posted on 2020-03-10, 15:12authored byPrasanta Panja, Nikhil R. Jana
Although
colloidal nanoparticles are known to enter into cells
via endocytosis, the direct membrane permeation of nanoparticles is
rarely reported, and the underlying mechanism of direct membrane permeation
is largely unsolved. However, a direct membrane-penetrating nanoparticle
has great advantage as a delivery carrier that offers high delivery
efficiency, faster delivery kinetics, and minimal lysosomal degradation.
Here we show that arginine-terminated Au nanoparticles of <10 nm
size enter via energy-independent direct membrane penetration, but
as the size increases, the nanoparticles switch to energy-dependent
endocytotic uptake. As a delivery carrier, <10 nm Au nanoparticles
directly transport an electrostatically bound protein into the cytosol
within a minute and allow direct access of the protein to subcellular
compartments. This direct delivery approach has been used for efficient
nuclear targeting of proteins and can be adapted for direct cytosolic
delivery or subcellular targeting applications with high efficiency.