Silver nanoparticles disrupt GDNF/Fyn kinase signaling in spermatogonial stem cells

Advanced Nanomaterials for Cancer Therapy: Gold, Silver, and Iron Oxide Nanoparticles in Oncological Applications

Cancer remains one of the most challenging health issues globally, demanding innovative therapeutic approaches for effective treatment. Nanoparticles, particularly those composed of gold, silver, and iron oxide, have emerged as promising candidates for changing cancer therapy. This comprehensive review demonstrates the landscape of nanoparticle-based oncological interventions, focusing on the remarkable advancements and therapeutic potentials of gold, silver, and iron oxide nanoparticles. Gold nanoparticles have garnered significant attention for their exceptional biocompatibility, tunable surface chemistry, and distinctive optical properties, rendering them ideal candidates for various cancer diagnostic and therapeutic strategies. Silver nanoparticles, renowned for their antimicrobial properties, exhibit remarkable potential in cancer therapy through multiple mechanisms, including apoptosis induction, angiogenesis inhibition, and drug delivery enhancement. With their magnetic properties and biocompatibility, iron oxide nanoparticles offer unique cancer diagnosis and targeted therapy opportunities. This review critically examines the recent advancements in the synthesis, functionalization, and biomedical applications of these nanoparticles in cancer therapy. Moreover, the challenges are discussed, including toxicity concerns, immunogenicity, and translational barriers, and ongoing efforts to overcome these hurdles are highlighted. Finally, insights into the future directions of nanoparticle-based cancer therapy and regulatory considerations, are provided aiming to accelerate the translation of these promising technologies from bench to bedside.

Exploring the green synthesis of silver nanoparticles using natural extracts and their potential for cancer treatment

Silver nanoparticles (AgNPs) have attracted increasing attention in nanomedicine, with versatile applications in drug delivery, antimicrobial treatments, and cancer therapies. While chemical synthesis remains a common approach for AgNP production, ensuring environmental sustainability requires a shift toward eco-friendly, "green" synthesis techniques. This article underscores the promising role of plant extracts in the green synthesis of AgNPs, highlighting the importance of their natural sources and diverse bioactive compounds. Various characterization methods for these nanomaterials are also reviewed. Furthermore, the anticancer potential of green AgNPs (Gr-AgNPs) is examined, focusing on their mechanisms of action and the challenges to their clinical implementation. Finally, future directions in the field are discussed.

Porous Polymersomes as Carriers for Silver Nanoparticles and Nanoclusters: Advantages of Compartmentalization for Antimicrobial Usage

The global threat to public health posed by antibiotic-resistant bacterial infections requires the exploration of innovative approaches. Nanomaterials, particularly silver nanoparticles (AgNPs) and nanoclusters (AgNCs), have emerged as potential solutions to address the pressing issue of a bacterial healthcare crisis. However, the high cytotoxicity levels and low stability associated with AgNPs and AgNCs limit their applicability. To overcome these challenges, AgNCs and AgNPs were synthesized in the presence of porous polymersomes, resulting in a compartmentalized system that enhances stability, reduces cytotoxicity, and maintains high antimicrobial activity. The encapsulated particles exhibit a distribution of silver components on both the surface and the core, which is confirmed through the analysis of surface charge and center of mass. Moreover, our investigation demonstrates improved stability of the nanoparticles and nanoclusters upon entrapment in the porous system, as evidenced by the ion release assay. The antimicrobial effectiveness of porous polymersomes containing AgNPs and AgNCs was demonstrated by visualizing the biofilms and quantifying the penetration depth. Furthermore, cytotoxicity studies showed that compartmentalization increases cell compatibility for AgNC-based systems, showcasing the many advantages this system holds.

Metal Ion-Doped Hydroxyapatite-Based Materials for Bone Defect Restoration

Hydroxyapatite (HA)-based materials are widely used in the bone defect restoration field due to their stable physical properties, good biocompatibility, and bone induction potential. To further improve their performance with extra functions such as antibacterial activity, various kinds of metal ion-doped HA-based materials have been proposed and synthesized. This paper offered a comprehensive review of metal ion-doped HA-based materials for bone defect restoration based on the introduction of the physicochemical characteristics of HA followed by the synthesis methods, properties, and applications of different kinds of metal ion (Ag+, Zn2+, Mg2+, Sr2+, Sm3+, and Ce3+)-doped HA-based materials. In addition, the underlying challenges for bone defect restoration using these materials and potential solutions were discussed.

Assessment of Genotoxicity of Zinc Oxide Nanoparticles Using Mosquito as Test Model

The widespread applications of ZnO NPs in the different areas of science, technology, medicine, agriculture, and commercial products have led to increased chances of their release into the environment. This created a growing public concern about the toxicological and environmental effects of the nanoparticles. The impact of these NPs on the genetic materials of living organisms is documented in some cultured cells and plants, but there are only a few studies regarding this aspect in animals. In view of this, the present work regarding the assessment of the genotoxicity of zinc oxide nanoparticles using the mosquito Culex quinquefaciatus has been taken up. Statistically significant chromosomal aberrations over the control are recorded after the exposure of the fourth instar larvae to a dose of less than LD20 for 24 h. In order to select this dose, LD20 of ZnO NPs for the mosquito is determined by Probit analysis. Lacto-aceto-orcein stained chromosomal preparations are made from gonads of adult treated and control mosquitoes. Both structural aberrations, such as chromosomal breaks, fragments, translocations, and terminal fusions, resulting in the formation of rings and clumped chromosomes, and numerical ones, including hypo- and hyper-aneuploidy at metaphases, bridges, and laggards at the anaphase stage are observed. The percentage frequency of abnormalities in the shape of sperm heads is also found to be statistically significant over the controls. Besides this, zinc oxide nanoparticles are also found to affect the reproductive potential and embryo development as egg rafts obtained from the genetic crosses of ZnO nanoparticle-treated virgin females and normal males are small in size with a far smaller number of eggs per raft. The percentage frequencies of dominant lethal mutations indicated by the frequency of unhatched eggs are also statistically significant (p < 0.05) over the control. The induction of abnormalities in all of the three short-term assays studied during the present piece of work indicates the genotoxic potential of ZnO NPs, which cannot be labeled absolutely safe, and this study pinpoints the need to develop strategies for the protection of the environment and living organisms thriving in it.

Current Trends on the Effects of Metal-Based Nanoparticles on Microbial Ecology

The growing field of nanotechnology and its many applications have led to the irregular release of nanoparticles (NPs), with unintended effects on the environment and continued contamination of water bodies. Metallic NPs are used more frequently in extreme environmental conditions due to their higher efficiency, which attracts more attention in various applications. Due to improper pre-treatment of biosolids, inefficient wastewater treatment practices, and other unregulated agricultural practices continue to contaminate the environment. In particular, the uncontrolled use of NPs in various industrial applications has led to damage to the microbial flora and caused irreplaceable damage to animals and plants. This study focuses on the effect of different doses, types, and compositions of NP on the ecosystem. The review also mentions the impact of various metallic NPs on microbial ecology, their interactions with microorganisms, ecotoxicity studies, and dosage evaluation of the NPs, mainly focused on the review article. However, further research is still needed to understand the complexity of interactions between NPs and microbes in soil and aquatic ecosystems.

High-content analysis of testicular toxicity of BPA and its selected analogs in mouse spermatogonial, Sertoli cells, and Leydig cells revealed BPAF induced unique multinucleation phenotype associated with the increased DNA synthesis

Bisphenol A is an endocrine disruptor that has been shown to have testicular toxicity in animal models. Its structural analog, including bisphenol S (BPS), bisphenol AF (BPAF), and tetrabromobisphenol A (TBBPA) have been introduced to the market as BPA alternatives. Previously, we developed high-content analysis (HCA) assays and applied machine learning to compare the testicular toxicity of BPA and its analogs in spermatogonial cells and testicular cell co-culture models. There are diverse cell populations in the testis to support spermatogenesis, but their cell type-specific toxicities are still not clear. The purpose of this study is to examine the selective toxicity of BPA, BPS), BPAF, and TBBPA on these testicular cells, including Sertoli cells, Leydig cells, and spermatogonia cells. We developed a high-content image-based single-cell analysis and measured a broad spectrum of adverse endpoints related to the development of reproductive toxicology, including cell number, nuclear morphology, DNA synthesis, cell cycle progression, early DNA damage response, cytoskeleton structure, DNA methylation status, and autophagy. We introduced an HCA index and spectrum to reveal multiple HCA parameters and observed distinct toxicity profiling of BPA and its analogs among three testicular types. The HCA spectrum shows the dynamic, chemical-specific, dose-dependent changes of each HCA parameter. Each chemical displayed a unique dose-dependent profile within each type of cell. All three types of cells showed the highest response to BPAF at 10 μM across all endpoints measured. BPAF targeted spermatogonial cell (C18) more significantly at 5 μM. BPS more likely targeted Sertoli cell (TM4) and Leydig cell (TM3) and less at spermatogonia cells. TBBPA targeted spermatogonia, Sertoli cells, and less at TM3 cells. BPA is mainly targeted at TM4, followed by TM3 cells, and less at spermatogonial cells. Most importantly, we observed that BPAF induced a dose-dependent increase in spermatogonia cells, not in Sertoli and Leydig cells. In summary, our current HCA assays revealed the cell-type-specific toxicities of BPA and its analogs in different testicular cells. Multinucleation induced by BPAF, along with increased DNA damage and synthesis at low doses, could possibly have a profound long-term effect on reproductive systems.

Effects of antimicrobial metal nanoparticles on characteristics and function properties of mouse mesenchymal stem cells

Nanoparticles (NPs) have a wide use in various field of industry and in medicine, where they represent a promise for their antimicrobial effects. Simultaneous application of NPs and therapeutic stem cells can speed up tissue regeneration and improve healing process but there is a danger of negative impacts of NPs on stem cells. Therefore, we tested effects of four types of metal antimicrobial NPs on characteristics and function properties of mouse mesenchymal stem cells (MSCs) in vitro. All types of tested NPs, i.e. zinc oxide, silver, copper oxide and titanium dioxide, exerted negative effects on the expression of phenotypic markers, metabolic activity, differentiation potential, expression of genes for immunoregulatory molecules and on production of cytokines and growth factors by MSCs. However, there were apparent differences in the impact of individual types of NPs on tested characteristics and function properties of MSCs. The results showed that individual types of NPs influence the activity of MSCs, and thus the use of metal NPs during tissue regeneration and in combination with stem cell therapy should be well considered.

Silver nanoparticles induced testicular damage targeting NQO1 and APE1 dysregulation, apoptosis via Bax/Bcl-2 pathway, fibrosis via TGF-β/α-SMA upregulation in rats

In medicine, silver nanoparticles (AgNPs) are employed often. They do, however, have negative impacts, particularly on the reproductive organs. This research aimed to assess AgNP impact on the testis and the possible intracellular mechanisms to induce testicular deteriorations in rats at various concentrations and different time intervals. Sprague Dawley rats (n = 40) were allocated into four equal groups: the control one, and three other groups injected intra-peritoneally with AgNP solution 0.25, 0.5, and 1 mg/kg b.w. respectively for 15 and 30 days. Our findings revealed that AgNPs reduced body and testicular weights, estradiol (E2) and testosterone (T) hormone levels, and sperm parameters while elevating the nitric oxide and malondialdehyde levels with inhibition of reduced glutathione contents in testicular tissue. Interestingly, AgNPs significantly upregulated the testicular inducible nitric oxide synthase, B cell lymphoma 2 (Bcl-2)-associated X, transforming growth factor, and alpha-smooth muscle actin (α-SMA) expression levels. However, apurinic/apyrimidinic endo deoxyribonuclease 1 (APE1), NAD (P) H quinone dehydrogenase 1 (NQO1), and Bcl-2 expression levels were all downregulated indicating exhaustion of body antioxidant and repairing defense mechanisms in testicles in comparison with the control rats. Various histological alterations were also detected which dramatically increased in rats sacrificed after 30 days such as loss of the lining cells of seminiferous tubules with no spermatozoa and tubular irregularities associated with thickening of their basement membranes. Immunolabeling implicated in the apoptotic pathway revealed a negative expression of Bcl-2 and marked immunoreactivity for caspase-3 after 30 days of AgNP treatment in comparison to the control rats. To our knowledge, there have been no previous publications on the role of the α-SMA, APE1, and NQO1 genes in the molecular pathogenesis of AgNP testicular cytotoxicity following AgNP acute and chronic exposure.

Putative adverse outcome pathways for silver nanoparticle toxicity on mammalian male reproductive system: a literature review

BACKGROUND

Adverse outcome pathways (AOPs) are conceptual frameworks that organize knowledge about biological interactions and toxicity mechanisms. They present a sequence of events commencing with initial interaction(s) of a stressor, which defines the perturbation in a biological system (molecular initiating event, MIE), and a dependent series of key events (KEs), ending with an adverse outcome (AO). AOPs have recently become the subject of intense studies in a view to better understand the mechanisms of nanomaterial (NM) toxicity. Silver nanoparticles (Ag NPs) are one of the most explored nanostructures and are extensively used in various application. This, in turn, has increased the potential for interactions of Ag NPs with environments, and toxicity to human health. The aim of this study was to construct a putative AOPs (pAOP) related to reproductive toxicity of Ag NPs, in order to lay the groundwork for a better comprehension of mechanisms affecting both undesired toxicity (against human cell) and expected toxicity (against microorganisms).

METHODS

PubMed and Scopus were systematically searched for peer-reviewed studies examining reproductive toxicity potential of Ag NPs. The quality of selected studies was assessed through ToxRTool. Eventually, forty-eight studies published between 2005 and 2022 were selected to identify the mechanisms of Ag NPs impact on reproductive function in human male. The biological endpoints, measurements, and results were extracted from these studies. Where possible, endpoints were assigned to a potential KE and an AO using expert judgment. Then, KEs were classified at each major level of biological organization.

RESULTS

We identified the impairment of intracellular SH-containing biomolecules, which are major cellular antioxidants, as a putative MIE, with subsequent KEs defined as ROS accumulation, mitochondrial damage, DNA damage and lipid peroxidation, apoptosis, reduced production of reproductive hormones and reduced quality of sperm. These successive KEs may result in impaired male fertility (AO).

CONCLUSION

This research recapitulates and schematically represents complex literature data gathered from different biological levels and propose a pAOP related to the reproductive toxicity induced by AgNPs. The development of AOPs specific to NMs should be encouraged in order to provide new insights to gain a better understanding of NP toxicity.

Impact of Nanoparticles on Male Fertility: What Do We Really Know? A Systematic Review

The real impact of nanoparticles on male fertility is evaluated after a careful analysis of the available literature. The first part reviews animal models to understand the testicular biodistribution and biopersistence of nanoparticles, while the second part evaluates their in vitro and in vivo biotoxicity. Our main findings suggest that nanoparticles are generally able to reach the testicle in small quantities where they persist for several months, regardless of the route of exposure. However, there is not enough evidence that they can cross the blood-testis barrier. Of note, the majority of nanoparticles have low direct toxicity to the testis, but there are indications that some might act as endocrine disruptors. Overall, the impact on spermatogenesis in adults is generally weak and reversible, but exceptions exist and merit increased attention. Finally, we comment on several methodological or analytical biases which have led some studies to exaggerate the reprotoxicity of nanoparticles. In the future, rigorous clinical studies in tandem with mechanistic studies are needed to elucidate the real risk posed by nanoparticles on male fertility.

Role of insulin signaling pathway in apoptosis induced by food chain delivery of nano-silver under the action of environmental factors

OBJECTIVE

To investigate how the environmental factor affects the delivery of nano silver through food chain, we set up a two-stage food delivery chain model of Escherichia coli and Caenorhabditis elegans system.

METHODS

Through a two-stage food delivery chain model of E. coli and C. elegans, the mRNA expression levels of DAF-2, age-1, PDK-1, Akt-1 and DAF-16 in the insulin growth factor 1 signaling pathway in nematode gonad cells which occurs AgNPs induced apoptosis were evaluated and the apoptosis of gonad cells in the mutant strains of the above key genes were detected.

RESULTS

DAF-2, age-1, PDK-1 and Akt-1 could significantly negatively regulate the apoptosis of nematode cells induced by AgNPs, while DAF-16 could significantly promote the apoptosis induced by AgNPs. The DAF-16 up-regulated expression was a protective effect on the body and the phenomenon of DNA double-strand breaks was significantly increased. The damage effect induced by AgNPs was significantly enhanced in the presence of the environmental factor fulvic acid.

CONCLUSION

The damage effect induced by AgNPs after food delivery involves the regulation of the insulin growth factor 1 signaling pathway and environmental factors have a significant impact on the biological effects.

An Overview of Essential Microelements and Common Metallic Nanoparticles and Their Effects on Male Fertility

Numerous factors affect reproduction, including stress, diet, obesity, the use of stimulants, or exposure to toxins, along with heavy elements (lead, silver, cadmium, uranium, vanadium, mercury, arsenic). Metals, like other xenotoxins, can cause infertility through, e.g., impairment of endocrine function and gametogenesis or excess production of reactive oxygen species (ROS). The advancement of nanotechnology has created another hazard to human safety through exposure to metals in the form of nanomaterials (NMs). Nanoparticles (NPs) exhibit a specific ability to penetrate cell membranes and biological barriers in the human body. These ultra-fine particles (<100 nm) can enter the human body through the respiratory tract, food, skin, injection, or implantation. Once absorbed, NPs are transported to various organs through the blood or lymph. Absorbed NPs, thanks to ultrahigh reactivity compared to bulk materials in microscale size, disrupt the homeostasis of the body as a result of interaction with biological molecules such as DNA, lipids, and proteins; interfering with the functioning of cells, organs, and physiological systems; and leading to severe pathological dysfunctions. Over the past decades, much research has been performed on the reproductive effects of essential trace elements. The research hypothesis that disturbances in the metabolism of trace elements are one of the many causes of infertility has been unquestionably confirmed. This review examines the complex reproductive risks for men regarding the exposure to potentially harmless xenobiotics based on a series of 298 articles over the past 30 years. The research was conducted using PubMed, Web of Science, and Scopus databases searching for papers devoted to in vivo and in vitro studies related to the influence of essential elements (iron, selenium, manganese, cobalt, zinc, copper, and molybdenum) and widely used metallic NPs on male reproduction potential.

New Insights for Exploring the Risks of Bioaccumulation, Molecular Mechanisms, and Cellular Toxicities of AgNPs in Aquatic Ecosystem

Silver nanoparticles (AgNPs) are commonly used in numerous consumer products, including textiles, cosmetics, and health care items. The widespread usage of AgNPs results in their unavoidable discharge into the ecosystem, which pollutes the aquatic, groundwater, sediments, and marine environments. These nanoparticles (NPs) activate the production of free radicals reactive species in aquatic organisms that interrupt the functions of DNA, cause mitochondrial dysfunction, and increase lipid peroxidation, which terminates the development and reproduction both in vivo and in vitro. The life present in the aquatic ecosystem is becoming threatened due to the release and exploitation of AgNPs. Managing the aquatic ecosystem from the AgNP effects in the near future is highly recommended. In this review, we discussed the background of AgNPs, their discharge, and uptake by aquatic organisms, the mechanism of toxicity, different pathways of cytotoxicity, and bioaccumulation, particularly in aquatic organisms. We have also discussed the antimicrobial activities of AgNPs along with acute and chronic toxicity in aquatic groups of organisms.

Nanomaterial-Augmented Formulation of Disinfectants and Antiseptics in Controlling SARS CoV-2

The worldwide COVID-19 pandemic has brought significant consideration toward innovative strategies for overcoming the viral spread. Nanotechnology will change our lives in several forms as its uses span from electronics to pharmaceutical procedures. The use of nanoparticles provides a possibility to promote new antiviral treatments with a low possibility of increasing drug resistance compared to typical chemical-based antiviral treatments. Since the long-term usage of disinfectants and antiseptics at high concentrations has deleterious impacts on well-being and the environment, this review was intended to discuss the antiviral activity of disinfectants and antiseptics required for their activity against respiratory viruses especially SARS-CoV-2. It could improve the inhibition of viral penetration into cells, solvation of the lipid bilayer envelope, and ROS production, therefore enhancing the effect of disinfectants. However, significant concerns about nanomaterial's hazardous effects on individuals and the environment are increasing as nanotechnology flourishes. In this review, we first discuss the significant and essential types of nanomaterials, especially silver and copper, that could be used as antiviral agents and their viral entry mechanisms into host cells. Further, we consider the toxicity on health, and environmental concerns of nanoparticles. Eventually, we present our outlook on the fate of nanomaterials toward viral diseases.

In Vitro Evaluation of Antibacterial, Antioxidant, and Antidiabetic Activities and Glucose Uptake through 2-NBDG by Hep-2 Liver Cancer Cells Treated with Green Synthesized Silver Nanoparticles

The alarming rise in diabetes owing to drug resistance necessitates the implementation of prompt countermeasures in the treatment module of diabetes. Due to their unique physicochemical features, silver nanoparticles may have potential applications in the medical and pharmaceutical industries. Silver nanoparticles (AgNPs) were synthesized from the culture filtrate of Salmonella enterica (ATCC-14028). UV-Vis spectrophotometry, FTIR, SEM, and energy dispersive X-rays were used in the characterization of the nanoparticles. Transmission electron microscopy (TEM) revealed that AgNPs are spherical and highly scattered and vary in size from 7.18 nm to 13.24 nm. AgNP stability and protein loss were confirmed by thermogravimetric analysis (TGA) at different temperatures. The AgNPs had excellent antibacterial activity and a strong synergistic effect against methicillin-resistant bacteria Staphylococcus aureus (MRSA) ATCC-4330 and Streptococcus epidermis (MRSE) ATCC-51625. The DPPH experiment revealed that the AgNPs had high antioxidant activity. The antidiabetic assay revealed that these AgNPs had an IC50 for alpha-amylase of 428.60 μg/ml and an IC50 for alpha-glucosidase of 562.02 μg/ml. Flow cytometry analysis of Hep-2 cells treated with AgNPs (40 μg/ml) revealed higher expression of 2-NBDG glucose absorption (uptake) compared to control metformin. These AgNPs have promising antidiabetic properties and could be used in pharmaceuticals and biomedical industries.

Particle Safety Assessment in Additive Manufacturing: From Exposure Risks to Advanced Toxicology Testing

Additive manufacturing (AM) or industrial three-dimensional (3D) printing drives a new spectrum of design and production possibilities; pushing the boundaries both in the application by production of sophisticated products as well as the development of next-generation materials. AM technologies apply a diversity of feedstocks, including plastic, metallic, and ceramic particle powders with distinct size, shape, and surface chemistry. In addition, powders are often reused, which may change the particles' physicochemical properties and by that alter their toxic potential. The AM production technology commonly relies on a laser or electron beam to selectively melt or sinter particle powders. Large energy input on feedstock powders generates several byproducts, including varying amounts of virgin microparticles, nanoparticles, spatter, and volatile chemicals that are emitted in the working environment; throughout the production and processing phases. The micro and nanoscale size may enable particles to interact with and to cross biological barriers, which could, in turn, give rise to unexpected adverse outcomes, including inflammation, oxidative stress, activation of signaling pathways, genotoxicity, and carcinogenicity. Another important aspect of AM-associated risks is emission/leakage of mono- and oligomers due to polymer breakdown and high temperature transformation of chemicals from polymeric particles, both during production, use, and in vivo, including in target cells. These chemicals are potential inducers of direct toxicity, genotoxicity, and endocrine disruption. Nevertheless, understanding whether AM particle powders and their byproducts may exert adverse effects in humans is largely lacking and urges comprehensive safety assessment across the entire AM lifecycle-spanning from virgin and reused to airborne particles. Therefore, this review will detail: 1) brief overview of the AM feedstock powders, impact of reuse on particle physicochemical properties, main exposure pathways and protective measures in AM industry, 2) role of particle biological identity and key toxicological endpoints in the particle safety assessment, and 3) next-generation toxicology approaches in nanosafety for safety assessment in AM. Altogether, the proposed testing approach will enable a deeper understanding of existing and emerging particle and chemical safety challenges and provide a strategy for the development of cutting-edge methodologies for hazard identification and risk assessment in the AM industry.

Nanotechnology Applications of Flavonoids for Viral Diseases

Recent years have witnessed the emergence of several viral diseases, including various zoonotic diseases such as the current pandemic caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Other viruses, which possess pandemic-causing potential include avian flu, Ebola, dengue, Zika, and Nipah virus, as well as the re-emergence of SARS (Severe Acute Respiratory Syndrome) and MERS (Middle East Respiratory Syndrome) coronaviruses. Notably, effective drugs or vaccines against these viruses are still to be discovered. All the newly approved vaccines against the SARS-CoV-2-induced disease COVID-19 possess real-time possibility of becoming obsolete because of the development of ‘variants of concern’. Flavonoids are being increasingly recognized as prophylactic and therapeutic agents against emerging and old viral diseases. Around 10,000 natural flavonoid compounds have been identified, being phytochemicals, all plant-based. Flavonoids have been reported to have lesser side effects than conventional anti-viral agents and are effective against more viral diseases than currently used anti-virals. Despite their abundance in plants, which are a part of human diet, flavonoids have the problem of low bioavailability. Various attempts are in progress to increase the bioavailability of flavonoids, one of the promising fields being nanotechnology. This review is a narrative of some anti-viral dietary flavonoids, their bioavailability, and various means with an emphasis on the nanotechnology system(s) being experimented with to deliver anti-viral flavonoids, whose systems show potential in the efficient delivery of flavonoids, resulting in increased bioavailability.

The antimicrobial effect of 400 nm femtosecond laser and silver nanoparticles on gram-positive and gram-negative bacteria

Silver nanoparticles are well-known for their antimicrobial effect. However, they are potentially toxic in high doses. We explored the possibility of enhancing the bactericidal effect of low concentrations of silver nanoparticles with blue light femtosecond laser irradiation, since such concentrations are less toxic. The growth dynamics of Pseudomonas aeruginosa, Listeria monocytogenes and methicillin-resistant Staphylococcus aureus grown in pre-synthesized silver nanoparticles were measured with or without pre-irradiation with 50 mW and 400 nm femtosecond laser irradiation. With each bacterium, combined treatment with laser and silver nanoparticles significantly reduced bacterial growth, indicating that this form of treatment could be beneficial in the ongoing efforts to reduce the deleterious effects of antibiotic resistant Gram-positive and Gram-negative bacteria. The combined treatment was more antimicrobial than treatment with silver nanoparticles alone or photo-irradiation alone. P. aeruginosa and L. monocytogenes were more susceptible to the bactericidal effects of silver nanoparticles, and the combination of laser treatment and silver nanoparticles than MRSA.

Colorful Pigments for Hair Dyeing Based on Enzymatic Oxidation of Tyrosine Derivatives

Melanin exists widely in nature and can afford a variety of colors from black to brown and red according to chemical structure differences and specific mixtures. Inspired by nature, this work reports that tyrosine derivatives with different protecting groups at its N- or C-terminal can be enzymatically oxidized into melanin-like pigments with a wide range of colors. The emergence of colorful pigments can be attributed to the incomplete enzymatic oxidation and polymerization caused by the chemical premodification of the tyrosine molecule. The pigments can be deposited on the surface of the hair to obtain a series of colorful and saturated hair dye effects. Moreover, after the pigments were coated on the hair, we can further deposit silver nanoparticles through in situ reduction, making these coatings have anti-inflammatory and antibacterial potential, thereby expanding their potential use for people with low immunity or those who work in hospitals. This work proposes a green and effective way to synthesize colorful pigments with great potential applications in the hair dying and cosmetic industries.

Revisiting inorganic nanoparticles as promising therapeutic agents: A paradigm shift in oncological theranostics

Cancer remains a global health problem largely due to a lack of effective therapies. Major cancer management strategies include chemotherapy, surgical resection, and radiation. Unfortunately, these strategies have a number of limitations, such as non-specific side effects, uneven delivery of the drugs, and lack of proper monitoring technology. Inorganic nanoparticles (NPs) are considered promising agents in treating and tracing cancer due to their unique physicochemical properties such as the controlled release of drugs, bioavailability, biocompatibility, stability, and large surface area. Also, they enhance the solubility of hydrophobic drugs, prolong their circulation time, prevent undesired off-targeting and subsequent side effects, making them efficient particles in cancer theranostics. Promising inorganic-NPs include gold, selenium, silica, and oxide NPs. Further, several techniques are used to modify the surface of inorganic-NPs, making them more efficient for the effective transport of therapeutic cargos to overcome cellular barriers. Thus, inorganic-NPs function effectively, surmounting the intrinsic drawbacks of traditional organic NPs. This mini-review summarizes the significant inorganic-NPs, their properties, surface modifications, cellular uptake, and bio-distributions, along with their potential use in cancer theranostics. We also discuss the promises and challenges faced during the inorganic-NPs mediated therapeutic approach for cancer and these particles' status in the clinical setting.

Can nanomaterials induce reproductive toxicity in male mammals? A historical and critical review

The nanotechnology enabled the development of nanomaterials (NMs) with a variety of industrial, biomedical, and consumer applications. However, the mechanism of action (MoA) and toxicity of NMs remain unclear, especially in the male reproductive system. Thus, this study aimed to perform a bibliometric and systematic review of the literature on the toxic effects of different types of NMs on the male reproductive system and function in mammalian models. A series of 236 articles related to the in vitro and in vivo reproductive toxicity of NMs in mammalian models were analyzed. The data concerning the bioaccumulation, experimental conditions (types of NMs, species, cell lines, exposure period, and routes of exposure), and the MoA and toxicity of NMs were summarized and discussed. Results showed that this field of research began in 2005 and has experienced an exponential increase since 2012. Revised data confirmed that the NMs have the ability to cross the blood-testis barrier and bioaccumulate in several organs of the male reproductive system, such as testis, prostate, epididymis, and seminal vesicle. A similar MoA and toxicity were observed after in vitro and in vivo exposure to NMs. The NM reproductive toxicity was mainly related to ROS production, oxidative stress, DNA damage and apoptosis. In conclusion, the NM exposure induces bioaccumulation and toxic effects on male reproductive system of mammal models, confirming its potential risk to human and environmental health. The knowledge concerning the NM reproductive toxicity contributes to safety and sustainable use of nanotechnology.

Toxicity mechanisms of nanoparticles in the male reproductive system

The field of nanotechnology has allowed for increasing nanoparticle (NP) exposure to the male reproductive system. Certain NPs have been reported to have adverse consequences on male germ and somatic cells. Germ cells are the bridge between generations and are responsible for the transmission of genetic and epigenetic information to future generations. A number of NPs have negative impacts on male germ and somatic cells which could ultimately affect fertility or the ability to produce healthy offspring. These impacts are related to NP composition, modification, concentration, agglomeration, and route of administration. NPs can induce severe toxic effects on the male reproduction system after passing through the blood-testis barrier and ultimately damaging the spermatozoa. Therefore, understanding the impacts of NPs on reproduction is necessary. This review will provide a comprehensive overview on the current state of knowledge derived from the previous in vivo and in vitro research on effects of NPs on the male reproductive system at the genetic, cellular, and molecular levels.

Co-exposure of Bi2O3 nanoparticles and bezo[a]pyrene-enhanced in vitro cytotoxicity of mouse spermatogonia cells

Recent attention has been focused on reproductive toxicity of nanoscale materials in combination with pre-existing environmental pollutants. Due to its unique characteristics, bismuth (III) oxide (Bi₂O₃) nanoparticles (BONPs) are being used in diverse fields including cosmetics and biomedicine. Benzo[a]pyrene (BaP) is a known endocrine disruptor that most common sources of BaP exposure to humans are cigarette smoke and well-cooked barbecued meat. Hence, joint exposure of BONPs and BaP in humans is common. There is scarcity of information on toxicity of BONPs in combination with BaP in human reproductive system. In this work, combined effects of BONPs and BaP in mouse spermatogonia (GC-1 spg) cells were assessed. Results showed that combined exposure of BONPs and BaP synergistically induced cell viability reduction, lactate dehydrogenase leakage, induction of caspases (-3 and -9) and mitochondrial membrane potential loss in GC-1 spg cells. Co-exposure of BONPs and BaP also synergistically induced production of pro-oxidants (reactive oxygen species and hydrogen peroxide) and reduction of antioxidants (glutathione and several antioxidant enzymes). Experiments with N-acetyl-cysteine (NAC, a reactive oxygen species scavenger) indicated that oxidative stress was a plausible mechanism of synergistic toxicity of BONPs and BaP in GC-1 spg cells. Present data could be helpful for future in vivo research and risk assessment of human reproductive system co-exposed to BONPs and BaP.

Zinc Nanoparticles Ameliorate the Reproductive Toxicity Induced by Silver Nanoparticles in Male Rats

Introduction

Silver nanoparticles (Ag-NPs) are among the most commonly used nanoparticles in different fields. Zinc nanoparticles (Zn-NPs) are known for their antioxidant effect. This study was designed to investigate the adverse effects of Ag-NPs (50 nm) on the male reproductive system and also the ameliorative effect of Zn-NPs (100 nm) against these harmful effects.

Methods

Forty adult male rats were used in this study; they were randomly divided into four equal groups: control group, Ag-NPs group, Zn-NPs group, Ag-NPs + Zn-NPs group. Ag-NPs (50 mg/kg) and/or Zn-NPs (30 mg/kg) were administered orally for 90 days.

Results

The results revealed that exposure to Ag-NPs adversely affected sperm motility, morphology, viability, and concentration. Ag-NPs also induced oxidative stress and lipid peroxidation in testicular tissue. The exposure to Ag-NPs decreased serum FSH, LH, and testosterone hormones. Additionally, comet assay revealed DNA degeneration in the testicular tissue of rats exposed to Ag-NPs. Histopathological examination showed various histological alterations in the testes of rats intoxicated with Ag-NPs. Furthermore, co-administration of Zn-NPs ameliorated most of the toxic effects of Ag-NPs via their antioxidative capacity.

Insight Study on the Comparison between Zinc Oxide Nanoparticles and Its Bulk Impact on Reproductive Performance, Antioxidant Levels, Gene Expression, and Histopathology of Testes in Male Rats

Background: Despite the beneficial effects of zinc oxide nanoparticles (ZnONPs) on different biomedical applications, including their antioxidant and anti-inflammatory ones, it might have cytotoxic and genotoxic impacts on the male reproductive system. Objective: The current study compares the effect of zinc oxide nanoparticles and their bulk form, at different doses, on male rats’ reproductive performance, testicular antioxidants, gene expression, and histopathology. Materials and Methods: Thirty male rats were randomly allocated equally in five groups. The control one was injected with Tween 80 (10%). The zinc oxide nanoparticle (ZnONP) groups received ZnONPs < 50 nm, specifically, 5 mg/kg (ZnONP-1) and 10 mg/kg (ZnONP-2). The bulk zinc oxide (BZnO) groups were administered 5 mg/kg (BZnO-1) and 10 mg/kg (BZnO-2), correspondingly. Rats were injected intraperitoneally with the respected materials, twice/week for eight consecutive weeks. Finally, the male rats’ sexual behavior and their pup’s performance were determined in a monogamous mating system. Rats were then anesthetized and sacrificed for semen characteristics evaluation and tissue collection for antioxidant and hormones analysis, gene expression, and histopathological examination. Results: It was shown that ZnONP-1 improved sexual behavior, semen characteristics, and pup’s performance compared to its bulk form. Similarly, the testicular antioxidants activity, glutathione (GSH), and superoxide dismutase (SOD) increased with a decrease in the malonaldehyde (MDA), interleukin 6 (IL-6), and tumor necrosis factor (TNF-α) levels. It also improves the reproductive hormone levels and mRNA expression of different steroidogenesis-associated genes and anti-apoptotic genes. Conclusion: It can be concluded that zinc oxide nanoparticles, administered at 5 mg/kg, had the most beneficial effect on male reproductive performance, while 10 mg/kg could have a detrimental effect.

Alterations in reproductive parameters and gene expression in Balb/c mice testes after exposure to silver nanoparticles

Silver nanoparticles (AgNPs) have become one of the most common nanomaterials in various commercial products; however, its potential toxicity to the male reproductive system and the possible mechanisms remains unknown. Our study aimed to investigate the toxicity of silver nanoparticle (AgNPs) in the testis and to elucidate its possible mechanisms. We exposed 6-week-old Balb/c male mice to AgNP daily [0 (control), 30 or 125 mg/kg BW] for 90 days. The histological structure, sperm production and levels of reproductive hormones were assessed; we also observed apoptotic cell nuclei and the ultrastructural characteristics of the testis. Microarray analyses were used to identify differentially expressed genes, and dysregulated apoptosis-related genes and protein were also analysed. Our results indicated that 125 mg/kg AgNP changed testis morphology and decreased sperm production. AgNP treatment also increased apoptosis of germ cells and induced the presence of swollen or dissolved mitochondria in the testis. Microarray analysis showed the expression of 383 genes was altered by AgNP treatment, with apoptosis-related genes showing the greatest changes. Furthermore, we verified dysregulated apoptosis-related genes and proteins (caspase3 and Myc). These results demonstrated that AgNP induced changes of testis morphology, sperm production and apoptosis-related genes, suggested this process maybe associated with apoptosis.

Effect of Zirconium oxide nanoparticle on serum level of testosterone and spermatogenesis in the rat: An experimental study

BACKGROUND

Zirconium nanoparticles are used as health agents, pharmaceutical carriers, and in dental and orthopedic implants.

OBJECTIVE

This studyaimed to investigate the effects of Zirconium oxide nanoparticles on the process of spermatogenesis in rat.

MATERIALS AND METHODS

In this experimental study, 32 male Wistar rats (150-200 gr), with range of age 2.5 to 3 months were used and divided into four groups of eight per each. The control group received 0.5 ml of distilled water and the three experimental groups received 50, 200, and 400 ppm doses of Zirconium oxide nanoparticles solution over a 30-day period, respectively. At the end of the experiment, tissue sections were taken from the testis and stained with hematoxylin-eosin. Serum concentration of testosterone was measured by enzyme-linked immunosorbent assay.

RESULTS

In the experimental group receiving 400 ppm Zirconium oxide nanoparticles, the number of Spermatogonia cells (p ≤ 0.01), Spermatocytes (p ≤ 0.01), Spermatids (p ≤ 0.001), and sertoli and Leydig cells (p ≤ 0.05) showed a significant decrease compared to the control group. Serum testosterone concentration did not change significantly in all experimental groups receiving Zirconium oxide nanoparticles compared to the control group. Experimental group received 400 ppm Zirconium oxide nanoparticles shrinkage of seminal tubules and reduced lumen space compared to control group.

CONCLUSION

Zirconium oxide nanoparticles are likely to damage the testes by increasing Reactive oxygen species production and free radicals.

Regulation of GDNF expression in Sertoli cells

Sertoli cells regulate male germ cell proliferation and differentiation and are a critical component of the spermatogonial stem cell (SSC) niche, where homeostasis is maintained by the interplay of several signaling pathways and growth factors. These factors are secreted by Sertoli cells located within the seminiferous epithelium, and by interstitial cells residing between the seminiferous tubules. Sertoli cells and peritubular myoid cells produce glial cell line-derived neurotrophic factor (GDNF), which binds to the RET/GFRA1 receptor complex at the surface of undifferentiated spermatogonia. GDNF is known for its ability to drive SSC self-renewal and proliferation of their direct cell progeny. Even though the effects of GDNF are well studied, our understanding of the regulation its expression is still limited. The purpose of this review is to discuss how GDNF expression in Sertoli cells is modulated within the niche, and how these mechanisms impact germ cell homeostasis.

Does Pharmacodynamics of Drugs Change After Presenting them as Nanoparticles Like their Pharmacokinetics?

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Nowadays, the breakthrough in different medical branches makes it feasible to designate new methods of drug delivery to achieve the most cost-effective and the least unpleasant consequenceimposing solutions to overcome a wide range of diseases.

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Nanoparticle (NP) drugs entered the therapeutic system, especially in cancer chemotherapy. These drugs are quite well-known for two traits of being long-acting and less toxic. For a long time, it has been investigated how NPs will change the kinetics of drugs. However, there are a few studies that inclined their attention to how NPs affect the dynamics of drugs. In this review, the latter point will mainly be discussed in an example-based manner. Besides, other particular features of NPs will be briefly noted.

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NPs are capable of affecting the biologic system as much as a drug. Moreover, NPs could arise a wide variety of effects by triggering their own receptors. NPs are able to change a receptor function and manipulate its downstream signaling cascade.

Acute reproductive toxicology after intratesticular injection of silver nanoparticles (AgNPs) in Wistar rats

This study aimed to evaluate the effects of an intratesticular injection of silver nanoparticles (AgNPs) on reproductive parameters and health of rats, and to evaluate the AgNPs biodistribution in order to develop a nanotechnological contraceptive agent for male animals. Treated animals received 220 μL of AgNPs solution (0.46 µg-Ag/ml) in each testicle and were euthanized: seven, 14, 28, and 56 days after injection. A significant decrease (p < 0.05) in the percentage of motile sperm in D7 (8.8%) was observed, comparing to the control (73.3%), D14 (86.0%), D28 (68.2%), and D56 (90.0%) groups. D7 group also presented a decrease (p < 0.05) in the percentage of normal spermatozoa. Additionally, D7 group showed an increase (p < 0.05) in abnormal midpiece and sperm head morphology compared to the Control group. Seminiferous tubules presented all germline cell types and spermatozoa for all groups. However, D7 group did not present spermatozoa in the epididymis, whereas some spermatozoa and cellular debris were visible in D14 and D28 groups. All animals presented hematological parameters, creatinine, and alanine aminotransferase values within the normal limits for Wistar rats. The percentage of silver found in the liver was always higher than in the other organs analyzed. A pioneering mathematical model is proposed, from which the half-life time of silver in the liver (17 days), spleen (23 days), lungs (30 days), and kidneys (35 days) was extracted. In conclusion, some acute and severe toxic effects were observed in sperm cells following intratesticular injection of AgNPs, although these effects were reversible. No adverse effects to general animal health were observed.

Toxicity and antimicrobial effect of silver nanoparticles in swine sperms

Bacterial contamination in swine semen affects the quality and longevity of sperm and consequently fertility is reduced. Antibiotics have been used to prevent bacterial growth, but the frequency of bacterial resistance to various antibiotics are increasing. Silver nanoparticles (AgNPs) of 10-20 nm in size have shown a biocide effect in bacteria and fungi microorganisms without toxicity to certain mammalian cells. The goal of this study was to analyze both, antimicrobial activity against Staphylococcus aureus and toxicity in swine sperms after 10-20 nm AgNPs treatment. S. aureus proliferation decreased when concentrations from 0.4 to 10 mM AgNPs were assayed. Also, sperm viability measured by mitochondrial metabolism after AgNPs treatment up to a concentration of 10 mM, was viable. In addition, viability determined by membrane integrity of sperms showed that AgNPs treatment up to a concentration of 10 mM was safe. Sperm morphology was evaluated by automated quantification of proximal and distal drops and whiptails. Data indicated that AgNPs treatment up to a concentration of 4 mM were harmless. Finally, sperm capacitation and acrosome reactions were determined by (chlortetracycline) CTC assay. Data showed that no changes in sperm capacitation were observed when sperms were treated with 2 mM of AgNPs, but data showed increased calcium mobilization when treated with 10 mM AgNPs, which suggested sperm capacitation. Finally, there were no significant changes encountered on sperm acrosome reaction for any of the treatments after AgNPs treatment. Taken together, these results show the potential of AgNPs as an alternative to conventional antimicrobial agents that are currently used in extenders to preserve semen required for storage.

ABBREVIATIONS

AgNPs: silver nanoparticles; AMK: amikacin; AMP: adenosine monophosphate; AR: acrosome reaction; C: capacitation; CF: cefallotin; CFU: colony-forming unit; CTC: chlortetracycline; CXM: cefuroxime; DMSO: dimethyl sulfoxide; NC: non-capacitation; NOM: Norma Oficial Mexicana; PBS: phosphate buffered saline; RLUs: relative light units; ROS: reactive oxygen species; SQS: Seminal Quality System.

Green Chemistry Synthesis of Silver Nanoparticles and Their Potential Anticancer Effects

Nanobiotechnology has grown rapidly and become an integral part of modern disease diagnosis and treatment. Biosynthesized silver nanoparticles (AgNPs) are a class of eco-friendly, cost-effective and biocompatible agents that have attracted attention for their possible biomedical and bioengineering applications. Like many other inorganic and organic nanoparticles, such as AuNPs, iron oxide and quantum dots, AgNPs have also been widely studied as components of advanced anticancer agents in order to better manage cancer in the clinic. AgNPs are typically produced by the action of reducing reagents on silver ions. In addition to numerous laboratory-based methods for reduction of silver ions, living organisms and natural products can be effective and superior source for synthesis of AgNPs precursors. Currently, plants, bacteria and fungi can afford biogenic AgNPs precursors with diverse geometries and surface properties. In this review, we summarized the recent progress and achievements in biogenic AgNPs synthesis and their potential uses as anticancer agents.

The Effects of 50 nm Unmodified Nano-ZnO on Lipid Metabolism and Semen Quality in Male Mice

Fifty male mice were exposed to 50 nm unmodified nano-ZnO through intragastric administration for 90 days to detect the long-term effects of unmodified nano-ZnO in mice. Results showed that the blood glucose, serum follicle stimulating hormone, luteinizing hormone, testosterone, and estradiol were significantly decreased (p < 0.05). The serum triglyceride, total cholesterol, and low-density lipoprotein were significantly increased (p < 0.05). The semen quality of the 160 mg/kg·bw group were significantly lowered (p < 0.05). The liver and testis catalase and CuZn-SOD activities were significantly elevated (p < 0.05). The abilities of •OH inhibition in the livers and testes of the 160 mg/kg·bw group were significantly lowered (p < 0.05). The liver and testis MDA levels of the 160 mg/kg·bw group were significantly elevated (p < 0.05). Results indicate that exposure of nano-ZnO could induce lipid metabolism disorder, hyperlipidemia, and reproductive toxicity to male mice through oxidative injury.

Morin ameliorates the testicular apoptosis, oxidative stress, and impact on blood-testis barrier induced by photo-extracellularly synthesized silver nanoparticles

Silver nanoparticles (AgNPs) have been widely produced for different industrial purposes. Recently, biogenic synthesis of AgNPs has emerged although the extent of effects from exposure, oral exposure in particular, to nanomaterials synthesized in such a manner remains elusive. The main objective of this study was to evaluate the effects of oral administration of a dose of 50 mg/Kg body weight AgNPs biosynthesized in baker's yeast (Saccharomyces cerevisiae) over a period of eight weeks on the reproductive performance and the possibility of a protective effect through co-administration of morin. Forty-eight male Sprague-Dawley rats were used in four experimental groups (control, morin-treated group, AgNP-treated, and AgNP + morin co-treatment). AgNPs produced no significant alteration in daily food intake or body weight. Both the absolute and relative testicular weights were significantly reduced but not the epididymal weight. Also, serum levels of urea, creatinine, uric acid, and liver enzymes were significantly elevated. Furthermore, AgNPs significantly downregulated the hypothalamic-pituitary-gonadal axis. This corresponds to lower motility and viability percent, reduced sperm concentration, and a higher abnormality ratio as well as a prominent alteration in the blood-testis barrier (BTB) and testicular histology and induction of testicular apoptosis and oxidative stress. The supplementation of morin evidently restored most of the reproductive characters to its physiological range. We can conclude that exposure to the biologically synthesized AgNPs for an extended period of time has proven to be a health risk that can be ameliorated via oral administration of some bioactive agents including morin.

Protective effect of Zingerone against mouse testicular damage induced by zinc oxide nanoparticles

The purpose of the present study was to evaluate the effect of Zingerone (Zing) on zinc oxide nanoparticle (ZNP)-induced spermatogenesis defects in mice. To this end, 50 mg/kg of ZNP was prescribed to the mice as an intoxicated group for 35 days. In protection groups, Zing (10, 20, and 40 mg/kg) was given prior to ZNP treatment for seven days and then co-administration of ZNP for 35 days. Epididymal sperm parameters, testicular histology, Johnsen's scoring, morphometric parameters, TUNEL staining, oxidative stress, and serum testosterone level were evaluated for determining ZNP and Zing effects on the mouse testicles. Effects of Zing and ZNP on the viability of mouse Leydig (TM3) and mouse Sertoli (TM4) cell lines were also done. Testicular weights, testosterone levels, sperm quality, morphometric parameters, Johnsen's score, and superoxide dismutase (SOD) and catalase (CAT) activities were significantly decreased in ZNP-intoxicated mice, while apoptotic index, Malondialdehyde (MDA) content, and histological features, including epithelial vacuolization, sloughing, and germ cell detachment, were improved significantly in ZNP-intoxicated mice. Pretreatment with 20 or 40 mg/kg Zing significantly reduced the histological criteria, increased morphometric parameters, enhanced testosterone levels, attenuated apoptotic index, improved sperm quality, and reversed oxidative stress by reducing the level of MDA and incrementing the activity level of SOD and CAT enzymes. Zing dose-dependently enhanced the viability of ZNP-treated TM3 and TM4 cells in comparison with only ZNP-exposed cells. According to the results of our study, Zing effectively prevented the defects in spermatogenesis among mice treated by ZNP.

Silver nanoparticles testicular toxicity in rat

To evaluate the potential testicular toxicity induced by silver nanoparticles (AgNPs) in Sprague Dawley rate. The protocol study was designed as follows: G1: 30 adult male rats were kept as control. G2: 30 adult male rats were administered 5.36 mg/kg of AgNPs orally, twice weekly for six months. G3: 30 adult male rats were administered 13.4 mg/kg of AgNPs orally, twice weekly for six months. The results of hormonal assay revealed that a significant decrease in testosterone level while a significant increase in LH level was obtained. The testicular homogenate showed a significant decrease in SOD activity accompanied by a significant increase in MDA level in both G2 and G3 in comparison with the control in a dose-response relationship. Sperm viability indicates a significant decrease in rats in G2 and G3 groups. A significant decrease in DNA chromatin integrity % was obtained in rats of G3 in comparison with G2 and control. The semithin and TEM sections of the testis of G2 and G3 groups showed Sertoli cells have vacuolations with a disturbance in the arrangement and the staining affinity of spermatogenic cells. The spermatogonia appeared with a moderate electron density of the nucleus and cytoplasm. The acrosome and its cap become oval and light electron dens of spermatid cells.

Comparative study on the toxic mechanisms of medical nanosilver and silver ions on the antioxidant system of erythrocytes: from the aspects of antioxidant enzyme activities and molecular interaction mechanisms

BACKGROUND

The wide application of silver nanoparticles (AgNPs) in medicals and daily utensils increases the risk of human exposure. The study on cell and protein changes induced by medical AgNPs (20 nm) and Ag+ gave insights into the toxicity mechanisms of them.

RESULTS

AgNPs and Ag+ affected the enzymatic and non-enzymatic antioxidant systems of red blood cells (RBCs). When RBCs were exposed to AgNPs or Ag+ (0-0.24 μg/mL), catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPX) were more sensitive to Ag+, whereas the RBCs had slightly higher glutathione (GSH) contents treated by AgNPs. Both AgNPs and Ag+ increased the malondialdehyde (MDA) content of RBCs, but the difference was not significant. The difference in the change of the enzyme activity indicated that AgNPs and Ag+ have different influencing mechanisms on CAT and GPX. And SOD has stronger resistance to both of AgNPs and Ag+. When AgNPs or Ag+ (0-10 μg/mL) was directly applied on enzymatic proteins, although AgNPs or Ag+ at a high concentration was toxic, at the concentration below 0.4 μg/mL could promote the activities of CAT/SOD/GPX. The spectroscopic results (fluorescence, synchronous fluorescence, resonance light scattering and ultraviolet absorption), including the changes in amino acid microenvironment, peptide chain conformation, and aggregation state, indicated that the interaction mechanism and conformational changes were also the important factors for the changes in the activities of SOD/CAT when SOD/CAT were directly exposed to AgNPs or Ag+.

CONCLUSIONS

Low concentration (< 0.4 μg/mL) of AgNPs is relatively safe and the direct effects of AgNPs and Ag+ on enzymes are important reasons for the change in antioxidant capacity of RBCs.

Induction of 8-hydroxydeoxyguanosine and ultrastructure alterations by silver nanoparticles attributing to placental transfer in pregnant rats and fetuses

A quantitative assessment of the genotoxicity of silver nanoparticles (AgNPs) ascribed to its transplacental transfer and tissue distribution in pregnant rats was carried out in this study. A single intravenous (i.v.) injection of AgNPs with a size range from 4.0 to 17.0 nm was administered to pregnant rats at a dose of 2 mg/kg b.w. on the 19th day of gestation. Five groups beside control, each of the five rats were euthanized after 10 min, 1, 6, 12, or 24 h, respectively. The accumulation of nanoparticles (NPs) in mother and fetal tissues was quantified by inductively coupled plasma optical emission spectroscopy, where the highest accumulation level was recorded in maternal blood (0.523 µg/ml) after 24 h of administration. AgNPs induced accumulation in spleen tissue higher than placenta and fetal tissue homogenates. The data showed significantly detected levels of 8-hydroxydeoxyguanosine in all collected samples from administered animals compared with untreated individuals. Level of 8-OHdG in amniotic fluid exhibited the greatest values followed by maternal spleen, kidneys, and liver, respectively. Investigation by transmission electron microscope showed that the transfer of AgNPs through placental wall caused indentation of nuclei, clumped chromatin, pyknotic nuclei, and focal necrotic areas, while AgNPs appeared mainly accumulated in the macrophages of the spleen. Therefore, the data assume that the genotoxicity studies of AgNPs must be recommended during a comprehensive assessment of the safety of novel types of NPs and nanomaterials. Additionally, exposure to AgNPs must be prevented or minimized during pregnancy or prenatal periods.

Emerging role for SRC family kinases in junction dynamics during spermatogenesis

SRC family kinases (SFKs) are known regulators of multiple cellular events, including cell movement, differentiation, proliferation, survival and apoptosis. SFKs are expressed virtually by all mammalian cells. They are non-receptor protein kinases that phosphorylate a variety of cellular proteins on tyrosine, leading to the activation of protein targets in response to environmental stimuli. Among SFKs, SRC, YES and FYN are the ubiquitously expressed and best studied members. In fact, SRC, the prototypical SFK, was the first tyrosine kinase identified in mammalian cells. Studies have shown that SFKs are regulators of cell junctions, and function in endocytosis and membrane trafficking to regulate junction restructuring events. Herein, we briefly summarize the recent findings in the field regarding the role of SFKs in the testis in regulating spermatogenesis, particularly in Sertoli-Sertoli and Sertoli-germ cell adhesion. While it is almost 50 years since the identification of the oncogene v-Src encoded by Rous sarcoma transforming virus, the understanding of SFK involvement during spermatogenesis in the testis remains far behind that in other epithelia and tissues. The goal of this review is to bridge this gap.

Silver Nanoparticles Compromise Female Embryonic Stem Cell Differentiation through Disturbing X Chromosome Inactivation

The widespread use of silver nanoparticles (AgNPs) has raised substantial health risks to human beings. Despite a wealth of progress on toxicity studies, the understanding of the adverse effects on fetuses, embryos, and early stage cells is still rather limited, particularly under low-dose exposure settings. Moreover, nearly all previous studies ascribed AgNP-induced toxic effects to oxidative stress. Differently, we here unearthed a mechanism, namely, interruption of X chromosome inactivation (XCI) in female mouse embryonic stem cells (mESCs). Albeit with no observable cytotoxicity, significant differentiation retardation was found in female mESCs upon low-dose AgNP exposure. Mechanistic investigations uncovered expedited inactivation for the inactive X chromosome (Xi) and attenuated maintenance of the active X chromosome (Xa) state during mESC differentiation upon the challenge of low-dose AgNPs, indicative of disordered XCI. Thereby, a few X-linked genes (which are closely involved in orchestrating ESC differentiation) were found to be repressed, partially attributable to reinforced enrichment of histone modification ( e. g., histone 3 lysine 27 trimethylation, H3K27me3) on their promoter regions, as the result of disordered XCI. In stark contrast to female mESCs, no impairment of differentiation was observed in male mESCs under low-dose AgNP exposure. All considered, our data unearthed that AgNPs at low concentrations compromised the differentiation program of female mESCs through disturbing XCI. Thus, this work would provide a model for the type of studies necessary to advance the understandings on AgNP-induced developmental toxicity.

Effects of silver nanoparticles functionalized with Cornus mas L. extract on architecture and apoptosis in rat testicle

Aim: To assess ultrastructural changes, alterations in matrix metalloproteinase activity and apoptosis induced by silver nanoparticles (AgNPs) in the rat testicle. Materials & methods: For 45 days, two groups of animals received different doses of AgNPs (0.8 and 1.5 mg/kg b.w.), and a control group was given the buffer used as vehicle for AgNPs. At 7 and 15 days post-treatment, transmission electron microscopy, TUNEL assay, evaluation of NFkB, pNFkB, p53, Bcl-2 and Nrf2 expressions were performed on the removed testes. Results: Transmission electron microscopy revealed severe ultrastructural changes of interstitial tissue and seminiferous epithelium sustained by positive signal for apoptosis. The promatrix metalloproteinase-2 activity and NFkB, Bcl-2 expressions were increased, mainly at 7 days. Conclusion: AgNPs induced severe cell lesions identified even a long time after the exposure.

Differential Cytotoxicity of Different Sizes of Graphene Oxide Nanoparticles in Leydig (TM3) and Sertoli (TM4) Cells

Graphene oxide (GO) is an common nanomaterial and has attracted unlimited interest in academia and industry due to its physical, chemical, and biological properties, as well as for its tremendous potential in applications in various fields, including nanomedicine. Whereas studies have evaluated the size-dependent cytotoxicity of GO in cancer cells, there have been no studies on the biological behavior of ultra-small graphene nanosheets in germ cells. To investigate, for the first time, the cyto- and geno- toxic effects of different sizes of GO in two different cell types, Leydig (TM3) and Sertoli (TM4) cells, we synthesized different sized GO nanosheets with an average size of 100 and 20 nm by a modification of Hummers’ method, and characterized them by various analytical techniques. Cell viability and proliferation assays showed significant size- and dose-dependent toxicity with GO-20 and GO-100. Interestingly, GO-20 induced significant loss of cell viability and cell proliferation, higher levels of leakage of lactate dehydrogenase (LDH) and reactive oxygen species (ROS) generation compared to GO-100. Both GO-100 and GO-20 induced significant loss of mitochondrial membrane potential (MMP) in TM3 and TM4 cells, which is a critical factor for ROS generation. Furthermore, GO-100 and GO-20 caused oxidative damage to DNA by increasing the levels of 8-oxo-dG, which is formed by direct attack of ROS on DNA; GO-100 and GO-20 upregulate various genes responsible for DNA damage and apoptosis. We found that phosphorylation levels of EGFR/AKT signaling molecules, which are related to cell survival and apoptosis, were significantly altered after GO-100 and GO-20 exposure. Our results showed that GO-20 has more potent toxic effects than GO-100, and that the loss of MMP and apoptosis are the main toxicity responses to GO-100 and GO-20 treatments, which likely occur due to EGFR/AKT pathway regulation. Collectively, our results suggest that both GO-100 and GO-20 exhibit size-dependent germ cell toxicity in male somatic cells, particularly TM3 cells, which seem to be more sensitive compared to TM4, which strongly suggests that applications of GO in commercial products must be carefully evaluated.

Ex vivo detection and quantification of gold nanoparticles in human seminal and follicular fluids

Increasing consumption of engineered nanoparticles and occupational exposure to novel, ultrafine airborne particles during the last decades has coincided with deterioration of sperm parameters and delayed fecundity. In order to prevent possible adverse health effects and ensure a sustainable growth for the nanoparticle industry, the ability to investigate the nanosized, mineralogical load of human reproductive systems is becoming a real clinical need. Toward this goal, the current study proposes two methods for the detection and quantification of engineered nanoparticles in human follicular and seminal fluid, developed with the use of well-defined 60 nm Au particles. Despite the complexity of these biological fluids, simple physical and chemical treatments allow for the precise quantification of more than 50 and 70% wt of the spiked Au nanoparticles at low μg ml^-1 levels in follicular and seminal fluids, respectively. The use of electron microscopy for the detailed observation of the detected analytes is also enabled. The proposed method is applied on a small patient cohort in order to demonstrate its clinical applicability by exploring the differences in the metal and particulate content between patients with normal and low sperm count.