Fig. 1.

Preparation of layer-by-layer encapsulation of RPE cells. a Schematic model of layer-by-layer self-assembly technique. Polycations and polyanions provide alternating layers that coat RPE cells due to the interaction of opposite charges. b Surface charge of gelatin-type A as a function of pH; the isoelectric point is approaching 9. c Surface charge of alginate as a function of pH; the isoelectric point is approaching 4. d MTT assay showed cell viability of untreated and LbL-RPE cells when cultured for 3 days. Data represent the mean ± SEM of three independent experiments. There were no significant differences (p > 0.05) between untreated RPE and LbL-RPE cells. e Gelatin/alginate/gelatin-FITC-encapsulated RPE cells; the last layer of gelatin was conjugated to FITC for detection using fluorescence microscopy. Scale bars 10 μm. f Gelatin/alginate-Rhodamine B-encapsulated RPE cells; the last layer of alginate was conjugated to Rhodamine B. Nuclei were stained with Hoechst (blue). Scale bars 10 μm