Graphene oxide nanoparticles (GONPs) have attracted a lot of attention due to their many applications. These applications include batteries, super capacitors, drug delivery and biosensing. However, few studies have investigated the effects of these nanoparticles on the immune system. In this study, the in vitro effects of GONPs on the immune system was evaluated by exposing murine macrophages, RAW 264.7 cells and human whole blood cell cultures (to GONPs. The effects of GONPs on RAW cells were monitored under basal conditions. The whole blood cell cultures were exposed to GONPs in the presence or absence of the mitogens lipopolysaccharide (LPS) and phytohaemmagglutinin (PHA). A number of parameters were monitored for both RAW and whole blood cell cultures, these included cytotoxicity, inflammatory biomarkers, cytokines of the acquired immune system and a proteome profile analysis. The GONPs were cytotoxic to both RAW and whole blood cell cultures at 500 μg/mL. In the absence of LPS, GONPs elicited an inflammatory response from the murine macrophage, RAW and whole blood cell cultures at 15.6 and 5 μg/mL respectively. This activation was further corroborated by proteome profile analysis of both experimental cultures. GONPs inhibited LPS induced interleukin 6 (IL-6) synthesis and PHA induced interferon gamma (IFNγ) synthesis by whole blood cell cultures in a dose dependent manner. In the absence of mitogens, GONPs stimulated IL-10 synthesis by whole blood cell cultures. The current study shows that GONPs modulate immune system biomarkers and that these may pose a health risk to individuals exposed to this type of nanoparticle.

Carbon dots (CDs) are engineered nanoparticles that are used in a number of bioapplications such as bioimaging, drug delivery and theranostics. The effects of CDs on the immune system have not been evaluated. The effects of CDs on the immune system were assessed by using RAW 264.7 cells and whole blood cell cultures. RAW cells were exposed to CD concentrations under basal conditions. Whole blood cell cultures were exposed to CD concentrations under basal conditions or in the presence of the mitogens, lipopolysaccharide (LPS) or phytohaemmagglutinin (PHA). After exposure, a number of parameters were assessed, such as cell viability, biomarkers of inflammation, cytokine biomarkers of the acquired immune system and a proteome profile analysis. CDs were cytotoxic to RAW and whole blood cell cultures at 62.5, 250 and 500 μg/mL, respectively. Biomarkers associated with inflammation were induced by CD concentrations ≥250 and 500 μg/mL under basal conditions for both RAW and whole blood cell cultures, respectively. The humoral immune cytokine interleukin (IL)-10 was increased at 500 μg/mL CD under both basal and PHA activated whole blood cell culture conditions. Proteome analysis supported the inflammatory data as upregulated proteins identified are associated with inflammation. The upregulated proteins provide potential biomarkers of risk that can be assessed upon CD exposure.

Titanium dioxide nanoparticles (TiO2NPs) are found in a wide range of products such as sunscreen, paints, toothpaste and cosmetics due to their white pigment and high refractive index. These wide-ranging applications could result in direct or indirect exposure of these NPs to humans and the environment. Accordingly, conflicting levels of toxicity has been associated with these NPs. Therefore, the risk associated with these reports and for TiO2NPs produced using varying methodologies should be measured. This study aimed to investigate the effects of various media on TiO2NP properties (hydrodynamic size and zeta potential) and the effects of TiO2NP exposure on human colorectal adenocarcinoma (Caco-2) epithelial cell viability, inflammatory and cell stress biomarkers and angiogenesis proteome profiles. The NPs increased in size over time in the various media, while zeta potentials were stable. TiO2NPs also induced cell stress biomarkers, which could be attributed to the NPs not being cytotoxic. Consequently, TiO2NP exposure had no effects on the level of inflammatory biomarkers produced by Caco-2. TiO2NPs expressed some anti-angiogenic properties when exposed to the no-observed-adverse-effect level and requires further in-depth investigation.

Introduction 3. Material and methods 3.1. Characterization of silver nanoparticles 3.2. Preparation of silver nanoparticles 3.