Fluorescence microscopy of HeLa and HaCaT cells incubated with various liposomal formulations containing FITC-dextran at 37°C and pH 7.4 for 4 hours.
Notes: green fluorescence represents cellular translocation of the probe-entrapped liposomal carrier. While peptide conjugation (P-Lipo) increased translocation into both cells with no difference, folate modification (F- and FP-Lipo) manifested the selectivity to FR-positive HeLa cells, resulting in the greatest uptake of FP-Lipo.
Abbreviations: FITC-dextran, fluorescein dextran isothiocyanate; P-Lipo, Pep-1 peptide–modified liposomes; F-Lipo, folate-modified liposomes; FP-Lipo, dual ligand–modified liposomes; C-Lipo, conventional liposomes.