A safety assessment of phototoxicity and sensitization of SiO2 nanoparticles

Bae

Experimental Dermatology

et al. 2017

Self Cite

Quantum dots (QDs) have shown great potential for biomedical use in a broad range including diagnostic agents. However, the regulatory mechanism of dermal toxicity is poorly understood. In this study, we investigated how QDs-induced apoptosis is regulated in human keratinocytes. We also examined the effect of carboxylic acid-coated QDs (QD 565 and QD 655) on reactive oxygen species (ROS) production and apoptosis-related cellular signalling. The viability of keratinocyte was inhibited by two types of QDs in a concentration-dependent manner. QDs induce ROS production and blockade of AKT phosphorylation. Moreover, the cleavage of AKT-dependent pro-apoptotic proteins such as poly (ADP-ribose) polymerase, caspases-3 and caspases-9 was significantly increased. We also found that a decrease in cellular ROS level by ROS scavenger, N-acetylcysteine (NAC), resulting in the abolishment of QDs-induced AKT de-phosphorylation and cellular apoptosis. Interestingly, QD 655 had a more cytotoxic effect including oxidative stress and AKT-dependent apoptosis than QD 565. In addition, QD 655 had the cytotoxic potential in the human skin equivalent model (HSEM). These data show that QD-induced intracellular ROS levels may be an important parameter in QD-induced apoptosis. These findings from this study indicate that intracellular ROS levels might determine the apoptotic potential of keratinocyte by QD via blockade of AKT phosphorylation.

Section: Discussionmentioning

confidence: 99%

Intracellular ROS levels determine the apoptotic potential of keratinocyte by Quantum Dot via blockade of AKT Phosphorylation

Bae

Experimental Dermatology

et al. 2017

Self Cite

“…13,14 SiO 2 (silica) nanoparticles are being utilized in a wide range of industrial applications, including as thickening agents, desiccants, toothpaste additives, and adsorbents. [15][16][17][18] With the increase in the demand for and production of nanomaterials, the general public will have a higher possibility of being exposed to engineered nanomaterials. Thus, the Working Party on Manufactured Nanomaterials (WPMN) of the Organization for Economic Cooperation and Development (OECD) selected 14 nanomaterials to analyze for potential human health risks.…”

Section: Introductionmentioning

confidence: 99%

Surface treatment of silica nanoparticles for stable and charge-controlled colloidal silica

An¹,

Kim²,

Kim³

et al. 2014

IJN

An attempt was made to control the surface charge of colloidal silica nanoparticles with 20 nm and 100 nm diameters. Untreated silica nanoparticles were determined to be highly negatively charged and have stable hydrodynamic sizes in a wide pH range. To change the surface to a positively charged form, various coating agents, such as amine containing molecules, multivalent metal cation, or amino acids, were used to treat the colloidal silica nanoparticles. Molecules with chelating amine sites were determined to have high affinity with the silica surface to make agglomerations or gel-like networks. Amino acid coatings resulted in relatively stable silica colloids with a modified surface charge. Three amino acid moiety coatings (L-serine, L-histidine, and L-arginine) exhibited surface charge modifying efficacy of L-histidine > L-arginine > L-serine and hydrodynamic size preservation efficacy of L-serine > L-arginine > L-histidine. The time dependent change in L-arginine coated colloidal silica was investigated by measuring the pattern of the backscattered light in a Turbiscan™. The results indicated that both the 20 nm and 100 nm L-arginine coated silica samples were fairly stable in terms of colloidal homogeneity, showing only slight coalescence and sedimentation.

“…8 SiO 2 nanoparticles have been widely used in a variety of industrial fields, including the plastics, rubber, ceramics, coatings, adhesives, and medical industries. 9,10 Numerous studies have reported the cytotoxicity, genotoxicity, and alterations in protein expression associated with SiO 2 nanoparticles in both in vitro and in vivo systems. 11,12 Further, it has been suggested that the genotoxicity caused by SiO 2 nanoparticles may be due to proinflammatory effects, modification of chromatin structure, and liberation of DNase or a potent inducer of cytogenetic damage.…”

Section: Introductionmentioning

confidence: 99%

Undetactable levels of genotoxicity of SiO2 nanoparticles in in vitro and in vivo tests

Kwon

Kim

et al. 2014

IJN

Background Silica dioxide (SiO 2 ) has been used in various industrial products, including paints and coatings, plastics, synthetic rubbers, and adhesives. Several studies have investigated the genotoxic effects of SiO 2 ; however, the results remain controversial due to variations in the evaluation methods applied in determining its physicochemical properties. Thus, well characterized chemicals and standardized methods are needed for better assessment of the genotoxicity of nanoparticles. Methods The genotoxicity of SiO 2 was evaluated using two types of well characterized SiO 2 , ie, 20 nm (−) charge (SiO EN20(−) 2) and 100 nm (−) charge (SiO EN100(−) 2). Four end point genotoxicity tests, ie, the bacterial mutation assay, in vitro chromosomal aberration test, in vivo comet assay, and in vivo micronucleus test, were conducted following the test guidelines of the Organization for Economic Cooperation and Development (OECD) with application of Good Laboratory Practice. Results No statistically significant differences were found in the bacterial mutation assay, in vitro chromosomal aberration test, in vivo comet assay, and in vivo micronucleus test when tested for induction of genotoxicity in both two types of SiO 2 nanoparticles. Conclusion These results suggest that SiO 2 nanoparticles, in particular SiO 2 EN20(−) and SiO 2 EN100(−) , are not genotoxic in both in vitro and in vivo systems under OECD guidelines. Further, the results were generated in accordance with OECD test guidelines, and Good Laboratory Practice application; it can be accepted as reliable information regarding SiO 2 -induced genotoxicity.