Elucidating the Mechanism of Cellular Uptake and Removal of Protein-Coated Gold Nanoparticles of Different Sizes and Shapes

TLDR

The study investigates how transferrin‑coated gold nanoparticles of varying sizes and shapes enter mammalian cells and aims to guide imaging, drug delivery, and nanotoxicity assessments. The authors developed a mathematical model to predict how nanoparticle size influences exocytosis in different cell lines. Transferrin‑coated Au nanoparticles enter cells through clathrin‑mediated endocytosis, and their exocytosis rate increases linearly with size, a pattern distinct from the uptake–size relationship.

Abstract

We investigated the mechanism by which transferrin-coated gold nanoparticles (Au NP) of different sizes and shapes entered mammalian cells. We determined that transferrin-coated Au NP entered the cells via clathrin-mediated endocytosis pathway. The NPs exocytosed out of the cells in a linear relationship to size. This was different than the relationship between uptake and size. Furthermore, we developed a mathematical equation to predict the relationship of size versus exocytosis for different cell lines. These studies will provide guidelines for developing NPs for imaging and drug delivery applications, which will require "controlling" NP accumulation rate. These studies will also have implications in determining nanotoxicity.