Intracellular delivery of universal proteins using a lysine headgroup containing cationic liposomes: Deciphering the uptake mechanism

Satya Ranjan Sarker, Ryosuke Hokama, Shinji Takeoka

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    27 Citations (Scopus)


    An amino acid-based cationic lipid having a TFA counterion (trifluoroacetic acid counterion) in the lysine headgroup was used to deliver functional proteins into human cervical cancer cells, HeLa, in the presence of serum. Proteins used in the study were fluorescein isothiocyanate (FITC) labeled bovine serum albumin, mouse anti-F actin antibody [NH3], and goat anti mouse IgG conjugated with FITC. The formation of liposome/protein complexes was confirmed using native polyacrylamide gel electrophoresis. Furthermore, the complexes were characterized in terms of their size and zeta potential at different pH values and found to be responsive to changes in pH. The highest delivery efficiency of the liposome/albumin complexes was 99% at 37 °C. The liposomes effectively delivered albumin and antibodies as confirmed by confocal laser scanning microscopy (CLSM). Inhibition studies showed that the cellular uptake mechanism of the complexes was via caveolae-mediated endocytosis, and the proteins were subsequently released from either the early endosomes or the caveosomes as suggested by CLSM. Thus, lysine-based cationic liposomes can be a useful tool for intracellular protein delivery.

    Original languageEnglish
    Pages (from-to)164-174
    Number of pages11
    JournalMolecular Pharmaceutics
    Issue number1
    Publication statusPublished - 2014 Jan 6



    • amino acid-based cationic liposome
    • antibody
    • endocytosis
    • fluorescent labeled protein
    • intracellular protein delivery

    ASJC Scopus subject areas

    • Pharmaceutical Science
    • Molecular Medicine
    • Drug Discovery

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