Nanoparticle Adhesion to the Cell Membrane and Its Effect on Nanoparticle Uptake Efficiency

Abstract

ABSTRACT:The interactions between nano-sized particles and living systems are commonly mediated by what adsorbs to the nanoparticle in the biological environment, its "biomolecular corona", rather than the pristine surface. Here we characterise the adhesion towards the cell membrane of nanoparticles of different material and size, and study how this is modulated by the presence or absence of a corona on the nanoparticle surface. The results are corroborated with adsorption to simple model supported lipid bilayers using a quartz crystal microbalance. We conclude that the adsorption of proteins on the nanoparticle surface strongly reduces nanoparticle adhesion in comparison to what is observed for the bare material. Nanoparticle uptake is described as a two-step process, where the nanoparticles initially adhere to the cell membrane and subsequently are internalised by the cells via energy-dependent pathways. The lowered adhesion in the presence of proteins thereby causes a concomitant decrease in nanoparticle uptake efficiency. The presence of a biomolecular corona may confer specific interactions between the nanoparticle-corona complex and the cell surface, including triggering of regulated cell uptake. An important effect of the corona is, however, a reduction in the purely unspecific interactions between the bare material and the cell membrane, which in itself disregarding specific interactions, causes a decrease in cellular uptake. We suggest that future nanoparticle-cell studies include, together with characterisation of size, charge and dispersion stability, an evaluation of the adhesion properties of the material to relevant membranes.

Reply to 'The interface of nanoparticles with proliferating mammalian cells'

“…The ranking in cell fluorescence, on the other hand, must be interpreted with care. Certainly, a large part of the signal at these short exposure times may come from nanoparticles adsorbed to the outer cell membrane, as we have shown previously 4 . This is consistent with larger (G2/M) cells exhibiting a higher fluorescence than smaller (G1) cells.…”

A surface plasmon enhanced FLIM-FRET imaging approach based on Au nanoparticles

“…Lifetime of GFP in cell culture is found to be around 2ns, as seen in the lifetime distribution in Figure 1(f). This lifetime value is in consistent with published results [43,44]. By comparing the images shown in Figure 1, we can confirm that early endosomes in Hela cells have been well stained by GFP.…”

The effect of the protein corona on the interaction between nanoparticles and lipid bilayers

“…Notwithstanding the limitation of our model with respect to a cellular membrane for which the structure is much more complex, we can state that both shear flow 60 and excess of proteins, which reduce NP surface free energy, 23,61 influence NP adhesion to lipid membranes when unspecific interactions are predominant. Overall, our results suggest that while the presence of hard corona flattens the interaction between NPs and model lipid bilayers, the associated soft corona affects the structure of the bilayer in a different way compared to free proteins.…”

“…22 Since the PC affects the properties of the NP surface, it has significant impact on the interaction between membrane and NPs. [23][24][25][26][27] Many studies are described in the literature where NP cellular uptake is related to the presence of a PC on the NPs in biological fluids, [28][29][30] in particular it has been shown that a key factor in NPs cellular uptake is their adhesion to the cell membrane that significantly affects their final uptake rates. 31 NP-cell membrane interaction is a complex dynamic process in which the environmental proteins are known to play an important multifaceted role: not only they adsorb onto the NP surface forming the PC, but also they compete with the NP in the interaction with the cell membrane.…”