Characterization of endocytosis and exocytosis of cationic nanoparticles in airway epithelium cells

Abstract

A major challenge of drug delivery using colloids via the airway is to understand the mechanism implied in their interactions with epithelial cells. The purpose of this work was to characterize the process of endocytosis and exocytosis of cationic nanoparticles (NPs) made of maltodextrin which were developed as a delivery system for antigens in vaccine applications. Confocal microscopy demonstrated that these NP are rapidly endocytosed after as little as 3 min incubation, and that the endocytosis was also faster than NP binding since most of the NPs were found in the middle of the cells around the nuclei. A saturation limit was observed after a 40 min incubation, probably due to an equilibrium becoming established between endocytosis and exocytosis. Endocytosis was dramatically reduced at 4 degrees C compared with 37 degrees C, or by NaN(3) treatment, both results suggesting an energy dependent process. Protamine pretreatment of the cells inhibited NPs uptake and we found that clathrin pathway is implied in their endocytosis. Cholesterol depletion increased NP uptake by 300% and this phenomenon was explained by the fact that cholesterol depletion totally blocked NP exocytosis. These results suggest that these cationic NPs interact with anionic sites, are quickly endocytosed via the clathrin pathway and that their exocytosis is cholesterol dependent, and are similar to those obtained in other studies with viruses such as influenza.

Biocompatibility, endocytosis, and intracellular trafficking of mesoporous silica and polystyrene nanoparticles in ovarian cancer cells: effects of size and surface charge groups

“…The uptake and retention efficiency of the nanoparticles, as well as their intracellular trafficking, also depend heavily on intrinsic cell characteristics, mainly the composition and fluidity of the plasma membrane, and the dynamics of endocytosis and exocytosis. 41 The above data demonstrate the relevance of cholesterol in the plasma membrane to endocytosis of nanoparticles. Plasma membrane cholesterol is a major constituent of caveolae, ie, invaginated regions of the plasma membrane that accomplish caveolin-1-dependent endocytosis.…”

Intracellular disposition of chitosan nanoparticles in macrophages: intracellular uptake, exocytosis, and intercellular transport

“…Compared with the endocytosis of NMs, exocytosis and intercellular transport of these NMs have been rarely studied. 10 In previous studies, the dependence of calcium, cholesterol, and energy for the exocytosis of some NPs, eg, gold, polysaccharide, and poly(d,l-lactide-co-glycolide), has been reported; [11][12][13] in addition, a study on lanthanide-doped upconverting NPs showed the significance of the microtubule system in NP exocytosis. 10,14 Following exocytosis, intercellular transport of mesoporous silica NPs was evident in mammalian cells.…”

Endocytosis and exocytosis of nanoparticles in mammalian cells

“…43 The cationic polymer hydroxycholine was used to coat nanoparticles. After the surface modification, the nanoparticles appeared to be an approximate size of 60 nm.…”