In vivo study of silver nanomaterials' toxicity with respect to size

Metallic and metallic oxide nanoparticles toxicity primarily targets the mitochondria of hepatocytes and renal cells

Nanoparticles (NPs) are utilized in various applications, posing potential risks to human health, tissues, cells, and macromolecules. This study aimed to investigate the ultrastructural alterations in hepatocytes and renal tubular cells induced by metallic and metal oxide NPs. Adult healthy male Wistar albino rats (Rattus norvegicus) were divided into 6 (n = 7) control and 6 treated groups (n = 7). The rats in the treated groups exposed daily to silver NPs, gold NPs, zinc oxide NPs, silicon dioxide NPs, copper oxide NPs, and ferric oxide NPs for 35 days. The members of the control group for each corresponding NPs received the respective vehicle. Liver and kidney tissue blocks from all rats were processed for Transmission Electron Microscopy (TEM) examinations. The hepatocytes and renal tubular cells of all NPs-treated rats demonstrated mitochondrial ultrastructural alterations mainly cristolysis, swelling, membrane disruption, lucent matrices, matrices lysis, and electron-dense deposits. However, other organelles demonstrated injury but to a lesser extent in the form of shrunken nuclei, nuclear membrane indentation, endoplasmic reticulum fragmentation, cellular membranes enfolding, brush border microvilli disruption, lysosomal hyperplasia, ribosomes dropping, and peroxisome formation. One may conclude from the findings that the hepatocytes and the renal tubular cells mitochondria are the main targets for nanoparticles toxicity ending in mitochondrial disruption and cell injury. Further studies taking into account the relation of mitochondrial ultrastructural damage with a weakened antioxidant defense system induced by chronic exposure to nanomaterials are needed.

Ultrasound-Based Micro-/Nanosystems for Biomedical Applications

Due to the intrinsic non-invasive nature, cost-effectiveness, high safety, and real-time capabilities, besides diagnostic imaging, ultrasound as a typical mechanical wave has been extensively developed as a physical tool for versatile biomedical applications. Especially, the prosperity of nanotechnology and nanomedicine invigorates the landscape of ultrasound-based medicine. The unprecedented surge in research enthusiasm and dedicated efforts have led to a mass of multifunctional micro-/nanosystems being applied in ultrasound biomedicine, facilitating precise diagnosis, effective treatment, and personalized theranostics. The effective deployment of versatile ultrasound-based micro-/nanosystems in biomedical applications is rooted in a profound understanding of the relationship among composition, structure, property, bioactivity, application, and performance. In this comprehensive review, we elaborate on the general principles regarding the design, synthesis, functionalization, and optimization of ultrasound-based micro-/nanosystems for abundant biomedical applications. In particular, recent advancements in ultrasound-based micro-/nanosystems for diagnostic imaging are meticulously summarized. Furthermore, we systematically elucidate state-of-the-art studies concerning recent progress in ultrasound-based micro-/nanosystems for therapeutic applications targeting various pathological abnormalities including cancer, bacterial infection, brain diseases, cardiovascular diseases, and metabolic diseases. Finally, we conclude and provide an outlook on this research field with an in-depth discussion of the challenges faced and future developments for further extensive clinical translation and application.

The Role of Phthalocyanine-Gold Nanoconjugates (Pc-Au NCs) in Ameliorating the Hepatic and Renal Toxicity-Induced by Silver Nanoparticles (Ag NPs) in Male Rats

Recently, gold nanoparticles (Au Nps) have gained tremendous attention for its unique properties as a safe nanocarrier for delivering drugs that are used in different disease diagnoses. Although silver nanoparticles (Ag NPs) have been generally applied due to their strong antibacterial, antiviral, antifungal, and antimicrobial properties, their toxicity is a subject of sustained debate, thus requiring further studies. The present study aims to evaluate the potential protective effect of gold nanoparticles and phthalocyanine-gold nanoconjugates (Pc-Au NCs) against the hepatorenal toxicity of silver nanoparticles in male rats. Herein, 60 adult male Rattus norvegicus rats were divided into six equal groups (n = 10/group); the first group was kept as control, the second received gold nanoparticles (Au NPs) intraperitoneally (10 µg/kg) daily for 3 weeks, the third group is gold-phthalocyanine (Pc-Au) group where rats were injected intraperitoneally with gold-phthalocyanine for 3 weeks (10 µg/kg), the fourth group received silver nanoparticles (Ag NPs) (4 mg/kg) daily intraperitoneally for 3 weeks, the fifth group is silver + gold nanoparticles group (Ag + Au), and the sixth is silver + gold-phthalocyanine nanoconjugates (Ag + Pc-Au) group in which rats were intraperitoneally injected firstly with Ag NPs (4 mg/kg) for 3 weeks then with gold or gold-phthalocyanine for another 3 weeks (10 µg/kg). Our results revealed that Ag NPs could increase the serum AST, ALT, ALP, urea, creatinine, and lipid profile and significantly decreased the total protein and albumin. Moreover, histopathological alterations detected in the kidney and the liver of the Ag NPs group included vascular congestion, inflammatory cell infiltration, and tissue distortion. Alongside, exposure to Ag NPs induces hepatic and renal oxidative stress by suppressing the antioxidant-related genes including glutathione peroxidase 1 (gpx1), superoxide dismutase (sod), and catalase (cat). Ag NPs also upregulated the hepatic and renal genes involved in inflammation such as the interleukin-6 (il-6) and tumor necrosis factor-α (tnf-α), nuclear factor kappa B (nf-κβ), apoptosis such as the BCL2 associated X (bax), casp3, and other related to metabolism including asparagine synthetase (asns), suppressor of cytokine signaling 3 (socs3), MYC proto-oncogene (myc), and C-C motif chemokine ligand 2 (ccl2). On the other hand, treatment with Au NPs and Pc-Au NCs could effectively ameliorate the hepatorenal damages induced by Ag NPs and improve liver and kidney architecture and function, especially in the Pc-Au NCs group. Briefly, our study revealed the underlined mechanism of Ag NPs hepatotoxic and nephrotoxic effects and that Pc-Au NCs could alleviate these adverse impacts via their anti-oxidative, anti-apoptotic, and anti-inflammatory activities.

Green synthesis of aminated hyaluronic acid-based silver nanoparticles on modified titanium dioxide surface: Influence of size and chemical composition on their biological properties

This is the first report on an efficient, "environmentally friendly" chemical reduction method for the synthesis of aminated hyaluronic acid-based silver nanoparticles on the modified surface of titanium dioxide nanoparticles aimed for biological applications. Silver nanoparticles exhibit well-known physical-chemical and optical properties appropriate for different biological applications. Modifying the nanoparticles leads to a change in their expected bioactivity. This represents an important topic for the current research. We have developed a novel aminated hyaluronic acid (HA-EDA)-based protocol to obtain silver nanoparticles, in which HA-EDA was used for the first time as a reducing and stabilizing agent. The effect of the size of silver nanoparticles on the titanium dioxide surface and the chemical composition of the obtained materials were investigated by TEM, XRD, XPS, ATR-FTIR, Raman spectroscopy, NMR and H2-TPR analyses. The antioxidant, in vitro biocompatibility, and antimicrobial activity of the fabricated composites have been evaluated. The results prove that the prepared materials exhibit antimicrobial, antioxidant, and anti-inflammatory activity, thus providing protection against infection and supporting tissue regeneration, these two key effects being of paramount importance for promoting wound healing.

Synthesis and in vivo evaluation of three fluid spray dried hybrid ciprofloxacin microparticles in Sprague Dawley rats

The aim of this study is to prepare and characterise mucoadhesive silica-coated silver nanoparticles loaded with ciprofloxacin (S-AgNPs-CSCFX), and investigate serum biochemical, haematological, and histopathological effects in Sprague Dawley rats upon oral administration. S-AgNPs-CSCFX microparticles were prepared using three fluid nozzle spray drying and characterised by scanning electron microscopy (SEM), X-ray dispersive spectrometry (EDX), transmission electron microscopy (TEM), Fourier transform infrared (FTIR), zeta potential and particles size measurements and X-ray powder diffraction (XRPD). Adult male Sprague Dawley rats were randomly divided between six-treated groups, including blank S-AgNPs and S-AgNPs-CSCFX (LD: Low dose; MD: Median Dose; HD: High Dose) and control group. Each group was treated daily to evaluate the effect of the prepared particles on the lipid profile, serum biochemical, hormonal level, haemogram, and vital organ histopathology. The results showed successful encapsulation of silver nanoparticles which resulted in spherical-shaped S-AgNPs-CSCFX with an average size of 1-5 μm and surface charge of 25.2 ± 5.52 mv. The in-vivo results showed that different doses of blank S-AgNPs and S-AgNPs-CSCFX had no significant toxic effects on the physiological, biochemical, and haematological parameters. There were no marked histopathological alterations in the vital organs of the treated rats with blank and loaded particles.

Nanoparticles for cancer therapy: a review of influencing factors and evaluation methods for biosafety

Nanoparticles are widely used in the biomedical field for diagnostic and therapeutic purposes due to their small size, high carrier capacity, and ease of modification, which enable selective targeting and as contrast agents. Over the past decades, more and more nanoparticles have received regulatory approval to enter the clinic, more nanoparticles have shown potential for clinical translation, and humans have increasing access to them. However, nanoparticles have a high potential to cause unpredictable adverse effects on human organs, tissues, and cells due to their unique physicochemical properties and interactions with DNA, lipids, cells, tissues, proteins, and biological fluids. Currently, issues, such as nanoparticle side effects and toxicity, remain controversial, and these pitfalls must be fully considered prior to their application to body systems. Therefore, it is particularly urgent and important to assess the safety of nanoparticles acting in living organisms. In this paper, we review the important factors influencing the biosafety of nanoparticles in terms of their properties, and introduce common methods to summarize the biosafety evaluation of nanoparticles through in vitro and in body systems.

On the toxicity of gold nanoparticles: Histological, histochemical and ultrastructural alterations

Gold nanoparticles (Au NPs) are used in diagnostic and therapeutic applications together with a variety of industrial purposes and in many biomedical sectors with potential risks to human health. The present study aimed to the histological, histochemical, and ultrastructural alterations induced by Au NPS in vital organs. Healthy male Wistar Albino rats (Rattus norvegicus) were subjected to 20 injections of 10-nm Au NPs at a daily dose of 2 mg/kg. Liver, kidney, heart, and lung biopsies from control and Au NPs-treated rats under study were subjected to histological and histochemical examinations. In comparison with the control rats, the renal tissue of Au NPs-treated rats demonstrated glomerular congestion, interstitial inflammatory cell infiltration, renal tubular hydropic degeneration, cloudy swelling, necrosis, and hyaline cast precipitation. In addition, Au NPs induced the following hepatic alterations: hepatocyte cytolysis, cytoplasmic vacuolation, hydropic degeneration, and nuclear alterations together with sinusoidal dilatation. Moreover, the hearts of the treated rats demonstrated myocarditis, cardiac congestion, hyalinosis, cardiomyocyte hydropic degeneration, myofiber disarray and cardiac congestion. The lungs of Au NPs-treated rats also exhibited the following pulmonary alterations: alectasis, emphysema, inflammatory cell inflammation, thickened alveolar walls, pulmonary interstitial edema, congestion, hypersensitivity, fibrocyte proliferation, and honeycombing. In conclusion, exposure to Au NPs induced histological, histochemical and ultrastructural alterations in the vital organs that may alter the function of these organs. Additional efforts are needed for better understanding the potential risks of Au NPs to human health.

Toxicologic Concerns with Current Medical Nanoparticles

Nanotechnology is one of the scientific advances in technology. Nanoparticles (NPs) are small materials ranging from 1 to 100 nm. When the shape of the supplied nanoparticles changes, the physiological response of the cells can be very different. Several characteristics of NPs such as the composition, surface chemistry, surface charge, and shape are also important parameters affecting the toxicity of nanomaterials. This review covered specific topics that address the effects of NPs on nanomedicine. Furthermore, mechanisms of different types of nanomaterial-induced cytotoxicities were described. The distributions of different NPs in organs and their adverse effects were also emphasized. This review provides insight into the scientific community interested in nano(bio)technology, nanomedicine, and nanotoxicology. The content may also be of interest to a broad range of scientists.

Yttrium Oxide Nanoparticles Moderate the Abnormal Cognitive Behaviors in Male Mice Induced by Silver Nanoparticles

Silver nanoparticles (Ag-NPs) have been used in medical, agricultural, and industrial purposes. Furthermore, NPs can cross the blood-brain barrier and encourage some effects on spatial learning and memory in organism. Here, we investigate the possible neurotoxicity of Ag-NPs with special emphasis on the neuroprotective impacts of yttrium-oxide nanoparticles (YO-NPs) in male mice. Male mice (n = 24) were weekly intraperitoneally injected for 35 days as the following; groups I, II, III, and IV received tap water (control), Ag-NPs (40 mg/kg), YO-NPs (40 mg/kg), and Ag-NPs/YO-NPs (40 mg/kg each), respectively. After that, animals were tested in shuttle box, Morris water-maze, and T-maze devices to evaluate the spatial learning and memory competence. Neurotransmitters and oxidative indices in the forebrain were estimated. According to behavioral studies, the male animals from the Ag-NP group presented worse memory than those in the control group. The biochemical changes after Ag-NP exposure were observed through increasing TBARS levels and decline in oxidative biomarkers (SOD, CAT, GST, and GSH) and neurotransmitters (DOP, SER, and AChE) in the forebrain of male mice compared to untreated animals. Interestingly, the animals treated with mixed doses of Ag-NPs and YO-NPs displayed improvements in behavioral tests, oxidative parameters, and neurotransmitters compared to males treated with Ag-NPs alone. In conclusion, the abnormal behavior related to learning and memory in male mice induced by Ag-NPs was significantly alleviated by YO-NPs. Specifically, the coinjection of YO-NPs with Ag-NPs moderates the disruption in neurotransmitters, oxidative indices of mice brains, which reflects on their cognitive behaviors.

Effects of iron oxide nanoparticles as T2-MRI contrast agents on reproductive system in male mice

Iron oxide nanoparticles (IONPs)-based contrast agents are widely used for T₂-weighted magnetic resonance imaging (MRI) in clinical diagnosis, highlighting the necessity and importance to evaluate their potential systematic toxicities. Although a few previous studies have documented the toxicity concerns of IONPs to major organs, limited data are available on the potential reproductive toxicity caused by IONPs, especially when administrated via intravenous injection to mimic clinical use of MRI contrast agents. Our study aimed to determine whether exposure to IONPs would affect male reproductive system and cause other related health concerns in ICR mice. The mice were intravenously injected with different concentrations IONPs once followed by routine toxicity tests of major organs and a series of reproductive function-related analyses at different timepoints. As a result, most of the contrast agents were captured by reticuloendothelial system (RES) organs such as liver and spleen, while IONPs have not presented adverse effects on the normal function of these major organs. In contrast, although IONPs were not able to enter testis through the blood testicular barrier (BTB), and they have not obviously impaired the overall testicular function or altered the serum sex hormones levels, IONPs exposure could damage Sertoli cells in BTB especially at a relative high concentration. Moreover, IONPs administration led to a short-term reduction in the quantity and quality of sperms in a dose-dependent manner, which might be attributed to the increase of oxidative stress and apoptotic activity in epididymis. However, the semen parameters have gradually returned to the normal range within 14 days after the initial injection of IONPs. Collectively, these results demonstrated that IONPs could cause reversible damage to the reproductive system of male mice without affecting the main organs, providing new guidance for the clinical application of IONPs as T₂-MRI contrast agents.

Use of an in silico knowledge discovery approach to determine mechanistic studies of silver nanoparticles-induced toxicity from in vitro to in vivo

BACKGROUND

Silver nanoparticles (AgNPs) are considered a double-edged sword that demonstrates beneficial and harmful effects depending on their dimensions and surface coating types. However, mechanistic understanding of the size- and coating-dependent effects of AgNPs in vitro and in vivo remains elusive. We adopted an in silico decision tree-based knowledge-discovery-in-databases process to prioritize the factors affecting the toxic potential of AgNPs, which included exposure dose, cell type and AgNP type (i.e., size and surface coating), and exposure time. This approach also contributed to effective knowledge integration between cell-based phenomenological observations and in vitro/in vivo mechanistic explorations.

RESULTS

The consolidated cell viability assessment results were used to create a tree model for generalizing cytotoxic behavior of the four AgNP types: SCS, LCS, SAS, and LAS. The model ranked the toxicity-related parameters in the following order of importance: exposure dose > cell type > particle size > exposure time ≥ surface coating. Mechanistically, larger AgNPs appeared to provoke greater levels of autophagy in vitro, which occurred during the earlier phase of both subcytotoxic and cytotoxic exposures. Furthermore, apoptosis rather than necrosis majorly accounted for compromised cell survival over the above dosage range. Intriguingly, exposure to non-cytotoxic doses of AgNPs induced G2/M cell cycle arrest and senescence instead. At the organismal level, SCS following a single intraperitoneal injection was found more toxic to BALB/c mice as compared to SAS. Both particles could be deposited in various target organs (e.g., spleen, liver, and kidneys). Morphological observation, along with serum biochemical and histological analyses, indicated that AgNPs could produce pancreatic toxicity, apart from leading to hepatic inflammation.

CONCLUSIONS

Our integrated in vitro, in silico, and in vivo study revealed that AgNPs exerted toxicity in dose-, cell/organ type- and particle type-dependent manners. More importantly, a single injection of lethal-dose AgNPs (i.e., SCS and SAS) could incur severe damage to pancreas and raise blood glucose levels at the early phase of exposure.

Sex-related response in mice after sub-acute intraperitoneal exposure to silver nanoparticles

Silver nanoparticles (AgNPs) are among the most commercialized nanomaterials in biomedicine due to their antimicrobial and anti-inflammatory properties. Nevertheless, possible health hazards of exposure to AgNPs are yet to be understood and therefore raise public concern in regards of their safety. In this study, sex-related differences, role of steroidal hormones and influence of two different surface stabilizing agents (polymer vs. protein) on distribution and adverse effects of AgNPs were investigated in vivo. Intact and gonadectomised male and female mice were treated with seven AgNPs doses administered intraperitoneally during 21 days. After treatment, steroid hormone levels in serum, accumulation of Ag levels and oxidative stress biomarkers in liver, kidneys, brain and lungs were determined. Sex-related differences were observed in almost all tissues. Concentration of Ag was significantly higher in the liver of females compared to males. No significant difference was found for AgNP accumulation in lungs between females and males, while the lungs of intact males showed significantly higher Ag accumulation compared to gonadectomised group. Effect of surface coating was also observed, as Ag accumulation was significantly higher in kidneys and liver of intact females, as well as in kidneys and brain of intact males treated with protein-coated AgNPs compared to polymeric AgNPs. Oxidative stress response to AgNPs was the most pronounced in kidneys where protein-coated AgNPs induced stronger effects compared to polymeric AgNPs. Interestingly, protein-coated AgNPs reduced generation of reactive oxygen species in brains of females and gonadectomised males. Although there were no significant differences in levels of hormones in the AgNP-exposed animals compared to controls, sex-related differences in oxidative stress parameters were observed in all organs. Results of this study highlight the importance of including the sex-related differences and effects of protein corona in biosafety evaluation of AgNPs exposure.

Quasi-SMILES as a basis for the development of models for the toxicity of ZnO nanoparticles

The application of nanomaterials is expanding. Therefore, it is necessary to investigate the relationship between the structure and toxicity of different nanomaterials. Quasi-SMILES is a line of symbols which are codes of corresponding conditions of experiments aimed to estimate the toxicity of ZnO nanoparticles towards the rat via intraperitoneal injections. By means of the Monte Carlo method, the so-called correlation weights for fragments of quasi-SMILES can be calculated. Having the numerical data on the correlation weights one can build up a one-variable model for the toxicity. The checking up of the approach with five random splits of all available data on results of thirty-six experiments into a sub-system of training and sub-system of validation has confirmed the significance of the statistical quality of models obtained with the above approach. The average determination coefficient equal to 0.957 (dispersion 0.010) and average root mean square error equal to 7.25 [mg/kg] (dispersion 0.59 [mg/kg]).

Silver nanoparticles: Correlating particle size and ionic Ag release with cytotoxicity, genotoxicity, and inflammatory responses in human cell lines

The widespread use of silver nanoparticles (AgNPs), their many sources for human exposure, and the ability of AgNPs to enter organisms and induce general toxicological responses have raised concerns regarding their public health and environmental safety. To elucidate the differential toxic effects of polyvinylpyrrolidone-capped AgNPs with different primary particle sizes (i.e. 5, 50, and 75 nm), we performed a battery of cytotoxicity and genotoxicity assays and examined the inflammatory responses in two human cell lines (i.e. HepG2 and A549). Concentration-dependent decreases in cell proliferation and mitochondrial membrane potential and increases in cytokine (i.e. interleukin-6 and interleukin-8) excretion indicated disruption of mitochondrial function and inflammation as the main mediating factors of AgNPs-induced cytotoxicity. An incremental increase in genotoxicity with decreasing AgNPs diameter was noted in HepG2 cells, which was associated with S and G2/M accumulation and transcriptional activation of the GADD45α promoter as reflected by luciferase activity. Dose-related genetic damage, as indicated by Olive tail moment and micronucleus formation, was also observed in A549 cells, but these effects as well as the AgNPs-induced cytotoxicity were more associated with ionic Ag release from nanoparticles (NPs). In summary, the present study addressed different toxicity mechanisms of AgNPs, depending on the cell model, toxicological endpoint, particle size, and degree of Ag+ release from NPs. The results suggest that the GADD45α promoter-driven luciferase reporter cell system provided a rapid screening tool for the identification of genotoxic properties of NPs across a range of different sizes and concentrations.

The Influence of Size and Chemical Composition of Silver and Gold Nanoparticles on in vivo Toxicity with Potential Applications to Central Nervous System Diseases

The physicochemical and optical properties of silver nanoparticles (SNPs) and gold nanoparticles (GNPs) have allowed them to be employed for various biomedical applications, including delivery, therapy, imaging, and as theranostic agents. However, since they are foreign body systems, they are usually redistributed and accumulated in some vital organs, which can produce toxic effects; therefore, this a crucial issue that should be considered for potential clinical trials. This review aimed to summarize the reports from the past ten years that have used SNPs and GNPs for in vivo studies on the diagnosis and treatment of brain diseases and those related to the central nervous system, emphasizing their toxicity as a crucial topic address. The article focuses on the effect of the nanoparticle´s size and chemical composition as relevant parameters for in vivo toxicity. At the beginning of this review, the general toxicity and distribution studies are discussed separately for SNPs and GNPs. Subsequently, this manuscript analyzes the principal applications of both kinds of nanoparticles for glioma, neurodegenerative, and other brain diseases, and discusses the advances in clinical trials. Finally, we analyze research prospects towards clinical applications for both types of metallic nanoparticles.