords: gold nanoparticles, pulsed laser abaltion, conjugation of multiple different ligands, surface modification, cellular internalization of nanoparticles

Summary:

For every biomedical application of gold nanoparticles, stability, biocompatibility, and targeting efficacy are the key requirements and surface modification and functionalization are essential for meeting these requirements. In this presentation, we demonstrate an approach for highly efficient and controllable surface modification/functionalization of gold nanoparticles. For the gold nanoparticles produced by femtosecond laser ablation, it is revealed that because of their unique surface chemistry, the conjugation of these nanoparticles to functional ligands (such as Poly (ethylene glycol)) could be carried out with surface coverage tunable between 0 and 100% and meantime, the suspension stability of gold nanocolloids is maintained. By taking advantage of this novel property, we fabricated a series of colloidal suspensions of multifunctional gold nanoconjugates bearing different number of PEG and peptide molecule. By incorporating PEG and peptide molecules on the surface of individual gold nanoparticles, we could simultaneously maintain stability of gold nanoparticles in buffer solutions and achieve cellular uptake of gold nanoparticles via receptor mediated endocytosis. We observed that the efficacy of cellular internalization of gold nanoparticles strongly depended on their surface chemistry and the cellular uptake of gold nanoparticles was maximized by finely tuning the amount of PEG and peptide molecules bound on their surface.