title: Understanding the mechanism of protamine in solid lipid nanoparticle-based lipofection: the importance of the entry pathway.
abstract: The aim of our study was to evaluate the effect of protamine on the transfection capacity of solid lipid nanoparticles (SLNs) by correlating it to the internalization mechanisms and intracellular trafficking of the vectors. Vectors were prepared with SLN, DNA, and protamine. ARPE-19 and HEK-293 cells were used for the evaluation of the formulations. Protamine induced a 6-fold increase in the transfection of SLNs in retinal cells due to the presence of nuclear localization signals (NLS), its protection capacity, and a shift in the internalization mechanism from caveolae/raft-mediated to clathrin-mediated endocytosis. However, protamine produced an almost complete inhibition of transfection in HEK-293 cells. In spite of the high DNA condensation capacity of protamine and its content in NLS, this does not always lead to an improvement in cell transfection since it may impair some of the limiting steps of the transfection processes.
authors: Pharmacy and Pharmaceutical Technology Laboratory, University of Basque Country (UPV-EHU), Vitoria-Gasteiz, Spain.
authors: Diego
authors: D
authors: Delgado
authors: Ana
authors: A
authors: del Pozo-Rodríguez
authors: Maria Ángeles
authors: MÁ
authors: Solinís
authors: Alicia
authors: A
authors: Rodríguez-Gascón
mesh_terms: D002470:Cell Survival / Q000187:drug effects; D004247:DNA / Q000008:administration & dosage / Q000235:genetics / Q000378:metabolism; D004337:Drug Carriers / Q000737:chemistry* / Q000633:toxicity; D004591:Electrophoresis, Polyacrylamide Gel; D004705:Endocytosis; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism; D005434:Flow Cytometry; D049452:Green Fluorescent Proteins / Q000235:genetics; D057809:HEK293 Cells; D006801:Humans; D008055:Lipids / Q000737:chemistry* / Q000633:toxicity; D008856:Microscopy, Fluorescence; D053758:Nanoparticles / Q000737:chemistry; D010316:Particle Size; D010957:Plasmids; D011479:Protamines / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D055213:Retinal Pigment Epithelium / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D013499:Surface Properties; D014162:Transfection / Q000379:methods*
chemical_list: D004337:Drug Carriers; D008055:Lipids; D011479:Protamines; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D004247:DNA