Toxicity of Nanoparticles and an Overview of Current Experimental Models

(Bio)nanotechnology in Food Science-Food Packaging

Background: Bionanotechnology, as a tool for incorporation of biological molecules into nanoartifacts, is gaining more and more importance in the field of food packaging. It offers an advanced expectation of food packaging that can ensure longer shelf life of products and safer packaging with improved food quality and traceability. Scope and approach: This review recent focuses on advances in food nanopackaging, including bio-based, improved, active, and smart packaging. Special emphasis is placed on bio-based packaging, including biodegradable packaging and biocompatible packaging, which presents an alternative to most commonly used non-degradable polymer materials. Safety and environmental concerns of (bio)nanotechnology implementation in food packaging were also discussed including new EU directives. Conclusions: The use of nanoparticles and nanocomposites in food packaging increases the mechanical strength and properties of the water and oxygen barrier of packaging and may provide other benefits such as antimicrobial activity and light-blocking properties. Concerns about the migration of nanoparticles from packaging to food have been expressed, but migration tests and risk assessment are unclear. Presumed toxicity, lack of additional data from clinical trials and risk assessment studies limit the use of nanomaterials in the food packaging sector. Therefore, an assessment of benefits and risks must be defined.

New Textile for Personal Protective Equipment—Plasma Chitosan/Silver Nanoparticles Nylon Fabric

Fabric structures are prone to contamination with microorganisms, as their morphology and ability to retain moisture creates a proper environment for their growth. In this work, a novel, easily processed and cheap coating for a nylon fabric with antimicrobial characteristics was developed. After plasma treatment, made to render the fabric surface more reactive sites, the fabric was impregnated with chitosan and silver nanoparticles by simply dipping it into a mixture of different concentrations of both components. Silver nanoparticles were previously synthesized using the Lee–Meisel method, and their successful obtention was proven by UV–Vis, showing the presence of the surface plasmon resonance band at 410 nm. Nanoparticles with 25 nm average diameter observed by STEM were stable, mainly in the presence of chitosan, which acted as a surfactant for silver nanoparticles, avoiding their aggregation. The impregnated fabric possessed bactericidal activity higher for Gram-positive Staphylococcus aureus than for Gram-negative Pseudomonas aeruginosa bacteria for all combinations. The percentage of live S. aureus and P. aeruginosa CFU was reduced to less than 20% and 60%, respectively, when exposed to each of the coating combinations. The effect was more pronounced when both chitosan and silver were present in the coating, suggesting an effective synergy between these components. After a washing process, the antimicrobial effect was highly reduced, suggesting that the coating is unstable after washing, being almost completely removed from the fabric. Nevertheless, the new-coated fabric can be successfully used in single-use face masks. To our knowledge, the coating of nylon fabrics intended for face-mask material with both agents has never been reported.

Recent advances in materials science: a reinforced approach toward challenges against COVID-19

With the recent COVID-19 pandemic, medical professionals and scientists have encountered an unprecedented trouble to make the latest technological solutions to work. Despite of abundant tools available as well as initiated for diagnosis and treatment, researchers in the healthcare systems were in backfoot to provide concrete answers to the demanding challenge of SARS-CoV-2. It has incited global collaborative efforts in every field from economic, social, and political to dedicated science to confront the growing demand toward solution to this outbreak. Field of materials science has been in the frontline to the current scenario to provide major diagnostic tools, antiviral materials, safety materials, and various therapeutic means such as, antiviral drug design, drug delivery, and vaccination. In the present article, we emphasized the role of materials science to the development of PPE kits such as protecting suits, gloves, and masks as well as disinfection of the surfaces/surroundings. In addition, contribution of materials science towards manufacturing diagnostic devices such as microfluidics, immunosensors as well as biomaterials with a point of care analysis has also been discussed. Further, the efficacy of nanoparticles and scaffolds for antiviral drug delivery and micro-physiological systems as well as materials derived from human tissues for extracorporeal membrane oxygenation (ECMO) devices have been elaborated towards therapeutic applications.

Toxicological Consequences of Titanium Dioxide Nanoparticles (TiO2NPs) and Their Jeopardy to Human Population

Titanium dioxide nanoparticles (TiO₂ NPs) are the most produced nanomaterial for food additives, pigments, photocatalysis, and personal care products. These nanomaterials are at the forefront of rapidly developing indispensable nanotechnology. In all these nanomaterials, titanium dioxide (TiO₂) is the most common nanomaterial which is being synthesized for many years. These nanoparticles of TiO₂ are widely used at the commercial level, especially in cosmetic industries. High usage in such a way has increased the toxicological consequences of the human population. Several studies have shown that TiO₂ NPs accumulated after oral exposure or inhalation in the alimentary canal, lungs, heart, liver, spleen, cardiac muscle, and kidneys. Additionally, in mice and rats, they disturb glucose and lipid homeostasis. Moreover, TiO₂ nanoparticles primarily cause adverse reactions by inducing oxidative stress that leads to cell damage, inflammation, genotoxicity, and adverse immune responses. The form and level of destruction are strongly based on the physical and chemical properties of TiO₂ nanoparticles, which administer their reactivity and bioavailability. Studies give indications that TiO₂ NPs cause both DNA strand breaks and chromosomal damages. The effects of genotoxicity do not depend only on particle surface changes, size, and exposure route, but also relies on the duration of exposure. Most of these effects may be because of a very high dose of TiO₂ NPs. Despite increased production and use, epidemiological data for TiO₂ NPs is still missing. This review discusses previous research regarding the impact of TiO₂ NP toxicity on human health and highlights areas that require further understanding in concern of jeopardy to the human population. This review is important to point out areas where extensive research is needed; thus, their possible impact on individual health should be investigated in more details.

Enhancing Combined Immunotherapy and Radiotherapy through Nanomedicine

Radiotherapy and immunotherapy are two key treatments for cancer. There is growing evidence that they are also synergistic, and combination treatments are being studied extensively in the clinical setting. In addition, there is emerging evidence that nanotechnology-enabled therapeutics can potentiate both radiotherapy and immunotherapy, in turn improving both treatments. This is an exciting new area of interdisciplinary science and has significant potential for major clinical impact. Some of the approaches in this area have already reached the clinical stage. In this review, we will discuss recent advances in the interface between radiotherapy, immunotherapy, and nanomedicine. We plan to review the many approaches to combine these three fields for cancer treatment.

Mechanisms for Tuning Engineered Nanomaterials to Enhance Radiation Therapy of Cancer

Engineered nanomaterials that produce reactive oxygen species on exposure to X- and gamma-rays used in radiation therapy offer promise of novel cancer treatment strategies. Similar to photodynamic therapy but suitable for large and deep tumors, this new approach where nanomaterials acting as sensitizing agents are combined with clinical radiation can be effective at well-tolerated low radiation doses. Suitably engineered nanomaterials can enhance cancer radiotherapy by increasing the tumor selectivity and decreasing side effects. Additionally, the nanomaterial platform offers therapeutically valuable functionalities, including molecular targeting, drug/gene delivery, and adaptive responses to trigger drug release. The potential of such nanomaterials to be combined with radiotherapy is widely recognized. In order for further breakthroughs to be made, and to facilitate clinical translation, the applicable principles and fundamentals should be articulated. This review focuses on mechanisms underpinning rational nanomaterial design to enhance radiation therapy, the understanding of which will enable novel ways to optimize its therapeutic efficacy. A roadmap for designing nanomaterials with optimized anticancer performance is also shown and the potential clinical significance and future translation are discussed.

Primary Amine Modified Gold Nanodots Regulate Macrophage Function and Antioxidant Response: Potential Therapeutics Targeting of Nrf2

BACKGROUND

Gold nanoparticles with high biocompatibility and immunomodulatory properties have potential applications in the development of new diagnostic and therapeutic strategies for nanomedicine. Nanoparticles targeting macrophages can manipulate or control immunological diseases. This study assessed the activity of dendrimer-encapsulated gold nanodots (AuNDs) with three surface modifications [ie, outfacing groups with primary amine (AuNDs-NH2), hydroxyl (AuNDs-OH), and quaternary ammonium ions (AuNDs-CH3)] regulated macrophage function and antioxidant response through Nrf2-dependent pathway.

METHODS

AuNDs were prepared and characterized. Intracellular distribution of AuNDs in human macrophages was observed through confocal microscopy. The activity of AuNDs was evaluated using macrophage functions and antioxidant response in the human macrophage cell line THP-1.

RESULTS

AuNDs-NH2 and AuNDs-CH3, but not AuNDs-OH, drove the obvious Nrf2-antioxidant response element pathway in THP-1 cells. Of the three, AuNDs-NH2 considerably increased mRNA levels and antioxidant activities of heme oxygenase 1 and NAD(P)H quinone dehydrogenase 1 in THP-1 cells. IL-6 mRNA and protein expression was mediated through Nrf2 activation in AuNDs-NH2-treated macrophages. Furthermore, Nrf2 activation by AuNDs-NH2 increased the phagocytic ability of THP-1 macrophages.

CONCLUSION

AuNDs-NH2 had immunomodulatory activities in macrophages. The findings of the present work suggested that AuNDs have potential effects against chronic inflammatory diseases via the Nrf2 pathway.

Induced Liver Regeneration Enhances CRISPR/Cas9-Mediated Gene Repair in Tyrosinemia Type 1

The efficiency of gene repair by homologous recombination in the liver is enhanced by CRISP/Cas9 incision near the mutation. In this study, we explored interventions designed to further enhance in vivo hepatocyte gene repair in a model of hereditary tyrosinemia. A two-AAV system was employed: one virus carried a Staphylococcus pyogenes Cas9 (SpCas9) expression cassette and the other harbored a U6 promoter-driven sgRNA and a fragment of fumarylacetoacetate hydrolase (Fah) genomic DNA as the homologous recombination donor. In neonatal mice, a gene correction frequency of ∼10.8% of hepatocytes was achieved. The efficiency in adult mice was significantly lower at ∼1.6%. To determine whether hepatocyte replication could enhance the targeting frequency, cell division was induced with thyroid hormone T3. This more than doubled the gene correction efficiency to 3.5% (p < 0.005). To determine whether SpCas9 delivery was rate limiting, the gene repair AAV was administered to SpCas9 transgenic mice. However, this did not significantly enhance gene repair. Finally, we tested whether the Fanconi anemia (FA) DNA repair pathway was important in hepatocyte gene repair. Gene correction frequencies were significantly lower in neonatal mice lacking the FA complementation group A (Fanca) gene. Taken together, we conclude that pharmacological induction of hepatocyte replication along with manipulation of DNA repair pathways could be a useful strategy for enhancing in vivo gene correction.

The in vitro toxicity evaluation of halloysite nanotubes (HNTs) in human lung cells

Halloysite nanotubes (HNTs) have been increasingly used in many industrial and biomedical fields. Therefore, the assessment of risk and consequences of exposure to HNTs is very important to better protect human safety. This study aims to investigate the short- (24 or 72 h) and long-term (7 days) cytotoxic effects of HNTs at doses 10-200 µg/mL on human alveolar carcinoma epithelial cells (A549) and human bronchial epithelial cells (BEAS-2B). The effect of HNTs on cell viability, apoptosis, cell proliferation, oxidative/antioxidative status and cell morphology was evaluated. Our results showed that cytotoxicity of HNTs is dependent on dose, cell model and time of exposure. During the time of exposition toxic effects were intensified. To the best of our knowledge, this is the first study to use holo-tomographic microscopy (HTM) to visualise changes in cell morphology due to exposure from HNTs. We observed cells contraction, changes in the size and shape, cell surface folding and cytoplasmic vacuolization, peripheral arrangement of cell nuclei and even increase number of nucleus, which undoubtedly confirmed cytotoxic effect of HNTs at low doses (5 µg/mL and 25 µg/mL). Our results demonstrated that HTM technique provides a new insight into the assessment of HNTs toxicity. Further studies with different cell models are recommended to assess the toxic effect of HNTs on whole human body.

Gene Editing by Extracellular Vesicles

CRISPR/Cas technologies have advanced dramatically in recent years. Many different systems with new properties have been characterized and a plethora of hybrid CRISPR/Cas systems able to modify the epigenome, regulate transcription, and correct mutations in DNA and RNA have been devised. However, practical application of CRISPR/Cas systems is severely limited by the lack of effective delivery tools. In this review, recent advances in developing vehicles for the delivery of CRISPR/Cas in the form of ribonucleoprotein complexes are outlined. Most importantly, we emphasize the use of extracellular vesicles (EVs) for CRISPR/Cas delivery and describe their unique properties: biocompatibility, safety, capacity for rational design, and ability to cross biological barriers. Available molecular tools that enable loading of desired protein and/or RNA cargo into the vesicles in a controllable manner and shape the surface of EVs for targeted delivery into specific tissues (e.g., using targeting ligands, peptides, or nanobodies) are discussed. Opportunities for both endogenous (intracellular production of CRISPR/Cas) and exogenous (post-production) loading of EVs are presented.

Caveolae-Mediated Transport at the Injured Blood-Brain Barrier as an Underexplored Pathway for Central Nervous System Drug Delivery

Drug delivery to the central nervous system (CNS) is generally hindered by the selectivity of the blood-brain barrier (BBB). However, there is strong evidence that the integrity of the BBB is compromised under certain pathological conditions, potentially providing a window to deliver drugs to injured brain regions. Recent studies suggest that caveolae-mediated transcytosis, a transport pathway suppressed in the healthy BBB, becomes elevated as an immediate response to ischemic stroke and at early stages of aging, where it may precede irreversible neurological damage. This article reviews early-stage caveolar transcytosis as a novel and promising drug delivery opportunity. We propose that albumin-binding and nanoparticle approaches have the potential to leverage this window of transcellular BBB disruption for trafficking therapeutic agents into the CNS.

Supermagnetic Sugarcane Bagasse Hydrochar for Enhanced Osteoconduction in Human Adipose Tissue-Derived Mesenchymal Stem Cells

Hydrothermally carbonized sugarcane bagasse (SCB) has exceptional surface properties. Looking at the huge amount of SCB produced, its biocompatible nature, cheap-cost for carbonization, and its easy functionalization can give impeccable nano-biomaterials for tissue engineering applications. Herein, sugarcane bagasse was converted into hydrochar (SCB-H) by hydrothermal carbonation. The SCB-H produced was further modified with iron oxide (Fe₃O₄) nanoparticles (denoted as SCB-H@Fe₃O₄). Facile synthesized nano-bio-composites were characterized by SEM, HR-TEM, XRD, FT-IR, XPS, TGA, and VSM analysis. Bare Fe₃O₄ nanoparticles (NPs), SCB-H, and SCB-H@Fe₃O₄ were tested for cytocompatibility and osteoconduction enhancement of human adipose tissue-derived mesenchymal stem cells (hADMSCs). The results confirmed the cytocompatible and nontoxic nature of SCB-H@Fe₃O₄. SCB-H did not show enhancement in osteoconduction, whilst on the other hand, Fe₃O₄ NPs exhibited a 0.5-fold increase in the osteoconduction of hADMSCs. However, SCB-H@Fe₃O₄ demonstrated an excellent enhancement in osteoconduction of a 3-fold increase over the control, and a 2.5-fold increase over the bare Fe₃O₄ NPs. Correspondingly, the expression patterns assessment of osteoconduction marker genes (ALP, OCN, and RUNX2) confirmed the osteoconductive enhancement by SCB-H@Fe₃O₄. In the proposed mechanism, the surface of SCB-H@Fe₃O₄ might provide a unique topology, and anchoring to receptors of hADMSCs leads to accelerated osteogenesis. In conclusion, agriculture waste-derived sustainable materials like “SCB-H@Fe₃O₄₄” can be potentially applied in highly valued medicinal applications of stem cell differentiation.

Cytotoxic effects of manganese oxide nanoparticles in combination with microbial components on intestinal epithelial cells

Background: Manganese oxide has been shown to cause toxicity and is associated with occupational-related disease (e.g., welders). With the goal to improve several biomedical areas, manganese oxide nanoparticles (MnO NP) are being considered for use in drug delivery and magnetic resonance imaging (MRI) to obtain high resolution anatomical images of tumors and gastrointestinal (GI) inflammation. Regardless of whether it is intentional or unintentional ingestion, the GI tract has been shown to be the primary route of entry for metal nanoparticles including MnO NP. However, studies assessing toxicity of MnO NP for intestinal epithelial cells (IECs) are virtually nonexistent. Methods: Given the proximity to the GI lumen, assessing the effects of nanoparticles on IECs in the presence of bacterial components presents a more holistic model of exposure. Therefore, we examined the effects of MnO NP alone and MnO NP in combination with Escherichia coli LF82 bacterial lysate on selected functions of MODE-K cells, a murine intestinal epithelial cell line. Data were analyzed using one-way ANOVA. Differences with p < 0.05 were considered significant. Results: Results showed MnO NP plus E. coli LF82 lysate added to MODE-K cells severely inhibited monolayer scratch wound healing, enhanced the secretion of interleukin 6 (IL-6), and induced mitochondrial dysfunction. Conclusions: Overall, our findings show that toxicity of MnO NP deleteriously affected MODE-K cells and demonstrated the necessity to integrate other environmental factors, such as microbial components and/or inflammatory cytokines, into studies assessing effects of nanoparticles on mucosal epithelia.

One-year chronic toxicity evaluation of single dose intravenously administered silica nanoparticles in mice and their Ex vivo human hemocompatibility

Chronic toxicity evaluations of nanotechnology-based drugs are essential to support initiation of clinical trials. Ideally such evaluations should address the dosing strategy in human applications and provide sufficient information for long-term usage. Herein, we investigated one-year toxicity of non-surface modified silica nanoparticles (SNPs) with variations in size and porosity (Stöber SNPs 46 ± 4.9 and 432.0 ± 18.7 nm and mesoporous SNPs 466.0 ± 86.0 nm) upon single dose intravenous administration to female and male BALB/c mice (10 animal/sex/group) along with their human blood compatibility. Our evidence of clinical observation and blood parameters showed no significant changes in body weight, cell blood count, nor plasma biomarker indices. No significant changes were noted in post necropsy examination of internal organs and organ-to-body weight ratio. However, microscopic examination revealed significant amount of liver inflammation and aggregates of histocytes with neutrophils within the spleen suggesting an ongoing or resolving injury. The fast accumulation of these plain SNPs in the liver and spleen upon IV administration and the duration needed for their clearance caused these injuries. There were also subtle changes which were attributed to prior infarctions or resolved intravascular thrombosis and included calcifications in pulmonary vessels, focal cardiac fibrosis with calcifications, and focal renal injury. Most of the pathologic lesions were observed when large, non-porous SNPs were administered. Statistically significant chronic toxicity was not observed for the small non-porous particles and for the mesoporous particles. This one-year post-exposure evaluation indicate that female and male BALB/c mice need up to one year to recover from acute tissue toxic effects of silica nanoparticles upon single dose intravenous administration at their 10-day maximum tolerated dose. Further, ex vivo testing with human blood and plasma revealed no hemolysis or complement activation following incubation with these silica nanoparticles. These results can inform the potential utility of silica nanoparticles in biomedical applications such as controlled drug delivery where intravenous injection of the particles is intended.

Opportunities for biomaterials to address the challenges of COVID-19

The coronavirus disease 2019 (COVID‐19) pandemic has revealed major shortcomings in our ability to mitigate transmission of infectious viral disease and provide treatment to patients, resulting in a public health crisis. Within months of the first reported case in China, the virus has spread worldwide at an unprecedented rate. COVID‐19 illustrates that the biomaterials community was engaged in significant research efforts against bacteria and fungi with relatively little effort devoted to viruses. Accordingly, biomaterials scientists and engineers will have to participate in multidisciplinary antiviral research over the coming years. Although tissue engineering and regenerative medicine have historically dominated the field of biomaterials, current research holds promise for providing transformative solutions to viral outbreaks. To facilitate collaboration, it is imperative to establish a mutual language and adequate understanding between clinicians, industry partners, and research scientists. In this article, clinical perspectives are shared to clearly define emerging healthcare needs that can be met by biomaterials solutions. Strategies and opportunities for novel biomaterials intervention spanning diagnostics, treatment strategies, vaccines, and virus‐deactivating surface coatings are discussed. Ultimately this review serves as a call for the biomaterials community to become a leading contributor to the prevention and management of the current and future viral outbreaks.

Dextran-coated iron oxide nanoparticle-induced nanotoxicity in neuron cultures

Recent technological advances have introduced diverse engineered nanoparticles (ENPs) into our air, water, medicine, cosmetics, clothing, and food. However, the health and environmental effects of these increasingly common ENPs are still not well understood. In particular, potential neurological effects are one of the most poorly understood areas of nanoparticle toxicology (nanotoxicology), in that low-to-moderate neurotoxicity can be subtle and difficult to measure. Culturing primary neuron explants on planar microelectrode arrays (MEAs) has emerged as one of the most promising in vitro techniques with which to study neuro-nanotoxicology, as MEAs enable the fluorescent tracking of nanoparticles together with neuronal electrical activity recording at the submillisecond time scale, enabling the resolution of individual action potentials. Here we examine the dose-dependent neurotoxicity of dextran-coated iron oxide nanoparticles (dIONPs), a common type of functionalized ENP used in biomedical applications, on cultured primary neurons harvested from postnatal day 0-1 mouse brains. A range of dIONP concentrations (5-40 µg/ml) were added to neuron cultures, and cells were plated either onto well plates for live cell, fluorescent reactive oxidative species (ROS) and viability observations, or onto planar microelectrode arrays (MEAs) for electrophysiological measurements. Below 10 µg/ml, there were no dose-dependent cellular ROS increases or effects in MEA bursting behavior at sub-lethal dosages. However, above 20 µg/ml, cell death was obvious and widespread. Our findings demonstrate a significant dIONP toxicity in cultured neurons at concentrations previously reported to be safe for stem cells and other non-neuronal cell types.

Role of Beetroot (Beta vulgaris) Juice on Chronic Nanotoxicity of Silver Nanoparticle-Induced Hepatotoxicity in Male Rats

Introduction

Nanoparticles are at the forefront of rapidly developing nanotechnology and have gained much attention for their application as an effective drug delivery system and as a mediated therapeutic agent for cancer. However, the cytotoxicity of nanoparticles is still relatively unknown and, therefore, additional study is required in order to elucidate the potential toxicity of these nanoparticles on cells.

Materials and Methods

Thus, the following work aimed to investigate the capability of Beta vulgaris (beetroot) water extract (BWE; 200 mg/kg) to protect hepatic tissue following silver nanoparticles (AgNPs; 80 mg/kg; >100 nm) intoxication in male rats.

Results

AgNPs-intoxication elevated the liver function markers – including serum transaminases and alkaline phosphatase activities – and decreased serum levels of albumin and total proteins, in addition to disturbing the oxidation homeostasis. This is evidenced by the increased lipid peroxidation, the depleted glutathione, and the suppressed activity of superoxide dismutase and catalase. In addition, an apoptotic reaction was observed following AgNPs treatment, as indicated by the up-regulation of p53 and down-regulating Bcl-2 expressions, examined by the immunohistochemistry method. Furthermore, AgNPs exhibited a marked elevation in liver DNA damage that was indicated by an increase in tail length, tail DNA% and tail movement. However, BWE eliminated the biochemical and histological alterations, reflecting its hepatoprotection effect in response to AgNPs.

Discussion

Collectively, the present data suggest that BWE could be used following AgNPs as a potential therapeutic intervention to minimize AgNPs-induced liver toxicity.

A Novel Biocompatible Titanium-Gadolinium Quantum Dot as a Bacterial Detecting Agent with High Antibacterial Activity

In this study, the titanium–gadolinium quantum dots (TGQDs) were novel, first of its type to be synthesized, and fully characterized to date. Multiple physical characterization includes scanning electron microscopy (SEM), scanning electrochemical microscope (SCEM), x-ray fluorescence, spectrophotometry, and dynamic light scattering were carried out. The obtained results confirmed appropriate size and shape distributions in addition to processing optical features with high quantum yield. The synthesized TGQD was used as a fluorescent dye for bacterial detection and imaging by fluorescent microscopy and spectrophotometry, where TGQD stained only bacterial cells, but not human cells. The significant antibacterial activities of the TGQDs were found against a highly pathogenic bacterium (Staphylococcus aureus) and its antibiotic resistant strains (vancomycin and methicillin resistant Staphylococcus aureus) using growth curve analysis and determination of minimum inhibitory concentration (MIC) analysis. Live/dead cell imaging assay using phase-contrast microscope was performed for further confirmation of the antibacterial activity. Cell wall disruption and release of cell content was observed to be the prime mode of action with the reduction of cellular oxygen demand (OD).

Human brain microvascular endothelial cell pairs model tissue-level blood-brain barrier function

The blood-brain barrier plays a critical role in delivering oxygen and nutrients to the brain while preventing the transport of neurotoxins. Predicting the ability of potential therapeutics and neurotoxicants to modulate brain barrier function remains a challenge due to limited spatial resolution and geometric constraints offered by existing in vitro models. Using soft lithography to control the shape of microvascular tissues, we predicted blood-brain barrier permeability states based on structural changes in human brain endothelial cells. We quantified morphological differences in nuclear, junction, and cytoskeletal proteins that influence, or indicate, barrier permeability. We established a correlation between brain endothelial cell pair structure and permeability by treating cell pairs and tissues with known cytoskeleton-modulating agents, including a Rho activator, a Rho inhibitor, and a cyclic adenosine monophosphate analog. Using this approach, we found that high-permeability cell pairs showed nuclear elongation, loss of junction proteins, and increased actin stress fiber formation, which were indicative of increased contractility. We measured traction forces generated by high- and low-permeability pairs, finding that higher stress at the intercellular junction contributes to barrier leakiness. We further tested the applicability of this platform to predict modulations in brain endothelial permeability by exposing cell pairs to engineered nanomaterials, including gold, silver-silica, and cerium oxide nanoparticles, thereby uncovering new insights into the mechanism of nanoparticle-mediated barrier disruption. Overall, we confirm the utility of this platform to assess the multiscale impact of pharmacological agents or environmental toxicants on blood-brain barrier integrity.

Iron-Doping of Copper Oxide Nanoparticles Lowers Their Toxic Potential on C6 Glioma Cells

Copper oxide nanoparticles (CuO-NPs) are well known for their cytotoxicity which in part has been attributed to the release of copper ions from CuO-NPs. As iron-doping has been reported to reduce the susceptibility of CuO-NPs to dissolution, we have compared pure CuO-NPs and CuO-NPs that had been doped with 10% iron (CuO-Fe-NPs) for copper release and for their toxic potential on C6 glioma cells. Physicochemical characterization revealed that dimercaptosuccinate (DMSA)-coated CuO-NPs and CuO-Fe-NPs did not differ in their size or zeta potential. However, the redox activity and liberation of copper ions from CuO-Fe-NPs was substantially slower compared to that from CuO-NPs, as demonstrated by cyclic voltammetry and by the photometric quantification of the copper ion-bathocuproine complex, respectively. Exposure of C6 cells to these NPs caused an almost identical cellular copper accumulation and each of the two types of NPs induced ROS production and cell toxicity. However, the time- and concentration-dependent loss in cell viability was more severe for cells that had been treated with CuO-NPs compared to cells exposed to CuO-Fe-NPs. Copper accumulation and toxicity after exposure to either CuO-NPs or CuO-Fe-NPs was prevented in the presence of copper chelators, while neutralization of the lysosomal pH by bafilomycin A1 prevented toxicity without affecting cellular copper accumulation or ROS production. These data demonstrate that iron-doping does not affect cellular accumulation of CuO-NPs and suggests that the intracellular liberation of copper ions from CuO-NPs is slowed by the iron doping, which in turn lowers the cell toxic potential of iron-doped CuO-NPs.

The Current Understanding of Autophagy in Nanomaterial Toxicity and Its Implementation in Safety Assessment-Related Alternative Testing Strategies

Nanotechnology has rapidly promoted the development of a new generation of industrial and commercial products; however, it has also raised some concerns about human health and safety. To evaluate the toxicity of the great diversity of nanomaterials (NMs) in the traditional manner, a tremendous number of safety assessments and a very large number of animals would be required. For this reason, it is necessary to consider the use of alternative testing strategies or methods that reduce, refine, or replace (3Rs) the use of animals for assessing the toxicity of NMs. Autophagy is considered an early indicator of NM interactions with cells and has been recently recognized as an important form of cell death in nanoparticle-induced toxicity. Impairment of autophagy is related to the accelerated pathogenesis of diseases. By using mechanism-based high-throughput screening in vitro, we can predict the NMs that may lead to the generation of disease outcomes in vivo. Thus, a tiered testing strategy is suggested that includes a set of standardized assays in relevant human cell lines followed by critical validation studies carried out in animals or whole organism models such as C. elegans (Caenorhabditis elegans), zebrafish (Danio rerio), and Drosophila (Drosophila melanogaster)for improved screening of NM safety. A thorough understanding of the mechanisms by which NMs perturb biological systems, including autophagy induction, is critical for a more comprehensive elucidation of nanotoxicity. A more profound understanding of toxicity mechanisms will also facilitate the development of prevention and intervention policies against adverse outcomes induced by NMs. The development of a tiered testing strategy for NM hazard assessment not only promotes a more widespread adoption of non-rodent or 3R principles but also makes nanotoxicology testing more ethical, relevant, and cost- and time-efficient.

Triple-Negative Breast Cancer: A Review of Conventional and Advanced Therapeutic Strategies

Triple-negative breast cancer (TNBC) cells are deficient in estrogen, progesterone and ERBB2 receptor expression, presenting a particularly challenging therapeutic target due to their highly invasive nature and relatively low response to therapeutics. There is an absence of specific treatment strategies for this tumor subgroup, and hence TNBC is managed with conventional therapeutics, often leading to systemic relapse. In terms of histology and transcription profile these cancers have similarities to BRCA-1-linked breast cancers, and it is hypothesized that BRCA1 pathway is non-functional in this type of breast cancer. In this review article, we discuss the different receptors expressed by TNBC as well as the diversity of different signaling pathways targeted by TNBC therapeutics, for example, Notch, Hedgehog, Wnt/b-Catenin as well as TGF-beta signaling pathways. Additionally, many epidermal growth factor receptor (EGFR), poly (ADP-ribose) polymerase (PARP) and mammalian target of rapamycin (mTOR) inhibitors effectively inhibit the TNBCs, but they face challenges of either resistance to drugs or relapse. The resistance of TNBC to conventional therapeutic agents has helped in the advancement of advanced TNBC therapeutic approaches including hyperthermia, photodynamic therapy, as well as nanomedicine-based targeted therapeutics of drugs, miRNA, siRNA, and aptamers, which will also be discussed. Artificial intelligence is another tool that is presented to enhance the diagnosis of TNBC.

Influences of Nanoparticles Characteristics on the Cellular Responses: The Example of Iron Oxide and Macrophages

Iron oxide nanoparticles/microparticles are widely present in a variety of environments, e.g., as a byproduct of steel and iron degradation, as, for example, in railway brakes (e.g., metro station) or in welding fumes. As all particulate material, these metallic nanoparticles are taken up by macrophages, a cell type playing a key role in the innate immune response, including pathogen removal phagocytosis, secretion of free radical species such as nitric oxide or by controlling inflammation via cytokine release. In this paper, we evaluated how macrophages functions were altered by two iron based particles of different size (100 nm and 20 nm). We showed that at high, but subtoxic concentrations (1 mg/mL, large nanoparticles induced stronger perturbations in macrophages functions such as phagocytic capacity (tested with fluorescent latex microspheres) and the ability to respond to bacterial endotoxin lipopolysaccharide stimulus (LPS) in secreting nitric oxide and pro-cytokines (e.g., Interleukin-6 (IL-6) and Tumor Necrosis Factor (TNF)). These stronger effects may correlate with an observed stronger uptake of iron for the larger nanoparticles.

Assessment of the Impact of the Addition of Nanoparticles on the Properties of Glass-Ionomer Cements

The aim of the study was to evaluate the effects of incorporation of Al2O3, ZrO2 and TiO2 nanoparticles into glass-ionomer cements (GICs). Two different GICs were used in the study. Four groups were prepared for each material: the control group (without nanoparticles) and three groups modified by the incorporation of nanoparticles at 2, 5 or 10 wt %, respectively. Cements were mixed and placed in moulds (4 mm × 6 mm); after setting, the samples were stored in saline (one day and one week). Compressive strengths were measured and the morphology of the fractured surfaces was analyzed by scanning electron microscopy. The elements released into the storage solutions were determined by Inductively coupled plasma-optical emission spectrometry (ICP-OES). Addition of nanoparticles was found to alter the appearance of cements as examined by scanning electron microscopy. Compressive strength increased with the addition of ZrO2 and especially TiO2 nanoparticles, whereas the addition of Al2O3 nanoparticles generally weakened the cements. The ion release profile of the modified cements was the same in all cases. The addition of Al2O3, ZrO2 and TiO2 nanoparticles into GICs is beneficial, since it leads to reduction of the microscopic voids in the set cement. Of these, the use of ZrO2 and TiO2 nanoparticles also led to increased compressive strength. Nanoparticles did not release detectable levels of ions (Al, Zr or Ti), which makes them suitable for clinical use.

Effects of Titanium Dioxide Nanoparticles Exposure on Human Health-a Review

Recently, an increased interest in nanotechnology applications can be observed in various fields (medicine, materials science, pharmacy, environmental protection, agriculture etc.). Due to an increasing scope of applications, the exposure of humans to nanoparticles (NPs) is inevitable. A number of studies revealed that after inhalation or oral exposure, NPs accumulate in, among other places, the lungs, alimentary tract, liver, heart, spleen, kidneys and cardiac muscle. In addition, they disturb glucose and lipid homeostasis in mice and rats. In a wide group of nanoparticles currently used on an industrial scale, titanium dioxide nanoparticles-TiO₂ NPs-are particularly popular. Due to their white colour, TiO₂ NPs are commonly used as a food additive (E 171). The possible risk to health after consuming food containing nanoparticles has been poorly explored but it is supposed that the toxicity of nanoparticles depends on their size, morphology, rate of migration and amount consumed. Scientific databases inform that TiO₂ NPs can induce inflammation due to oxidative stress. They can also have a genotoxic effect leading to, among others, apoptosis or chromosomal instability. This paper gives a review of previous studies concerning the effects of exposure to TiO₂ NPs on a living organism (human, animal). This information is necessary in order to demonstrate potential toxicity of inorganic nanoparticles on human health.

Mangiferin-Loaded Polymeric Nanoparticles: Optical Characterization, Effect of Anti-topoisomerase I, and Cytotoxicity

Mangiferin is an important xanthone compound presenting various biological activities. The objective of this study was to develop, characterize physicochemical properties, and evaluate the anti-topoisomerase activity of poly(lactic-co-glycolic acid) (PLGA) nanoparticles containing mangiferin. The nanoparticles were developed by the emulsion solvent evaporation method and the optimal formulation was obtained with a response surface methodology (RSM); this formulation showed a mean size of 176.7 ± 1.021 nm with a 0.153 polydispersibility index (PDI) value, and mangiferin encapsulation efficiency was about 55%. The optimal conditions (6000 rpm, 10 min, and 300 μg of mangiferin) obtained 77% and the highest entrapment efficiency (97%). The in vitro release profile demonstrated a gradual release of mangiferin from 15 to 180 min in acidic conditions (pH 1.5). The fingerprint showed a modification in the maximum absorption wavelength of both the polymer and the mangiferin. Results of anti-toposiomerase assay showed that the optimal formulation (MG4, 25 µg/mL) had antiproliferative activity. High concentrations (2500 µg/mL) of MG4 showed non-in vitro cytotoxic effect on BEAS 2B and HEPG2. Finally, this study showed an encapsulation process with in vitro gastric digestion resistance (1.5 h) and without interfering with the metabolism of healthy cells and their biological activity.

In vivo Studies on Pharmacokinetics, Toxicity and Immunogenicity of Polyelectrolyte Nanocapsules Functionalized with Two Different Polymers: Poly-L-Glutamic Acid or PEG

Background

The functionalization of a nanoparticle surface with PEG (polyethylene glycol) is an approach most often used for extending nanomaterial circulation time, enhancing its delivery and retention in the target tissues, and decreasing systemic toxicity of nanocarriers and their cargos. However, because PEGylated nanomedicines were reported to induce immune response including production of anti-PEG antibodies, activation of the complement system as well as hypersensitivity reactions, hydrophilic polymers other than PEG are gaining interest as its replacement in nanomaterial functionalization. Here, we present the results of in vivo evaluation of polyelectrolyte nanocapsules with biodegradable, polyelectrolyte multilayer shells consisting of poly-l-lysine (PLL) and poly-l-glutamic (PGA) acid as a potential drug delivery system. We compared the effects of nanocapsules functionalized with two different “stealth” polymers as the external layer of tested nanocapsules was composed of PGA (PGA-terminated nanocapsules, NC-PGA) or the copolymer of poly-l-lysine and polyethylene glycol (PEG-terminated nanocapsules, NC-PEG).

Methods

Nanocapsules pharmacokinetics, biodistribution and routes of eliminations were analysed postmortem by fluorescence intensity measurement. Toxicity of intravenously injected nanocapsules was evaluated with analyses of blood morphology and biochemistry and by histological tissue analysis. DNA integrity was determined by comet assay, cytokine profiling was performed using flow cytometer and detection of antibodies specific to PEG was performed by ELISA assay.

Results

We found that NC-PGA and NC-PEG had similar pharmacokinetic and biodistribution profiles and both were eliminated by hepatobiliary and renal clearance. Biochemical and histopathological evaluation of long-term toxicity performed after a single as well as repeated intravenous injections of nanomaterials demonstrated that neither NC-PGA nor NC-PEG had any acute or chronic hemato-, hepato- or nephrotoxic effects. In contrast to NC-PGA, repeated administration of NC-PEG resulted in prolonged increased serum levels of a number of cytokines.

Conclusion

Our results indicate that NC-PEG may cause undesirable activation of the immune system. Therefore, PGA compares favorably with PEG in equipping nanomaterials with stealth properties. Our research points to the importance of a thorough assessment of the potential influence of nanomaterials on the immune system.

Effect of Microwave Irradiation on Polyvinyl Alcohol as a Carrier of Silver Nanoparticles in Short Exposure Time

Microwave heating of Ag+ in polyvinyl alcohol (PVA) is an effective method to synthesize silver nanoparticles (AgNPs), a broad-range antibacterial agent. However, the microwave may cause PVA solution to dry out and degrade. This study is aimed at investigating the effect of microwave irradiation on different concentrations of PVA in PVA/Ag+ solution in short periods of exposure. Fourier-transform infrared (FTIR) spectroscopy was employed to evaluate chemical changes of samples with different exposure times and PVA concentration. The results confirm the redox reaction of Ag+ with PVA. In addition, Ag+ reduces the rate of hydrolysis of PVA, and the ether bridges are limited by the spatial structure.

Trends in Atopic Dermatitis-From Standard Pharmacotherapy to Novel Drug Delivery Systems

Atopic dermatitis (AD) is a predominant and deteriorating chronic inflammation of the skin, categorized by robust burning and eczematous lacerations in diverse portions of the body. AD affects about 20% of both offspring and adults worldwide. The pathophysiology of AD combines environmental, hereditary, and immunological aspects, together with skin barrier dysfunction. The procedures used to prevent the disease are the everyday usage of creams to support the restoration of the epidermal barrier. The classical treatments include the use of topical corticosteroids as a first-line therapy, but also calcineurin inhibitors, antihistamines, antibiotics, phototherapy, and also immunosuppressant drugs in severe cases of AD. Topical drug delivery to deeper skin layers is a difficult task due to the skin anatomic barrier, which limits deeper penetration of drugs. Groundbreaking drug delivery systems, based on nanoparticles (NPs), have received much attention due to their ability to improve solubility, bioavailability, diffusion, targeting to specific types of cells, and limiting the secondary effects of the drugs employed in the treatment of AD. Even so, additional studies are still required to recognize the toxicological characteristics and long-term safety of NPs. This review discusses the current classical pharmacotherapy of AD against new nanoparticle skin delivery systems and their toxicologic risks.

Synergistic Antibacterial Effects of Metallic Nanoparticle Combinations

Metallic nanoparticles have unique antimicrobial properties that make them suitable for use within medical and pharmaceutical devices to prevent the spread of infection in healthcare. The use of nanoparticles in healthcare is on the increase with silver being used in many devices. However, not all metallic nanoparticles can target and kill all disease-causing bacteria. To overcome this, a combination of several different metallic nanoparticles were used in this study to compare effects of multiple metallic nanoparticles when in combination than when used singly, as single elemental nanoparticles (SENPs), against two common hospital acquired pathogens (Staphylococcus aureus and Pseudomonas. aeruginosa). Flow cytometry LIVE/DEAD assay was used to determine rates of cell death within a bacterial population when exposed to the nanoparticles. Results were analysed using linear models to compare effectiveness of three different metallic nanoparticles, tungsten carbide (WC), silver (Ag) and copper (Cu), in combination and separately. Results show that when the nanoparticles are placed in combination (NPCs), antimicrobial effects significantly increase than when compared with SENPs (P < 0.01). This study demonstrates that certain metallic nanoparticles can be used in combination to improve the antimicrobial efficiency in destroying morphologically distinct pathogens within the healthcare and pharmaceutical industry.

Caveats to the use of MTT, neutral red, Hoechst and Resazurin to measure silver nanoparticle cytotoxicity

The extensive use of silver nanoparticles (AgNPs) in manufactured products will inevitably increase environmental exposure, highlighting the importance of accurate toxicity assessments. A frequent strategy to estimate AgNP cytotoxicity is to use absorbance or fluorescent-based assays. In this study we report that AgNPs - with or without surface functionalizations (polyvinyl pyrrolidone or gum arabic), and of different sizes (2-15 nm) - can interfere with the spectrometric quantification of different dyes commonly used in cytotoxicity assays, such as 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), neutral red (NR), Hoechst, and Resazurin. Some AgNP types caused more interference than others, which was dependent on the assay. Overall most AgNPs caused the direct reduction of MTT, as well as Hoechst and NR fluorescence quenching, and absorbed light at the same wavelength as NR. None of the AgNPs tested caused the direct reduction of Resazurin; however, depending on AgNP characteristics and concentration, they may still promote fluorescence quenching of this dye. Our results show that AgNPs with different size and coatings can interfere with spectroscopy-based assays to different degrees, suggesting that their cytotoxicity may be underestimated or overestimated. We suggest that when using any spectroscopy-based assay it is essential that each individual nanoparticle formulation be tested first for potential interferences at all intended concentrations.

Effects of Iron Oxide Nanoparticles (γ-Fe2O3) on Liver, Lung and Brain Proteomes following Sub-Acute Intranasal Exposure: A New Toxicological Assessment in Rat Model Using iTRAQ-Based Quantitative Proteomics

Iron Oxide Nanoparticles (IONPs) present unique properties making them one of the most used NPs in the biomedical field. Nevertheless, for many years, growing production and use of IONPs are associated with risks that can affect human and the environment. Thus, it is essential to study the effects of these nanoparticles to better understand their mechanism of action and the molecular perturbations induced in the organism. In the present study, we investigated the toxicological effects of IONPs (γ-Fe2O3) on liver, lung and brain proteomes in Wistar rats. Exposed rats received IONP solution during 7 consecutive days by intranasal instillation at a dose of 10 mg/kg body weight. An iTRAQ-based quantitative proteomics was used to study proteomic variations at the level of the three organs. Using this proteomic approach, we identified 1565; 1135 and 1161 proteins respectively in the brain, liver and lung. Amon them, we quantified 1541; 1125 and 1128 proteins respectively in the brain, liver and lung. Several proteins were dysregulated comparing treated samples to controls, particularly, proteins involved in cytoskeleton remodeling, cellular metabolism, immune system stimulation, inflammation process, response to oxidative stress, angiogenesis, and neurodegenerative diseases.

Safety Assessment of Nanomaterials to Eyes: An Important but Neglected Issue

The production and application of nanomaterials have grown tremendously during last few decades. The widespread exposure of nanoparticles to the public is provoking great concerns regarding their toxicity to the human body. However, in comparison with the extensive studies carried out to examine nanoparticle toxicity to the human body/organs, one especially vulnerable organ, the eye, is always neglected. Although it is a small part of the body, 90% of outside information is obtained via the ocular system. In addition, eyes usually directly interact with the surrounding environment, which may get severer damage from toxic nanoparticles compared to inner organs. Therefore, the study of assessing the potential nanoparticle toxicity to the eyes is of great importance. Here, the recent advance of some representative manufactured nanomaterials on ocular toxicity is summarized. First, a brief introduction of ocular anatomy and disorders related to particulate matter exposure is presented. Following, the factors that may influence toxicity of nanoparticles to the eye are emphasized. Next, the studies of representative manufactured nanoparticles on eye toxicity are summarized and classified. Finally, the limitations that are associated with current nanoparticle-eye toxicity research are proposed.

Reversible rearrangement of magnetic nanoparticles in solution studied using time-resolved SAXS method

Superparamagnetic nanoparticles have broad applications in biology and medicines. Quantitative measurements of magnetic beads in solution are essential in gaining comprehensive understanding of their dynamics and developing applications. Here, using synchrotron X-ray sources combined with well controlled magnetic fields, the results from small-angle X-ray scattering (SAXS) experiments on superparamagnetic particles in solution under the influence of external magnetic fields are reported. The particles mostly remain in monodispersed states and the linear aggregates tend to be aligned with the external magnetic field. After removing the magnetic fields, the superparamagnetic nanoparticles quickly recover to their original states indicating high reversibility of the rearrangement under the control of a magnetic field. The external magnetic field instrument composed of paired permanent magnets is integrated into the SAXS beamline at the Shanghai Synchrotron Radiation Facility providing a platform for studying time-resolved dynamics induced by magnetic fields.

Importance of Choosing Relevant Biological End Points To Predict Nanoparticle Toxicity with Computational Approaches for Human Health Risk Assessment

Because it is impossible to assess in vitro or in vivo the toxicity of all nanoparticles available on the market on a case-by-case basis, computational approaches have been proposed as useful alternatives to predict in silico the hazard potential of engineered nanoparticles. Despite promising results, a major issue associated with these mathematical models lies in the a priori choice of the physicochemical descriptors and the biological end points. We performed a thorough bibliographic survey on the biological end points used for nanotoxicology purposes and compared them between experimental and computational approaches. They were found to be disparate: while conventional in vitro nanotoxicology assays usually investigate a large array of biological effects using eukaryotic cells (cytotoxicity, pro-inflammatory response, oxidative stress, genotoxicity), computational studies mostly focus on cell viability and also include studies on prokaryotic cells. We may thus wonder the relevance of building complex mathematical models able to predict accurately a biological end point if this latter is not the most relevant to support human health risk assessment. The choice of biological end points clearly deserves to be more carefully discussed. This could bridge the gap between experimental and computational nanotoxicology studies and allow in silico predictive models to reach their full potential.

Green synthesis of gold nanoparticles using Euphrasia officinalisleaf extract to inhibit lipopolysaccharide-induced inflammation through NF-κB and JAK/STAT pathways in RAW 264.7 macrophages

Background

Gold nanoparticles (AuNPs) have potential applications in the treatment and diagnosis process, which are attributed to their biocompatibility and high efficiency of drug delivery. In the current study, we utilized an extract of Euphrasia officinalis, a traditional folk medicine, to synthesize gold nanoparticles (EO-AuNPs), and investigated their anti-inflammatory effects on lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages.

Materials and methods

The AuNPs were synthesized from an ethanol extract of E. officinalis leaves and characterized using several analytical techniques. Anti-inflammatory activities of EO-AuNPs were detected by a model of LPS-induced upregulation of inflammatory mediators and cytokines including nitric oxide (NO), inducible nitric oxide synthase (iNOS), tumor necrosis factor-α (TNF-α), IL-1β, and IL-6 in RAW 264.7 cells. The activation of nuclear factor (NF)-κB and Janus kinase/signal transducer and activators of transcription (JAK/STAT) signaling pathways was investigated by Western blot.

Results

The results confirmed the successful synthesis of AuNPs by E. officinalis. Transmission electron microscopy images showed obvious uptake of EO-AuNPs and internalization into intracellular membrane–bound compartments, resembling endosomes and lysosomes by RAW 264.7 cells. Cell viability assays showed that EO-AuNPs exhibited little cytotoxicity in RAW 264.7 cells at 100 µg/mL concentration after 24 hours. EO-AuNPs significantly suppressed the LPS-induced release of NO, TNF-α, IL-1β, and IL-6 as well as the expression of the iNOS gene and protein in RAW 264.7 cells. Further experiments demonstrated that pretreatment with EO-AuNPs significantly reduced the phosphorylation and degradation of inhibitor kappa B-alpha and inhibited the nuclear translocation of NF-κB p65. In addition, EO-AuNPs suppressed LPS-stimulated inflammation by blocking the activation of JAK/STAT pathway.

Conclusion

The synthesized EO-AuNPs showed anti-inflammatory activity in LPS-induced RAW 264.7 cells, suggesting they may be potential candidates for treating inflammatory-mediated diseases.

Gelatin-stabilized composites of silver nanoparticles and curcumin: characterization, antibacterial and antioxidant study

This is a preliminary study of a material comprising gelatin (Gel), silver nanoparticles (AgNPs) and curcumin (Cur) aimed for wound-healing treatment. Gelatin was used to stabilize AgNPs and encapsulate curcumin to form a therapeutic composite (GelCurAg) for their strong bactericidal and antioxidant properties. GelCurAg formulations with different gelatin concentrations were characterized to attain information about their physiochemical properties and the loading efficiency of therapeutic agents. In vitro assessment of GelCurAg focused on antibacterial, antioxidant and cytotoxic aspects. The results suggested that Gel1CurAg (synthesized from 1% gelatin solution) could be utilized as potential therapeutic agents in treating infectious wound owing to its bactericidal and antioxidant effects and low toxicity for clinical uses.

The Significance of Lactoperoxidase System in Oral Health: Application and Efficacy in Oral Hygiene Products

Lactoperoxidase (LPO) present in saliva are an important element of the nonspecific immune response involved in maintaining oral health. The main role of this enzyme is to oxidize salivary thiocyanate ions (SCN^-) in the presence of hydrogen peroxide (H₂O₂) to products that exhibit antimicrobial activity. LPO derived from bovine milk has found an application in food, cosmetics, and medical industries due to its structural and functional similarity to the human enzyme. Oral hygiene products enriched with the LPO system constitute an alternative to the classic fluoride caries prophylaxis. This review describes the physiological role of human salivary lactoperoxidase and compares the results of clinical trials and in vitro studies of LPO alone and complex dentifrices enriched with bovine LPO. The role of reactivators and inhibitors of LPO is discussed together with the possibility of using nanoparticles to increase the stabilization and activity of this enzyme.

Strategic use of nanotechnology in drug targeting and its consequences on human health: A focused review

Since the development of first lipid-based nanocarrier system, about 15% of the present pharmaceutical market uses nanomedicines to achieve medical benefits. Nanotechnology is an advanced area to meliorate the delivery of compounds for improved medical diagnosis and curing disease. Nanomedicines are gaining significant interest due to the ultra small size and large surface area to mass ratio. In this review, we discuss the potential of nanotechnology in delivering of active moieties for the disease therapy including their toxicity evidences. This communication will help the formulation scientists in understanding and exploring the new aspects of nanotechnology in the field of nanomedicine.

Innovative Magnetic Nanoparticles for PET/MRI Bimodal Imaging

Superparamagnetic iron oxide nanoparticles were developed as positron emission tomography (PET) and magnetic resonance imaging (MRI) bimodal imaging agents. These nanoparticles (NPs), with a specific nanoflower morphology, were first synthesized and simultaneously functionalized with 3,4-dihydroxy-l-phenylalanine (LDOPA) under continuous hydrothermal conditions. The resulting NPs exhibited a low hydrodynamic size of 90 ± 2 nm. The functional groups of LDOPA (-NH₂ and -COOH) were successfully used for the grafting of molecules of interest in a second step. The nanostructures were modified by poly(ethylene glycol) (PEG) and a new macrocyclic chelator MANOTA for further ⁶⁴Cu radiolabeling for PET imaging. The functionalized NPs showed promising bimodal (PET and MRI) imaging capability with high r ₂ and r ₂* (T ₂ and T ₂* relaxivities) values and good stability. They were mainly uptaken from liver and kidneys. No cytotoxicity effect was observed. These NPs appear as a good candidate for bimodal tracers in PET/MRI.

Nano-engineered delivery systems for cancer imaging and therapy: Recent advances, future direction and patent evaluation

Cancer is the second highest cause of death worldwide. Several therapeutic approaches, such as conventional chemotherapy, antibodies and small molecule inhibitors and nanotherapeutics have been employed in battling cancer. Amongst them, nanotheranostics is an example of successful personalized medicine bearing dual role of early diagnosis and therapy to cancer patients. In this review, we have focused on various types of theranostic polymer and metal nanoparticles for their role in cancer therapy and imaging concerning their limitation, future application such as dendritic cell cancer vaccination, gene delivery, T-cell activation and immune modulation. Also, some of the recorded patent applications and clinical trials have been illustrated. The impact of the biological microenvironment on the biodistribution and accumulation of nanoparticles have been discussed.

Response of the antioxidant enzymes of rats following oral administration of metal-oxide nanoparticles (Al2O3, CuO, TiO2)

Metal-oxide nanoparticles (NPs), as a new emerging technological compound, promise a wide range of usage areas and consequently have the potential to cause environmental toxicology. In the present work, aluminum (Al₂O₃), copper (CuO), and titanium (TiO₂) nanoparticles (NPs) were administered via oral gavage to mature female rats (Rattus norvegicus var. albinos) for 14 days with a dose series of 0 (control), 0.5, 5, and 50 (mg/kg b.w./day). Enzyme activities of the antioxidant system such as catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione S-transferase (GST), and glutathione reductase (GR) in the liver were measured. Transmission electron microscope (TEM) images of the liver were taken to demonstrate NP accumulation and distribution in liver tissue. Data showed that all NPs caused some significant (P > 0.05) alterations in the activities of antioxidant enzymes. CAT activity increased after CuO and TiO₂ administrations, while SOD activity decreased after Al₂O₃ administration. The activities of enzymes associated with glutathione (GR, GPx, GST) metabolisms were also significantly altered by NPs. GPx activity increased in rats received Al₂O₃, CuO NPs, while GR activity increased only by Al₂O₃. However, there were increases (TiO₂) and decreases (CuO) in GST activity in the liver of rats. TEM images of the liver demonstrated that all NPs accumulated in the liver, even at the lowest dose. This study indicated that the antioxidant enzymes in the liver of rats were affected by all NPs, suggesting the antioxidant system of rats suffered after NP administration.

Pentagalloyl Glucose and Its Functional Role in Vascular Health: Biomechanics and Drug-Delivery Characteristics

Pentagalloyl glucose (PGG) is an elastin-stabilizing polyphenolic compound that has significant biomedical benefits, such as being a free radical sink, an anti-inflammatory agent, anti-diabetic agent, enzymatic resistant properties, etc. This review article focuses on the important benefits of PGG on vascular health, including its role in tissue mechanics, the different modes of pharmacological administration (e.g., oral, intravenous and endovascular route, intraperitoneal route, subcutaneous route, and nanoparticle based delivery and microbubble-based delivery), and its potential therapeutic role in vascular diseases such as abdominal aortic aneurysms (AAA). In particular, the use of PGG for AAA suppression and prevention has been demonstrated to be effective only in the calcium chloride rat AAA model. Therefore, in this critical review we address the challenges that lie ahead for the clinical translation of PGG as an AAA growth suppressor.

Smart nanocarrier-based drug delivery systems for cancer therapy and toxicity studies: A review

Nonspecific distribution and uncontrollable release of drugs in conventional drug delivery systems (CDDSs) have led to the development of smart nanocarrier-based drug delivery systems, which are also known as Smart Drug Delivery Systems (SDDSs). SDDSs can deliver drugs to the target sites with reduced dosage frequency and in a spatially controlled manner to mitigate the side effects experienced in CDDSs. Chemotherapy is widely used to treat cancer, which is the second leading cause of death worldwide. Site-specific drug delivery led to a keen interest in the SDDSs as an alternative to chemotherapy. Smart nanocarriers, nanoparticles used to carry drugs, are at the focus of SDDSs. A smart drug delivery system consists of smart nanocarriers, targeting mechanisms, and stimulus techniques. This review highlights the recent development of SDDSs for a number of smart nanocarriers, including liposomes, micelles, dendrimers, meso-porous silica nanoparticles, gold nanoparticles, super paramagnetic iron-oxide nanoparticles, carbon nanotubes, and quantum dots. The nanocarriers are described in terms of their structures, classification, synthesis and degree of smartness. Even though SDDSs feature a number of advantages over chemotherapy, there are major concerns about the toxicity of smart nanocarriers; therefore, a substantial study on the toxicity and biocompatibility of the nanocarriers has been reported. Finally, the challenges and future research scope in the field of SDDSs are also presented. It is expected that this review will be widely useful for those who have been seeking new research directions in this field and for those who are about to start their studies in smart nanocarrier-based drug delivery.

Distinctive impact of polystyrene nano-spherules as an emergent pollutant toward the environment

The increasing load of nanoplastic pollution in the environment has become a major concern toward human and environmental safety. The current investigation mainly focused on assessing the toxic behavior of nanoplastics (polystyrene nano-spheres (PNS)) toward blood cells and marine crustacean. The study also investigated the temporal stability of PNS under different water matrices and its size-dependent sedimentation behavior in the sea water dispersion. The nano-dispersion showed mean particle size of 561.4 ± 0.80 and 613.7 ± 0.11 nm for PNS 1 and 781.4 ± 0.80 and 913.7 ± 0.11 nm for PNS 2 in lake and seawater, respectively after 48-h incubation, which is ~ 8-fold increase from its original size. The LC50 value against Artemia salina and lymphocytes were found to be 4.82 and 8.79 μg/mL, and 75 μg/mL, respectively for PNS 1 and PNS 2. The genotoxic study reveals that around 50% of lymphocytes were affected by both PNS at 50 μg/mL concentration, whereas the cytotoxic studies on RBC and lymphocytes showed 50% toxicity only at 100 μg/mL concentration. The genotoxic study displayed numerous tri- and multi-nucleated cells. The biochemical profile of A. salina exposed to lethal concentration demonstrated a significant decrease in the total protein, reduced glutathione, and catalase activity and increase in lipid peroxidation activity as a result of PNS permeation to tissues. In conclusion, the present study demonstrated that the polystyrene nano-spheres are emerging pollutant in the environment and are hazardous to humans.

In Vitro Methods for Assessing Nanoparticle Toxicity

As a consequence of their increase in annual production and widespread distribution in the environment, nanoparticles potentially pose a significant public health risk. The sought-after catalytic activity granted by their physiochemical properties doubles as a hazard to physiological processes following exposure through inhalation, oral, transdermal, subcutaneous, and intravenous uptake. Upon uptake into the body, their size, morphology, surface charge, coating, and chemical composition augment the response of biological systems to the materials and enhance their toxicity. Identification of each property is necessary to predict the harm imposed by foreign nanomaterials in the body. Assay methods ranging from endotoxin and lactate dehydrogenase (LDH) signaling to apoptosis and oxidative stress detection supply valuable techniques for exposing biomarkers of nanoparticle-induced cellular damage. Spectroscopic investigation of epithelial barrier permeation and distribution within living cells reveals the proclivity of nanoparticles to penetrate the body's natural defensive boundaries and deposit themselves in cytotoxic locations. Combination of the various characterization methodologies and assays is required for every new nanoparticulate system despite preexisting data for similar systems due to the lack of deterministic trends among investigated nanoparticles. The propensity of nanomaterials to denature proteins and oxidize substrates in their local environment generates significant concern for the applicability of several traditional in vitro assays, and the modification of susceptible approaches into novel methods suitable for the evaluation of nanoparticles comprises the focus of future work centered on nanoparticle toxicity analysis.

Intrinsically absorbing photoacoustic and ultrasound contrast agents for cancer therapy and imaging

Nanoparticles are submicrometer in size and are used in a variety of ways in the biomedical field. They can carry therapeutic drugs, either in the particle core or surface to target cancer sites in the body. Additionally they can contain imaging agents to diagnose and monitor the tumor size using different imaging modalities, such as fluorescence and nuclear magnetic resonance imaging. Novel theranostic nanoparticle agents, called perfluorohexane nanoemulsions (PFH-NEs) were synthesized whose intrinsic properties could be used for both imaging (ultrasound and photoacoustic) and therapy. Compared to other theranostic agents, our PFH-NEs can absorb sufficient near-infrared light to enhance contrast and provide deeper penetration imaging at laser fluences causing minimal damage to healthy tissue. One contrast mechanism (optical absorption/photoacoustics) allows us to validate localization of the agent and another (acoustic impedance/ultrasound) allows the imaging of therapeutic delivery after particle activation. In this work, we show the potential of these PFH-NEs to be used as multimodal imaging agents and for therapy.

A systematic review of nano formulation of natural products for the treatment of inflammatory bowel disease: drug delivery and pharmacological targets

Inflammatory bowel diseases (IBD), which is classified into Crohn's disease and ulcerative colitis, are among chronic gastrointestinal diseases with unknown pathogenesis. Diverse strategies have been applied for the treatment of this chronic disease. However, selective and site-specific routes of drug delivery to the inflamed location of the colon remain of high importance. Consequently, the application and effects of natural products in the form of nanoformulation and stimuli responsive nanoparticles as a novel strategy for the treatment of IBD are discussed in this review article. This approach may potentially overcome some complications that are associated with conventional means of colon drug delivery. Meanwhile, in vitro and in vivo studies pave the way for understanding of the mechanism that lies behind this chronic relapsing disease and potentially more effective treatment. Graphical abstract ᅟ.

Novel nano therapeutic materials for the effective treatment of rheumatoid arthritis-recent insights

Rheumatoid arthritis (RA) is the most common complex multifactorial joint related autoimmune inflammatory disease with unknown etiology accomplished with increased cardiovascular risks. RA is characterized by the clinical findings of synovial inflammation, autoantibody production, and cartilage/bone destruction, cardiovascular, pulmonary and skeletal disorders. Pro-inflammatory cytokines such as IL-1, IL-6, IL-8, and IL-10 were responsible for the induction of inflammation in RA patients. Drawbacks such as poor efficacy, higher doses, frequent administration, low responsiveness, and higher cost and serious side effects were associated with the conventional dosage forms for RA treatment. Nanomedicines were recently gaining more interest towards the treatment of RA, and researchers were also focusing towards the development of various anti-inflammatory drug loaded nanoformulations with an aid to both actively/passively targeting the inflamed site to afford an effective treatment regimen for RA. Alterations in the surface area and nanoscale size of the nanoformulations elicit beneficial physical and chemical properties for better pharmacological activities. These drug loaded nanoformulations may enhances the solubility of poorly water soluble drugs, improves the bioavailability, affords targetability and may improve the therapeutic activity. In this regimen, the present review focus towards the novel nanoparticulate formulations (nanoparticles, nanoemulsions, solid lipid nanoparticles, nanomicelles, and nanocapsules) utilized for the treatment of RA. The recent advancements such as siRNA, peptide and targeted based nanoparticulate systems for RA treatment were also discussed. Special emphasis was provided regarding the pathophysiology, prevalence and symptoms towards the development of RA.

Nano-Mediated Photodynamic Therapy for Cancer: Enhancement of Cancer Specificity and Therapeutic Effects

Deregulation of cell growth and development lead to cancer, a severe condition that claims millions of lives worldwide. Targeted or selective approaches used during cancer treatment determine the efficacy and outcome of the therapy. In order to enhance specificity and targeting and obtain better treatment options for cancer, novel modalities are currently under development. Photodynamic therapy has the potential to eradicate cancer, and combination therapy would yield even greater outcomes. Nanomedicine-aided cancer therapy shows enhanced specificity for cancer cells and minimal side-effects coupled with effective cancer destruction both in vitro and in vivo. Nanocarriers used in drug-delivery systems are very capable of penetrating the cancer stem cell niche, simultaneously killing cancer cells and eradicating drug-resistant cancer stem cells, yielding therapeutic efficiency of up to 100-fold against drug-resistant cancer in comparison with free drugs. Safety precautions should be considered when using nano-mediated therapy as the effects of extended exposure to biological environments are still to be determined.