Quantitative Assessment of the Comparative Nanoparticle‐Uptake Efficiency of a Range of Cell Lines

Abstract

The mechanism(s) of nanoparticle-cell interactions are still not understood. At present there is little knowledge of the relevant length- and timescales for nanoparticle intracellular entry and localization within cells, or the cell-specificity of nanoparticle uptake and localisation. Here, the effect of particle size on the in-vitro intracellular uptake of model fluorescent carboxyl-modified polystyrene nanoparticles is investigated in various cell lines. A range of micro- and nanoparticles of defined sizes (40 nm to 2 μm) are incubated with a series of cell types, including HeLa and A549 epithelial cells, 1321N1 astrocytes, HCMEC D3 endothelial cells, and murine RAW 264.7 macrophages. Techniques such as confocal microscopy and flow cytometry are used to study particle uptake and subcellular localisation, making significant efforts to ensure reproducibility in a semiquantitative approach. The results indicate that internalization of (nano)particles is highly size-dependent for all cell lines studied, and the kinetics of uptake for the same type of nanoparticle varies in the different cell types. Interestingly, even cells not specialized for phagocytosis are able to internalize the larger nanoparticles. Intracellular uptake of all sizes of particles is observed to be highest in RAW 264.7 cells (a specialized phagocytic cell line) and the lowest in the HeLa cells. These results suggest that (nano)particle uptake might not follow commonly defined size limits for uptake processes, and highlight the variability of uptake kinetics for the same material in different cell types. These conclusions have important implications for the assessment of the safety of nanomaterials and for the potential biomedical applications of nanoparticles.

Differences in Magnetic Particle Uptake by CNS Neuroglial Subclasses: Implications for Neural Tissue Engineering

“…Most work to date evaluating cellular MP uptake and handling has utilized cell lines [34][35][36][37][38]. This risks chronic contamination by mycoplasma -such 'cryptic' contamination can alter cell structure, metabolism and growth, all of which can impact the interpretation of data [42].…”

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

“…8,9 Previous studies have shown that the uptake of NPs by living cells is affected by NP properties such as size [10][11][12][13] and surface. [14][15][16] However, NPs dispersed in a biological fluid are rapidly covered by biomolecules, such as proteins and lipids, forming a biomolecular 'corona' that effectively screens the bare NP surface.…”

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

“…[1][2][3] Studying these interactions is a challenging topic due to the complexity and heterogeneity of the cell membrane. 1,4 Simpler models representative of the biological membranes provide a useful tool to perform focused studies and unravel the physical and chemical nature of NP-membrane interactions. 3 In fact, model membranes are versatile systems whose composition and structure can be precisely controlled and customized capturing essential aspects of the real membranes, without the influence of cell metabolism and growth.…”

“…5 NPs can adhere to the lipid bilayer and cause changes in the lipid phase, 7 induce formation of lipid domains [8][9] or pores and extract lipids 10 inducing lipid bilayer disruption. [11][12] Physical chemical properties of NPs, 5,13 such as size, 4,11,[14][15] charge 12,16 and surface chemistry [17][18][19][20] are the main factors modulating NP-membrane interactions.…”