Fig. 4

Improved uptake of DEX-PS by RAW264.7 cells. Mean fluorescence of whole cells (a) and Nile Red⁺ cells (b), and the percentage of Nile Red⁺ cells (c) after incubation with various NPs. d Confocal laser-scanning microscopy images of RAW264.7 cells after incubation with PS, COOH-PS, or DEX-PS for 4 h. e Kinetic profile of mean fluorescence of whole RAW264.7 cells. f Rates of DEX-PS uptake by RAW264.7 cells were influenced by various inhibitors. g Dynamic changes in mean intensity of MMR on RAW264.7 cells after incubation with DEX-PS. h Relative expression changes of MMR on RAW264.7 cells after 4-h incubation with PS, COOH-PS, or DEX-PS. Scale bars in d indicate 20 µm. Data are presented as the mean ± SD (n = 3), * Indicates p < 0.05. COOH-PS, carboxyl-functionalized polystyrene; DEX-PS: dextran-functionalized polystyrene; MMR: macrophage mannose receptor; PS: polystyrene