title: Clathrin-mediated endocytosis of gold nanoparticles in vitro.
abstract: Gold nanoparticles (AuNPs) have potential biomedical and scientific applications. In this study, we evaluated the uptake and internalization of FBS-coated 20 nm AuNPs into lung fibroblasts and liver cells by different microscopy techniques. AuNP aggregates were observed inside MRC5 lung fibroblasts and Chang liver cells under light microscopy, especially after enhancement with automegallography. Clusters of AuNPs were observed to be adsorbed on the cell surface by scanning electron microscopy. Ultrathin sections showed that AuNPs were mainly enclosed within cytoplasmic vesicles when viewed under transmission electron microscopy. We also investigated the mechanism of uptake for AuNPs, using endocytosis inhibitors and quantification of Au with inductively coupled plasma mass spectrometry. Cells treated with concanavalin A and chlorpromazine showed significant decrease of Au uptake in MRC5 lung fibroblasts and Chang liver cells, respectively, implying that the uptake of AuNPs was facilitated by clathrin-mediated endocytosis. It would therefore appear that uptake of 20 nm AuNPs in both cell types with different tissues of origin, was dependent upon clathrin-mediated endocytosis.
authors.affiliation: Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
authors.forename: Cheng Teng
authors.initials: CT
authors.lastname: Ng
authors.forename: Florence Mei Ai
authors.initials: FM
authors.lastname: Tang
authors.forename: Jasmine Jia'en
authors.initials: JJ
authors.lastname: Li
authors.forename: Cynthia
authors.initials: C
authors.lastname: Ong
authors.forename: Lanry Lin Yue
authors.initials: LL
authors.lastname: Yung
authors.forename: Boon Huat
authors.initials: BH
authors.lastname: Bay
mesh_terms: D002460:Cell Line; D002470:Cell Survival; D002966:Clathrin / Q000032:analysis / Q000378:metabolism*; D004705:Endocytosis / Q000502:physiology*; D005347:Fibroblasts / Q000737:chemistry / Q000378:metabolism*; D006046:Gold / Q000032:analysis / Q000378:metabolism*; D006801:Humans; D053768:Metal Nanoparticles / Q000032:analysis
chemical_list: D002966:Clathrin; D006046:Gold
keywords: autometallography; clathrin-mediated endocytosis; endocytosis inhibitors; gold nanoparticles; transmission microscopy