Surface adsorption of protein corona controls the cell internalization mechanism of DC-Chol-DOPE/DNA lipoplexes in serum.
Serum has often been reported as a barrier to efficient lipid-mediated transfection. Here we found that the transfection efficiency of DC-Chol-DOPE/DNA lipoplexes increases in serum. To provide insight into the mechanism of lipoplex-serum interaction, several state-of-the-art methodologies have been applied. The nanostructure of DC-Chol-DOPE/DNA lipoplexes was found to be serum-resistant as revealed by high resolution synchrotron small angle X-ray scattering, while dynamic light scattering measurements showed a marked size increase of complexes. The structural stability of DC-Chol-DOPE/DNA lipoplexes was confirmed by electrophoresis on agarose gel demonstrating that plasmid DNA remained well protected by lipids. Proteomics experiments showed that serum proteins competed for the cationic surface of lipid membranes leading to the formation of a rich a 'protein corona'. Combining structural results with proteomics findings, we suggest that such a protein corona can promote large aggregation of intact lipoplexes. According to a recently proposed size-dependent mechanism of lipoplex entry within cells, protein corona-induced formation of large aggregates most likely results in a switch from a clathrin-dependent to caveolae-mediated entry pathway into the cells which is likely to be responsible for the observed transfection efficiency boost. As a consequence, we suggest that surface adsorption of protein corona can have a high biological impact on serum-resistant cationic formulations for in vitro and in vivo lipid-mediated gene delivery applications.
Caracciolo
Giulio
G
Chemistry Department, Sapienza University of Rome, P.le A. Moro 5, 00185 Rome, Italy. g.caracciolo@caspur.it
Callipo
Luciano
L
De Sanctis
Sofia Candeloro
SC
Cavaliere
Chiara
C
Pozzi
Daniela
D
Laganà
Aldo
A
D000327:Adsorption; D000818:Animals; D002784:Cholesterol / Q000031:analogs & derivatives* / Q000378:metabolism; D004247:DNA / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D004705:Endocytosis; D005347:Fibroblasts / Q000166:cytology* / Q000378:metabolism*; D006801:Humans; D008081:Liposomes / Q000378:metabolism*; D051379:Mice; D041681:NIH 3T3 Cells; D010316:Particle Size; D010714:Phosphatidylethanolamines / Q000378:metabolism*; D040901:Proteomics; D053838:Scattering, Small Angle; D044967:Serum; D055672:Static Electricity; D013499:Surface Properties; D017356:Synchrotrons; D014162:Transfection; D014961:X-Ray Diffraction
C410262:1,2-dioleoyl-glycero-3-phosphatidyl ethanolamine; D008081:Liposomes; D010714:Phosphatidylethanolamines; C070648:3-(N-(N',N'-dimethylaminoethane)carbamoyl)cholesterol; D004247:DNA; D002784:Cholesterol