Intravenous administration of silver nanoparticles causes organ toxicity through intracellular ROS-related loss of inter-endothelial junction

Shikonin and chitosan-silver nanoparticles synergize against triple-negative breast cancer through RIPK3-triggered necroptotic immunogenic cell death

Necroptotic immunogenic cell death (ICD) can activate the human immune system to treat the metastasis and recurrence of triple-negative breast cancer (TNBC). However, developing the necroptotic inducer and precisely delivering it to the tumor site is the key issue. Herein, we reported that the combination of shikonin (SHK) and chitosan silver nanoparticles (Chi-Ag NPs) effectively induced ICD by triggering necroptosis in 4T1 cells. Moreover, to address the lack of selectivity of drugs for in vivo application, we developed an MUC1 aptamer-targeted nanocomplex (MUC1@Chi-Ag@CPB@SHK, abbreviated as MUC1@ACS) for co-delivering SHK and Chi-Ag NPs. The accumulation of MUC1@ACS NPs at the tumor site showed a 6.02-fold increase compared to the free drug. Subsequently, upon reaching the tumor site, the acid-responsive release of SHK and Chi-Ag NPs from MUC1@ACS NPs cooperatively induced necroptosis in tumor cells by upregulating the expression of RIPK3, p-RIPK3, and tetrameric MLKL, thereby effectively triggering ICD. The sequential maturation of dendritic cells (DCs) subsequently enhanced the infiltration of CD8+ and CD4+ T cells in tumors, while inhibiting regulatory T cells (Treg cells), resulting in the effective treatment of primary and distal tumor growth and the inhibition of TNBC metastasis. This work highlights the importance of nanoparticles in mediating drug interactions during necroptotic ICD.

Biocompatibility and Antibacterial Properties of NiTiAg Porous Alloys for Bone Implants

In order to reduce infections, porous NiTi alloys with 62% porosity were obtained by self-propagating high-temperature synthesis with the addition of 0.2 and 0.5 at. % silver nanoparticles. Silver significantly improved the alloys' antibacterial activity without compromising cytocompatibility. An alloy with 0.5 at. % Ag showed the best antibacterial ability against Staphylococcus epidermidis. All alloys exhibited good biocompatibility with no cellular toxicity against embryonic fibroblast 3T3 cells. Clinical evaluation of the results after implantation showed a complete absence of purulent-inflammatory complications in all animals. Even distribution of silver nanoparticles in the surface layer of the porous NiTi alloy provides a uniform antibacterial effect.

Beyond the promise: Exploring the complex interactions of nanoparticles within biological systems

The exploration of nanoparticle applications is filled with promise, but their impact on the environment and human health raises growing concerns. These tiny environmental particles can enter the human body through various routes, such as the respiratory system, digestive tract, skin absorption, intravenous injection, and implantation. Once inside, they can travel to distant organs via the bloodstream and lymphatic system. This journey often results in nanoparticles adhering to cell surfaces and being internalized. Upon entering cells, nanoparticles can provoke significant structural and functional changes. They can potentially disrupt critical cellular processes, including damaging cell membranes and cytoskeletons, impairing mitochondrial function, altering nuclear structures, and inhibiting ion channels. These disruptions can lead to widespread alterations by interfering with complex cellular signaling pathways, potentially causing cellular, organ, and systemic impairments. This article delves into the factors influencing how nanoparticles behave in biological systems. These factors include the nanoparticles' size, shape, charge, and chemical composition, as well as the characteristics of the cells and their surrounding environment. It also provides an overview of the impact of nanoparticles on cells, organs, and physiological systems and discusses possible mechanisms behind these adverse effects. Understanding the toxic effects of nanoparticles on physiological systems is crucial for developing safer, more effective nanoparticle-based technologies.

Silver nanoparticles induce endothelial cytotoxicity through ROS-mediated mitochondria-lysosome damage and autophagy perturbation: The protective role of N-acetylcysteine

Silver nanoparticles (AgNPs) are used increasingly often in the biomedical field, but their potential deleterious effects on the cardiovascular system remain to be elucidated. The primary aim of this study was to evaluate the toxic effects, and the underlying mechanisms of these effects, of AgNPs on human umbilical vein endothelial cells (HUVECs), as well as the protective role of N-acetylcysteine (NAC) against cytotoxicity induced by AgNPs. In this study, we found that exposure to AgNPs affects the morphology and function of endothelial cells which manifests as decreased cell proliferation, migration, and angiogenesis ability. Mechanistically, AgNPs can induce excessive cellular production of reactive oxygen species (ROS), leading to damage to cellular sub-organs such as mitochondria and lysosomes. More importantly, our data suggest that AgNPs causes autophagy defect, inhibits mitophagy, and finally activates the mitochondria-mediated apoptosis signaling pathway and evokes cell death. Interestingly, treatment with ROS scavenger-NAC can effectively suppress AgNP-induced endothelial damage.Our results indicate that ROS-mediated mitochondria-lysosome injury and autophagy dysfunction are potential factors of endothelial toxicity induced by AgNPs. This study may provide new evidence for the cardiovascular toxicity of AgNPs and serve as a reference for the safe use of nanoparticles(NPs) in the future.

Sodium Selenite Ameliorates Silver Nanoparticles Induced Vascular Endothelial Cytotoxic Injury by Antioxidative Properties and Suppressing Inflammation Through Activating the Nrf2 Signaling Pathway

Silver nanoparticles (AgNP) are the dominant nanomaterials in commercial products and the medical field, but the widespread occurrence of AgNP has become a global threat to human health. Growing studies indicate that AgNP exposure can induce vascular endothelial toxicity by excessive oxidative stress and inflammation, which is closely related to cardiovascular disease (CVD), but the potential intrinsic mechanism remains poorly elucidated. Thus, it has been crucial to control the toxicological effects of AgNP in order to improve their safety and increase the outcome of their applications.Multiple researches have demonstrated that sodium selenite (Se) possesses the capability to counteract the toxicity of AgNP, but the functional role of Se in AgNP-induced CVD is largely unexplored. The aim of this study was to explore the potential protective effect of Se on AgNP-induced vascular endothelial lesion and elucidate the underlying mechanisms. An in vivo model of toxicity in animals was established by the instillation of 200 µL of AgNP into the trachea of rats both with (0.2 mg/kg/day) and without Se treated. In vitro experiments, human umbilical vein endothelial cells (HUVECs) were incubated with AgNP (0.3 µg/mL ) and Se for a duration of 24 h. Utilizing transmission electron microscopy, we observed that the internalization of AgNP-induced endothelial cells was desquamated from the internal elastic lamina, the endoplasmic reticulum was dilated, and the medullary vesicle formed. Se treatment reduced the levels of vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1), inhibited the release of pro-inflammatory cytokines (specifically tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6), improved endothelial cell permeability, integrity, and dysfunction, and prevented damage to the aortic endothelium caused by AgNP. Importantly, we found that Se showed the capacity against AgNP with biological functions in guiding the intracellular reactive oxygen species (ROS) scavenging and meanwhile exhibiting anti-inflammation effects. Se supplementation decreased the intracellular ROS release and suppressed NOD-like receptor protein 3 (NLRP3) and nuclear factor kappa-B (NF-κB) mediated inflammation within AgNP-intoxicated rats and HUVECs. The anti-oxidant stress and anti-inflammatory effects of Se were at least partly dependent on nuclear factor erythroid 2-related factor 2 (Nrf2). Overall, our results indicated that the protectiveness of Se against AgNP-induced vascular endothelial toxicity injury was at least attributed to the inhibition of oxidative ROS and pro-inflammatory NF-κB/NLRP3 inflammasome by activating the Nrf2 and antioxidant enzyme (HO-1) signal pathway.

Helicobacter pylori infection selectively attenuates endothelial function in male mice via exosomes-mediated ROS production

Background

Substantial sex differences exist in atherosclerosis. Excessive reactive oxygen species (ROS) formation could lead to endothelial dysfunction which is critical to atherosclerosis development and progression. Helicobacter pylori (H. pylori) infection has been shown to attenuate endothelial function via exosomes-mediated ROS formation. We have demonstrated that H. pylori infection selectively increases atherosclerosis risk in males with unknown mechanism(s). The present study was to test the hypothesis that H. pylori infection impaired endothelial function selectively in male mice through exosome-mediated ROS formation.

Methods and results

Age-matched male and female C57BL/6 mice were infected with CagA+ H. pylori to investigate sex differences in H. pylori infection-induced endothelial dysfunction. H. pylori infection attenuated acetylcholine (ACh)-induced endothelium-dependent aortic relaxation without changing nitroglycerine-induced endothelium-independent relaxation in male but not female mice, associated with increased ROS formation in aorta compared with controls, which could be reversed by N-acetylcysteine treatment. Treatment of cultured mouse brain microvascular endothelial cells with exosomes from H. pylori infected male, not female, mice significantly increased intracellular ROS production and impaired endothelial function with decreased migration, tube formation, and proliferation, which could be prevented with N-acetylcysteine treatment.

Conclusions

H. pylori infection selectively impairs endothelial function in male mice due to exosome-mediated ROS formation.

Immunotoxicity of metal and metal oxide nanoparticles: from toxic mechanisms to metabolism and outcomes

The influence of metal and metal oxide nanomaterials on various fields since their discovery has been remarkable. They have unique properties, and therefore, have been employed in specific applications, including biomedicine. However, their potential health risks cannot be ignored. Several studies have shown that exposure to metal and metal oxide nanoparticles can lead to immunotoxicity. Different types of metals and metal oxide nanoparticles may have a negative impact on the immune system through various mechanisms, such as inflammation, oxidative stress, autophagy, and apoptosis. As an essential factor in determining the function and fate of immune cells, immunometabolism may also be an essential target for these nanoparticles to exert immunotoxic effects in vivo. In addition, the biodegradation and metabolic outcomes of metal and metal oxide nanoparticles are also important considerations in assessing their immunotoxic effects. Herein, we focus on the cellular mechanism of the immunotoxic effects and toxic effects of different types of metal and metal oxide nanoparticles, as well as the metabolism and outcomes of these nanoparticles in vivo. Also, we discuss the relationship between the possible regulatory effect of nanoparticles on immunometabolism and their immunotoxic effects. Finally, we present perspectives on the future research and development direction of metal and metal oxide nanomaterials to promote scientific research on the health risks of nanomaterials and reduce their adverse effects on human health.

Crosstalk between the aryl hydrocarbon receptor (AhR) and the peroxisome proliferator-activated receptor gamma (PPARγ) as a key factor in the metabolism of silver nanoparticles in neuroblastoma (SH-SY5Y) cells in vitro

The potential usefulness of silver nanoparticles (AgNPs) in anticancer therapy has been postulated for many years. However, little is known to date about the exact impact of such NPs on intracellular detoxication pathways. Therefore, the aim of this study was to determine the impact of AgNPs on the AhR-PPARγ-CYP1A1 pathway in neuroblastoma (SH-SY5Y) cells. The obtained results showed a decrease in the metabolic activity of the SH-SY5Y cells at the 50 and 100 μg/mL concentrations with an increase in caspase-3 activity. An increase in the intercellular ROS production was observed at the 1 and 10 μg/mL concentrations. The co-treatment of the AgNP-treated cells with the AhR and PPARγ inhibitors abolished the effect of the tested AgNPs in the SH-SY5Y cells. In turn, the CYP1A1 activity assay showed a decrease in this parameter in the AgNP-treated cells. Moreover, the gene expression analysis demonstrated that AgNPs were able to increase the AhR and CYP1A1 mRNA expression and decrease the PPARγ gene expression after the 6-h treatment. In turn, an increase in the AhR and PPARγ protein expression was observed after 24 h. Summarizing, the study shows for the first time that AgNPs with a 5-nm diameter size are able to exert a cytotoxic effect on SH-SH5Y cells in a ROS-dependent manner affect the AhR-PPARγ-CYP1A1 pathway inter alia by inhibiting the activity of CYP1A1. This is important due to given present research approaches using such NPs as enhancer agents in the modern PPARγ inhibitor-based anticancer therapy.

Mg-based materials diminish tumor spreading and cancer metastases

Cancer metastases are the most common causes of cancer-related deaths. The formation of secondary tumors at different sites in the human body can impair multiple organ function and dramatically decrease the survival of the patients. In this stage, it is difficulty to treat tumor growth and spreading due to arising therapy resistances. Therefore, it is important to prevent cancer metastases and to increase subsequent cancer therapy success. Cancer metastases are conventionally treated with radiation or chemotherapy. However, these treatments elicit lots of side effects, wherefore novel local treatment approaches are currently discussed. Recent studies already showed anticancer activity of specially designed degradable magnesium (Mg) alloys by reducing the cancer cell proliferation. In this work, we investigated the impact of these Mg-based materials on different steps of the metastatic cascade including cancer cell migration, invasion, and cancer-induced angiogenesis. Both, Mg and Mg–6Ag reduced cell migration and invasion of osteosarcoma cells in coculture with fibroblasts. Furthermore, the Mg-based materials used in this study diminished the cancer-induced angiogenesis. Endothelial cells incubated with conditioned media obtained from these Mg and Mg–6Ag showed a reduced cell layer permeability, a reduced proliferation and inhibited cell migration. The tube formation as a last step of angiogenesis was stimulated with the presence of Mg under normoxia and diminished under hypoxia.

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Magnesium (Mg)-based material degradation decrease cell migration and invasion of an osteosarcoma coculture.

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Mg-based material degradation products reduce cancer-induced angiogenesis at an early stage.

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These materials may reduce secondary tumor formation and metastases.

Lung Pneumonitis and Fibrosis in Cancer Therapy: A Review on Cellular and Molecular Mechanisms

Fibrosis and pneumonitis are the most important side effects of lung tissue following cancer therapy. Radiotherapy and chemotherapy by some drugs, such as bleomycin, can induce pneumonitis and fibrosis. Targeted therapy and immunotherapy also may induce pneumonitis and fibrosis to a lesser extent compared to chemotherapy and radiotherapy. Activation of lymphocytes by immunotherapy or infiltration of inflammatory cells such as macrophages, lymphocytes, neutrophils, and mast cells following chemo/radiation therapy can induce pneumonitis. Furthermore, the polarization of macrophages toward M2 cells and the release of anti-inflammatory cytokines stimulate fibrosis. Lung fibrosis and pneumonitis may also be potentiated by some other changes such as epithelial-mesenchymal transition (EMT), oxidative stress, reduction/oxidation (redox) responses, renin-angiotensin system, and the upregulation of some inflammatory mediators such as a nuclear factor of kappa B (NF-κB), inflammasome, cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS). Damages to the lung vascular system and the induction of hypoxia also can induce pulmonary injury following chemo/radiation therapy. This review explains various mechanisms of the induction of pneumonitis and lung fibrosis following cancer therapy. Furthermore, the targets and promising agents to mitigate lung fibrosis and pneumonitis will be discussed.

Modulation Effects of Eugenol on Nephrotoxicity Triggered by Silver Nanoparticles in Adult Rats

The use of silver nanoparticles (AgNPs) is expanding. This study evaluates the modulator effect of eugenol (Eug) on AgNP-induced nephrotoxicity in rats. Sixty male rats were separated into six groups: control, Eug, AgNPs low-dose, AgNPs high-dose, Eug + AgNPs low-dose, and Eug + AgNPs high-dose. After 30 days, kidney function, antioxidative and proinflammatory status, histopathological, histomorphometrical, and immunohistochemical assessments were performed. AgNPs markedly induced oxidative stress in renal tissues, characterized by increased levels of blood urea nitrogen, creatinine, uric acid, kidney injury molecule-1, the total oxidant capacity, malondialdehyde, tumor necrosis factor-alpha (TNF-α), and interleukin-6, as well as decreased levels of the total antioxidant capacity, superoxide dismutase, catalase, reduced glutathione, and glutathione peroxidase. Moreover, the normal renal architecture was destroyed, and the thickness of the renal capsules, cortex, and medulla, alongside the diameter and quantity of the normal Malpighian corpuscles and the proximal and distal convoluted tubules were decreased. Immunoreactivity for P53, caspase-3, and TNF-α reactive proteins were significantly increased; however, Bcl-2 immunoreactivity was decreased. Eug reversed most biochemical, histological, histomorphometrical, and immunohistochemical changes in AgNP-treated animals. This study demonstrated that nephrotoxicity in AgNP-treated rats was mitigated by an Eug supplementation. Eug's antioxidant, antiapoptotic, and anti-inflammatory capabilities were the key in modulating AgNPs nephrotoxicity.

How Nanoparticles Open the Paracellular Route of Biological Barriers: Mechanisms, Applications, and Prospects

Biological barriers are essential physiological protective systems and obstacles to drug delivery. Nanoparticles (NPs) can access the paracellular route of biological barriers, either causing adverse health impacts on humans or producing therapeutic opportunities. This Review introduces the structural and functional influences of NPs on the key components that govern the paracellular route, mainly tight junctions, adherens junctions, and cytoskeletons. Furthermore, we evaluate their interaction mechanisms and address the influencing factors that determine the ability of NPs to open the paracellular route, which provides a better knowledge of how NPs can open the paracellular route in a safer and more controllable way. Finally, we summarize limitations in the research models and methodologies of the existing research in the field and provide future research direction. This Review demonstrates the in-depth causes for the reversible opening or destruction of the integrity of barriers generated by NPs; more importantly, it contributes insights into the design of NP-based medications to boost paracellular drug delivery efficiency.

Removal of contaminant in electroplating wastewater and its toxic effect using biosynthesized silver nanoparticles

Abstract

This research is designed to remove contaminant in electroplating wastewater, using biosynthesize silver nanoparticles (SNPs) and to determine its in-vivo toxic effect. Silver nanoparticles (SNPs: 1,2,3 and 4) synthesized at different conditions and characterised, yielded spherical shapes of irregular sizes comprising of − OH, − C=C, − C=O, − C–H and − NO functional groups. The electroplating wastewater treated with the synthesized SNPs, were subjected to physicochemical analysis which revealed the ability of the SNPs to remove pollutants, with SNP4 displaying a higher affinity. The haematological investigation disclosed no significant impact on haemoglobin, packed cell volume, mean corpuscular haemoglobin concentration, red blood cell, neutrophils and lymphocytes compared to the control group. Although, the liver tissues revealed toxic effects of the treated wastewater. The study validates that the biosynthesized SNPs contained stabilizing and reducing agent and also has the ability to eliminate pollutant in electroplating wastewater.

Article highlights

Investigation of Antimicrobial Activity and Biocompatibility of Biogenic Silver Nanoparticles Synthesized using Syzigyum cymosum Extract

Nanotherapeutics has emerged as the most sought after approach to tackle the menace of drug-resistant pathogenic bacteria. Among others, biogenic silver nanoparticles (bAgNPs) synthesized using medicinal plant extracts demonstrate promising antibacterial propensity with excellent biocompatibility. Herein, bAgNPs were synthesized through the green chemistry approach using Syzygium cymosum leaf extract as a reducing agent at different pH values (i.e., 5, 7, 8, and 10). The average size of bAgNPs synthesized at pH 5, 7, 8, and 10 was 23.3, 21.3, 17.2, and 35.3 nm, respectively, and all the nanoparticles were negatively charged. Their antibacterial potential was investigated against Bacillus subtilis, Escherichia coli DH5α, E. coli K12, enteropathogenic E. coli, and Salmonella typhi. The highest antibacterial activity was exhibited by bAgNPs synthesized at pH 8 against all the tested bacterial strains, which can be attributed to their small size and greater surface area to volume ratio. The bAgNPs demonstrated the highest zone of inhibition (29.5 ± 0.8 mm) against B. subtilis through oxidation of membrane fatty acids that resulted in the formation of the malondialdehyde-thiobarbituric acid (MDA-TBA) adduct. However, bAgNPs demonstrated excellent hemocompatibility with rat and human red blood cells. Biogenic AgNPs synthesized at pH 8 also exhibited biocompatibility in terms of liver and kidney function biomarkers. Furthermore, hematoxylin and eosin staining of the tissue sections of vital organs (i.e., liver, kidneys, lungs, heart, spleen, and brain) also confirmed the biocompatibility of bAgNPs.

Inducible endothelial leakiness in nanotherapeutic applications

All intravenous delivered nanomedicine needs to escape from the blood vessel to exert their therapeutic efficacy at their designated site of action. Failure to do so increases the possibility of detrimental side effects and negates their therapeutic intent. Many powerful anticancer nanomedicine strategies rely solely on the tumor derived enhanced permeability and retention (EPR) effect for the only mode of escaping from the tumor vasculature. However, not all tumors have the EPR effect nor can the EPR effect be induced or controlled for its location and timeliness. In recent years, there have been exciting developments along the lines of inducing endothelial leakiness at the tumor to decrease the dependence of EPR. Physical disruption of the endothelial-endothelial cell junctions with coordinated biological intrinsic pathways have been proposed that includes various modalities like ultrasound, radiotherapy, heat and even nanoparticles, appear to show good progress towards the goal of inducing endothelial leakiness. This review explains the intricate and complex biological background behind the endothelial cells with linkages on how updated reported nanomedicine strategies managed to induce endothelial leakiness. This review will also end off with fresh insights on where the future of inducible endothelial leakiness holds.

Ferritin: A Promising Nanoreactor and Nanocarrier for Bionanotechnology

The essence of bionanotechnology lies in the application of nanotechnology/nanomaterials to solve the biological problems. Quantum dots and nanoparticles hold potential biomedical applications, but their inherent problems such as low solubility and associated toxicity due to their interactions at nonspecific target sites is a major concern. The self-assembled, thermostable, ferritin protein nanocages possessing natural iron scavenging ability have emerged as a potential solution to all the above-mentioned problems by acting as nanoreactor and nanocarrier. Ferritins, the cellular iron repositories, are hollow, spherical, symmetric multimeric protein nanocages, which sequester the excess of free Fe(II) and synthesize iron biominerals (Fe₂O₃·H₂O) inside their ∼5-8 nm central cavity. The electrostatics and dynamics of the pore residues not only drives the natural substrate Fe²⁺ inside ferritin nanocages but also uptakes a set of other metals ions/counterions during in vitro synthesis of nanomaterial. The current review aims to report the recent developments/understanding on ferritin structure (self-assembly, surface/pores electrostatics, metal ion binding sites) and chemistry occurring inside these supramolecular protein cages (protein mediated metal ion uptake and mineralization/nanoparticle formation) along with its surface modification to exploit them for various nanobiotechnological applications. Furthermore, a better understanding of ferritin self-assembly would be highly useful for optimizing the incorporation of nanomaterials via the disassembly/reassembly approach. Several studies have reported the successful engineering of these ferritin protein nanocages in order to utilize them as potential nanoreactor for synthesizing/incorporating nanoparticles and as nanocarrier for delivering imaging agents/drugs at cell specific target sites. Therefore, the combination of nanoscience (nanomaterials) and bioscience (ferritin protein) projects several benefits for various applications ranging from electronics to medicine.

Cytotoxicity of Metal-Based Nanoparticles: From Mechanisms and Methods of Evaluation to Pathological Manifestations

Metal-based nanoparticles (NPs) are particularly important tools in tissue engineering-, drug carrier-, interventional therapy-, and biobased technologies. However, their complex and varied migration and transformation pathways, as well as their continuous accumulation in closed biological systems, cause various unpredictable toxic effects that threaten human and ecosystem health. Considerable experimental and theoretical efforts have been made toward understanding these cytotoxic effects, though more research on metal-based NPs integrated with clinical medicine is required. This review summarizes the mechanisms and evaluation methods of cytotoxicity and provides an in-depth analysis of the typical effects generated in the nervous, immune, reproductive, and genetic systems. In addition, the challenges and opportunities are discussed to enhance future investigations on safer metal-based NPs for practical commercial adoption.

CagA+Helicobacter pylori, Not CagA–Helicobacter pylori, Infection Impairs Endothelial Function Through Exosomes-Mediated ROS Formation

Background

Helicobacter pylori (H. pylori) infection increases the risk for atherosclerosis, and ROS are critical to endothelial dysfunction and atherosclerosis. CagA is a major H. pylori virulence factor associated with atherosclerosis. The present study aimed to test the hypothesis that CagA+H. pylori effectively colonizes gastric mucosa, and CagA+H. pylori, but not CagA–H. pylori, infection impairs endothelial function through exosomes-mediated ROS formation.

Methods

C57BL/6 were used to determine the colonization ability of CagA+H. pylori and CagA–H. pylori. ROS production, endothelial function of thoracic aorta and atherosclerosis were measured in CagA+H. pylori and CagA–H. pylori infected mice. Exosomes from CagA+H. pylori and CagA–H. pylori or without H. pylori infected mouse serum or GES-1 were isolated and co-cultured with bEND.3 and HUVECs to determine how CagA+H. pylori infection impairs endothelial function. Further, GW4869 was used to determine if CagA+H. pylori infection could lead to endothelial dysfunction and atherosclerosis through an exosomes-mediated mechanism.

Results

CagA+H. pylori colonized gastric mucosa more effectively than CagA–H. pylori in mice. CagA+H. pylori, not CagA–H. pylori, infection significantly increased aortic ROS production, decreased ACh-induced aortic relaxation, and enhanced early atherosclerosis formation, which were prevented with N-acetylcysteine treatment. Treatment with CagA-containing exosomes significantly increased intracellular ROS production in endothelial cells and impaired their function. Inhibition of exosomes secretion with GW4869 effectively prevented excessive aortic ROS production, endothelial dysfunction, and atherosclerosis in mice with CagA+H. pylori infection.

Conclusion

These data suggest that CagA+H. pylori effectively colonizes gastric mucosa, impairs endothelial function, and enhances atherosclerosis via exosomes-mediated ROS formation in mice.

Recent Advances and Mechanistic Insights into Antibacterial Activity, Antibiofilm Activity, and Cytotoxicity of Silver Nanoparticles

The substantial increase in multidrug-resistant (MDR) pathogenic bacteria is a major threat to global health. Recently, the Centers for Disease Control and Prevention reported possibilities of greater deaths due to bacterial infections than cancer. Nanomaterials, especially small-sized (size ≤10 nm) silver nanoparticles (AgNPs), can be employed to combat these deadly bacterial diseases. However, high reactivity, instability, susceptibility to fast oxidation, and cytotoxicity remain crucial shortcomings for their uptake and clinical application. In this review, we discuss various AgNPs-based approaches to eradicate bacterial infections and provide comprehensive mechanistic insights and recent advances in antibacterial activity, antibiofilm activity, and cytotoxicity (both in vitro and in vivo) of AgNPs. The mechanistic of antimicrobial activity involves four steps: (i) adhesion of AgNPs to cell wall/membrane and its disruption; (ii) intracellular penetration and damage; (iii) oxidative stress; and (iv) modulation of signal transduction pathways. Numerous factors affecting the bactericidal activity of AgNPs such as shape, size, crystallinity, pH, and surface coating/charge have also been described in detail. The review also sheds light on antimicrobial photodynamic therapy and the role of AgNPs versus Ag⁺ ions release in bactericidal activities. In addition, different methods of synthesis of AgNPs have been discussed in brief.

Ag-Contained Superabsorbent Curdlan–Chitosan Foams for Healing Wounds in a Type-2 Diabetic Mice Model

This study focused on the synthesis and characterization of pure curdlan–chitosan foams (CUR/CS), as well as foams containing Ag nanoparticles (CUR/CS/Ag), and their effect on the skin repair of diabetic mice (II type). The layer of antibacterial superabsorbent foam provides good oxygenation, prevents bacterial infection, and absorbs exudate, forming a soft gel (moist environment). These foams were prepared from a mixture of hydrolyzed curdlan and chitosan by lyophilization. To enhance the antibacterial properties, an AgNO₃ solution was added to the curdlan/chitosan mixture during the polymerization and was then reduced by UV irradiation. The membranes were further investigated for their structure and composition using optical microscopy, scanning electron microscopy, energy-dispersive spectroscopy, FT-IR spectroscopy, and XPS analysis and modeling. In vivo tests demonstrated that CUR/CS/Ag significantly boosted the regeneration process compared with pure CUR/CS and the untreated control.

Silver Nanoparticles as Chlorhexidine and Metronidazole Drug Delivery Platforms: Their Potential Use in Treating Periodontitis

Purpose

Materials and Methods

Results

Conclusion

Vascular Graft Infections: An Overview of Novel Treatments Using Nanoparticles and Nanofibers

Vascular disease in elderly patients is a growing health concern, with an estimated prevalence of 15–20% in patients above 70 years old. Current treatment for vascular diseases requires the use of a vascular graft (VG) to revascularize lower or upper extremities, create dialysis access, treat aortic aneurysms, and repair dissection. However, postoperative infection is a major complication associated with the use of these VG, often necessitating several operations to achieve complete or partial graft excision, vascular coverage, and extra-anatomical revascularization. There is also a high risk of morbidity, mortality, and limb loss. Therefore, it is important to develop a method to prevent or reduce the incidence of these infections. Numerous studies have investigated the efficacy of antibiotic- and antiseptic-impregnated grafts. In comparison to these traditional methods of creating antimicrobial grafts, nanotechnology enables researchers to design more efficient VG. Nanofibers and nanoparticles have a greater surface area compared to bulk materials, allowing for more efficient encapsulation of antibiotics and better control over their temporo-spatial release. The disruptive potential of nanofibers and nanoparticles is exceptional, and they could pave the way for a new generation of prosthetic VG. This review aims to discuss how nanotechnology is shaping the future of cardiovascular-related infection management.

Lipoic Acid-Coated Silver Nanoparticles: Biosafety Potential on the Vascular Microenvironment and Antibacterial Properties

Purpose: To study and compare the antibacterial properties and the potential cytotoxic effects of commercially available uncoated silver nanoparticles (AgNPs) with lipoic acid coated silver nanoparticles (AgNPsLA) developed by our group. The antibacterial, cytotoxic, and hemolytic properties of those NPs were assessed with the main objective of investigating if AgNPsLA could maintain their antibacterial properties while improving their biosafety profile over uncoated AgNPs within the blood vessel’s microenvironment.

Methods: Comercially available uncoated 2.6 nm AgNPs and 2.5 nm AgNPsLA synthesized and characterized as previously described by our group, were used in this study. Antimicrobial activity was assessed on a wide range of pathogens and expressed by minimal inhibitory concentrations (MIC). Assessment of cytotoxicity was carried out on human umbilical vein endothelial cells (HUVEC) using an MTT test. Detection of reactive oxygen species, cell apoptosis/necrosis in HUVEC, and measurement of mitochondrial destabilization in HUVEC and platelets were performed by flow cytometry. The potential harmful effect of nanoparticles on red blood cells (RBCs) was investigated measuring hemoglobin and LDH released after exposure to NPs. Transmission electron microscopy was also used to determine if AgNPs and AgNPsLA could induce any ultrastructural changes on HUVEC cells and Staphylococcus aureus bacteria.

Results: AgNPs and AgNPsLA had antimicrobial properties against pathogens associated with catheter-related bloodstream infections. AgNPs, in contrast to AgNPsLA, induced ROS production and apoptosis in HUVEC, ultrastructural changes in HUVEC and S. aureus, depolarization of mitochondrial membrane in HUVEC and platelets, and also hemolysis.

Conclusion: AgNPsLA synthesized by our group have antimicrobial activity and a better biosafety profile than uncoated AgNPs of similar size. Those observations are of critical importance for the future in vivo investigations and the potential application of AgNPsLA in medical devices for human use.

Exacerbation of Thrombotic Responses to Silver Nanoparticles in Hypertensive Mouse Model

With advent of nanotechnology, silver nanoparticles, AgNPs owing majorly to their antibacterial properties, are used widely in food industry and biomedical applications implying human exposure by various routes including inhalation. Several reports have suggested AgNPs induced pathophysiological effects in a cardiovascular system. However, cardiovascular diseases such as hypertension may interfere with AgNPs-induced response, yet majority of them are understudied. The aim of this work was to evaluate the thrombotic complications in response to polyethylene glycol- (PEG-) coated AgNPs using an experimental hypertensive (HT) mouse model. Saline (control) or PEG-AgNPs (0.5 mg/kg) were intratracheally (i.t.) instilled four times, i.e., on days 7, 14, 21, and 28 post-angiotensin II-induced HT, or vehicle (saline) infusion. On day 29, various parameters were assessed including thrombosis in pial arterioles and venules, platelet aggregation in whole blood in vitro, plasma markers of coagulation, and fibrinolysis and systemic oxidative stress. Pulmonary exposure to PEG-AgNPs in HT mice induced an aggravation of in vivo thrombosis in pial arterioles and venules compared to normotensive (NT) mice exposed to PEG-AgNPs or HT mice given saline. The prothrombin time, activated partial thromboplastin time, and platelet aggregation in vitro were exacerbated after exposure to PEG-AgNPs in HT mice compared with either NT mice exposed to nanoparticles or HT mice exposed to saline. Elevated concentrations of fibrinogen, plasminogen activator inhibitor-1, and von Willebrand factor were seen after the exposure to PEG-AgNPs in HT mice compared with either PEG-AgNPs exposed NT mice or HT mice given with saline. Likewise, the plasma levels of superoxide dismutase and nitric oxide were augmented by PEG-AgNPs in HT mice compared with either NT mice exposed to nanoparticles or HT mice exposed to saline. Collectively, these results demonstrate that PEG-AgNPs can potentially exacerbate the in vivo and in vitro procoagulatory and oxidative stress effect in HT mice and suggest that population with hypertension are at higher risk of the toxicity of PEG-AgNPs.

Plant-derived nanotherapeutic systems to counter the overgrowing threat of resistant microbes and biofilms

Since antiquity, the survival of human civilization has always been threatened by the microbial infections. An alarming surge in the resistant microbial strains against the conventional drugs is quite evident in the preceding years. Furthermore, failure of currently available regimens of antibiotics has been highlighted by the emerging threat of biofilms in the community and hospital settings. Biofilms are complex dynamic composites rich in extracellular polysaccharides and DNA, supporting plethora of symbiotic microbial life forms, that can grow on both living and non-living surfaces. These enforced structures are impervious to the drugs and lead to spread of recurrent and non-treatable infections. There is a strong realization among the scientists and healthcare providers to work out alternative strategies to combat the issue of drug resistance and biofilms. Plants are a traditional but rich source of effective antimicrobials with wider spectrum due to presence of multiple constituents in perfect synergy. Other than the biocompatibility and the safety profile, these phytochemicals have been repeatedly proven to overcome the non-responsiveness of resistant microbes and films via multiple pathways such as blocking the efflux pumps, better penetration across the cell membranes or biofilms, and anti-adhesive properties. However, the unfavorable physicochemical attributes and stability issues of these phytochemicals have hampered their commercialization. These issues of the phytochemicals can be solved by designing suitably constructed nanoscaled structures. Nanosized systems can not only improve the physicochemical features of the encapsulated payloads but can also enhance their pharmacokinetic and therapeutic profile. This review encompasses why and how various types of phytochemicals and their nanosized preparations counter the microbial resistance and the biofouling. We believe that phytochemical in tandem with nanotechnological innovations can be employed to defeat the microbial resistance and biofilms. This review will help in better understanding of the challenges associated with developing such platforms and their future prospects.

Transcriptomic and proteomic responses of silver nanoparticles in hepatocyte-like cells derived from human induced pluripotent stem cells

Silver nanoparticles (AgNPs) have been increasingly used in a variety of consumer products over the last decades. However, their potential adverse effects have not been fully understood. In a previous study, we characterized transcriptomic changes in human induced pluripotent stem cell (iPSC)-derived hepatocyte-like cells (HLCs) in response to AgNP exposure. Here, we report findings of a follow-up proteomic study that evaluated alternations at the protein level in the same cell after being exposed to 10 μg/ml AgNPs for 24 h. In total, 6287 proteins were identified across two groups of samples (n = 3). Among these proteins, 665 were found to be differentially regulated (fold change ≥1.25, p < 0.01) between the AgNP-treated group and the untreated control group, including 264 upregulated and 401 downregulated. Bioinformatics analysis of the proteomics data, in side-by-side comparison to the transcriptomics data, confirms and substantiates previous findings on AgNP-induced alterations in metabolism, oxidative stress, inflammation, and potential association with cancer. A mechanism of action was proposed based on these results. Collectively, the findings of the current proteomic study are consistent with those of the previous transcriptomic study and further demonstrate the usefulness of iPSC-derived HLCs as an in vitro model for liver nanotoxicology.

Understanding the interactions between inorganic-based nanomaterials and biological membranes

The interactions between inorganic-based nanomaterials (NMs) and biological membranes are among the most important phenomena for developing NM-based therapeutics and resolving nanotoxicology. Herein, we introduce the structural and functional effects of inorganic-based NMs on biological membranes, mainly the plasma membrane and the endomembrane system, with an emphasis on the interface, which involves highly complex networks between NMs and biomolecules (such as membrane proteins and lipids). Significant efforts have been devoted to categorizing and analyzing the interaction mechanisms in terms of the physicochemical characteristics and biological effects of NMs, which can directly or indirectly influence the effects of NMs on membranes. Importantly, we summarize that the biological membranes act as platforms and thereby mediate NMs-immune system contacts. In this overview, the existing challenges and potential applications in the areas are addressed. A strong understanding of the discussed concepts will promote therapeutic NM designs for drug delivery systems by leveraging the NMs-membrane interactions and their functions.

Fructose-coated Ångstrom silver prevents sepsis by killing bacteria and attenuating bacterial toxin-induced injuries

Serious infection caused by multi-drug-resistant bacteria is a major threat to human health. Bacteria can invade the host tissue and produce various toxins to damage or kill host cells, which may induce life-threatening sepsis. Here, we aimed to explore whether fructose-coated Ångstrom-scale silver particles (F-AgÅPs), which were prepared by our self-developed evaporation-condensation system and optimized coating approach, could kill bacteria and sequester bacterial toxins to attenuate fatal bacterial infections.

Methods: A series of in vitro assays were conducted to test the anti-bacterial efficacy of F-AgÅPs, and to investigate whether F-AgÅPs could protect against multi-drug resistant Staphylococcus aureus (S. aureus)- and Escherichia coli (E. coli)-induced cell death, and suppress their toxins (S. aureus hemolysin and E. coli lipopolysaccharide)-induced cell injury or inflammation. The mouse models of cecal ligation and puncture (CLP)- or E. coli bloodstream infection-induced lethal sepsis were established to assess whether the intravenous administration of F-AgÅPs could decrease bacterial burden, inhibit inflammation, and improve the survival rates of mice. The levels of silver in urine and feces of mice were examined to evaluate the excretion of F-AgÅPs.

Results: F-AgÅPs efficiently killed various bacteria that can cause lethal infections and also competed with host cells to bind with S. aureus α-hemolysin, thus blocking its cytotoxic activity. F-AgÅPs inhibited E. coli lipopolysaccharide-induced endothelial injury and macrophage inflammation, but not by directly binding to lipopolysaccharide. F-AgÅPs potently reduced bacterial burden, reversed dysregulated inflammation, and enhanced survival in mice with CLP- or E. coli bloodstream infection-induced sepsis, either alone or combined with antibiotic therapy. After three times injections within 48 h, 79.18% of F-AgÅPs were excreted via feces at the end of the 14-day observation period.

Conclusion: This study suggests the prospect of F-AgÅPs as a promising intravenous agent for treating severe bacterial infections.

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

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

Adverse cardiovascular responses of engineered nanomaterials: Current understanding of molecular mechanisms and future challenges

Nanotechnology is spanning multiple fields of study from materials science to computer engineering and drug discovery. Since the early 21st century, nanotechnology and nano-enabled research have received great attention and governmental funding accompanied with interest to ensure human and environmental safety of engineered nanomaterials (ENMs). Optimal functioning of the cardiovascular (CV) system is of utmost importance for the overall health of the body. Following exposure, ENMs essentially end up in the circulation (at least partially) and hence it is key to assess any associated adverse CV consequences. Accumulating research suggests that exposure to ENMs (different compositions and physicochemical properties) has the capacity to directly and indirectly interact with CV components resulting in adverse events and worsening of CV complications. However, the underlying molecular mechanisms driving these events remain to be elucidated. In this article, we review state-of-art literature on ENM-associated adverse CV responses and discuss the potential underlying molecular mechanisms.

Update on the role of antiseptics in the management of chronic wounds with critical colonisation and/or biofilm

Biofilms play a major role in delaying chronic wounds from healing. A wound infiltrated with biofilm, or "critically colonised" wound, may become clinically infected if the number of microbes exceeds a critical level. Chronic wound biofilms represent a significant treatment challenge by demonstrating recalcitrance towards antimicrobial agents. However, a "window of opportunity" may exist after wound debridement when biofilms are more susceptible to topical antiseptics. Here, we discuss the role of antiseptics in the management of chronic wounds and biofilm, focusing on povidone-iodine (PVP-I) in comparison with two commonly used antiseptics: polyhexanide (PHMB) and silver. This article is based on the literature reviewed during a focus group meeting on antiseptics in wound care and biofilm management, and on a PubMed search conducted in March 2020. Compared with PHMB and silver, PVP-I has a broader spectrum of antimicrobial activity, potent antibiofilm efficacy, no acquired bacterial resistance or cross-resistance, low cytotoxicity, good tolerability, and an ability to promote wound healing. PVP-I represents a viable therapeutic option in wound care and biofilm management, with the potential to treat biofilm-infiltrated, critically colonised wounds. We propose a practical algorithm to guide the management of chronic, non-healing wounds due to critical colonisation or biofilm, using PVP-I.

Potential cytotoxicity of silver nanoparticles: Stimulation of autophagy and mitochondrial dysfunction in cardiac cells

In the present study, we elucidated the potential cytotoxicity of AgNPs in H9c2 rat cardiomyoblasts and assessed the underlying toxicological manifestations responsible for their toxicity thereof. The results indicated that the exposure of AgNPs to H9c2 cardiac cells decreased cell viability in a dose-dependent manner and caused cell cycle arrest followed by induction of apoptosis. The AgNPs treated cardiac cells showed a generation of reactive oxygen species (ROS) and mitochondrial dysfunction where mitochondrial ATP was reduced and the expression of AMPK1α increased. AgNPs also induced ROS-mediated autophagy in H9c2 cells. There was a significant time-dependent increase in intracellular levels of Atg5, Beclin1, and LC3BII after exposure to AgNPs, signifying the autophagic response in H9c2 cells. More importantly, the addition of N-acetyl-L-cysteine (NAC) inhibited autophagy and significantly reduced the cytotoxicity of AgNPs in H9c2 cells. The study highlights the prospective toxicity of AgNPs on cardiac cells, collectively signifying a potential health risk.

Remote effects and biodistribution of pulmonary instilled silver nanoparticles in mice

Silver nanoparticles (AgNPs) are the most commonly used nanoparticles (NPs) owing to their anti-microbial properties, and the pulmonary system provides a major portal of entry for these NPs used in aerosolized products. AgNPs have the potential to cause pulmonary toxicity, cross the alveolar-capillary barrier, and distribute to remote organs following pulmonary exposure. The mechanism underlying the effects of AgNPs, secondary to lung exposure, on the major organs including liver, spleen, kidney and brain, however, is still not completely understood. The aim of this study was to analyze the organ toxicity and distribution of pulmonary exposure to single dose of 5 mg/kg AgNPs (10 nm) with varying coatings (polyvinylpyrrolidone and citrate), at different time points (1 and 7 days), in Balb/C mice. Silver ions (Ag⁺) were used as ionic control. Histological evidence of inflammation was observed in lungs for both types of AgNPs. Markers of inflammation including tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6) were significantly increased in lung, brain and liver in AgNPs exposed animals. Ag⁺ ions caused significant increase of TNF-α and IL-6 in the spleen and kidney. Significant increase of reduced glutathione, nitric oxide, and 8-isoprostane was observed in most of the organs investigated. Furthermore, AgNPs induced DNA damage and apoptosis in the lung, liver and brain. The biodistribution showed that, AgNPs were distributed mainly in the spleen, liver, lung and little in kidney and brain. Comparatively, reduced amount of Ag was detected in most organs 7 days after exposure, except for AgAc in the kidney and brain. In conclusion, pulmonary exposure to AgNPs caused oxidative stress markers, inflammation, DNA damage and biodistribution in remote organs. These findings provide a novel mechanistic insight into the pathophysiological effects and tissue distribution of lung exposure to AgNPs.

Combined Toxicity of Metal Nanoparticles: Comparison of Individual and Mixture Particles Effect

Toxicity of metal nanoparticles (NPs) are closely associated with increasing intracellular reactive oxygen species (ROS) and the levels of pro-inflammatory mediators. However, NP interactions and surface complexation reactions alter the original toxicity of individual NPs. To date, toxicity studies on NPs have mostly been focused on individual NPs instead of the combination of several species. It is expected that the amount of industrial and highway-acquired NPs released into the environment will further increase in the near future. This raises the possibility that various types of NPs could be found in the same medium, thereby, the adverse effects of each NP either could be potentiated, inhibited or remain unaffected by the presence of the other NPs. After uptake of NPs into the human body from various routes, protein kinases pathways mediate their toxicities. In this context, family of mitogen-activated protein kinases (MAPKs) is mostly efficient. Despite each NP activates almost the same metabolic pathways, the toxicity induced by a single type of NP is different than the case of co-exposure to the combined NPs. The scantiness of toxicological data on NPs combinations displays difficulties to determine, if there is any risk associated with exposure to combined nanomaterials. Currently, in addition to mathematical analysis (Response surface methodology; RSM), the quantitative-structure-activity relationship (QSAR) is used to estimate the toxicity of various metal oxide NPs based on their physicochemical properties and levels applied. In this chapter, it is discussed whether the coexistence of multiple metal NPs alter the original toxicity of individual NP. Additionally, in the part of "Toxicity of diesel emission/exhaust particles (DEP)", the known individual toxicity of metal NPs within the DEP is compared with the data regarding toxicity of total DEP mixture.

Ameliorating effect of leukotriene receptor antagonist in multi-organ toxicity induced in rat offspring, a possible role for epidermal growth factor

Purpose: Nowadays, there is a dramatic increase in the interest of potential impact of consumer-relevant engineered nanoparticles on pregnancy.Materials and methods: This study investigated the possible protective effect of montelukast in neonatal organ toxicity induced by maternal exposure to silver nanoparticles (AgNPs) in rats.Results: It was noticed that montelukast reduced serum urea, creatinine, renal caspase-3 immunoreactivity and IL-1β and increased total antioxidant capacity, as compared to AgNPs. In kidney and bone tissue, montelukast reduced oxidative stress parameters and TNF-α level that was increased with AgNPs. Surprisingly, montelukast administration increased epidermal growth factor (EGF) in bone and reduced it in kidney. Furthermore, as compared to AgNPs, montelukast improved histopathological picture of kidney and bone.Conclusions: In conclusion, montelukast antagonized the biochemical and histopathological changes occurred in kidneys and bones of rat offspring by maternal exposure to AgNPs, mostly by anti-oxidant, anti-apoptotic and anti-inflammatory actions with a possible role for EGF.

Silver ion doped hydroxyapatite-coated titanium pins prevent bacterial colonization

Objectives

This study aims to evaluate the effectiveness of silver ion doped calcium phosphate-based ceramic nano powder-coated titanium pins in preventing bacterial colonization.

Materials and methods

A total of 66 titanium pins were divided into three groups of 22 implants. The first group was coated with silver ion doped calcium phosphate-based ceramic powder by using electrospray method. The second group was coated with pure hydroxyapatite (HA), and the remaining pins were used without any coating. The remaining 22 pins were used without any coating. Staphylococcus epidermidis clinical isolate was used for the study. Each pin was placed in 1¥104 CFU/mL bacterial suspension containing tube and at 24 h quantitative culture of bacteria on the broth and on the pins were performed. Free silver ions were determined by atomic absorption method. The antibacterial culture tests were repeated on Day 2 and Weeks 2, 4, 6, and 8.

Results

Bacterial growth was statistically higher in broth containing uncoated pins, compared to broth media containing silver ion doped HA-coated, and pure HA-coated pins at 24 h (p=0.036 and p=0.009, respectively). The release of bacteria from silver doped HA-coated pins was statistically less, compared to pure HA-coated pins and uncoated pins (p=0.039 and p=0.002, respectively). No significant differences were observed between the HA-coated and uncoated pin groups. Minimum inhibitory concentration levels for silver ion doped powder was 8 μg/mL for coagulase-negative Staphylococcus. No free silver ions were detected in the broth media.

Conclusion

Silver ion doped nano size calcium phosphate-based powder-coated titanium pins reduced the bacterial colonization significantly. Using silver ion doped materials in the body can be a good option to prevent from implant related infections.

Assessment of Amphiphilic Poly-N-vinylpyrrolidone Nanoparticles' Biocompatibility with Endothelial Cells in Vitro and Delivery of an Anti-Inflammatory Drug

Nanoparticles (NPs) produced from amphiphilic derivatives of poly-N-vinylpyrrolidone (Amph-PVP), composed of various molecular weight polymeric hydrophilic fragments linked into hydrophobic n-alkyl chains of varying lengths, were previously shown to exert excellent biocompatibility. Although routes of administration can be different, finally, most nanosystems enter the blood circulation or lymphatic vessels, and by this, they establish direct contact with endothelial cells. In this study, Amph-PVP NPs and fluorescently labeled Amph-PVP-based NPs, namely "PVP" NPs (Amph-PVP-NPs (6000 Da) unloaded) and "F"-NPs (Amph-PVP-NPs (6000 Da) loaded with fluorescent FITC), were synthesized to study Amph-PVP NPs interactions with HMEC-1 endothelial cells. PVP NPs were readily uptaken by HMEC-1 cells in a concentration-dependent manner, as demonstrated by immunofluorescence imaging. Upon uptake, the FITC dye was localized to the perinuclear region and cytoplasm of treated cells. The generation of lipopolysaccharide (LPS)-induced activated endothelium model revealed an increased uptake of PVPNPs, as shown by confocal microscopy. Both unloaded PVP NPs and F-NPs did not affect EC viability in the 0.01 to 0.066 mg/mL range. Furthermore, we focused on the potential immunological activation of HMEC-1 endothelial cells upon PVPNPs treatment by assessing the expression of their E-Selectin, ICAM-1, and VCAM-1 adhesion receptors. None of the adhesion molecules were affected by NP treatments of both activated by LPS and nonactivated HMEC-1 cells, at the utilized concentrations (p = NS). In this study, PVP (6000 Da) NPs were used to encapsulate indomethacin, a widely used anti-inflammatory drug. The synthesized drug carrier complex did not affect HMEC-1 cell growth and expression of E-selectin, ICAM-1, and VCAM-1 adhesion receptors. In summary, PVP-based NPs are safe for use on both basal and activated endothelium, which more accurately mimics pathological conditions. Amph-PVP NPs are a promising drug delivery system.

Silver nanoparticles: Synthesis, medical applications and biosafety

Silver nanoparticles (AgNPs) have been one of the most attractive nanomaterials in biomedicine due to their unique physicochemical properties. In this paper, we review the state-of-the-art advances of AgNPs in the synthesis methods, medical applications and biosafety of AgNPs. The synthesis methods of AgNPs include physical, chemical and biological routes. AgNPs are mainly used for antimicrobial and anticancer therapy, and also applied in the promotion of wound repair and bone healing, or as the vaccine adjuvant, anti-diabetic agent and biosensors. This review also summarizes the biological action mechanisms of AgNPs, which mainly involve the release of silver ions (Ag+), generation of reactive oxygen species (ROS), destruction of membrane structure. Despite these therapeutic benefits, their biological safety problems such as potential toxicity on cells, tissue, and organs should be paid enough attention. Besides, we briefly introduce a new type of Ag particles smaller than AgNPs, silver Ångstrom (Å, 1 Å = 0.1 nm) particles (AgÅPs), which exhibit better biological activity and lower toxicity compared with AgNPs. Finally, we conclude the current challenges and point out the future development direction of AgNPs.

All Roads Lead to the Liver: Metal Nanoparticles and Their Implications for Liver Health

Metal nanoparticles (NPs) are frequently encountered in daily life, and concerns have been raised about their toxicity and safety. Among which, they naturally accumulate in the liver after introduction into the body, independent of the route of administration. Some NPs exhibit intrinsic pharmaceutical effects that are related to their physical parameters, and their inadvertent accumulation in the liver can exert strong effects on liver function and structure. Even as such physiological consequences are often categorically dismissed as toxic and deleterious, there are cell type-specific and NP-specific biological responses that elicit distinctive pharmacological consequences that can be harnessed for good. By limiting the scope of discussion to metallic NPs, this work attempts to provide a balanced perspective on their safety in the liver, and discusses both possible therapeutic benefits and potential accidental liver damage arising from their interaction with specific parenchymal and nonparenchymal cell types in the liver.

Health Impact of Silver Nanoparticles: A Review of the Biodistribution and Toxicity Following Various Routes of Exposure

Engineered nanomaterials (ENMs) have gained huge importance in technological advancements over the past few years. Among the various ENMs, silver nanoparticles (AgNPs) have become one of the most explored nanotechnology-derived nanostructures and have been intensively investigated for their unique physicochemical properties. The widespread commercial and biomedical application of nanosilver include its use as a catalyst and an optical receptor in cosmetics, electronics and textile engineering, as a bactericidal agent, and in wound dressings, surgical instruments, and disinfectants. This, in turn, has increased the potential for interactions of AgNPs with terrestrial and aquatic environments, as well as potential exposure and toxicity to human health. In the present review, after giving an overview of ENMs, we discuss the current advances on the physiochemical properties of AgNPs with specific emphasis on biodistribution and both in vitro and in vivo toxicity following various routes of exposure. Most in vitro studies have demonstrated the size-, dose- and coating-dependent cellular uptake of AgNPs. Following NPs exposure, in vivo biodistribution studies have reported Ag accumulation and toxicity to local as well as distant organs. Though there has been an increase in the number of studies in this area, more investigations are required to understand the mechanisms of toxicity following various modes of exposure to AgNPs.

In Vivo Metabolic Response upon Exposure to Gold Nanorod Core/Silver Shell Nanostructures: Modulation of Inflammation and Upregulation of Dopamine

With the increasing applications of silver nanoparticles (Ag NPs), the concerns of widespread human exposure as well as subsequent health risks have been continuously growing. The acute and chronic toxicities of Ag NPs in cellular tests and animal tests have been widely investigated. Accumulating evidence shows that Ag NPs can induce inflammation, yet the overall mechanism is incomplete. Herein, using gold nanorod core/silver shell nanostructures (Au@Ag NRs) as a model system, we studied the influence on mice liver and lungs from the viewpoint of metabolism. In agreement with previous studies, Au@Ag NRs' intravenous exposure caused inflammatory reaction, accompanying with metabolic alterations, including energy metabolism, membrane/choline metabolism, redox metabolism, and purine metabolism, the disturbances of which contribute to inflammation. At the same time, dopamine metabolism in liver was also changed. This is the first time to observe the production of dopamine in non-neural tissue after treatment with Ag NPs. As the upregulation of dopamine resists inflammation, it indicates the activation of antioxidant defense systems against oxidative stress induced by Au@Ag NRs. In the end, our findings deepened the understanding of molecular mechanisms of Ag NPs-induced inflammation and provide assistance in the rational design of their biomedical applications.

Activatable superparamagnetic iron oxide nanoparticles scavenge reactive oxygen species in macrophages and endothelial cells

Complexed IPC-SPIOs scavenge intracellular ROS after internalization.

Nanoparticles' interactions with vasculature in diseases

The ever-growing use of inorganic nanoparticles (NPs) in biomedicine provides an exciting approach to develop novel imaging and drug delivery systems, owing to the ease with which these NPs can be functionalized to cater to various applications. In cancer therapeutics, nanomedicine generally relies on the enhanced permeability and retention (EPR) effect observed in tumour vasculature to deliver anti-cancer drugs across the endothelium. However, such a phenomenon is dependent on the tumour microenvironment and is not consistently observed in all tumour types, thereby limiting drug transport to the tumour site. On the other hand, there is a rise in utilizing inorganic NPs to intentionally induce endothelial leakiness, creating a window of opportunity to control drug delivery across the endothelium. While this active targeting approach creates a similar phenomenon compared to the EPR effect arising from tumour tissues, its drug delivery applications extend beyond cancer therapeutics and into other vascular-related diseases. In this review, we summarize the current findings of the EPR effect and assess its limitations in the context of anti-cancer drug delivery systems. While the EPR effect offers a possible route for drug passage, we further explore alternative uses of NPs to create controllable endothelial leakiness within short exposures, a phenomenon we coined as nanomaterial-induced endothelial leakiness (NanoEL). Furthermore, we discuss the main mechanistic features of the NanoEL effect that make it unique from conventionally established endothelial leakiness in homeostatic and pathologic conditions, as well as examine its potential applicability in vascular-related diseases, particularly cancer. Therefore, this new paradigm changes the way inorganic NPs are currently being used for biomedical applications.

Biogenic Aspergillus tubingensis silver nanoparticles' in vitro effects on human umbilical vein endothelial cells, normal human fibroblasts, HEPG2, and Galleria mellonella

Silver nanoparticles (AgNPs) are widely incorporated into different hygiene, personal care, and healthcare products. However, few studies have been undertaken to determine the effects of biogenic AgNPs on human health. The effect of biosynthesized AgNPs using the fungus Aspergillus tubingensis culture was evaluated on human umbilical vein endothelial cells (HUVECs), normal human fibroblasts (FN1), human hepatoma cells (HEPG2) and a Galleria mellonella model. HUVECs were more susceptible to biogenic AgNPs than normal fibroblasts FN1 and intense cytotoxicity was observed only for very high concentrations at and above 2.5 μM for both cells. Normal human fibroblasts FN1 exposed to AgNPs for 24 h showed viability of 98.83 ± 8.40% and 94.86 ± 5.50% for 1.25 and 2.5 μM, respectively. At 5 and 10 μM, related to the control, an increase in cell viability was observed being 112.66 ± 9.94% and 117.86 ± 8.86%, respectively. Similar results were obtained for treatment for 48 and 72 h. At 1.25, 2.5, 5 and 10 μM of AgNPs, at 24 h, HUVECs showed 51.34 ± 7.47%, 27.01 ± 5.77%, 26.00 ± 3.03% and 27.64 ± 5.85% of viability, respectively. No alteration in cell distribution among different cycle phases was observed after HUVEC and normal fibroblast FN1 exposure to AgNPs from 0.01 to 1 μM for 24, 48 and 72 h. Based on the clonogenic assay, nanoparticles successfully inhibited HEPG2 cell proliferation when exposed to concentrations up to 1 μM. In addition to that, AgNPs did not induce senescence and no morphological alteration was observed by scanning electron microscopy on the endothelial cells. In the larvae of the wax moth, Galleria mellonella, a model for toxicity, AgNPs showed no significant effects, which corroborates to the safety of their use in mammalian cells. These results demonstrate that the use of A. tubingensis AgNPs is a promising biotechnological approach and these AgNPs can be applied in several biomedical situations.

Quantifying the effects of engineered nanomaterials on endothelial cell architecture and vascular barrier integrity using a cell pair model

Engineered nanomaterials (ENMs) are increasingly used in consumer products due to their unique physicochemical properties, but the specific hazards they pose to the structural and functional integrity of endothelial barriers remain elusive. When assessing the effects of ENMs on vascular barrier function, endothelial cell monolayers are commonly used as in vitro models. Monolayer models, however, do not offer a granular understanding of how the structure-function relationships between endothelial cells and tissues are disrupted due to ENM exposure. To address this issue, we developed a micropatterned endothelial cell pair model to quantitatively evaluate the effects of 10 ENMs (8 metal/metal oxides and 2 organic ENMs) on multiple cellular parameters and determine how these parameters correlate to changes in vascular barrier function. This minimalistic approach showed concerted changes in endothelial cell morphology, intercellular junction formation, and cytoskeletal organization due to ENM exposure, which were then quantified and compared to unexposed pairs using a "similarity scoring" method. Using the cell pair model, this study revealed dose-dependent changes in actin organization and adherens junction formation following exposure to representative ENMs (Ag, TiO2 and cellulose nanocrystals), which exhibited trends that correlate with changes in tissue permeability measured using an endothelial monolayer assay. Together, these results demonstrate that we can quantitatively evaluate changes in endothelial architecture emergent from nucleo-cytoskeletal network remodeling using micropatterned cell pairs. The endothelial pair model therefore presents potential applicability as a standardized assay for systematically screening ENMs and other test agents for their cellular-level structural effects on vascular barriers.

Molecular and Morphological Evidence of Hepatotoxicity after Silver Nanoparticle Exposure: A Systematic Review, In Silico, and Ultrastructure Investigation

Silver nanoparticles (AgNPs) have been widely used in a variety of applications in innovative development; consequently, people are more exposed to this particle. Growing concern about toxicity from AgNP exposure has attracted greater attention, while questions about nanosilver-responsive genes and consequences for human health remain unanswered. By considering early detection and prevention of nanotoxicology at the genetic level, this study aimed to identify 1) changes in gene expression levels that could be potential indicators for AgNP toxicity and 2) morphological phenotypes correlating to toxicity of HepG2 cells. To detect possible nanosilver-responsive genes in xenogenic targeted organs, a comprehensive systematic literature review of changes in gene expression in HepG2 cells after AgNP exposure and in silico method, connection up- and down-regulation expression analysis of microarrays (CU-DREAM), were performed. In addition, cells were extracted and processed for transmission electron microscopy to examine ultrastructural alterations. From the Gene Expression Omnibus (GEO) Series database, we selected genes that were up- and down-regulated in AgNPs, but not up- and down-regulated in silver ion exposed cells, as nanosilver-responsive genes. HepG2 cells in the AgNP-treated group showed distinct ultrastructural alterations. Our results suggested potential representative gene data after AgNPs exposure provide insight into assessment and prediction of toxicity from nanosilver exposure.