Cellular Uptake and Cytotoxicity of Varying Aspect Ratios of Gold Nanorods in HeLa Cells

Abstract

Gold nanorods (GNRs) have received broad attention due to their tunable surface plasmonic resonance modes, which make them an attractive candidate for biomedical applications in drug and gene delivery, biological imaging, and cancer treatment. In this study, we highlight the interactions of four different aspect ratios (ARs), 2.6, 3.2, 5.4 and 11.5, of GNRs with HeLa cells with respect to cellular uptake and cellular viability while also considering the effects of other parameters such as the surface stabilizer, supernatant, and serum proteins present in the medium. From this work, it was determined that the cell viability depended on the chemical composition of the supernatant, especially the amount of excess surfactant, hexadecyltrimethylammonium bromide (CTAB), used for the synthesis of GNRs; thus, the effect of aspect ratio of GNRs on endocytosis could not be directly discerned. For example, when exposed to GNRs of aspect ratio 11.5, HeLa cells showed higher cellular uptake compared to the shorter aspect ratios and a lower cytotoxicity simply because of the lower concentration of CTAB used during the synthesis, and a gentler purification method, such as sedimentation, also appeared to be a factor. Overall, the synthesis protocols, functionalization, purification processes, and the stability of GNRs in media have a major effect on cellular uptake and viability. Our results suggest that perhaps AR does play a role in endocytosis although an overall trend could not be unequivocally established, and sedimentation, contact time, and internalization kinetics need to be probed further using more biocompatible ligands in future studies.

The Potential of Cell-Penetrating Peptides for mRNA Delivery to Cancer Cells

“…Moreover, p5RHH and RALA promote effective membrane permeability because of their facial amphiphilicity, which indicates a segregated structural type with cationic moieties on one side and hydrophobic moieties on the other side [49]. Since the cellular uptake of nanoparticles disrupts membrane stability and leads to cytotoxicity [50], our results confirmed that the cytotoxicity (Figure 4) and uptake efficiencies are strongly correlated. Taken together, these data suggest that amphipathic CPPs capable of forming nano-sized (<200) complexes with mRNA are suitable for cellular uptake.…”

Improvements in Gold Nanorod Biocompatibility with Sodium Dodecyl Sulfate Stabilization

“…Fernando et al [70] tested the cytotoxicity and cellular uptake of CTAB-GNRs and PEG coated GNRs in HeLa cells, demonstrating that CTAB-GNRs are more toxic to HeLa…”

“…Fernando et al [70] tested the cytotoxicity and cellular uptake of CTAB-GNRs and PEG coated GNRs in HeLa cells, demonstrating that CTAB-GNRs are more toxic to HeLa cells because of the persistence in solution of unbound CTAB from the synthesis. Even though the PEG-GNRs were safer than the CTAB-capped GNRs, this study reports that HeLa cells did not readily internalize the PEG-GNRs at 10, 24, or 48 h after treatment.…”

Multifunctional Gold Nanorod for Therapeutic Applications and Pharmaceutical Delivery Considering Cellular Metabolic Responses, Oxidative Stress and Cellular Longevity

“…Another biocompatible overcoating agent, phosphatidylcholine, reduces the reported cytotoxicity of CTAB-coated GNR. Deshani et al observed that GNR covered with CTAB and then overcoated with polyelectrolytes show 90 percent cell viability for HeLa cells and cause no change in gene expression levels: only 35 of the 10,000 genes analyzed were slightly down-regulated [ 114 ].…”