The Study of Cyclosporin A Nanocrystals Uptake and Transport across an Intestinal Epithelial Cell Model

Abstract

Cyclosporin A nanocrystals (CsA-NCs) interaction with Caco-2 cells were investigated in this study, including cellular uptake and transport across Caco-2 cell monolayers. CsA-NCs of 165 nm, 240 nm and 450 nm were formulated. The dissolution of CsA-NCs was investigated by paddle method. The effect of size, concentration and incubation time on cellular uptake and dissolution kinetics of CsA-NCs in cells were studied. Uptake mechanisms were also evaluated using endocytotic inhibitors and low temperature (4 °C). The cell monolayers were incubated with each diameter CsA-NCs to evaluate the effect of size on the permeation characteristics of CsA across the intestinal mucosa. The results of dissolution study showed that 165 nm CsA-NC had the highest dissolution rate followed by 240 CsA-NC and finally 450 nm CsA-NC. The saturation of cell uptake of CsA-NCs was observed with the increase of incubation concentration and time. 240 nm and 450 nm CsA-NCs had the lowest and highest uptake efficiency at different time and drug concentration, respectively. The uptake of all three-sized CsA-NCs declined significantly in some different degree after the pre-treatment with different endocytosis inhibitors. 165 nm CsA-NC showed a highest transport capacity across monolayers at the same concentration and time. The results suggest that the size of CsA-NCs can not only affect the efficiency of cellular uptake, but also the type of endocytosis. Decreasing particle size of CsA-NCs can improve transport capacity of CsA through cell monolayer.

Y-Shaped Backbone-Rigidified DNA Tiles for the Construction of Supersized Nondeformable Tetrahedrons for Precise Cancer Therapies

“…It is found that, while different DNA nanostructures, for example, DNA tetrahedral nanostructure and folic acid-functionalized Y-shaped nanoprobe, may be internalized by the same endocytosis pathway (caveolin-dependent endocytosis mechanism), DNA nanoassemblies modified with the same targeting ligand could be uptaken by the cells through different endocytosis mechanisms (e.g., the cellular internalization of AS1411-functionalized DNA ribbon-gold nanoparticles is mainly dependent on macropinocytosis; while clathrin-mediated endocytosis is the main pathway responsible for the cellular uptake of AS1411-functionalized DNA nanoflowers). Presumably, the type of endocytotic pathway is closely associated with the size and shape of nanovehicles and the nature of targeting ligands . In this section, the cellular uptake pathway of RDT was explored by pretreating HeLa cells with chemical endocytosis inhibitors, including methyl-β-cyclodextrin (MβCD) (an inhibitor for caveolin-dependent endocytosis), amiloride (an inhibitor for the macropinocytosis pathway), and sucrose (an inhibitor for the clathrin-mediated endocytosis pathway) .…”