Figure 3: Visualizing and quantifying nanoparticle interactions with individual B cells.

(A-C) Confocal laser scanning microscopy (CLSM) maximum intensity projections (MIP) of B cells exposed to 13-nm AuNPs surface-modified with K7C peptides for 8 h without (A) and with (B) exposure to KI/I₂ etchant that dissolves AuNPs. (C) CLSM maximum intensity projection (MIP) images of B cells without AuNPs exposure (cell only control group). Scale bar represents 20 μm. The intracellular vesicles were labeled with fluorescently-tagged dextran. (D) Average ¹⁹⁷Au masses of individual B cells exposed to 13-nm AuNPs surface-modified with K7C peptides under different conditions for 8 h without etchant (blue) and with an etchant (red). Circles represent the average ¹⁹⁷Au mass of ≥ 500 ¹⁹⁷Au events. Bars represent the averages of three independent measurements. Unpaired T-Test was used to determine the statistical significance between the average ¹⁹⁷Au mass before and after etching (n.s. - no significance; *** p ≤ 0.001, **** p ≤ 0.0001) (E) The ¹⁹⁷Au mass distribution based on individual B cells exposed to 13-nm AuNPs surface-modified with K7C peptides without etchant (blue) and with an etchant (red).