Cationic Carbon Nanotubes Bind to CpG Oligodeoxynucleotides and Enhance Their Immunostimulatory Properties
Functionalized cationic carbon nanotubes are able to form a stable complex with CpG ODN based on charge interaction and to increase the immunostimulatory activity of CpG motifs.
Available from: Ebrahim Esfandiari
- "However, some controversy exists with regard to the biocompatible character of SWNTs and MWNTs, with some in vitro studies reporting that CNTs are cytotoxic. Additionally, some studies suggested CNTs to be excellent substrates for cellular growth. Mooney et al., reported that CNT suspension has good biocompatibility with mesenchymal stem cells (MSCs) and supports proliferation as well as differentiation of MSCs in the presence of an induction medium. "
[Show abstract] [Hide abstract]
ABSTRACT: Carbon nanotubes (CNTs) have a large variety of applications in tissue engineering and biomedical devices. The biocompatibility and cytotoxicity of CNTs have been studied widely, however, up until now; there was uncertainty on how nanosized materials behave in the human body and stem cells. The current study describes the functionalized carbon nanotubes on adipose-derived stem cells (ADSCs) for viability and proliferation purposes in vitro.
After chemical modification of the CNTs, the ADSCs were cultured in Dulbecco's Modified Eagle's. Medium (DMEM) having doses of 0.1, 1, 10, 20, 50, and 100 μg/ml of CNTs. On the third and seventh days of the experiment, the cellular viability, proliferation, and stemness were determined, using the MTT, trypan Blue, and flow cytometry assays in variable CNTs dosage.
In doses of 0.1 and 1 μg/ml, the expression of the surface markers were similar to the control groups on day three, but decreased in higher dosages on day seven. The viability of both groups was the same on day three, but in comparison to the control groups, was found to decrease in the higher dosages on day seven.
The effect of CNTs on the viability and proliferation of ADSCs is a function of time and the doses used. Through further investigation by using these particles, we expect that we should be able to increase the viability and proliferation of ADSCs.
Available from: Reinhild Klein
- "They can enter primary immune cells without exerting cytotoxicity, and this would fit our observations that poly-C60 and nepo-C60 also did not exhibit any cytotoxic action on PBMC, even when fullerene concentrations 100 times higher than those presented in this study were used (data not shown). There is, however another study indicating that different concentrations of f-CNT had no significant effect on the proliferation of activated or nonactivated splenic lymphocytes as well as the IL-6 production from mice, the authors also observing a modest increase in immunostimulatory activity when mouse splenocytes were cocultured with synthetic oligodeoxynucleotides containing CpG motifs known to react with TLR9.49 "
[Show abstract] [Hide abstract]
ABSTRACT: C60 nanoparticles, the so-called buckminsterfullerenes, have attracted great attention for medical applications as carriers, enzyme inhibitors or radical scavengers. However, publications evaluating their immunological mechanisms are still rather limited. Therefore, we aimed to analyze systematically the in vitro influence of polyhydroxy-C60 (poly-C60) and N-ethyl-polyamino-C60 (nepo-C60) on peripheral blood mononuclear cells (PBMC) from healthy individuals, angling their effect on proliferation, expression of surface markers, and cytokine production. We isolated PBMC from 20 healthy subjects and incubated them in a first step only with poly-C60 or nepo-C60, and in a second step together with recall antigens (purified protein derivative, tetanus toxoid, bacillus Calmette-Guérin). Proliferation was determined by (3)H-thymidine incorporation, activation of PBMC-subpopulations by flow cytometry by measurement of the activation marker CD69, and secretion of T helper cell type 1 (TH1)- (interferon-gamma [IFN-γ], tumor necrosis factor beta [TNF-β]), TH2- (interleukin-5 [IL-5], -13, -10) and macrophage/monocyte-related cytokines (IL-1, IL-6, TNF-α) into the supernatants by enzyme-linked immunosorbent assay. Both fullerenes did not influence T cell reactivity, with no enhanced expression of CD69 and production of T cell cytokines observed, the CD4/CD8 ratio remaining unaffected. In contrast, they significantly enhanced the release of IL-6 and CD69-expression by CD56 positive natural killer cells. PBMC, which had been cultured together with the three recall antigens were not affected by both fullerenes at all. These data indicate that fullerenes do not interact with T cell reactivity but may activate cells of the innate immune system. Furthermore, they seem to act only on 'naïve' cells, which have not been prestimulated with recall antigens, there are however, large inter individual differences.
Available from: Mathias Lösche
- "Previous studies involving several different cell types have demonstrated uptake of various types of functionalized CNTs[38-43]. Most studies show that CNTs enter cells via endocytosis[10-14]. "
[Show abstract] [Hide abstract]
ABSTRACT: Carbon nanotubes are increasingly being tested for use in cellular applications. Determining the mode of entry is essential to control and regulate specific interactions with cells, to understand toxicological effects of nanotubes, and to develop nanotube-based cellular technologies. We investigated cellular uptake of Pluronic copolymer-stabilized, purified ~145 nm long single wall carbon nanotubes (SWCNTs) through a series of complementary cellular, cell-mimetic, and in vitro model membrane experiments.
SWCNTs localized within fluorescently labeled endosomes, and confocal Raman spectroscopy showed a dramatic reduction in SWCNT uptake into cells at 4°C compared with 37°C. These data suggest energy-dependent endocytosis, as shown previously. We also examined the possibility for non-specific physical penetration of SWCNTs through the plasma membrane. Electrochemical impedance spectroscopy and Langmuir monolayer film balance measurements showed that Pluronic-stabilized SWCNTs associated with membranes but did not possess sufficient insertion energy to penetrate through the membrane. SWCNTs associated with vesicles made from plasma membranes but did not rupture the vesicles.
These measurements, combined, demonstrate that Pluronic-stabilized SWCNTs only enter cells via energy-dependent endocytosis, and association of SWCNTs to membrane likely increases uptake.
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.