Effects of naked gold nanoparticles on proinflammatory cytokines mRNA expression in rat liver and kidney

Accumulation and toxicity of biologically produced gold nanoparticles in different types of specialized mammalian cells

The biologically produced gold nanoparticles (AuNPs) are novel carriers with promising use in targeted tumor therapy. Still, there are no studies regarding the efficacy of nanoparticle internalization by cancer and noncancer cells. In this study, AuNPs were produced by Fusarium oxysporum and analyzed by spectrophotometry, transmission electron microscopy (TEM), energy dispersive x-ray spectroscopy (EDS), and Zetasizer. Obtained AuNPs were about 15 nm in size with a zeta potential of -35.8 mV. The AuNPs were added to cancer cells (4T1), noncancer cells (NIH/3T3), and macrophages (RAW264.7). The viability decreased in 4T1 (77 ± 3.74%) in contrast to NIH/3T3 and RAW264.7 cells (89 ± 4.9% and 90 ± 3.5%, respectively). The 4T1 cancer cells also showed the highest uptake and accumulation of Au (∼80% of AuNPs was internalized) as determined by graphite furnace atomic absorption spectroscopy. The lowest amount of AuNPs was internalized by the NIH/3T3 cells (∼30%). The NIH/3T3 cells exhibited prominent reorganization of F-actin filaments as examined by confocal microscopy. In RAW264.7, we analyzed the release of proinflammatory cytokines by flow cytometry and we found the AuNP interaction triggered transient secretion of tumor necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ). In summary, we proved the biologically produced AuNPs entered all the tested cell types and triggered cell-specific responses. High AuNP uptake by tumor cells was related to decreased cell viability, while low nanoparticle uptake by fibroblasts triggered F-actin reorganization without remarkable toxicity. Thus, the biologically produced AuNPs hold promising potential as cancer drug carriers and likely require proper surface functionalization to shield phagocytizing cells.

Gold Nanoparticles (AuNPs)-Toxicity, Safety and Green Synthesis: A Critical Review

In recent years, the extensive exploration of Gold Nanoparticles (AuNPs) has captivated the scientific community due to their versatile applications across various industries. With sizes typically ranging from 1 to 100 nm, AuNPs have emerged as promising entities for innovative technologies. This article comprehensively reviews recent advancements in AuNPs research, encompassing synthesis methodologies, diverse applications, and crucial insights into their toxicological profiles. Synthesis techniques for AuNPs span physical, chemical, and biological routes, focusing on eco-friendly "green synthesis" approaches. A critical examination of physical and chemical methods reveals their limitations, including high costs and the potential toxicity associated with using chemicals. Moreover, this article investigates the biosafety implications of AuNPs, shedding light on their potential toxic effects on cellular, tissue, and organ levels. By synthesizing key findings, this review underscores the pressing need for a thorough understanding of AuNPs toxicities, providing essential insights for safety assessment and advancing green toxicology principles.

Zinc citrate-coated whey protein nanoparticles alleviate kidney damage and the disturbances in inflammatory gene expression in rats

This work was conducted to synthesize whey protein nanoparticles (WPNPs) for the coating of zinc citrate (Zn CITR) at three levels and to study their protective role against CCl4 -induced kidney damage and inflammatory gene expression disorder in rats. Seventy male Sprague-Dawley rats were divided into seven groups and treated orally for 4 weeks as follows; the control group, the group treated twice a week with CCl4 (5 mL/kg b.w), the groups received CCl4 plus WPNPs (300 mg/kg b.w); the group received 50 mg/kg b.w of Zn CITR or the three formulas of Zn CITR-WPNPs at low, medium and high doses (LD, MD, and HD). Blood and kidney samples were collected for different assays and histological analyses. The fabricated particles were semispherical, with an average size of 160 ± 2.7, 180 ± 3.1, and 200 ± 2.6 nm and ζ potential of -126, -93, and -84 mV for ZN CITR-WPNPs (LD), Zn CITR-WPNPs (MD), and ZN CITR-WPNPs (HD), respectively. CCl4 significantly increased (p ≤ 0.05) kidney function indices, oxidative stress markers, messenger RNA expression of transforming growth factor-β1, interleukin (IL)-1β, IL-10, IL-6, inducible nitric oxide synthase, and tumor necrosis factor-α and significantly decreased (p ≤ 0.05) renal superoxide dismutase, catalase, and glutathione peroxidase along with the histological changes in the kidney tissues. WPNPs, Zn CITR, and Zn CITR loaded WPNPS showed a protective effect against these complications and Zn CITR-WPNPs (LD) was more effective. WPNPs can be used effectively for coating Zn CITR at a level of 7 mg/g WPNPs to be used as a supplement for the protection of the kidney against different toxicants to enhance immunity and avoid harm of excess Zn.

Impact of gold nanoparticles (AuNPs) on eosinophils isolated from male and female individuals

It is well established that some differences exist between the male and female immune systems. Despites this, a sex-based analysis is not frequently performed in most scientific published reports. Knowing that inflammation is a common undesired effect observed resulting from nanoparticle (NP) exposure, we investigate here how in vitro treatment of gold NPs with a primary size of 20 and 70 nm (AuNP20 and AuNP70, respectively) will alter the biology of human eosinophils isolated from men and women blood. We found that treatment of AuNP70, but not AuNP20, significantly delay apoptosis only in eosinophils isolated from women. AuNPs were found to decrease eosinophil phagocytosis, however, significance was only observed in AuNP20-induced eosinophils isolated from women. The production of IL-8 was significantly increased in response to both AuNPs but only in eosinophils isolated from men and the production of IL-1β was increased in AuNPs-induced eosinophils, although significance was observed only in AuNP70-induced eosinophils isolated from women. We conclude that future studies investigating the toxicity of AuNPs (or other NPs) should include a sex-based analysis, especially if the tested NPs have potential medical applications knowing the increased interest in the development of personalized precision medicine.

Impact of gold nanoparticles (AuNPs) in human neutrophils in vitro and in leukocytes attraction in vivo: A sex-based analysis

Some differences exist between the male and female immune systems. Despite this, a sex-based analysis is not frequently performed in most studies. Knowing that inflammation is a common undesired effect observed resulting from nanoparticle (NP) exposure, we investigate here how gold NPs with a primary size of 20 (AuNP20) and 70 nm (AuNP70) will alter the biology of polymorphonuclear neutrophil cells (PMNs) isolated from men and women as well as their potential pro-inflammatory effect in vivo in male and female mice. We found that AuNP20 significantly delay apoptosis only in PMN isolated from men. The production of interleukin (IL)- 8 by PMNs was increased by both AuNPs regardless of sex although significance was only observed in AuNP20-induced PMNs. Using the murine air pouch model of inflammation, AuNPs did not induce a neutrophilic infiltration regardless of sex. In conclusion, AuNPs could differently alter the biology of PMNs according to sex.

Metal-Based Nanoparticles and Their Relevant Consequences on Cytotoxicity Cascade and Induced Oxidative Stress

Emerging nanoscience allows us to take advantage of the improved evolutionary components and apply today’s advanced characterization and fabrication techniques to solve environmental and biological problems. Despite the promise that nanotechnology will improve our lives, the potential risks of technology remain largely uncertain. The lack of information on bio-impacts and the absence of consistent standards are the limitations of using metal-based nanoparticles (mNPs) for existing applications. To analyze the role played by the mNPs physicochemical characteristics and tactics to protect live beings, the field of nanotoxicology nowadays is focused on collecting and analyzing data from in vitro and in vivo investigations. The degree of reactive oxygen species (ROS) and oxidative stress caused by material nanoparticles (NPs) depends on many factors, such as size, shape, chemical composition, etc. These characteristics enable NPs to enter cells and interact with biological macromolecules and cell organelles, resulting in oxidative damage, an inflammatory response, the development of mitochondrial dysfunction, damage to genetic material, or cytotoxic effects. This report explored the mechanisms and cellular signaling cascades of mNPs-induced oxidative stress and the relevant health consequences.

Effects of Antioxidant Combinations on the Renal Toxicity Induced Rats by Gold Nanoparticles

This study investigated some possible mechanisms underlying the nephrotoxic effect of gold nanoparticles (AuNPs) in rats and compared the protective effects of selected known antioxidants-namely, melanin, quercetin (QUR), and α-lipoic acid (α-LA). Rats were divided into five treatment groups (eight rats per group): control, AuNPs (50 nm), AuNPs + melanin (100 mg/kg), AuNPs + QUR (200 mg/kg), and AuNPs + α-LA (200 mg/kg). All treatments were administered i.p., daily, for 30 days. AuNPs promoted renal glomerular and tubular damage and impaired kidney function, as indicated by the higher serum levels of creatinine (Cr), urinary flow, and urea and albumin/Cr ratio. They also induced oxidative stress by promoting mitochondrial permeability transition pore (mtPTP) opening, the expression of NOX4, increasing levels of malondialdehyde (MDA), and suppressing glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT). In addition, AuNPs induced renal inflammation and apoptosis, as evidenced by the increase in the total mRNA and the cytoplasmic and nuclear levels of NF-κB, mRNA levels of Bax and caspase-3, and levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). Treatment with melanin, QUR, and α-lipoic acid (α-LA) prevented the majority of these renal damage effects of AuNPs and improved kidney structure and function, with QUR being the most powerful. In conclusion, in rats, AuNPs impair kidney function by provoking oxidative stress, inflammation, and apoptosis by suppressing antioxidants, promoting mitochondrial uncoupling, activating NF-κB, and upregulating NOX4. However, QUR remains the most powerful drug to alleviate this toxicity by reversing all of these mechanisms.

18F-fluorodeoxyglucose (18F-FDG) Functionalized Gold Nanoparticles (GNPs) for Plasmonic Photothermal Ablation of Cancer: A Review

The meeting and merging between innovative nanotechnological systems, such as nanoparticles, and the persistent need to outperform diagnostic-therapeutic approaches to fighting cancer are revolutionizing the medical research scenario, leading us into the world of nanomedicine. Photothermal therapy (PTT) is a non-invasive thermo-ablative treatment in which cellular hyperthermia is generated through the interaction of near-infrared light with light-to-heat converter entities, such as gold nanoparticles (GNPs). GNPs have great potential to improve recovery time, cure complexity, and time spent on the treatment of specific types of cancer. The development of gold nanostructures for photothermal efficacy and target selectivity ensures effective and deep tissue-penetrating PTT with fewer worries about adverse effects from nonspecific distributions. Regardless of the thriving research recorded in the last decade regarding the multiple biomedical applications of nanoparticles and, in particular, their conjugation with drugs, few works have been completed regarding the possibility of combining GNPs with the cancer-targeted pharmaceutical fluorodeoxyglucose (FDG). This review aims to provide an actual scenario on the application of functionalized GNP-mediated PTT for cancer ablation purposes, regarding the opportunity given by the 18F-fluorodeoxyglucose (18F-FDG) functionalization.

Concomitant Sub-Chronic Administration of Small-Size Gold Nanoparticles Aggravates Doxorubicin-Induced Liver Oxidative and Inflammatory Damage, Hyperlipidemia, and Hepatic Steatosis

This study examined the effect of gold nanoparticles (AuNPs) on doxorubicin (DOX)-induced liver damage and steatosis in rats and tested its effect mechanism. Wistar male rats were divided into four groups (each of eight rats) as control, AuNPs (50 µL of 10 nm), DOX (15 mg/kg; 3 mg/kg/week), and DOX + AuNPs-treated rats. DOX is known to induce fasting hyperglycemia and hyperinsulinemia in treated rats. Individual treatment of both DOX and AuNPs also promoted liver damage, increased circulatory levels of ALT and AST, and stimulated serum and liver levels of TGs, CHOL, LDL-c, and FFAs. They also stimulated MDA, TNF-α, and IL-6, reduced GSH, SOD, HO-1, and CAT, upregulated mRNA levels of Bax and caspases-3 and -8 and downregulated mRNA levels of Bcl2 in the livers of rats. However, while DOX alone reduced hepatic levels of PPARα, both AuNPs and DOX stimulated mRNA levels of SREBP1, reduced the mRNA, cytoplasmic and nuclear levels of Nrf2, and increased mRNA, cytoplasmic, and nuclear levels of NF-κB. The liver damage and the alterations in all these parameters were significantly more profound when both AuNPs and DOX were administered together. In conclusion, AuNPs exaggerate liver damage, hyperlipidemia, and hepatic steatosis in DOX-treated rats by activating SREBP1 and NF-κB and suppressing the Nrf2/antioxidant axis.

Quercetin Abates Aluminum Trioxide Nanoparticles and Lead Acetate Induced Altered Sperm Quality, Testicular Oxidative Damage, and Sexual Hormones Disruption in Male Rats

This study examined the effects of exposure to lead acetate (PbAc) and/or aluminum trioxide nanoparticles (Al2O3NPs) on testicular function. Additionally, the probable reproprotective effects of quercetin (QTN) against Al2O3NPs and PbAc co-exposure in male Sprague Dawely rats were assessed. Al2O3NPs (100 mg/kg b.wt.), PbAc (50 mg/kg b.wt.), and QTN (20 mg/kg b.wt.) were orally administered for 60 days. Then, spermiogram, histopathological examinations of the testis and accessory glands, and immunohistochemical detection of androgen receptors (AR) and tumor necrotic factor alpha (TNF-α) were achieved. Moreover, serum levels of male sex hormones and testicular levels of antioxidant indices were estimated. The results showed that Al2O3NPs and/or PbAc caused significant sperm abnormalities, testicular oxidative stress, and histopathological changes. Furthermore, serum testosterone, LH, and FSH levels significantly decreased, while estradiol levels significantly increased. The Al2O3NPs and/or PbAc co-exposed group had more obvious disturbances. Furthermore, QTN co-administration significantly reversed the Al2O3NPs and PbAc-induced testicular histopathological alterations, reduced antioxidant defenses, and altered AR and TNF-α immune expression in testicular tissues. Conclusively, Al2O3NPs and/or PbAc evoked testicular dysfunction by inducing oxidative injury and inflammation. However, QTN oral dosing effectively mitigated the negative effects of Al2O3NPs and PbAc by suppressing oxidative stress and inflammation and improving the antioxidant defense system.

Microbial resistance to nanotechnologies: An important but understudied consideration using antimicrobial nanotechnologies in orthopaedic implants

Microbial resistance to current antibiotics therapies is a major cause of implant failure and adverse clinical outcomes in orthopaedic surgery. Recent developments in advanced antimicrobial nanotechnologies provide numerous opportunities to effective remove resistant bacteria and prevent resistance from occurring through unique mechanisms. With tunable physicochemical properties, nanomaterials can be designed to be bactericidal, antifouling, immunomodulating, and capable of delivering antibacterial compounds to the infection region with spatiotemporal accuracy. Despite its substantial advancement, an important, but under-explored area, is potential microbial resistance to nanomaterials and how this can impact the clinical use of antimicrobial nanotechnologies. This review aims to provide a better understanding of nanomaterial-associated microbial resistance to accelerate bench-to-bedside translations of emerging nanotechnologies for effective control of implant associated infections.

Improvement of the antioxidant activity of thyme essential oil against biosynthesized titanium dioxide nanoparticles-induced oxidative stress, DNA damage, and disturbances in gene expression in vivo

BACKGROUND

Titanium dioxide nanoparticles (TiO₂-NPs) are widely utilized in medicine and industry; however, their safety in biological organisms is still unclear. In this study, we determined the bioactive constitutes of thyme essential oil (TEO) and utilized the nanoemulsion technique to improve its protective efficiency against oxidative stress, genotoxicity, and DNA damage of biosynthesized titanium dioxide nanoparticles (TiO₂-NPs).

METHODS

TEO nanoemulsion (TEON) was prepared using whey protein isolate (WPI). Sixty male Sprague-Dawley rats were divided into six groups and treated orally for 21 days including the control group, TEO, or TEON- treated groups (5 mg/kg b.w), TiO₂-NPs-treated group (50 mg/kg b.w) and the groups received TiO₂-NPs plus TEO or TEON. Blood and tissues samples were collected for different assays.

RESULTS

The GC-MS analysis identified 17 bioactive compounds in TEO and thymol and carvacrol were the major compounds. TEON was irregular with average particles size of 230 ± 3.7 nm and ζ-potential of -24.17 mV. However, TiO2-NPs showed a polygonal shape with an average size of 50 ± 2.4 nm and ζ-potential of -30.44 mV. Animals that received TiO2-NPs showed severe disturbances in liver and kidney indices, lipid profile, oxidant/antioxidant indices, inflammatory cytokines, gene expressions, increased DNA damage, and pathological changes in hepatic tissue. Both TEO and TEON showed potential protection against these hazards and TEON was more effective than TEO.

CONCLUSION

The nanoemulsion of TEO enhances the oil bioactivity, improves its antioxidant characteristics, and protects against oxidative damage and genotoxicity of TiO2-NPs.

Zinc-loaded whey protein nanoparticles alleviate the oxidative damage and enhance the gene expression of inflammatory mediators in rats

BACKGROUND

Zinc (Zn) is an essential trace element required for the function of the immune system. However, Zn fortification of food has faced some challenges, although excess Zn may be induced obesity and other related. This study aimed to use Zn-loaded whey protein nanoparticles (Zn-WPNPs) to enhance the immunomodulatory activity of Zn in rats treated with CCl₄.

METHODS

Zn was loaded to WPNPs at a level of 14 mg/g. Four experimental groups of male albino Wistar rats were treated for 30 days including the control group, CCl₄-treated group (0.5 ml/100 g b.w), Zn plus CCl₄-treated group (50 mg/kg b.w), and CCl₄ plus Zn-WPNPs-treated group (50 mg/kg b.w). Blood and tissue samples were collected for different assays and histological examinations.

RESULTS

The results revealed that CCl₄ disturbs the serum biochemical, hematological, and immune indicators in different organs besides the liver as a target organ. Animals that received CCl₄ showed a significant increase in oxidative stress markers, cytokines, and the mRNA expression of inflammatory mediators in the lung and spleen accompanied by a significant decrease in the hepatic and renal antioxidant enzymes along with histological changes in the liver, kidney, spleen, and lung. Zn or Zn-WPNPs could improve these parameters and the histological picture of the tested organs and Zn-WPNPs were more effective than Zn alone.

CONCLUSION

WPNPs induced synergistic immune-modulating effects which may control Zn release and may be a suitable candidate to enhance the immune system during any pandemic or the exposure to any chemicals that affect the immune system.

The Protective Effect of α-Lipoic Acid against Gold Nanoparticles (AuNPs)-Mediated Liver Damage Is Associated with Upregulating Nrf2 and Suppressing NF-κB

This study examined if regulating the keap-1? Nrf2 antioxidant pathway mediated gold nanoparticles (AuNPs) induced liver damage, and examined the protective effect of co-supplement of α-lipoic acid (α-LA). Rats were separated into 4 groups (n = 8/each) as control, α-LA (200 mg/kg), AuNPs (5 µg/2.85 × 10¹¹), and AuNPs (5 µg/2.85 × 10¹¹) + α-LA (200 mg/kg). After 7 days, AuNPs induced severe degeneration in the livers of rats with the appearance of some fatty changes. In addition, it increased serum levels of alanine aminotransferase (ALT) and gamma-glutamyl transferase (ɣ-GTT), and aspartate aminotransferase (AST), as well as liver levels of malondialdehyde (MDA). Concomitantly, AuNPs significantly depleted hepatic levels of total glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT) but increased hepatic levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). It also reduced mRNA levels of B-cell lymphoma 2 (Bcl2) and heme oxygenase-1 (HO-1) but significantly increased those of Bax and cleaved caspase-3, as well as the ratio of Bax/Bcl2. In addition, AuNPs enhanced the total and nuclear levels of NF-κB p65 but reduced the mRNA and total and nuclear protein levels of Nrf2. Of note, AuNPs did not affect the mRNA levels of keap-1. All these events were reversed by α-LA in the AuNPs-treated rats. In conclusion, α-LA attenuated AuNPs-mediated liver damage in rats by suppressing oxidative stress and inflammation, effects that are associated with upregulation/activation of Nrf2.

Short- and long-term effect of colorectal cancer targeting peptides conjugated to gold nanoparticles in rats' liver and colon after single exposure

Peptides play important roles in the diagnosis, prognostic predictors, and treatment of various kinds of cancer. Peptides (p.C, p.L and p.14), derived from the phage display peptide libraries, specifically binds to colorectal cancer (CRC) cells in vitro. To allow tumor specificity and selectivity for in vivo diagnosis of CRC, biotinylated p.C, p.L and p.14 were conjugated to AuNPs (14 nm) via the biotin-streptavidin interaction. Male Wistar rats were intravenously injected with a single dose (100 µg/kg body weight) of AuNPs (citrate-AuNPs, PEG-AuNPs, p.C-PEG-, p.L-PEG- and p.14-PEG-AuNPs). Animals were monitored for behavioral changes, and sacrificed either 14 days or 84 days post-injection. Biochemical changes, oxidative stress, and histology of the liver and colon were assessed. No significant changes were noted in the rats injected with all the AuNPs, except p.L-PEG-AuNPs that caused significant toxicity (p < 0.05) 14 days post-exposure when compared to control group, as evidenced by increased relative liver weight, increased malondialdehyde levels and histological changes in the liver. These changes, however, returned to normalcy 84 days post-injection. It can be concluded, based on these findings, that p.L induced a transient toxicity in rats after a single intravenous injection, and can therefore be considered non-toxic long-term after a single exposure.

Three-dimensional (3D) liver cell models - a tool for bridging the gap between animal studies and clinical trials when screening liver accumulation and toxicity of nanobiomaterials

Despite the exciting properties and wide-reaching applications of nanobiomaterials (NBMs) in human health and medicine, their translation from bench to bedside is slow, with a predominant issue being liver accumulation and toxicity following systemic administration. In vitro 2D cell-based assays and in vivo testing are the most popular and widely used methods for assessing liver toxicity at pre-clinical stages; however, these fall short in predicting toxicity for NBMs. Focusing on in vitro and in vivo assessment, the accurate prediction of human-specific hepatotoxicity is still a significant challenge to researchers. This review describes the relationship between NBMs and the liver, and the methods for assessing toxicity, focusing on the limitations they bring in the assessment of NBM hepatotoxicity as one of the reasons defining the poor translation for NBMs. We will then present some of the most recent advances towards the development of more biologically relevant in vitro liver methods based on tissue-mimetic 3D cell models and how these could facilitate the translation of NBMs going forward. Finally, we also discuss the low public acceptance and limited uptake of tissue-mimetic 3D models in pre-clinical assessment, despite the demonstrated technical and ethical advantages associated with them.

The Research of Toxicity and Sensitization Potential of PEGylated Silver and Gold Nanomaterials

Polyethylene glycol (PEG) is a polymer used for surface modification of important substances in the modern pharmaceutical industry and biopharmaceutical fields. Despite the many benefits of PEGylation, there is also the possibility that the application and exposure of the substance may cause adverse effects in the body, such as an immune response. Therefore, we aimed to evaluate the sensitization responses that could be induced through the intercomparison of nanomaterials of the PEG-coated group with the original group. We selected gold/silver nanomaterials (NMs) for original group and PEGylated silver/gold NMs in this study. First, we measured the physicochemical properties of the four NMs, such as size and zeta potential under various conditions. Additionally, we performed the test of the NM's sensitization potential using the KeratinoSens™ assay for in vitro test method and the LLNA: 5-bromo-2-deoxyuridine (BrdU)-FCM for in vivo test method. The results showed that PEGylated-NMs did not lead to skin sensitization according to OECD TG 442 (alternative test for skin sensitization). In addition, gold nanomaterial showed that cytotoxicity of PEGylated-AuNMs was lower than AuNMs. These results suggest the possibility that PEG coating does not induce an immune response in the skin tissue and can lower the cytotoxicity of nanomaterials.

Growth-Promoting Gold Nanoparticles Decrease Stress Responses in Arabidopsis Seedlings

The global economic success of man-made nanoscale materials has led to a higher production rate and diversification of emission sources in the environment. For these reasons, novel nanosafety approaches to assess the environmental impact of engineered nanomaterials are required. While studying the potential toxicity of metal nanoparticles (NPs), we realized that gold nanoparticles (AuNPs) have a growth-promoting rather than a stress-inducing effect. In this study we established stable short- and long-term exposition systems for testing plant responses to NPs. Exposure of plants to moderate concentrations of AuNPs resulted in enhanced growth of the plants with longer primary roots, more and longer lateral roots and increased rosette diameter, and reduced oxidative stress responses elicited by the immune-stimulatory PAMP flg22. Our data did not reveal any detrimental effects of AuNPs on plants but clearly showed positive effects on growth, presumably by their protective influence on oxidative stress responses. Differential transcriptomics and proteomics analyses revealed that oxidative stress responses are downregulated whereas growth-promoting genes/proteins are upregulated. These omics datasets after AuNP exposure can now be exploited to study the underlying molecular mechanisms of AuNP-induced growth-promotion.

Nano-bio surface interactions, cellular internalisation in cancer cells and e-data portals of nanomaterials: A review

Nanomaterials (NMs) have abundant applications in areas such as electronics, energy, environment industries, biosensors, nano devices, theranostic platforms, etc. Nanoparticles can increase the solubility and stability of drug-loaded materials, enhance their internalisation, protect them from initial destruction in the biological system, and lengthen their circulation time. The biological interaction of proteins present in the body fluid with NMs can change the activity and natural surface properties of NMs. The size and charge of NMs, properties of the coated and uncoated NMs, nature of proteins, cellular interactions direct their internalisation pathway in the cellular system. Thus, the present review emphasises the impact of coated, uncoated NMs, size and charge, nature of proteins on nano-bio surface interactions and on internalisation with specific focus on cancer cells. The increased activity of NPs may also result in toxicity on health and environment, thus emphasis should be given to assess the toxicity of NMs in the medical field. The e-data sharing portals of NMs have also been discussed in this review that will be helpful in providing the information about the chemical, physical, biological properties and toxicity of NMs.

Gold Nanoparticles: Multifaceted Roles in the Management of Autoimmune Disorders

Gold nanoparticles (GNPs) have been recently applied for various diagnostic and therapeutic purposes. The unique properties of these nanoparticles (NPs), such as relative ease of synthesis in various sizes, shapes and charges, stability, high drug-loading capacity and relative availability for modification accompanied by non-cytotoxicity and biocompatibility, make them an ideal field of research in bio-nanotechnology. Moreover, their potential to alleviate various inflammatory factors, nitrite species, and reactive oxygen production and the capacity to deliver therapeutic agents has attracted attention for further studies in inflammatory and autoimmune disorders. Furthermore, the characteristics of GNPs and surface modification can modulate their toxicity, biodistribution, biocompatibility, and effects. This review discusses in vitro and in vivo effects of GNPs and their functionalized forms in managing various autoimmune disorders (Ads) such as rheumatoid arthritis, type 1 diabetes, and multiple sclerosis.

Renoprotective and therapeutic effects of newly water, ethanol, and butanol ginseng fractions in hypertensive and chronic kidney disease with L-NAME

The present study investigated the protective and treatment effects of different ginseng fractions against L-NAME-induced renal toxicity in rats. The data obtained demonstrated that L-NAME significantly increased creatinine, urea, KIM-1, and lipocalin-2 levels in serum; and also increased renal MDA and eNOS levels compared with the control group. Three bioactive fractions were newly extracted from ginseng, analyzed by GC-MS analysis, and were examined for antimicrobial, prebiotic, and histological activities. All ginseng fractions improved such histological changes, as reflected by significant reductions in creatinine, urea, KIM-1, and LCN-2 levels in serum, and renal MDA and eNOS contents in tissue homogenate. The water ginseng fraction (WGF) has the highest prebiotic index of 4.7 toward Lactobacillus reuteri, and can improve the renal functions more than butanol ginseng fraction (BGF) and ethanol ginseng fraction (EGF). These three ginseng fractions significantly reversed L-NAME-induced depletion in the TNF-α gene expression level. Interestingly, WGF was able to improve the renal functions more than BGF and EGF. L-NAME led to alterations in the histological structure and functions of renal tissue of rats and ginseng supplementation could offer greater protection against these changes. Moreover, the WGF exhibited superior renoprotection properties when compared with the other two fractions: BGF and EGF, and the reference drug losartan.

Toxicity of gold nanoparticles (AuNPs): A review

Gold nanoparticles are a kind of nanomaterials that have received great interest in field of biomedicine due to their electrical, mechanical, thermal, chemical and optical properties. With these great potentials came the consequence of their interaction with biological tissues and molecules which presents the possibility of toxicity. This paper aims to consolidate and bring forward the studies performed that evaluate the toxicological aspect of AuNPs which were categorized into in vivo and in vitro studies. Both indicate to some extent oxidative damage to tissues and cell lines used in vivo and in vitro respectively with the liver, spleen and kidney most affected. The outcome of these review showed small controversy but however, the primary toxicity and its extent is collectively determined by the characteristics, preparations and physicochemical properties of the NPs. Some studies have shown that AuNPs are not toxic, though many other studies contradict this statement. In order to have a holistic inference, more studies are required that will focus on characterization of NPs and changes of physical properties before and after treatment with biological media. So also, they should incorporate controlled experiment which includes supernatant control Since most studies dwell on citrate or CTAB-capped AuNPs, there is the need to evaluate the toxicity and pharmacokinetics of functionalized AuNPs with their surface composition which in turn affects their toxicity. Functionalizing the NPs surface with more peculiar ligands would however help regulate and detoxify the uptake of these NPs.

Gold Nanoclusters Display Low Immunogenic Effect in Microglia Cells

Gold nanoparticles hold a great promise for both clinical and preclinical applications. The major factors impeding such applications are toxicity of new nanomaterials including e.g., pro-apoptotic activities or inflammatory effects, but also their potential to accumulate in the body or inadequate absorption, distribution, metabolism and excretion (ADME) profiles. Since such adverse effects depend on the size, form and coating of nanomaterials, the search for new, less toxic nanomaterials with low tendency to accumulate is highly active domain of research. Here, we describe optical and biological properties of Au18 gold nanoclusters (NCs), small gold nanoparticles composed of 18 atoms of gold and stabilized with glutathione ligands. These nanoclusters may be suitable for in vivo applications owing to their low toxicity and biodistribution profile. Specifically, using lactate dehydrogenase (LDH) test in P19 cell line we found that Au18 NCs display low toxicity in vitro. Importantly, using primary microglial cells we showed that at low concentrations Au18 NCs display anti-inflammatory signaling on evidence of reduced interleukin 1-β (IL1-β) levels and unchanged levels of tumor necrosis factor (TNF-α) or Ym1/2. Such effect was dose dependent as higher concentrations of Au18 NCs induced expression of pro-inflammatory cytokines and suppression of anti-inflammatory cytokine Ym1/2, pointing, thus, to global inflammatory activity. Finally, we also showed that within 3 days Au18 NCs can be completely eliminated from the liver reported as the major target organ for accumulation of gold nanoparticles. These data point to a potential of gold nanoparticles for further biomedical studies.

Screening for Effects of Inhaled Nanoparticles in Cell Culture Models for Prolonged Exposure

Respiratory exposure of humans to environmental and therapeutic nanoparticles repeatedly occurs at relatively low concentrations. To identify adverse effects of particle accumulation under realistic conditions, monocultures of Calu-3 and A549 cells and co-cultures of A549 and THP-1 macrophages in the air–liquid interphase culture were exposed repeatedly to 2 µg/cm² 20 nm and 200 nm polystyrene particles with different functionalization. Particle accumulation, transepithelial electrical resistance, dextran (3–70 kDa) uptake and proinflammatory cytokine secretion were determined over 28 days. Calu-3 cells showed constant particle uptake without any change in barrier function and cytokine release. A549 cells preferentially ingested amino- and not-functionalized particles combined with decreased endocytosis. Cytokine release was transiently increased upon exposure to all particles. Carboxyl-functionalized demonstrated higher uptake and higher cytokine release than the other particles in the A549/THP-1 co-cultures. The evaluated respiratory cells and co-cultures ingested different amounts and types of particles and caused small (partly transient) effects. The data suggest that the healthy cells can adapt to low doses of non-cytotoxic particles.

Antibacterial and Immunomodulatory Potentials of Biosynthesized Ag, Au, Ag-Au Bimetallic Alloy Nanoparticles Using the Asparagus racemosus Root Extract

Two noble metals, such as silver and gold alloy nanoparticles, were successfully synthesized by the microwave assisted method in the presence of the Asparagus racemosus root extract and were used as an antibacterial and immunomodulatory agent. The nanostuctures of the synthesized nanoparticles were confirmed by various spectroscopic and microscopic techniques. The UV-vis spectrum exhibits a distinct absorption peak at 483 nm for the bimetallic alloy nanoparticles. The microscopic analysis revealed the spherical shaped morphology of the biosynthesized nanoparticles with a particle size of 10-50 nm. The antibacterial potential of the green synthesized single metal (AgNPs and AuNPs) and bimetallic alloy nanoparticles was tested against five bacterial strains. The bimetallic alloy nanoparticles displayed the highest zone of inhibition against P. aeurgnosia and S.aureus strains when compared to single metal nanoparticles and plant extract. In addition, the inmmunomodulatory potential of the root extract of A. racemosus, AgNPs, AuNPs, and Ag-Au alloy NPs is achieved by measuring the cytokine levels in macrophages (IL-1β, IL-6, and TNF-α) and NK cells (IFN-γ) of NK92 and THP1 cells using the solid phase sandwich ELISA technique. The results showed that the root extract of A. racemosus, AgNPs, and AuNPs can reduce the pro-inflammatory cytokine levels in the macrophages cells, while Ag-Au alloy NPs can reduce cytokine responses in NK92 cells. Overall, this study shows that the microwave assisted biogenic synthesized bimetallic nanoalloy nanoparticles could be further explored for the development of antibacterial and anti-inflammatory therapies.

Effects of silver and gold nanoparticles phytosynthesized with Cornus mas extract on oral dysplastic human cells

Background: Oral cancer is highly aggressive due to difficult diagnosis, therapy resistance and increasing frequency; thus finding prevention therapies is very important. Aim: This study evaluates the use of gold and silver nanoparticles (NPs), phyto-synthesized with Cornus mas extract against oral dysplastic lesions. Methods: NPs were characterized by UV-Vis, Fourier-transform infrared spectroscopy, transmission electron microscopy, x-ray diffraction and laser Doppler microelectrophoresis. Biological testing employed two human oral cell lines: gingival fibroblasts and dysplastic keratinocytes and evaluated viability, cell death mechanisms and cellular uptake. Results: NPs induced selective toxic effects against dysplastic cells. p53/BAX/BCL2 activation and PI3K/AKT inhibition led to cell death through necrosis and apoptosis. NPs also induced antioxidant and anti-inflammatory effects. Conclusion: NPs of gold and silver showed promising beneficial effects in the therapy of oral dysplasia.

Susceptibility Factors in Chronic Lung Inflammatory Responses to Engineered Nanomaterials

Engineered nanomaterials (ENMs) are products of the emerging nanotechnology industry and many different types of ENMs have been shown to cause chronic inflammation in the lungs of rodents after inhalation exposure, suggesting a risk to human health. Due to the increasing demand and use of ENMs in a variety of products, a careful evaluation of the risks to human health is urgently needed. An assessment of the immunotoxicity of ENMs should consider susceptibility factors including sex, pre-existing diseases, deficiency of specific genes encoding proteins involved in the innate or adaptive immune response, and co-exposures to other chemicals. This review will address evidence from experimental animal models that highlights some important issues of susceptibility to chronic lung inflammation and systemic immune dysfunction after pulmonary exposure to ENMs.

Hesperidin Loaded on Gold Nanoparticles as a Drug Delivery System for a Successful Biocompatible, Anti-Cancer, Anti-Inflammatory and Phagocytosis Inducer Model

Hesperidin is a flavonoid glycoside with proven therapeutic activities for various diseases, including cancer. However, its poor solubility and bioavailability render it only slightly absorbed, requiring a delivery system to reach its therapeutic target. Hesperidin loaded on gold nanoparticles (Hsp-AuNPs) was prepared by a chemical synthesis method. Various characterization techniques such as UV-VIS spectroscopy, FTIR, XRD, FESEM, TEM and EDX, Zeta potential analysis, particle size analysis, were used to confirm the synthesis of Hsp-AuNPs. The cytotoxic effect of Hsp-AuNPs on human breast cancer cell line (MDA-MB-231) was assessed using MTT and crystal violet assays. The results revealed significant decrease in proliferation and inhibition of growth of the treated cells when compared with human normal breast epithelial cell line (HBL-100). Determination of apoptosis by fluorescence microscope was also performed using acridine orange-propidium iodide dual staining assay. The in vivo study was designed to evaluate the toxicity of Hsp-AuNPs in mice. The levels of hepatic and kidney functionality markers were assessed. No significant statistical differences were found for the tested indicators. Histological images of liver, spleen, lung and kidney showed no apparent damages and histopathological abnormalities after treatment with Hsp-AuNPs. Hsp-AuNPs ameliorated the functional activity of macrophages against Ehrlich ascites tumor cells-bearing mice. The production of the pro-inflammatory cytokines was also assessed in bone marrow–derived macrophage cells treated with Hsp-AuNPs. The results obviously demonstrated that Hsp-AuNPs treatment significantly inhibited the secretion of IL-1β, IL-6 and TNF.

Gold Nanoparticles Induce Oxidative Stress and Apoptosis in Human Kidney Cells

Gold nanoparticles (AuNPs) are highly attractive for biomedical applications. Therefore, several in vitro and in vivo studies have addressed their safety evaluation. Nevertheless, there is a lack of knowledge regarding their potential detrimental effect on human kidney. To evaluate this effect, AuNPs with different sizes (13 nm and 60 nm), shapes (spheres and stars), and coated with 11-mercaptoundecanoic acid (MUA) or with sodium citrate, were synthesized, characterized, and their toxicological effects evaluated 24 h after incubation with a proximal tubular cell line derived from normal human kidney (HK-2). After exposure, viability was assessed by the MTT assay. Changes in lysosomal integrity, mitochondrial membrane potential (ΔΨm), reactive species (ROS/RNS), intracellular glutathione (total GSH), and ATP were also evaluated. Apoptosis was investigated through the evaluation of the activity of caspases 3, 8 and 9. Overall, the tested AuNPs targeted mainly the mitochondria in a concentration-dependent manner. The lysosomal integrity was also affected but to a lower extent. The smaller 13 nm nanospheres (both citrate- and MUA-coated) proved to be the most toxic among all types of AuNPs, increasing ROS production and decreasing mitochondrial membrane potential (p ≤ 0.01). For the MUA-coated 13 nm nanospheres, these effects were associated also to increased levels of total glutathione (p ≤ 0.01) and enhanced ATP production (p ≤ 0.05). Programmed cell death was detected through the activation of both extrinsic and intrinsic pathways (caspase 8 and 9) (p ≤ 0.05). We found that the larger 60 nm AuNPs, both nanospheres and nanostars, are apparently less toxic than their smaller counter parts. Considering the results herein presented, it should be taken into consideration that even if renal clearance of the AuNPs is desirable, since it would prevent accumulation and detrimental effects in other organs, a possible intracellular accumulation of AuNPs in kidneys can induce cell damage and later compromise kidney function.

Paeonol protects against testicular ischaemia-reperfusion injury in rats through inhibition of oxidative stress and inflammation

Ischaemia-reperfusion (IR) is the most common form of testicular injury that results in oxidative damage and inflammation ending by subinfertility. Paeonol, a natural phenolic compound, exhibits antioxidant and anti-inflammatory effects. Thus, the present study investigated the role of paeonol in rat testicular IR injury. Thirty adult Wistar rats were randomly divided into five groups; sham, sham treated with paeonol, IR injury, and IR pre-treated with paeonol at low and high doses. Serum testosterone and testicular levels of malondialdehyde and reduced glutathione (GSH) besides superoxide dismutase (SOD) activity were determined. Gene quantifications for tumour necrosis factor-α (TNF-α), hypoxia-inducible factor-1α (HIF-1α) and heat shock protein 70 (HSP70) were also assessed. Histopathological pictures and the immunohistochemical expression of testicular nuclear factor erythroid 2-related factor 2 (Nrf2), interleukin-1β (IL-1β) and interleukin-6 (IL-6) were shown. Pre-treatment with paeonol prevented the drop in serum testosterone, alongside with improvement of testicular malondialdehyde and GSH levels plus SOD activity. Paeonol regained the normal spermatogenesis with prevention of IR-induced increase in TNF-α, HIF-1α and HSP70 gene expression besides IL-1β and IL-6 immunostaining and reduction in Nrf2 protein expression. Paeonol exerted a dose-dependent beneficial effect on testicular IR injury. This effect was achieved by its antioxidant and anti-inflammatory effects.

Immunohistochemistry of IL-1β, IL-6 and TNF-α in spleens of mice treated with gold nanoparticles

Gold nanoparticles (AuNPs) possess considerable biocompatibility and therefore gaining more attention for their biomedical applications. Previous studies have shown the transient increase in pro-inflammatory cytokines expression in different organs of rats and mice exposed to AuNPs. Structural changes in the spleen of mice treated with AuNPs have also been reported. This investigation was aimed to study the immunostaining of IL-1β, IL-6 and TNF-α in mice treated with different sizes of AuNPs. The animals were divided into 7 groups of 4 animals in each group. One group received saline and served as control. Two sets of three groups were treated with 5 nm, 20 nm and 50 nm diameter AuNPs. One set was sacrificed on day 1 and the other on day 7 following the AuNPs injections. Spleens were dissected out and promptly fixed in formalin for 3 days and then processed for IL-1β, IL-6 and TNF-α immunostaining using target-specific antibodies. The immunoreactivities of IL-1β and IL-6 were increased with the increase of AuNP size. The immunostaining of IL-1β in spleen of 20 nm AuNP treated mice was subsequently decreased on day 7 whereas it persisted in 50 nm AuNP group. The increase in the immunoreactivity of IL-6 on day 1 was decreased on day 7 in the spleens of mice treated with 20 nm or 50 nm AuNPs. The immunostaining of TNF-α was found to be negative in all the treatment groups. In conclusion, the size of AuNPs plays an important role in the expression of proinflammatory cytokines in mouse spleen; small size (5 nm) AuNPs caused minimal effect, whereas larger (50 nm) AuNPs produced intense immunostaining.

Noble Metals and Soft Bio-Inspired Nanoparticles in Retinal Diseases Treatment: A Perspective

We are witnessing an exponential increase in the use of different nanomaterials in a plethora of biomedical fields. We are all aware of how nanoparticles (NPs) have influenced and revolutionized the way we supply drugs or how to use them as therapeutic agents thanks to their tunable physico-chemical properties. However, there is still a niche of applications where NP have not yet been widely explored. This is the field of ocular delivery and NP-based therapy, which characterizes the topic of the current review. In particular, many efforts are being made to develop nanosystems capable of reaching deeper sections of the eye such as the retina. Particular attention will be given here to noble metal (gold and silver), and to polymeric nanoparticles, systems consisting of lipid bilayers such as liposomes or vesicles based on nonionic surfactant. We will report here the most relevant literature on the use of different types of NPs for an efficient delivery of drugs and bio-macromolecules to the eyes or as active therapeutic tools.

Effect of naked and PEG-coated gold nanoparticles on histopathology and cytokines expression in rat liver and kidneys

Aim: To compare the effects of 5- and 50-nm naked and PEG-coated gold nanoparticles (AuNP) on proinflammatory cytokines (IL-1β, IL-6, TNF-α) expression and histopathological changes in liver and kidneys of rats. Materials & methods: Rats were injected with different nanoparticles and sacrificed after 24 h. Results: Both 5- and 50-nm AuNPs, and 50-nm PEG-AuNPs caused granular clumping of cytoplasm, edema and hydropic dystrophy in hepatic cells. Naked AuNPs of both sizes caused mild shrinkage, whereas 50-nm PEG-AuNPs enlarged the Bowman's space and capsule. Larger nanoparticles produced more profound mRNA expression of cytokines in both the organs. Conclusion: These findings suggest the roles of particle size and coating on immunological response and histopathological changes.

Immunotoxicity Considerations for Next Generation Cancer Nanomedicines

Although interest and funding in nanotechnology for oncological applications is thriving, translating these novel therapeutics through the earliest stages of preclinical assessment remains challenging. Upon intravenous administration, nanomaterials interact with constituents of the blood inducing a wide range of associated immunotoxic effects. The literature on the immunological interactions of nanomaterials is vast and complicated. A small change in a particular characteristic of a nanomaterial (e.g., size, shape, or charge) can have a significant effect on its immunological profile in vivo, and poor selection of specific assays for establishing these undesirable effects can overlook this issue until the latest stages of preclinical assessment. This work describes the current literature on unintentional immunological effects associated with promising cancer nanomaterials (liposomes, dendrimers, mesoporous silica, iron oxide, gold, and quantum dots) and puts focus on what is missing in current preclinical evaluations. Opportunities for avoiding or limiting immunotoxicity through efficient preclinical assessment are discussed, with an emphasis placed on current regulatory views and requirements. Careful consideration of these issues will ensure a more efficient preclinical assessment of cancer nanomedicines, enabling a smoother clinical translation with less failures in the future.

Reproductive Toxicity of Pomegranate Peel Extract Synthesized Gold Nanoparticles: A Multigeneration Study in C. elegans

C. elegans is a preferential model for testing environmental toxicity of compounds including nanomaterials. The impact of multigeneration exposure of gold nanoparticles (AuNPs) on the lifespan and fertility of C. elegans is not known and therefore is investigated in this study. We used pomegranate (Punica granatum) peel extracts as a reducing agent to synthesize gold nanoparticles (PPE-AuNPs) from chloroauric acid. Nematodes were grown till adult stage and then exposed to 25, 50, and 100 μg/ml of PPE-AuNPs at 20°C for 72 hours and then assessed for lifespan and fertility. The same protocols were followed for subsequent F1, F2, and F3 generations. The results showed that PPE-AuNPs dose-dependently but insignificantly reduced the lifespan of C. elegans. Exposure of PPE-AuNPs significantly and dose-dependently reduced the fertility of C. elegans in terms of the number of eggs produced. The reproductive toxicity of PPE-AuNPs was found to be minimal in parental generation (F0) and maximal in F3 generation. In conclusion, biologically synthesized PPE-AuNPs adversely affect the fertility of C. elegans while the factors responsible for reproductive toxicity are inherited by subsequent generations.

Effect of gold nanoparticles treatment on the testosterone-induced benign prostatic hyperplasia in rats

Background: Gold nanoparticles (AuNps) are promising agents for prostate cancer therapy. Herein, the in vivo effects of 20 and 50 nm sized AuNps on experimentally induced benign prostatic hyperplasia (BPH) was examined.

Materials and methods: Adult male rats were divided into four groups (n=6–8 each). A negative control group and three groups were injected daily with testosterone (3 mg/kg/subcutaneously) to induce BPH. Animals receiving testosterone were randomized to untreated BPH group and two BPH groups which were treated intraperitoneally with 20 and 50 nm AuNps (5 mg/kg/daily) in addition to testosterone. After three weeks, histopathological changes and serum levels of testosterone and dihydrotestosterone (DHT) were analyzed. In addition, the prostate tissue levels of transforming growth factor-β₁ (TGF-β₁), vascular endothelial growth factor-a (VEGF-A) and interleukin-6 (IL-6) were measured using ELISA.

Results: There were significant increases in the prostate weight/body weight ratio, serum testosterone and DHT and in the prostate tissue content of TGF-β₁, IL-6 and VEGF-A in the untreated BPH group. histological examination showed morphological abnormalities with more proliferation in the glandular epithelial and stromal area and with abundant epithelial papillary folds in the BPH group. Simultaneous administration of 50 nm AuNps with testosterone tended to increase the prostate weight/body weight ratio and increase the tissue level of IL-6 in compared to the BPH group. Conversely, treatment with 20 nm AuNps significantly reduced the elevated tissue content of TGF-β₁, IL-6, and VEGF-A. Histopathological examination also showed that 20 nm but not the 50 nm AuNps administration ameliorates testosterone-induced prostatic hyperplasia.

Conclusions: In experimentally induced BPH, AuNps can inhibit the progression of BPH in a size-dependent manner. while 20 nm AuNps ameliorate BPH by its inhibitory effects on the prostatic cell proliferation, inflammation and angiogenesis, the 50 nm AuNps could potentially exacerbate the development of BPH in rats, mainly through enhancing the inflammatory process.

Time-Course Evaluation of Iminodipropionitrile-Induced Liver and Kidney Toxicities in Rats: A Biochemical, Molecular and Histopathological Study

Iminodipropionitrile (IDPN) is known to produce axonopathy and vestibular hair cell degeneration. Recent histopathological studies have shown IDPN-induced liver and kidney toxicities in rodents; however, the associated mechanisms are not clearly understood. We investigated the role of proinflammatory cytokines in IDPN-induced liver and kidney toxicities in rats. Rats were treated with saline (control) and IDPN (100 mg/kg, intraperitoneally) daily for 1, 5, and 10 days, respectively. Animals were killed 24 hours after the last dose and liver and kidneys were collected for histopathology and interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α messenger RNA expression analysis. Serum aspartate aminotransferase and alanine aminotransferase activities were significantly increased after 10 doses of IDPN. The level of serum creatinine was initially increased after the first dose of IDPN but subsided on days 5 and 10. Blood urea nitrogen levels were significantly increased on days 5 and 10 following IDPN exposure. Histopathology showed dose-dependent hepatotoxicity in IDPN-treated rats. Iminodipropionitrile-induced expression of proinflammatory cytokines peaked after day 1 in liver and after day 5 in kidneys. In conclusion, repeated exposure of IDPN for 10 days produced significant structural and functional damages in rat liver whereas kidneys showed gradual recovery with time. These findings point toward the role of inflammatory mediators in IDPN-induced toxicity in rats.

Size and time-dependent induction of proinflammatory cytokines expression in brains of mice treated with gold nanoparticles

Gold nanoparticles (GNPs) are among the ideal nano-sized materials for medical applications such as imaging and drug delivery. Considering the significance of recent reports on acute phase induction of inflammatory mediators by GNPs, we studied the effect of GNPs on proinflammatory cytokines gene expression in mouse brain. Group 1 served as control whereas groups 2-4 were given only one intraperitoneal dose of 5, 20 and 50 nm GNPs, respectively and sacrificed after 24 h. The animals in groups 5-7 also received the same treatment but sacrificed after 7 days. Groups 8-10 received two injections of GNPs (5, 20 and 50 nm, respectively), first at the beginning of study and second on day 6, and sacrificed on day 7. Total RNA was extracted from the cerebral tissue and analyzed for the gene expressions of IL-1β, IL-6 and TNF-α. A single injection of 5 nm diameter GNPs significantly increased the mRNA expression of IL-1β and IL-6 in mouse brain on day 7, which was not augmented by the second dose of the same GNPs. Larger size GNPs (20 nm and 50 nm) did not cause any significant change in the expression of proinflammatory cytokines in mouse brain. In conclusion, systemic administration of small sized GNPs (5 nm) induced a proinflammatory cascade in mouse brain indicating a crucial role of GNPs size on immune response. It is important to use the right sized GNPs in order to avoid an acute phase inflammatory response that could be cytotoxic or interfere with the bioavailability of nanomaterials.

UV-light mediated green synthesis of silver and gold nanoparticles using Cornelian cherry fruit extract and their comparative effects in experimental inflammation

The purpose of our study is to investigate the comparative effects of materials based on silver and gold nanoparticles functionalized with polyphenols from Cornus Mas extract (AgNPs-CM and AuNPs-CM) in vivo on experimental inflammation. The nanoparticles were obtained at room temperature under UV irradiation and were characterized by different methods: ultraviolet-visible spectroscopy, transmission electron microscopy, X ray diffraction, Fourier transform infrared spectroscopy and dynamic light scattering. The modulatory effects of AgNPs-CM and AuNPs-CM on inflammation were quantified by oxidative stress parameters, pro and anti-inflammatory cytokines levels and apoptosis assessment at 2 h, 24 and 48 h after induction of inflammation with carrageenan in the paw tissue of Wistar rats. Our results showed that silver and gold nanoparticles only partial and for a short period have mobilized the antioxidant defense mechanisms. In addition, they diminished inflammation and apoptosis in the early stage while later, at 48 h, exerted an immunomodulatory effect, activated ERK ½ and induced apoptosis. The photoreduced silver and gold nanoparticles, functionalized with natural compounds, modulated the inflammation in a similar manner in the soft tissue injected with carrageenan. In order to decipher the mechanisms involved in interactions of metallic nanoparticles with biological systems and for a complete assessment of the risks and benefits of these products in clinical practice long term studies are necessary.

Histopathology of the Liver, Kidney, and Spleen of Mice Exposed to Gold Nanoparticles

Gold nanoparticles (GNPs) are biocompatible nanomaterials that are currently researched for biomedical applications such as imaging and targeted drug delivery. In this investigation, we studied the effects of a single dose (injected on day 1) as well as a priming dose (two injections with a gap of one week) of 5 nm, 20 nm, and 50 nm diameter GNPs on the structural and biochemical changes in the liver, kidney, and spleen of mice. The results showed that small sized GNPs (5 nm) produced significant pathological changes in the liver on day 2 that gradually reduced on day 8. The medium (20 nm) and large (50 nm) sized GNPs preferentially targeted the spleen and caused significant pathological changes to the spleen architecture on day 2 that persisted on day 8 as well. There were minimal and insignificant pathological changes to the kidneys irrespective of the GNPs size. The animals that were primed with the pre-exposure of GNPs did not show any aggravation of histological changes after the second dose of the same GNPs. None of the dose regimens of the GNPs were able to significantly affect the markers of oxidative stress including glutathione (GSH) and malondialdehyde (MDA) in all of the organs that were studied. In conclusion, the size of GNPs plays an important role in their pathological effects on different organs of mice. Moreover, the primed animals become refractory to further pathological changes after the second dose of GNPs, suggesting the importance of a priming dose in medical applications of GNPs.

Naked physically synthesized gold nanoparticles affect migration, mitochondrial activity, and proliferation of vascular smooth muscle cells

Introduction

Vascular smooth muscle cells (VSMCs) play an important role in the development and progression of atherosclerosis and vascular injuries in terms of proliferation and migration. Therefore, the aim of this study was to investigate the anti-migratory and proliferative effects of naked gold nanoparticles (AuNPs) on VSMCs.

Materials and methods

One set of physically synthesized AuNPs (pAuNPs) and three sets of chemically synthesized AuNPs (cAuNPs) were tested.

Results and discussion

Among them, the pAuNPs were found to significantly and markedly inhibit platelet-derived growth factor (PDGF)-induced VSMC migration. Transmission electron microscopy revealed that the pAuNPs were ingested and aggregated in the cytoplasm at an early stage of treatment, while the viability of VSMCs was not affected within 24 hours of treatment. The pAuNP treatment enhanced cellular mitochondrial activity but inhibited basal and PDGF-induced VSMC proliferation, as determined by MTT, WST-1, and BrdU cell proliferation assays. Furthermore, the pAuNPs did not interfere with PDGF signaling or matrix metalloproteinase-2 expression/activity. Unlike the cAuNPs, the pAuNPs could markedly reduce VSMC adhesion to collagen, which was supported by the findings that the pAuNPs could inhibit collagen-induced tyrosine protein and focal adhesion kinase (FAK) phosphorylation and actin cytoskeleton reorganization during cell adhesion. The in vitro effects of the pAuNPs were confirmed in the in vivo rat balloon-injured carotid artery model by diminishing the proliferating VSMCs.

Conclusion

Taken together, the present study provides the first evidence that naked pAuNPs can reduce VSMC migration and compromise cell adhesion by affecting FAK and tyrosine-protein activation. The pAuNPs also have an inhibitory effect on PDGF-induced VSMC proliferation and can reduce proliferating/migrating VSMC expression in vivo.

Gold Nanoparticle Toxicity in Mice and Rats: Species Differences

Nanotoxicity studies are greatly needed to advance nanomedical technologies into clinical practice. We assessed the toxic effects of a single intravenous exposure to commercially available gold nanoparticles (GNPs) in mice and rats. Fifteen-nm GNPs were purchased and independently characterized. Animals were exposed to either 1,000 mg GNPs/kg body weight (GNP group) or phosphate-buffered saline. Subsets of animals were euthanized and samples collected at 1, 7, 14, 21, and 28 days postexposure. Independent characterization demonstrated that the physicochemical properties of the purchased GNPs were in good agreement with the information provided by the supplier. Mice exposed to GNPs developed granulomas in the liver and transiently increased serum levels of the pro-inflammatory cytokine interleukin-18. No such alterations were found in rats. While there was no fatality in mice post-GNP exposure, a number of the rats died within hours of GNP administration. Differences in GNP biodistribution and excretion were also detected between the two species, with rats having a higher relative accumulation of GNPs in spleen and greater fecal excretion. In conclusion, GNPs have the ability to incite a robust macrophage response in mice, and there are important species-specific differences in their biodistribution, excretion, and potential for toxicity.

Exposure to Inorganic Nanoparticles: Routes of Entry, Immune Response, Biodistribution and In Vitro/In Vivo Toxicity Evaluation

The development of different kinds of nanoparticles, showing different physico-chemical properties, has fostered their large use in many fields, including medicine. As a consequence, inorganic nanoparticles (e.g., metals or semiconductors), have raised issues about their potential toxicity. The scientific community is investigating the toxicity mechanisms of these materials, in vitro and in vivo, in order to provide accurate references concerning their use. This review will give the readers a thorough exploration on the entry mechanisms of inorganic nanoparticles in the human body, such as titanium dioxide nanoparticles (TiO₂NPs), silicon dioxide nanoparticles (SiO₂NPs), zinc oxide nanoparticles (ZnONPs), silver nanoparticles (AgNPs), gold nanoparticles (AuNPs) and quantum dots (QDsNPs). In addition, biodistribution, the current trends and novelties of in vitro and in vivo toxicology studies will be discussed, with a particular focus on immune response.

Effect of inhibitors of endocytosis and NF-kB signal pathway on folate-conjugated nanoparticle endocytosis by rat Kupffer cells

The regular accumulation of nanoparticles in the liver makes them hepatotoxic and decreases the circulation time, thus reducing their therapeutic effect. Resolving this problem will be significant in improving bioavailability and reducing side effects. In this study, we reduced the phagocytosis of epirubicin (EPI)-loaded folic acid-conjugated pullulan acetate (FPA/EPI) nanoparticles by Kupffer cells (KCs) through internalization and nuclear factor kappa B (NF-kB) signal pathway inhibitors, thus allowing development of FPA/EPI nanoparticles as a nanodrug delivery system (NDDS) based on our previous study. FPA/EPI nanoparticles were prepared by the dialysis method. Rat KCs were preincubated with the following individual or compound inhibitors: chlorpromazine (CPZ), nystatin (NY), colchicine (Col), amiloride (AMR), and pyrrolidine dithiocarbamate (PDTC). Dose- and time-dependent cellular uptake effects of inhibitors on FPA/EPI nanoparticles were determined through fluorometry. The cytokine levels of tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), and IL-6 were tested in culture supernatants by bead-based multiplex flow cytometry. The uptake study demonstrated that inhibitors had an obvious inhibitory effect (P<0.05 or P<0.01), with NY, AMR and Col all showing time-dependent inhibitory effects. PDTC + NY had the strongest inhibitory effect, with an uptake rate of 14.62%. The levels of the three proinflammatory cytokines were changed significantly by the compound inhibitors. TNF-α was significantly inhibited (P<0.05 or P<0.01), but IL-1β and IL-6 showed smaller decreases. These results suggested that clathrin- and caveolae-mediated endocytosis were the main routes via which nanoparticles entered KCs and that the NF-kB signal pathway was very important too. In summary, multiple mechanisms, including clathrin- and caveolae-mediated endocytosis, contribute to cytokine production in macrophages following exposure to folic acid-conjugated pullulan acetate nanoparticles. Thus, the endocytosis inhibition strategy has great potential for improving therapy and reducing toxicity of an NDDS in the treatment of cancer.