Identification of multiple cellular uptake pathways of polystyrene nanoparticles and factors affecting the uptake: relevance for drug delivery systems.
Nanoparticles may address challenges by human diseases through improving diagnosis, vaccination and treatment. The uptake mechanism regulates the type of threat a particle poses on the host cells and how a cell responds to it. Hence, understanding the uptake mechanisms and cellular interactions of nanoparticles at the cellular and subcellular level is a prerequisite for their effective biomedical applications. The present study shows the uptake mechanisms of polystyrene nanoparticles and factors affecting their uptake in bone marrow-derived macrophages, 293T kidney epithelial cells and L929 fibroblasts. Labeling with the endocytic marker FM4-64 and transmission electron microscopy studies show that the nanoparticles were internalized rapidly via endocytosis and accumulated in intracellular vesicles. Soon after their internalizations, nanoparticles trafficked to organelles with acidic pH. Analysis of the ultrastructural morphology of the plasma membrane invaginations or extravasations provides clear evidence for the involvement of several uptake routes in parallel to internalize a given type of nanoparticles by mammalian cells, highlighting the complexity of the nanoparticle-cell interactions. Blocking the specific endocytic pathways by different pharmacological inhibitors shows similar outcomes. The potential to take up nanoparticles varies highly among different cell types in a particle sizes-, time- and energy-dependent manner. Furthermore, infection and the activation status of bone marrow-derived macrophages significantly affect the uptake potential of the cells, indicating the need to understand the diseases' pathogenesis to establish effective and rational drug-delivery systems. This study enhances our understanding of the application of nanotechnology in biomedical sciences.
['Firdessa|Rebuma|R|', 'Oelschlaeger|Tobias A|TA|', 'Moll|Heidrun|H|']
D000818:Animals D002462:Cell Membrane D002478:Cells, Cultured D016503:Drug Delivery Systems D011992:Endosomes D004847:Epithelial Cells D005260:Female D005347:Fibroblasts D005456:Fluorescent Dyes D006863:Hydrogen-Ion Concentration D007668:Kidney D018320:Leishmania major D008264:Macrophages D008807:Mice, Inbred BALB C D046529:Microscopy, Electron, Transmission D053758:Nanoparticles D010316:Particle Size D011137:Polystyrenes D011726:Pyridinium Compounds D000644:Quaternary Ammonium Compounds D013997:Time Factors D057900:Transcytosis
Nanoparticle Endocytosis Ultrastructure Factor determining uptake Multiple uptake