Interaction between carbon nanotubes and mammalian cells: characterization by flow cytometry and application

Abstract

We show herein that CNT-cell complexes are formed in the presence of a magnetic field. The complexes were analyzed by flow cytometry as a quantitative method for monitoring the physical interactions between CNTs and cells. We observed an increase in side scattering signals, where the amplitude was proportional to the amount of CNTs that are associated with cells. Even after the formation of CNT-cell complexes, cell viability was not significantly decreased. The association between CNTs and cells was strong enough to be used for manipulating the complexes and thereby conducting cell separation with magnetic force. In addition, the CNT-cell complexes were also utilized to facilitate electroporation. We observed a time constant from CNT-cell complexes but not from cells alone, indicating a high level of pore formation in cell membranes. Experimentally, we achieved the expression of enhanced green fluorescence protein by using a low electroporation voltage after the formation of CNT-cell complexes. These results suggest that higher transfection efficiency, lower electroporation voltage, and miniaturized setup dimension of electroporation may be accomplished through the CNT strategy outlined herein.

Functional motor recovery from brain ischemic insult by carbon nanotube-mediated siRNA silencing

“…Most importantly, f -CNT have the ability to interact with biological components and be internalized efficiently in different cell types by different mechanisms (20)(21)(22). Several studies have shown promising results, exploiting f -CNT characteristics for pDNA and siRNA delivery in vitro and in vivo (17,18,20,(23)(24)(25)(26)(27)(28). Chemically functionalized single-walled CNT have been able to deliver siRNA to knockdown the expression of telomerase reverse transcriptase in an Lewis Lung Carcinoma mouse tumor model (26).…”

Zinc oxide nanoparticles as selective killers of proliferating cells

“…Hence, flow cytometry is a powerful tool for investigating the interaction between nanoparticles and cells. 32 The effect of zinc oxide nanoparticles on plasma membrane damage was assessed by permeability to propidium iodide. Cells were incubated with 20 µg/mL of zinc oxide nanoparticles for 6 hours (corresponding to an intracellular zinc concentration of 0.5 mM).…”

“…The strong interaction between osteocytes and the nanoparticles is reflected by the parallel strong increase of side scatter compared with the control cultures, indicative of increased cellular complexity due to nanoparticle-cell interaction. 32 It has been reported that nanomaterials can promote autophagy, [33][34][35][36] and this could be an alternative biological process altering the side scatter profile. Because autophagy ultimately causes cell death, the negligible cytotoxicity induced by zinc oxide nanoparticles on osteocytes (Figure 8) suggests that the alteration in side scatter could be a result of interaction with the nanomaterials rather than an autophagic process.…”

Molecular extraction in single live cells by sneaking in and out magnetic nanomaterials

“…Magnetized carbon nanotubes (MCNTs) driven by a magnetic force spear into cells and deliver molecular payloads. This method has demonstrated remarkable biocompatibility regarding cell viability, cell growth, cell cycle, DNA synthesis, cellular stimulation, and Akt and MAP kinase activities (25,26). Given that the nanotube can enter cells without detectable perturbations, using it to extract molecules from live cells would be an appealing mode of exploration.…”