Cellular uptake and transport characteristics of chitosan modified nanoparticles in Caco-2 cell monolayers.

The bioadhesive drug delivery systems, chitosan modified nanoparticles, can efficiently adhere to mucosal surface of gastrointestinal tract and prolong residence time but a deeper understanding about its cellular uptake and transport is still lack. Hence, the present study was designed to compare the process of uptake and transport between chitosan modified and unmodified PLGA nanoparticles. Chitosan modified nanoparticles were formulated by classic and chemical methods. The morphology and modification potency were characterized by zeta potential, FTIR, DSC, XPS and TEM. Coumarin-6 load chitosan modified nanoparticles were incubated with Caco-2 cells to study the process of uptake and transport. The kinetic of cellular uptake for chitosan modified and unmodified nanoparticles was time- and concentration-dependent endocytosis but the cellular uptake efficiency of modified nanoparticles was significantly higher than that of unmodified one within the high concentration range (25.0-100.0 μg/mL). The modified nanoparticles underwent clathrin-mediated endocytosis and macropinocytosis but unmodified nanoparticles occurred a clathrin-mediated endocytosis. Both types of nanoparticles can increase caulophine with low solubility and poor stability transmembrane transport and the modified nanoparticles exhibited a better transcellular permeability. Therefore, the chitosan modified nanoparticles showed significantly improved cellular uptake and transcellular transport and a potential improvement in the efficacy of oral drug delivery.