MOESM1 of Uptake of label-free graphene oxide by Caco-2 cells is dependent on the cell differentiation status
Creators: name: Kucki, Melanie
name: Diener, Liliane
name: Bohmer, Nils
name: Hirsch, Cordula
name: Krug, Harald
name: Palermo, Vincenzo
name: Wick, Peter
Publisher: name: Figshare
Year: 2017
Subjects: subject: Biophysics
subject: Biochemistry
subject: Microbiology
subject: FOS: Biological sciences
subject: FOS: Biological sciences
subject: Cell Biology
subject: Molecular Biology
subject: Physiology
subject: Pharmacology
subject: Biotechnology
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: FOS: Chemical sciences
subject: Immunology
subject: FOS: Clinical medicine
subject: FOS: Clinical medicine
subject: Developmental Biology
subject: Cancer
subject: Hematology
subject: Plant Biology
subject: Virology

description: Additional file 1: Figure S1. Differential interference contrast (DIC) images of non-confluent Caco-2 cells grown on glass cover slips. Cells were exposed to either 20 μg/ml GO1, GO3 or GNP for 24 hours. GRM-exposed cells showed no morphological differences in comparison to the unexposed control cells. Accumulation of dark material in the perinuclear region gives hints towards uptake of GO3 by non-confluent Caco-2 cells. Microscopy analysis was performed with an Axio ImagerZ.1 microscope (Zeiss, Oberkochen, Germany). Figure S2. Fluorescence microscopy images (overlays) of non-confluent Caco-2 cells. Cells were exposed for 24 hours to 20 μg/ml GO1, GO3 or GNP respectively. Control cells not exposed to GO were run in parallel. Cell nuclei were labelled with DAPI (blue; λex = 335-383 nm, λem = 420-470 nm). Actin-network was labelled with Phalloidin-Alexa Fluor® 488 (green; λex = 455-495 nm, λem = 505-555 nm). GRM is visible by transmitted differential interference contrast (TL DIC) microscopy. Microscopy analysis was performed with an Axio ImagerZ.1 microscope (Zeiss, Oberkochen, Germany). Figure S3. SEM images of non-confluent Caco-2 cells after exposure to GO1 or GO3 for 24 hours. Cells were exposed to 40 μg GO1/ml (top, left) or 20 μg GO1/ml (top, right). GO1 sheets exhibited either highly crumpled morphology especially at the cell-substrate border or were aligned parallel to the cell surface. GO3 was applied in a concentration of 40 μg GO3/ml. GO3 is visible in form of mat-like agglomerates of folded and wrinkled sheets both on the substrate and cell surface (bottom, right). Formation of circular wave-like protrusions on the surface of GO3-exposed cells give hints towards the possible uptake mechanism macropinocytosis (bottom, left). Figure S4. Interaction of GNP and the surface of non-confluent Caco-2 cells. SEM images of cells after exposure to 20 μg GNP/ml for 24 h. Most of the shown GNP aggregates were found on the cell surface near the edges of Caco-2 islets and were associated with membrane protrusions. Bottom images: GNP aggregate is exemplarily displayed in purple to facilitate identification. Figure S5. FACS analysis. Scatter plots of non-confluent Caco-2 cells after 24 h exposure to GRM. Figure S6. Cell surface morphology of differentiated Caco-2 cells. SEM images of control cells without GO exposure and cells after exposure to 20 μg GO1/ml for 24 h. Only a few GO1 sheets could be identified on top of the brush border (highlighted by red boxes). Figure S7. Fluorescence microscopy images of differentiated Caco-2 cell monolayer. Control cells without GO exposure and Caco-2 cells after exposure to GO; cells were exposed for 24 hours to 20 μg GO1/ml or 20 μg GO3/ml respectively. Channel 1 (Ch1; λex = 335-383 nm, λem = 420-470 nm) shows cell nuclei labelled with DAPI (blue). Channel 2 (Ch2; λex = 455-495 nm, λem = 505-555 nm) shows the presence of tight junctions by labelling with ZO-1 mouse monoclonal antibody-Alexa Fluor® 488 (green). Channel 3 (Ch3; λex = 538-562 nm, λem = 570-640 nm) shows the actin-network labelled with Phalloidin-Alexa Fluor® 546.