Showing papers by "Cheol-Su Kim published in 2014"

Immunotoxicity of zinc oxide nanoparticles with different size and electrostatic charge.

Abstract: While zinc oxide (ZnO) nanoparticles (NPs) have been recognized to have promising applications in biomedicine, their immunotoxicity has been inconsistent and even contradictory. To address this issue, we investigated whether ZnO NPs with different size (20 or 100 nm) and electrostatic charge (positive or negative) would cause immunotoxicity in vitro and in vivo, and explored their underlying molecular mechanism. Using Raw 264.7 cell line, we examined the immunotoxicity mechanism of ZnO NPs as cell viability. We found that in a cell viability assay, ZnO NPs with different size and charge could induce differential cytotoxicity to Raw 264.7 cells. Specifically, the positively charged ZnO NPs exerted higher cytotoxicity than the negatively charged ones. Next, to gauge systemic immunotoxicity, we assessed immune responses of C57BL/6 mice after oral administration of 750 mg/kg/day dose of ZnO NPs for 2 weeks. In parallel, ZnO NPs did not alter the cell-mediated immune response in mice but suppressed innate immunity such as natural killer cell activity. The CD4(+)/CD8(+) ratio, a marker for matured T-cells was slightly reduced, which implies the alteration of immune status induced by ZnO NPs. Accordingly, nitric oxide production from splenocyte culture supernatant in ZnO NP-fed mice was lower than control. Consistently, serum levels of pro/anti-inflammatory (interleukin [IL]-1β, tumor necrosis factor-α, and IL-10) and T helper-1 cytokines (interferon-γ and IL-12p70) in ZnO NP-fed mice were significantly suppressed. Collectively, our results indicate that different sized and charged ZnO NPs would cause in vitro and in vivo immunotoxicity, of which nature is an immunosuppression.

Toxicity of 100 nm zinc oxide nanoparticles: a report of 90-day repeated oral administration in Sprague Dawley rats

Abstract: Nanoparticles (NPs) are used commercially in health and fitness fields, but information about the toxicity and mechanisms underlying the toxic effects of NPs is still very limited. The aim of this study is to investigate the toxic effect(s) of 100 nm negatively (ZnOAE100[−]) or positively (ZnOAE100[+]) charged zinc oxide (ZnO) NPs administered by gavage in Sprague Dawley rats, to establish a no observed adverse effect level, and to identify target organ(s). After verification of the primary particle size, morphology, hydrodynamic size, and zeta potential of each test article, we performed a 90-day study according to Organisation for Economic Co-operation and Development test guideline 408. For the 90-day study, the high dose was set at 500 mg/kg and the middle and low doses were set at 125 mg/kg and 31.25 mg/kg, respectively. Both ZnO NPs had significant changes in hematological and blood biochemical analysis, which could correlate with anemia-related parameters, in the 500 mg/kg groups of both sexes. Histopathological examination showed significant adverse effects (by both test articles) in the stomach, pancreas, eye, and prostate gland tissues, but the particle charge did not affect the tendency or the degree of the lesions. We speculate that this inflammatory damage might result from continuous irritation caused by both test articles. Therefore, the target organs for both ZnOAE100(−) and ZnOAE100(+) are considered to be the stomach, pancreas, eye, and prostate gland. Also, the no observed adverse effect level for both test articles was identified as 31.25 mg/kg for both sexes, because the adverse effects were observed at all doses greater than 125 mg/kg.

Immunotoxicity of silicon dioxide nanoparticles with different sizes and electrostatic charge

Abstract: Silicon dioxide (SiO2) nanoparticles (NPs) have been widely used in the biomedical field, such as in drug delivery and gene therapy. However, little is known about the biological effects and potential hazards of SiO2. Herein, the colloidal SiO2 NPs with two different sizes (20 nm and 100 nm) and different charges (L-arginine modified: SiO2EN20[R], SiO2EN100[R]; and negative: SiO2EN20[−], SiO2EN100[−] were orally administered (750 mg/kg/day) in female C57BL/6 mice for 14 days. Assessments of immunotoxicity include hematology profiling, reactive oxygen species generation and their antioxidant effect, stimulation assays for B- and T-lymphocytes, the activity of natural killer (NK) cells, and cytokine profiling. In vitro toxicity was also investigated in the RAW 264.7 cell line. When the cellularity of mouse spleen was evaluated, there was an overall decrease in the proliferation of B- and T-cells for all the groups fed with SiO2 NPs. Specifically, the SiO2EN20(−) NPs showed the most pronounced reduction. In addition, the nitric oxide production and NK cell activity in SiO2 NP-fed mice were significantly suppressed. Moreover, there was a decrease in the serum concentration of inflammatory cytokines such as interleukin (IL)-1β, IL-12 (p70), IL-6, tumor necrosis factor-α, and interferon-γ. To elucidate the cytotoxicity mechanism of SiO2 in vivo, an in vitro study using the RAW 264.7 cell line was performed. Both the size and charge of SiO2 using murine macrophage RAW 264.7 cells decreased cell viability dose-dependently. Collectively, our data indicate that different sized and charged SiO2 NPs would cause differential immunotoxicity. Interestingly, the small-sized and negatively charged SiO2 NPs showed the most potent in vivo immunotoxicity by way of suppressing the proliferation of lymphocytes, depressing the killing activity of NK cells, and decreasing proinflammatory cytokine production, thus leading to immunosuppression.

Toxicity of colloidal silica nanoparticles administered orally for 90 days in rats

Abstract: This study was undertaken to investigate the potential toxicity and establish the no observed adverse effect level (NOAEL) and target organ(s) of negatively charged colloidal silica particles of different sizes, ie, SiO2 (EN20(-)) (20 nm) or SiO2 (EN100(-)) 2(100 nm), administered by gavage in Sprague-Dawley rats. After verification of the physicochemical properties of the SiO2 particles to be tested, a preliminary dose range-finding study and 90-day repeated dose study were conducted according to the Organisation for Economic Cooperation and Development test guideline. Based on the results of the 14-day dose range-finding study, a high dose was determined to be 2,000 mg/kg, and middle and low doses were set at 1,000 and 500 mg/kg, respectively. In the 90-day toxicity study, there were no animal deaths in relation to administration of SiO2 particles of either size. In addition, no treatment-related clinical changes or histopathological findings were observed in any of the experimental groups. Moreover, no difference in toxic effects from chronic exposure to SiO2 (EN20(-))(20 nm) or SiO2 (EN100(-)) (100 nm) was observed. The results of this study indicate that the NOAEL for SiO2 (EN20(-)) and SiO2 (EN100(-)) would most likely be 2,000 mg/kg, and no target organ was identified in rats of either sex.

Association of serum and intratumoral cytokine profiles with tumor stage and neutrophil lymphocyte ratio in colorectal cancer.

Abstract: Background We examined cytokine profiles and evaluated the association between cytokine levels, pathological stages, and neutrophil/lymphocyte ratio (NLR). Materials and methods Patients with colorectal cancer (n=20, TNM stage I, II, and III) were enrolled. Levels of nine cytokines [interleukin (IL)-4,-6, -8, -10, -12, tumor necrosis factor-alpha (TNF-α), granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon-gamma (IFN-γ), and vascular endothelial growth factor (VEGF)] were measured in serum, normal mucosa, and tumor using the Bio-Plex® cytokine assay. Results The mean IL8, GM-CSF and VEGF levels were higher in tumors, whereas the mean IL6 level was higher in serum. Cytokine levels correlated with TNM stage (IL6 and IL8 in serum, and IL8 and VEGF in tumor) and with NLR (IL6 and IL8 in serum, and IL8 in tumor). Conclusion Different cytokine profiles were observed in serum, normal mucosa, and tumor tissue. The elevation of specific cytokines in sera or tumors reflects features of advanced disease.

Positive Effects of hydrogen water on 2,4-dinitrochlorobenzene-induced atopic dermatitis in NC/Nga mice.

Abstract: Atopic dermatitis (AD) is a chronically relapsing, pruritic, eczematous skin disorder accompanying allergic inflammation. AD is triggered by oxidative stress and immune imbalance. In the present study, we investigated the effect of drinking hydrogen water (HW) on 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis in NC/Nga mice and found that HW ameliorated DNCB-induced AD-like clinical symptoms. In line with this, the level of reactive oxygen species in the HW group was significantly inhibited compared with that in the purified water (PW) group. In parallel, HW enhanced glutathione peroxidase activity in DNCB-induced AD as compared with the PW group. Accordingly, the levels of thymus and activation-regulated chemokine and cytokines were significantly decreased in the HW group compared with the PW group. Notably, the levels of Th2 cytokine, interleukin-5 (IL-5), and proinflammatory cytokines such as tumor necrosis factor-α and IL-6 in HW-fed mice were significantly lower than in control and PW-fed mice. The total serum immunoglobulin E level was also markedly reduced in the HW group. The collective results indicate that HW suppresses DNCB-induced AD in NC/Nga mice via redox balance and immune modulation and could be a safe clinical fluid treatment for AD.

Immunological Profiling of Obesity.

Abstract: It is widely accepted that chronic inflammation contributes to the pathogenesis of obesity. Researchers have recently discovered that increased inflammatory cytokines and the infiltration and activation of macrophage cells in the adipose tissue are related to chronic obesity. This immunologic dysregulation has led to the development of the classical pro-inflammatory paradigm. However, since chronic inflammation associated with obesity is more than just the overproduction of pro-inflammatory cytokines, precise dissection requires beyond the classical pro-inflammatory cytokines. The purpose of this review is to summarize the immunological profiling of obesity for theragnostic convenience, focusing on the cytokine and adipokine network in obesity and the significance of the balance of Th1/Th2 immunity.

Immunotoxicity of metal oxide nanoparticle: zinc oxide

Abstract: Nanoparticles (NPs) are characterized by notable physico-chemical features such as size, surface charge, porosity, and shape when compared to their bulk counterparts. Recent studies on NPs have drawn tremendous attention owing to their accelerating demands and applications in diverse sectors such as industry, medicine, agriculture and energy production. However, the novel properties of nanoparticles hold uncertainty in terms of safety, specifically during interaction with the cell, DNA, protein, lipid and cellular membrane. Even though nanotechnology holds considerable promise, the novel properties of NPs may pose detriment to the biological system. While NPs interact with the immune system of host, their immunotoxicity (toxicity of the NPs to the immune system) still remain unexplored. Furthermore, NPs can pose danger to the immune system, which can be categorized as immunostimulation and/or immunosuppression. Despite this divergent category, there is no international guideline for immunotoxicity assessment of NPs. Existing parameters for toxicity evaluation are designed for toxic substances, not specific for NPs. This review will focus on the immunotoxicity of metal oxide nanoparticles in general as well as nano zinc oxide in particular, followed by the limitations of the existing parameters in gauging immunotoxicity and the new aspect of nanoimmunotoxicity based on current techniques.