Figure 2.

Kinetics of cellular binding and uptake of polyplexes prepared with chitosans of different degree of deacetylation (DDA) and molecular weight (MW). HEK293 cells were incubated with fluorescent chitosan polyplexes for the indicated periods of time and analyzed by flow cytometry. Flow cytometry quantitative analysis of mean fluorescence per cell for polyplex (a) binding and (b) uptake and (c) of % cells with internalized polyplexes was performed following trypsinization and extensive washes, except for (a) cell binding, where cells were detached by enzyme-free cell dissociation buffer and analyzed directly. (b) Mean uptake levels per cell and (c) % positive cells were obtained from the same set of flow cytometry data. Graphs show that binding and uptake are time and DDA-dependent, with both 92% DDA chitosans binding more effectively than the lower DDA chitosans, resulting in increased uptake. Results are the average of three (N = 3) independent experiments ± SD where each experiment included two replicates. RLU, relative light units.