Toxic Impacts of Amorphous Silica Nanoparticles on Liver and Kidney of Male Adult Rats: an In Vivo Study

Health burden of sugarcane burning on agricultural workers and nearby communities

Sugarcane is the most widely cultivated crop in the world, with equatorial developing nations performing most of this agriculture. Burning sugarcane is a common practice to facilitate harvest, producing extremely high volumes of respirable particulate matter in the process. These emissions are known to have deleterious effects on agricultural workers and nearby communities, but the extent of this exposure and potential toxicity remain poorly characterized. As the epidemicof chronic kidney disease of an unknown etiology (CKDu) and its associated mortality continue to increase along with respiratory distress, there is an urgent need to investigate the causes, determine viable interventions to mitigate disease andimprove outcomes for groups experiencing disproportionate impact. The goal of this review is to establish the state of available literature, summarize what is known in terms of human health risk, and provide recommendations for what areas should be prioritized in research.

Proteomics revealed composition- and size-related regulators for hepatic impairments induced by silica nanoparticles

Along with the growing production and application of silica nanoparticles (SiNPs), increased human exposure and ensuing safety evaluation have progressively attracted concern. Accumulative data evidenced the hepatic injuries upon SiNPs inhalation. Still, the understanding of the hepatic outcomes resulting from SiNPs exposure, and underlying mechanisms are incompletely elucidated. Here, SiNPs of two sizes (60 nm and 300 nm) were applied to investigate their composition- and size-related impacts on livers of ApoE-/- mice via intratracheal instillation. Histopathological and biochemical analysis indicated SiNPs promoted inflammation, lipid deposition and fibrosis in the hepatic tissue, accompanied by increased ALT, AST, TC and TG. Oxidative stress was activated upon SiNPs stimuli, as evidenced by the increased hepatic ROS, MDA and declined GSH/GSSG. Of note, these alterations were more dramatic in SiNPs with a smaller size (SiNPs-60) but the same dosage. LC-MS/MS-based quantitative proteomics unveiled changes in mice liver protein profiles, and filtered out particle composition- or size-related molecules. Interestingly, altered lipid metabolism and oxidative damage served as two critical biological processes. In accordance with correlation analysis and liver disease-targeting prediction, a final of 10 differentially expressed proteins (DEPs) were selected as key potential targets attributable to composition- (4 molecules) and size-related (6 molecules) liver impairments upon SiNPs stimuli. Overall, our study provided strong laboratory evidence for a comprehensive understanding of the harmful biological effects of SiNPs, which was crucial for toxicological evaluation to ensure nanosafety.

Biocompatibility and sub-chronic toxicity studies of phlorotannin/polycaprolactone coated trachea tube for advancing medical device applications

The phlorotannin-polycaprolactone-coated endotracheal tube (PP tube) has been developed with the aim of preventing tracheal stenosis that can result from endotracheal intubation, a factor that can lead to a serious airway obstruction. Its preventive efficacy has been assessed through both in vitro and in vivo investigations. However, there is a lack of studies concerning its biocompatibility and sub-chronic toxicity in animal models, a crucial factor to ensure the safety of its usage as a functional endotracheal tube. Thus, this study aimed to evaluate the biocompatibility and sub-chronic (13 weeks) toxicity of the PP tube through L929 cell line and diverse in vivo models. The cytotoxicity testing was performed using the extracts of PP tube on L929 cells for 72 h. Furthermore, other tests conducted on animal models, including ICR mice (acute systemic toxicity), New Zealand white rabbit (intradermal reactivity and pyrogen tests), guinea pig (maximization sensitization), and Sprague Dawley rats (sub-chronic toxicity). In both biocompatibility and sub-chronic toxicity analyses, no significant adverse effects are observed in the groups exposed to the PP tube, when compared to control group. Altogether, the findings suggested that the PP tube exhibits relative non-toxic and safety, supporting its suitability for clinical usage. However, extended periods of intubation may produce mild irritant responses, highlighting the clinical caution of limiting intubation duration to less than 13 weeks.

Lipidomics Investigation Reveals the Reversibility of Hepatic Injury by Silica Nanoparticles in Rats After a 6-Week Recovery Duration

Given the inevitable human exposure owing to its increasing production and utilization, the comprehensive safety evaluation of silica nanoparticles (SiNPs) has sparked concerns. Substantial evidence indicated liver damage by inhaled SiNPs. Notwithstanding, few reports focused on the persistence or reversibility of hepatic injuries, and the intricate molecular mechanisms involved remain limited. Here, rats are intratracheally instilled with SiNPs in two regimens (a 3-month exposure and a subsequent 6-week recovery after terminating SiNPs administration) to assess the hepatic effects. Nontargeted lipidomics revealed alterations in lipid metabolites as a contributor to the hepatic response and recovery effects of SiNPs. In line with the functional analysis of differential lipid metabolites, SiNPs activated oxidative stress, and induced lipid peroxidation and lipid deposition in the liver, as evidenced by the elevated hepatic levels of ROS, MDA, TC, and TG. Of note, these indicators showed great improvements after a 6-week recovery, even returning to the control levels. According to the correlation, ROC curve, and SEM analysis, 11 lipids identified as potential regulatory molecules for ameliorating liver injury by SiNPs. Collectively, the work first revealed the reversibility of SiNP-elicited hepatotoxicity from the perspective of lipidomics and offered valuable laboratory evidence and therapeutic strategy to facilitate nanosafety.

Bioinformatics-driven discovery of silica nanoparticles induces apoptosis and renal damage via the unfolded protein response in NRK-52E cells and rat kidney

Silica nanoparticles (SiNPs) are nanomaterials with widespread applications in drug delivery and disease diagnosis. Despite their utility, SiNPs can cause chronic kidney disease, hindering their clinical translation. The molecular mechanisms underlying SiNP-induced renal toxicity are complex and require further investigation. To address this challenge, we employed bioinformatics tools to predict the potential mechanisms underlying renal damage caused by SiNPs. We identified 1627 upregulated differentially expressed genes (DEGs) and 1334 downregulated DEGs. Functional enrichment analysis and protein-protein interaction network revealed that SiNP-induced renal damage is associated with apoptosis. Subsequently, we verified that SiNPs induced apoptosis in an in vitro model of NRK-52E cells via the unfolded protein response (UPR) in a dose-dependent manner. Furthermore, in an in vivo rat model, high-dose SiNP administration via tracheal drip caused hyalinization of the renal tubules, renal interstitial lymphocytic infiltration, and collagen fiber accumulation. Concurrently, we observed an increase in UPR-related protein levels at the onset of renal damage. Thus, our study confirmed that SiNPs induce apoptosis and renal damage through the UPR, adding to the theoretical understanding of SiNP-related kidney damage and offering a potential target for preventing and treating kidney injuries in SiNP clinical applications.

Amorphous silica nanoparticles cause abnormal cytokinesis and multinucleation through dysfunction of the centralspindlin complex and microfilaments

BACKGROUND

With the large-scale production and application of amorphous silica nanoparticles (aSiNPs), its adverse health effects are more worthy of our attention. Our previous research has demonstrated for the first time that aSiNPs induced cytokinesis failure, which resulted in abnormally high incidences of multinucleation in vitro, but the underlying mechanisms remain unclear. Therefore, the purpose of this study was firstly to explore whether aSiNPs induced multinucleation in vivo, and secondly to investigate the underlying mechanism of how aSiNPs caused abnormal cytokinesis and multinucleation.

METHODS

Male ICR mice with intratracheal instillation of aSiNPs were used as an experimental model in vivo. Human hepatic cell line (L-02) was introduced for further mechanism study in vitro.

RESULTS

In vivo, histopathological results showed that the rate of multinucleation was significantly increased in the liver and lung tissue after aSiNPs treatment. In vitro, immunofluorescence results manifested that aSiNPs directly caused microfilaments aggregation. Following mechanism studies indicated that aSiNPs increased ROS levels. The accumulation of ROS further inhibited the PI3k 110β/Aurora B pathway, leading to a decrease in the expression of centralspindlin subunits MKLP1 and CYK4 as well as downstream cytokines regulation related proteins Ect2, Cep55, CHMP2A and RhoA. Meanwhile, the particles caused abnormal co-localization of the key mitotic regulatory kinase Aurora B and the centralspindlin complex by inhibiting the PI3k 110β/Aurora B pathway. PI3K activator IGF increased the phosphorylation level of Aurora B and improved the relative ratio of the centralspindlin cluster. And ROS inhibitors NAC reduced the ratio of multinucleation, alleviated the PI3k 110β/Aurora B pathway inhibition, and then increased the expression of MKLP1, CYK4 and cytokinesis-related proteins, whilst NAC restored the clustering of the centralspindlin.

CONCLUSION

This study demonstrated that aSiNPs led to multinucleation formation both in vivo and in vitro. ASiNPs exposure caused microfilaments aggregation and inhibited the PI3k 110β/Aurora B pathway through excessive ROS, which then hindered the centralspindlin cluster as well as restrained the expression of centralspindlin subunits and cytokinesis-related proteins, which ultimately resulted in cytokinesis failure and the formation of multinucleation.

Synthesis and Characterization of Silica, Silver-Silica, and Zinc Oxide-Silica Nanoparticles for Evaluation of Blood Biochemistry, Oxidative Stress, and Hepatotoxicity in Albino Rats

Evaluation of nanoparticles (NPs) for biomedical applications has received a lot of attention for detailed study on pharmacokinetics prior to clinical application. In this study, pure C-SiO₂ (crystalline silica) NPs and SiO₂ nanocomposites with silver (Ag) and zinc oxide (ZnO) were prepared by utilizing different synthesis routes such as sol-gel and co-precipitation techniques. The prepared NPs showed highly crystalline nature as confirmed by X-ray diffraction analysis where average crystallite sizes of 35, 16, and 57 nm for C-SiO₂, Ag-SiO₂, and ZnO-SiO₂ NPs, respectively, were calculated. Fourier transform infrared analysis confirmed the presence of functional groups related to the chemicals and procedures used for sample preparation. Due to agglomeration of the prepared NPs, the scanning electron microscope images showed large particle sizes when compared to their crystalline sizes. The optical properties of the prepared NPs such as absorption were obtained with UV-Vis spectroscopy. For in vivo biological evaluation, albino rats, both male and female, kept in different groups were exposed to NPs with 500 μg/kg dose. Hematological, serum biochemistry, histo-architecture, oxidative stress biomarkers, and antioxidant parameters in liver tissues along with various biomarkers for the evaluation of erythrocytes were estimated. The results on hemato-biochemistry, histopathological ailments, and oxidative stress parameters exhibited 95% alteration in the liver and erythrocytes of C-SiO₂ NPs-treated rats while 75 and 60% alteration in the liver tissues of rats due to exposure to Ag-SiO₂ and ZnO-SiO₂ NPs, respectively, when compared with the albino rats of the control (untreated) group. Therefore, the current study showed that the prepared NPs had adverse effects on the liver and erythrocytes causing hepatotoxicity in the albino rats in respective order C-SiO₂ > Ag SiO₂ > ZnO-SiO₂. As the C-SiO₂ NPs appeared to be the most toxic, it has been concluded that coating SiO₂ on Ag and ZnO reduced their toxicological impact on albino rats. Consequently, it is suggested that Ag-SiO₂ and ZnO-SiO₂ NPs are more biocompatible than C-SiO₂ NPs.

Survival, growth, behavior, hematology and serum biochemistry of mice under different concentrations of orally administered amorphous silica nanoparticle

Silica nanoparticles (SiNPs) are used extensively in consumer products and biomedical research basically due to ease of production and low cost. However, insufficient literature is reported regarding the toxicity and biocompatibility of SiNPs. The present study aimed to investigate the potential role of amorphous SiNPs on survival, growth, behavioral alterations, hematology and serum biochemistry of mice at four concentrations (control, 50, 100 and 150 mg/kg/day) of an oral supplementation for a period of 3 months. Signs of toxicity (lethargy, nausea, coma, tremors, vomiting and diarrhea, etc.) were noted at 9:00 am and 9:00 pm (twice a day) and the body weight of each of these mice was measured every week. The data were subjected to mean, standard deviation (S.D). Moreover, One-Way Analysis of Variance (ANOVA) and Dunnett's test were applied for analysis of statistical significance between groups by using SPSS software, version 20. All the mice survived with minor alterations in behavior and no significant weight changes were observed during the stipulated time period. Complete blood count (CBC) analysis indicated non-significant (P ≥ 0.05) systemic dysfunctions of organ systems. However, there was elevation in the level of AST and ALT in the analysis of serum biochemistry, while the values of all other examined parameters were not-significant (P ≥ 0.05). The study concluded that orally administered large silica nanoparticles up to the dose level of 150 mg/kg/day are nontoxic for the in vivo use in mice.

Toxicity and Impact of Silica Nanoparticles on the Configuration of Gut Microbiota in Immunodeficient Mice

Nanoparticles (NPs), having exceptional physicochemical and electrical characteristics with lower toxicity, have evolved as dynamic drug delivery carriers in living organisms. Potentially, the intragastric gavage of silica nanoparticles (SiNPs) affects gut microbiota profiles in immunodeficient mice. In this study, the impact of SiNPs of variable size and dosage was investigated in cyclophosphamide (Cy)-induced immunodeficient mice, specifically on their immune functions and gut microbiota, through physicochemical and metagenomic analysis. SiNPs of different sizes and doses were gavaged to Cy-induced immunodeficient mice for 12 days at an interval of 24 h to investigate their effects on immunological functions and the gut microbiome of mice. Our results showed that SiNPs had no significant toxicological effects on the cellular and hematological activities of immunodeficient mice. Furthermore, after the administration of different levels of SiNPs, no immune dysfunction was found in the immunosuppressed mice groups. However, gut-microbial studies and comparisons of characteristic bacterial diversity and compositions demonstrated that SiNPs significantly affect the abundance of different bacterial communities. LEfSe analysis revealed that SiNPs significantly increased the abundance of Lactobacillus, Sphingomonas, Sutterella, Akkermansia, and Prevotella, and potentially reduced Ruminococcus and Allobaculum. Thus, SiNPs significantly regulate and modify the configuration of the gut microbiota in immunodeficient mice. These dynamic variations in the intestinal bacterial community, abundance, and diversity provide new insight into the regulation and administration of silica-based NPs. This would be helpful for the further demonstration of the mechanism of action and prediction of the potential effects of SiNPs.

Magnesium Supplementation Alleviates the Toxic Effects of Silica Nanoparticles on the Kidneys, Liver, and Adrenal Glands in Rats

Concerns regarding the possible hazards to human health have been raised by the growing usage of silica nanoparticles (SiNPs) in a variety of applications, including industrial, agricultural, and medical applications. This in vivo subchronic study was conducted to assess the following: (1) the toxicity of orally administered SiNPs on the liver, kidneys, and adrenal glands; (2) the relationship between SiNPs exposure and oxidative stress; and (3) the role of magnesium in mitigating these toxic effects. A total of 24 Sprague Dawley male adult rats were divided equally into four groups, as follows: control group, magnesium (Mg) group (50 mg/kg/d), SiNPs group (100 mg/kg/d), and SiNPs+ Mg group. Rats were treated with SiNPs by oral gavage for 90 days. The liver transaminases, serum creatinine, and cortisol levels were evaluated. The tissue malondialdehyde (MDA) and reduced glutathione (GSH) levels were measured. Additionally, the weight of the organs and the histopathological changes were examined. Our results demonstrated that SiNPs exposure caused increased weight in the kidneys and adrenal glands. Exposure to SiNPs was also associated with significant alterations in liver transaminases, serum creatinine, cortisol, MDA, and GSH. Additionally, histopathological changes were significantly reported in the liver, kidneys, and adrenal glands of SiNPs-treated rats. Notably, when we compared the control group with the treated groups with SiNPs and Mg, the results revealed that magnesium could mitigate SiNPs-induced biochemical and histopathologic changes, confirming its effective role as an antioxidant that reduced the accumulation of SiNPs in tissues, and that it returns the levels of liver transaminases, serum creatinine, cortisol, MDA, and GSH to almost normal values.

Silica Nanoparticle-Induced Reproductive Toxicity in Male Albino Rats via Testicular Apoptosis and Oxidative Stress

Amorphous silica nanoparticles (SiNPs) are being utilized in different fields such as medicine, cosmetics, and foods. However, the causes and mechanisms underlying SiNP testicular damage remain largely unclear. In the present study, we aimed to investigate this issue. Thirty male rats were randomly divided into three groups: control group (n = 10), 500 ppm SiNP-treated group (n = 10), and 1000 ppm SiNP-treated group (n = 10). SiNPs were given orally in drinking water for 30 days. Micronucleus assay was performed on blood RBCs. The concentrations of testicular malondialdehyde (MDA) and glutathione (GSH) and catalase (CAT) activity were measured. Moreover, the histopathological alterations and the expression of apoptotic (caspase-3) and pro-inflammatory and oxidative stress markers (iNOS) in testes and epididymis were analyzed and compared between the three groups. The results showed an increased level of micronucleus frequencies in the 1000 ppm-treated group, as well as increased levels of MDA and decreased activity of CAT and GSH content in testicular tissues in the 1000 ppm-treated group, suggesting DNA damage and oxidative stress mechanisms. Also, there were significant testicular histopathological alterations in this group. Furthermore, 1000-ppm SiNPs could enhance testicular apoptosis, inflammation, and oxidative stress by increasing the expression of apoptotic, pro-inflammatory, and oxidative stress genes including caspase 3 and iNOS in the examined tissue. The lower concentration of SiNPs did not produce any significant biochemical, histopathological, or immunohistochemical alterations whereas 1000-ppm SiNPs resulted in significant testicular changes by exacerbating apoptotic, inflammatory, and oxidative stress-mediated testicular damage.

Life Cycle Assessment of Functionalized Bionanocompounds with Ice Nucleation Protein for Freezing Applications

The objective of this study was to assess the effectiveness of functionalized bionanocompounds with ice nucleation protein (INP) as a novel approach for freezing applications in terms of how much energy is used during each step of freezing when water bionanocompound solutions were compared with pure water. According to the results of the manufacturing analysis, water required 28 times less energy than the silica + INA bionanocompound and 14 times less than the magnetite + INA bionanocompound. These findings showed that water used the least energy during the manufacturing process. In order to determine the associated environmental implications, an analysis of the operating stage was also conducted, taking the defrosting time of each bionanocompound during a 4 h work cycle into account. Our results showed that bionanocompounds may substantially reduce the environmental effects by achieving a 91% reduction in the impact after their use during all four work cycles in the operation stage. Additionally, given the energy and raw materials needed in this process, this improvement was more significant than at the manufacturing stage. The results from both stages indicated that, when compared with water, the magnetite + INA bionanocompound and the silica + INA bionanocompound would save an estimated 7% and 47% of total energy, respectively. The study’s findings also demonstrated the great potential for using bionanocompounds in freezing applications to reduce the effects on the environment and human health.

Curcumin-loaded hydroxyapatite nanocomposite as a novel biocompatible shield for male Wistar rats from γ-irradiation hazard

Curcumin (CUR) is well known for its extraordinary benefits as an anti-cancer, anti-inflammatory, and wound healing agent. However, nano-formulation could maintain and regulate its pharmacological effect. Herein, we report the preparation of CUR/hydroxyapatite nanocomposite (CUR/HA NC) and its application in the protection of male Wistar rats from γ-irradiation carcinogenic consequences. TEM images of the nanocrystalline HA nanoparticles (NPs) had a rod-like form with average dimensions of 40±5 nm in length and 10 ± 5 nm in width. XRD analysis illustrated the formation of a single phase of hexagonal crystalline HA NPs. The presence of the CUR fingerprint is visible in its FTIR spectra of the CUR/HA NC. Biochemical analysis and histological examinations revealed that CUR/HA NC injection does not significantly affect non-irradiation rats compared to the control. However, when injected pre-irradiation, it controls the pro-inflammatory cytokines (tumor necrosis factor-alpha, interleukin-6) GSH level, kidney, and liver functions as proved by biochemical histopathological and immunohistochemical findings. This research introduces a novel effective protection modality for the γ-irradiation hazard via biocompatible CUR/HA NC injection.

Adverse effects and underlying mechanism of amorphous silica nanoparticles in liver

Amorphous silica nanoparticles (SiNPs) have been widely used and mass-producted due to its unique properties. With the life cycle of SiNPs-based products, SiNPs are further released into the air, soil, surface water and sediment, resulting in an increasing risk to humans. SiNPs could enter into the human body through vein, respiratory tract, digestive tract or skin. Moreover, recent evidences have showed that, regardless of exposure pathways, SiNPs could even be traced in liver, which is gradually considered as one of the main organs that SiNPs accumulate. Increasing evidences supported the link between SiNPs exposure and adverse liver effects. However, the research models are diverse and the molecular mechanisms have not been well integrated. In this review, the liver-related studies of SiNPs in vivo and in vitro were screened from the PubMed database by systematic retrieval method. We explored the interaction between SiNPs and the liver, and especially proposed a framework of SiNPs-caused liver toxicity, considering AOP Wiki and existing studies. We identified increased reactive oxygen species (ROS) as a molecular initiating event (MIE), oxidative stress, endoplasmic reticulum stress, lysosome disruption and mitochondrial dysfunction as subsequent key events (KEs), which gradually led to adverse outcomes (AOs) containing liver dysfunction and liver fibrosis through a series of key events about cell inflammation and death such as hepatocyte apoptosis/pyroptosis, hepatocyte autophagy dysfuncton and hepatic macrophages pyroptosis. To our best knowledge, this is the first AOP proposed on SiNPs-related liver toxicity. In the future, more epidemiological studies need to be performed and more biomarkers need to be explored to improve the AOP framework for SiNPs-associated liver toxicity.

From Synthetic Route of Silica Nanoparticles to Theranostic Applications

The advancements in nanotechnology have quickly developed a new subject with vast applications of nanostructured materials in medicine and pharmaceuticals. The enormous surface-to-volume ratio, ease of surface modification, outstanding biocompatibility, and, in the case of mesoporous nanoparticles, the tunable pore size make the silica nanoparticles (SNPs) a promising candidate for nano-based medical applications. The preparation of SNPs and their contemporary usage as drug carriers, contrast agents for imaging, carrier of photosensitizers (PS) in photodynamic, as well as photothermal treatments are intensely discussed in this review. Furthermore, the potential harmful responses of silica nanoparticles are reviewed using data obtained from in vitro and in vivo experiments conducted by several studies. Moreover, we showcase the engineering of SNPs for the theranostic applications that can address several intrinsic limitations of conventional therapeutics and diagnostics. In the end, a personal perspective was outlined to state SNPs’ current status and future directions, focusing on SNPs’ significant potentiality and opportunities.

Insecticidal efficacy of nanomaterials used to control mosquito, Culex quinquefasciatus Say, 1823 with special reference to their hepatotoxicity in rats

The present study aimed to develop a novel methodology for controlling the mosquito larvae using different nanoparticles, with special reference to their effect on rats (a non-target mammalian model). The mosquito species of Culex quinquefasciatus was reared in the laboratory. Chitosan, silver nanoparticles and their combination as well as lavender (Lavandula officinalis) nanoemulsion with different concentrations were tested as biological insecticides against the mosquito larvae. Mammalian toxicity of the used nanoparticles were evaluated using 27 adult male rats, experimental rats were divided into 9 equal groups (n=3). The nanoparticles were added to the drinking water for 30 days. At the end of the study, blood and tissue samples were collected to assess the levels of the serum alanine aminotransferase and aspartate aminotransferase, different genes expression as interleukin 6 (IL-6) and IL-1β activity. Histopathological and immunohistochemical studies using two markers (TNF-α and BAX expression) were also applied. The LC₅₀ and LC₉₀ were recorded for each tested nanoparticles, and also the changes of the treated mosquito larvae cuticle were assessed using the scanning electron microscopy. Green nanoemulsion (Lavandula officinalis) was more effective than metal (silver) or even biodegradable (chitosan) nanoparticles in controlling of Culex quiquefasciatus mosquito larvae, and also it proved its safety by evaluation of the mammalian hepatotoxicity of the tested nanoparticles.

Silica nanoparticles: Biomedical applications and toxicity

Silica nanoparticles (SiNPs) are composed of silicon dioxide, the most abundant compound on Earth, and are used widely in many applications including the food industry, synthetic processes, medical diagnosis, and drug delivery due to their controllable particle size, large surface area, and great biocompatibility. Building on basic synthetic methods, convenient and economical strategies have been developed for the synthesis of SiNPs. Numerous studies have assessed the biomedical applications of SiNPs, including the surface and structural modification of SiNPs to target various cancers and diagnose diseases. However, studies on the in vitro and in vivo toxicity of SiNPs remain in the exploratory stage, and the toxicity mechanisms of SiNPs are poorly understood. This review covers recent studies on the biomedical applications of SiNPs, including their uses in drug delivery systems to diagnose and treat various diseases in the human body. SiNP toxicity is discussed in terms of the different systems of the human body and the individual organs in those systems. This comprehensive review includes both fundamental discoveries and exploratory progress in SiNP research that may lead to practical developments in the future.

Biodegradable polyaspartamide-g-C18 /DOPA/GLY-NEO nano-adhesives for wound closure/healing with antimicrobial activity

This study was focused on the development of biodegradable nano-adhesives with efficient sealing and antibiotic effects for wound healing. Biodegradable polyaspartamide (PASPAM) was grafted with several functional groups to implement diverse roles-octadecylamine (C₁₈ ) for nano-aggregate formation, dopamine (DOPA) for adhesive function, neomycin (NEO) for inhibition of bacterial infection. Specifically, NEO was conjugated to PASPAM with a pH-sensitive glycine (GLY) linker for targeted delivery on the acidic wound site. About 60% of the drug was ramteleased at pH 6.0, while about 22% was released at pH 7.4, showing the faster drug release pattern of nano-adhesives in the acidic environment. The C₁₈ /DOPA/GLY-NEO-g-PASPAM nano-adhesives showed the bacterial viability higher than 70% at pH 7.4, but about 40% at pH 6.0. The wound breaking strength of the polymer-treated skin was much higher than that of the bare skin. According to the in vivo wound healing test using a mouse model, C₁₈ /DOPA/GLY-NEO-g-PASPAM nano-adhesives showed much faster healing performance than sutures. From those results, C₁₈ /DOPA/GLY-NEO-g-PASPAM nano-adhesives are expected to be utilized as effective adhesives that promote the wound healing with inhibition of bacterial infection.

Pyrogenic synthetic amorphous silica (NM-203): Genotoxicity in rats following sub-chronic oral exposure

The genotoxicity of nano-structured synthetic amorphous silica (SAS), a common food additive, was investigated in vivo in rats. A 90-day oral toxicity study was performed according to OECD test guideline 408 and the genotoxicity of pyrogenic SAS nanomaterial NM-203 was assessed in several organs, using complementary tests. Adult Sprague-Dawley rats of both sexes were treated orally for 90 days with 0, 2, 5, 10, 20, or 50 mg SAS/kg bw per day. Dose levels were selected to approximate expected human dietary exposures to SAS. DNA strand breaks were evaluated by the comet assay in blood, bone marrow, liver, and spleen according to OECD test guideline 489; mutations induced in bone marrow precursors of erythrocytes were assessed by the Pig-a assay and chromosome/ genome damage by the micronucleus assay in blood (OECD test guideline 474) and colon. No treatment-related increases of gene (Pig-a) or chromosome/genome (micronucleus) mutations were detected in the blood. The percentage of micronucleated cells was not increased in the colon of treated rats. Among the organs analyzed by the comet assay, the spleen was the only target showing a weak but biologically relevant genotoxic effect.

Protective and Therapeutic Efficacy of Hesperidin versus Cisplatin against Ehrlich Ascites Carcinoma-Induced Renal Damage in Mice

This study evaluates the antitumor efficacy of hesperidin (Hesp) versus cisplatin (Cis) in Ehrlich ascites carcinoma (EAC)-bearing mice, as well as its protective effect against Cis-triggered nephrotoxicity. Seventy female mice were allocated into control, Hesp, EAC, Hesp-protected, Hesp-treated, Cis-treated, and Cis+Hesp-treated groups. The inoculation of mice with EAC cells significantly reduced the mean survival time, while significantly increased the body weight, abdominal circumference, ascitic fluid volume, viable tumor cell count, and serum carcinoembryonic antigen, urea and creatinine levels, besides various hematological changes. Additionally, kidney tissue of EAC-bearing mice showed a significant increase in the malondialdehyde level, significant decreases in the reduced glutathione content and catalase activity, marked pathological alterations, and a strong Ki-67 expression with a weak caspase-3 expression in neoplastic cells infiltrating the renal capsule. Conversely, the administration of Hesp and/or Cis to the EAC-bearing mice induced, to various degrees, antitumor responses and alleviated the cytotoxic effects of EAC. In addition to the potent antitumor effect of the concomitant administration of Hesp and Cis, Hesp minimized the renal adverse side effects of Cis. In conclusion, Hesp may open new avenues for safe and effective cancer therapy and could be valuable for enhancing the antitumor potency and minimizing the renal adverse side effects of chemotherapeutic drugs.

Genotoxicity evaluation of silica nanoparticles in murine: a systematic review and meta-analysis

Silica nanoparticles (SiNPs) have been widely used in nanotechnology, and more attention has been paid to their safety evaluation. However, there are still inconsistent conclusions about the genotoxicity of SiNPs. A systematic review was conducted to explore whether SiNPs have genotoxicity followed by a meta-analysis of in vivo and in vitro murine genotoxicity tests. A total of 26 eligible studies were identified in this meta-analysis through a detailed process of inclusion and exclusion, which included 9 in vivo studies, 15 in vitro studies, and 2 in both. The results of in vitro studies showed that SiNPs exposure significantly increased the indicators of the comet assay, such as tail DNA content (T DNA%), tail length (TL), and olive tail moment (OTM). Indicators of mutagenicity had not been affected in vitro studies, such as mutation frequency (MF) and micronucleus (MN) frequency. There was a significant increase in MN frequency, but there was no influence on T DNA% in vivo. Results of subgroup analysis indicated that size and treatment time of SiNPs were the associated factors in vitro genotoxicity. The size of SiNPs, <21 nm, induced more DNA damage than larger sized SiNPs. It could induce MN formation when the treatment time of SiNPs was <12 h, and even more DNA damage when the exposure time over 12 h. SiNPs can induce genotoxicity both in vivo and in vitro. Comet assay may be more sensitive to detect in vitro genotoxicity, and MN frequency may be more suitable to detect in vivo genotoxicity.