Jong Ah Kim, Christoffer Åberg, Anna Salvati, Kenneth A. Dawson Role of cell cycle on the cellular uptake and dilution of nanoparticles in a cell population Jong Ah Kim, Christoffer Åberg, Anna Salvati, Kenneth A. Dawson This presentation contains a simple scheme of the cell cycle and shows nanoparticle uptake in a single cell, as it progresses through its cell cycle and undergoes cell division. The generation of the ranking (Fig. 1c) of the intracellular nanoparticle concentration for cells in the different cell cycle phases is also illustrated. Supplementary Discussion

Cell Cycle The cell cycle is a series of events that lead to cell division and replication, consisting of four phases: G1, S, G2 and M. The activation of each phase depends on the proper completion of the previous one. The cell cycle commences with the G1 phase, during which the cell increases its size. During the S phase the cell synthesizes DNA, and in the G2 phase it synthesizes proteins to prepare for cell division. Finally during the M phase the cell divides and the two daughter cells enter the G1 phase. Cells that have temporarily stopped dividing can enter a resting phase called G0.

cell growth, protein synthesis Cell Cycle G1 phase: cell growth, protein synthesis G0/G1

cell growth, protein synthesis Cell Cycle G1 phase: cell growth, protein synthesis G0/G1 S phase: DNA synthesis S

Cell Cycle G2/M G0/G1 S G2 phase: preparation for cell division, protein synthesis G1 phase: cell growth, protein synthesis G2/M G0/G1 S phase: DNA synthesis S

Cell Cycle G2/M G0/G1 S G2 phase: M phase: mitosis (cell division) G2 phase: preparation for cell division, protein synthesis G1 phase: cell growth, protein synthesis G2/M G0/G1 S phase: DNA synthesis S

Two new daughter cells in G1 phase Cell Cycle M phase: mitosis (cell division) G2 phase: preparation for cell division, protein synthesis Two new daughter cells in G1 phase G2/M G0/G1 S phase: DNA synthesis S

Proliferation of a cell culture S G2/M G0/G1 A cell culture is a mixture of cells in different phases of their cell cycle, simultaneously undergoing progression and cell division. G0/G1 S G2/M Time

Proliferation of a cell culture S G2/M G0/G1 A cell culture is a mixture of cells in different phases of their cell cycle, simultaneously undergoing progression and cell division. G0/G1 S S G2/M G0/G1 G2/M Cell division Time

Proliferation of a cell culture S G2/M G0/G1 A cell culture is a mixture of cells in different phases of their cell cycle, simultaneously undergoing progression and cell division. G0/G1 S G2/M S G2/M Cell division G0/G1 G0/G1 G2/M Cell division S Time

Nanoparticle uptake in a cycling cell: example of a cell in G1 phase at the moment of exposure to nanoparticles S G2/M G0/G1

Nanoparticles enter the cells and accumulate in the lysosomes. Nanoparticle uptake in a cycling cell: example of a cell in G1 phase at the moment of exposure to nanoparticles S G2/M G0/G1 Nanoparticles enter the cells and accumulate in the lysosomes.

Nanoparticle uptake in a cycling cell: example of a cell in G1 phase at the moment of exposure to nanoparticles S G2/M G0/G1 Nanoparticles enter the cells and accumulate in the lysosomes. Nanoparticles are taken up throughout the cell cycle.

Nanoparticle uptake in a cycling cell: example of a cell in G1 phase at the moment of exposure to nanoparticles Uptake rate in the different phases is similar. S G2/M G0/G1 Nanoparticles enter the cells and accumulate in the lysosomes. Nanoparticles are taken up throughout the cell cycle.

Nanoparticle uptake in a cycling cell: example of a cell in G1 phase at the moment of exposure to nanoparticles Upon cell division, cells dilute their intracellular nanoparticle concentration. Uptake rate in the different phases is similar. S G2/M G0/G1 Nanoparticles enter the cells and accumulate in the lysosomes. Nanoparticles are taken up throughout the cell cycle.

Nanoparticle uptake in a cycling cell: example of a cell in G1 phase at the moment of exposure to nanoparticles Upon cell division, cells dilute their intracellular nanoparticle concentration. Uptake rate in the different phases is similar. S G2/M G0/G1 Daughter cells will have (on average) half of the amount of nanoparticles compared to the parent cell. Nanoparticles are taken up throughout the cell cycle.

Nanoparticle uptake in a cell population G0/G1 G2/M S Time

Nanoparticle uptake in a cell population During the first 10 hours of uptake there is no major difference between the concentrations of nanoparticles in cells in the different phases. G0/G1 G2/M S Time

Nanoparticle uptake in a cell population Once a significant fraction of the cells in G0/G1 are cells that divided during the exposure to nanoparticles, then the G0/G1 cells show a reduced nanoparticle concentration in comparison to the other phases. G0/G1 G2/M S G0/G1 S G2/M Cell division Time

Nanoparticle uptake in a cell population When cells that have divided begin to populate the S phase, then those cells also show a reduced intracellular nanoparticle concentration (compared to the cells in G2/M). G0/G1 S G2/M G0/G1 S G2/M Cell division Time