Effects of lipid redistribution on protocell nanoparticles uptake by cells

Coating of biomembrane on the nanoparticles can enhance their biocompatibility, targeting and controllability of inclusions release. However, the interaction mechanism between the protocell nanoparticles and cell membranes remains unclear. In this study, we have investigated the in vitro endocytosis of porous silicon nanoparticles coated with negative lipid membranes with different lateral fluidities. It was found that the fluid liquid-phase lipid coating produced a high endocytosis efficiency, while its endocytosis pathway was also different from that of the low fluid gel-phase lipid coating. Derjaguin-Landau-Verway-Overbeek theoretical analysis showed that lipid rearrangement can promote the fusion between biomembrane and cell membrane as well as particle endocytosis in the former case. However, a high energy barrier was observed in the membrane fusion in the latter case. So a pinocytosis uptake pathway was preferred. Our research deepens the understanding of the endocytosis of protocell nanoparticles. It also provides new insight and references for the design of complex nanoparticle-based drug carriers in the future. (authors)