Journal Article

Effects of Transport Inhibitors on the Cellular Uptake of Carboxylated Polystyrene Nanoparticles in Different Cell Lines

Lynch, Iseult, Dawson, Kenneth A., dos Santos, Tiago, Salvati, Anna, Varela, Juan

2011

Overview

Nanotechnology is expected to play a vital role in the rapidly developing field of nanomedicine, creating innovative solutions and therapies for currently untreatable diseases, and providing new tools for various biomedical applications, such as drug delivery and gene therapy. In order to optimize the efficacy of nanoparticle (NP) delivery to cells, it is necessary to understand the mechanisms by which NPs are internalized by cells, as this will likely determine their ultimate sub-cellular fate and localisation. Here we have used pharmacological inhibitors of some of the major endocytic pathways to investigate nanoparticle uptake mechanisms in a range of representative human cell lines, including HeLa (cervical cancer), A549 (lung carcinoma) and 1321N1 (brain astrocytoma). Chlorpromazine and genistein were used to inhibit clathrin and caveolin mediated endocytosis, respectively. Cytochalasin A and nocodazole were used to inhibit, respectively, the polymerisation of actin and microtubule cytoskeleton. Uptake experiments were performed systematically across the different cell lines, using carboxylated polystyrene NPs of 40 nm and 200 nm diameters, as model NPs of sizes comparable to typical endocytic cargoes. The results clearly indicated that, in all cases and cell types, NPs entered cells via active energy dependent processes. NP uptake in HeLa and 1321N1 cells was strongly affected by actin depolymerisation, while A549 cells showed a stronger inhibition of NP uptake (in comparison to the other cell types) after microtubule disruption and treatment with genistein. A strong reduction of NP uptake was observed after chlorpromazine treatment only in the case of 1321N1 cells. These outcomes suggested that the same NP might exploit different uptake mechanisms to enter different cell types.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Actin / Actins - chemistry / Actins - metabolism / Analysis / Astrocytoma / Biology / Biomedical materials / Biotechnology / Brain / Cancer / Carboxylic Acids - chemistry / Care and treatment / Caveolin / Caveolins - antagonists & inhibitors / Caveolins - metabolism / Cell adhesion & migration / Cell Line / Cells (Biology) / Cervical cancer / Cervix / Chemistry / Chlorpromazine / Chlorpromazine - pharmacology / Cholera / Clathrin / Clathrin - antagonists & inhibitors / Clathrin - metabolism / Cytochalasins - pharmacology / Cytoskeleton / Depolymerization / Disruption / Drug delivery / Drug delivery systems / Endocytosis / Endocytosis - drug effects / Energy Metabolism - drug effects / Gene therapy / Genistein / Genistein - pharmacology / HeLa Cells / Humans / Inhibitors / Isoflavones / Lipids / Low density lipoprotein / Lung cancer / Lung carcinoma / Materials Science / Medical innovations / Microtubules - drug effects / Microtubules - metabolism / Muscle proteins / Nanoparticles / Nanoparticles - chemistry / Nanotechnology / Nocodazole / Nocodazole - pharmacology / Particle Size / Permeability / Pharmacology / Physiology / Plasma / Polystyrene / Polystyrene resins / Polystyrenes - chemistry / Polystyrenes - metabolism / Protein Multimerization - drug effects / Protein Structure, Quaternary / Protein-Tyrosine Kinases - antagonists & inhibitors / Proteins / Tumor cell lines