title: Multimodal analysis of PEI-mediated endocytosis of nanoparticles in neural cells.
abstract: Polymer nanoparticles are widely used as a highly generalizable tool to entrap a range of different drugs for controlled or site-specific release. However, despite numerous studies examining the kinetics of controlled release, the biological behavior of such nanoparticles remains poorly understood, particularly with respect to endocytosis and intracellular trafficking. We synthesized polyethylenimine-decorated polymer nanospheres (ca. 100-250 nm) of the type commonly used for drug release and used correlated electron microscopy, fluorescence spectroscopy and microscopy, and relaxometry to track endocytosis in neural cells. These capabilities provide insight into how polyethylenimine mediates the entry of nanoparticles into neural cells and show that polymer nanosphere uptake involves three distinct steps, namely, plasma membrane attachment, fluid-phase as well as clathrin- and caveolin-independent endocytosis, and progressive accumulation in membrane-bound intracellular vesicles. These findings provide detailed insight into how the intracellular delivery of nanoparticles is mediated by polyethylenimine, which is presently the most commonly used nonviral gene transfer agent. This fundamental knowledge may also assist in the preparation of next-generation nonviral vectors.
authors: School of Biomedical, Biomolecular and Chemical Sciences, The University of Western Australia, 35 Stirling Highway, Crawley WA 6009, Australia.
authors: Cameron W
authors: CW
authors: Evans
authors: Melinda
authors: M
authors: Fitzgerald
authors: Tristan D
authors: TD
authors: Clemons
authors: Michael J
authors: MJ
authors: House
authors: Benjamin S
authors: BS
authors: Padman
authors: Jeremy A
authors: JA
authors: Shaw
authors: Martin
authors: M
authors: Saunders
authors: Alan R
authors: AR
authors: Harvey
authors: Bogdan
authors: B
authors: Zdyrko
authors: Igor
authors: I
authors: Luzinov
authors: Gabriel A
authors: GA
authors: Silva
authors: Sarah A
authors: SA
authors: Dunlop
authors: K Swaminathan
authors: KS
authors: Iyer
mesh_terms: D000818:Animals; D004705:Endocytosis; D042541:Intracellular Space / Q000378:metabolism; D053758:Nanoparticles / Q000633:toxicity; D054118:Nanospheres / Q000633:toxicity; D009474:Neurons / Q000166:cytology* / Q000187:drug effects; D016716:PC12 Cells; D011094:Polyethyleneimine / Q000378:metabolism* / Q000633:toxicity; D051381:Rats; D013050:Spectrometry, Fluorescence
chemical_list: D011094:Polyethyleneimine