Table 1 Brief overview of recent publications pointing at a possible role of surface charge in interaction of nanoparticles with cells
Citation (Year) | Nanoparticle tested | Size of nanoparticle (nm) | Cell Line tested (in vitro/in vivo) | Endpoints studied | Results/Inferences |
|---|---|---|---|---|---|
Ruizendaal et al. (2009) [6] | Si NP with amine (+), azide (neutral) and acid (-) surface functionalization | 1.6 ± 0.2 | Caco-2 | MTT, BrdU | Positively charged Si NP-NH2 more cytotoxic than neutral Si NP-N3. Negatively charged Si NP-COOH did not show toxicity. |
Geys et al. (2009) [11] | Quantum dots (amine terminated, neutral, carboxylate terminated) | 25 | Primary alveolar epithelial cells | MTT, TEER, sodium fluorescein leakage, confocal microscopy | Surface charge did not show any influence on translocation through the cell line. |
Corsi et al. (2009) [12] | Iron based magnetic nanoparticles | 7 ± 3 | MCF7 carcinoma cells | MTT | Anionic nanoparticles were spontaneously internalized. Cationic ones were taken up by clathrin receptor mediated endocytosis. |
Sadiq et al. (2009) [13] | Aluminium oxide | 179 | E. coli | Bacterial growth, Infrared spectroscopy | Interaction between positively charged particles and bacteria was found |
Xu et al. (2009) [14] | Hemoglobin loaded polymeric NPs | < 200 | (MPM) cell line from SD mice | MTT, in vivo biodistribution and clearance of NPs | No influence of surface charge on cytotoxicity was observed. |
Nafee et al. (2009) [15] | Chitosan modified PLGA | between 150 and 250 | COS-1, A549, Calu-3 | MTT, LDH, ATP, TEER, SFM | Higher zeta potential was connected with lower toxicity for COS-1, while no effect of surface charge was found for A549 cells. |
Pathak et al. (2009) [16] | Branched polyethylenimine with chondroitin sulphate | between 80 and 190 | HeLa, HepG2 | MTT, DNA release, protein adsorption, confocal microscopy, gene transfection, radiolabelling, biodistribution, scintigraphy | Reduction in positive charge by increasing the percentage of chondroitin sulphate decreases cytotoxicity. |
Mayer et al. (2009) [17] | Polystyrene | 26, 34, 62, 160, and 220 | Human blood | Flow cytometry for thrombocyte and granulocyte activation, plasma coagulation assay, light microscopy, membrane integrity assay, C3a and C5a ELISA, hemolysis | Positive surface charge led to complement activation. |
Zhang et al. (2009) [18] | Amine, PEG and carboxylic acid terminated CdSe quantum dots with ZnS shell | 12×6 | HEK | TEM, quantification of quantum dot fluorescence, immunostaining | Uptake of amine-terminated quantum dots proceeds by caveolin/clathrin pathway, while that of carboxylic acid terminated ones proceed by GPCR pathway |
Nam et al. (2009) [19] | Glycol chitosan with 5β cholanic acid | 359 | HeLa | Cellular uptake studies | Increase in positive charge results in enhanced uptake and distribution by clathrin, caveolin receptor mediated, macropinocytosis. |
Gupta et al. (2009) [20] | Polyacrylic acid and YFa | 83 ± 8 | HepG2, N2a, HEK293 | MTT, RBC, WBC, platelet count from blood samples, in vitro peptide release study | Positively charged particles do not have any toxic behaviour. |
Kim et al. (2008) [21] | Quantum dot nanocomposites | 104.5 ± 7.8 | SNB19 | Scanning electron microscopy, TIRF, cell viability | Cationic coating at basic pH, makes the NPs more biocompatible. |
Hauck et al. (2008) [22] | Gold nanorods with polyelectrolyte surface coating | 18×40 | Vi-cell, HeLa | TEM, Trypan Blue exclusion, gene expression | Only CTAB (positively charged) coated particles were toxic in absence of FCS. |
Orr et al. (2007) [23] | Silica | 100, 500 | C10 (alveolar type II epithelial cell line) | X-ray diffraction, TEM, DIC, SEM | Positively charged particles can reach the cells through filopodia and microvilli-like structures. Positive surface charge and intact actin filaments are essential for retrograde movement of the particles. |