Nanotechnology safety concerns revisited

In vitro assessment of nanomedicines' propensity to cause palmar-plantar erythrodysesthesia: A Doxil vs. doxorubicin case study

Palmar-plantar erythrodysesthesia (PPE), also known as hand and foot syndrome, is a condition characterized by inflammation-mediated damage to the skin on the palms and soles of the hands and feet. PPE limits the successful therapeutic applications of anticancer drugs. However, identifying this toxicity during preclinical studies is challenging due to the lack of accurate in vitro and in vivo animal-based models. Therefore, there is a need for reliable models that would allow the detection of this toxicity early during the drug development process. Herein, we describe the use of an in vitro skin explant assay to assess traditional DXR, Doxil reference listed drug (RLD) and two generic PEGylated liposomal DXR formulations for their abilities to cause inflammation and skin damage. We demonstrate that the results obtained with the in vitro skin explant assay model for traditional DXR and Doxil correlate with the clinical data.

Toxicological Comparison between Gold Nanoparticles in Different Shapes: Nanospheres Exhibit Less Hepatotoxicity and Lipid Dysfunction and Nanotriangles Show Lower Neurotoxicity

Gold nanoparticles (AuNPs) in different shapes have been developed and investigated for the treatment of various diseases. However, the potential toxicological vulnerability of different organs to morphologies of AuNPs and the complication of the toxicological profile of AuNPs by other health risk factors (e.g., plastic particles) have rarely been investigated systematically. Therefore, in this study, we aimed to investigate the toxicological differences between the spherical and triangular AuNPs (denoted as AuS and AuT, respectively) and the toxicological modulations by micro- or nanosized polystyrene plastic particles (denoted as mPS and nPS, respectively) in mice. Systemic biochemical characterizations were performed after a 90 day oral gavage feeding to obtain toxicological comparisons in different organs. In the case of single exposure to gold nanoparticles, AuT was associated with significantly higher aspartate amino-transferase (168.2%, P < 0.05), superoxide dismutase (183.6%, P < 0.001), catalase (136.9%, P < 0.01), total cholesterol (132.6%, P < 0.01), high-density lipoprotein cholesterol (131.3%, P < 0.05), and low-density lipoprotein cholesterol (204.6%, P < 0.01) levels than AuS. In contrast, AuS was associated with a significantly higher nitric oxide level (355.1%, P < 0.01) than AuT. Considering the overall toxicological profiles in single exposure and coexposure with multiscale plastics, it has been found that AuS is associated with lower hepatotoxicity and lipid metabolism malfunction, and AuT is associated with lower neurotoxicity than AuS. This finding may facilitate the future therapeutic design by considering the priority in protections of different organs and utilizing appropriate material morphologies.

Atmospheric emissions of particulate matter-bound heavy metals from industrial sources

Although industrial activities are significant contributors to atmospheric releases of particulate matter (PM) and associated toxic substances that lead to adverse human health effects, a knowledge gap exists concerning the human health risk resulting from such activities owing to lack of evaluation of industrial emissions. Here, we comprehensively characterized and quantified PM from 118 full-scale industrial plants. The dominant (97.9 %) PM showed diameters of <2.5 μm; 79.0 % had diameters below 1 μm. Annual atmospheric releases of Fe and heavy metals (As, Cd, Cr, Cu, Ni, Pb, Zn) contained in fine PM from these global industrial activities are estimated to be 51,161 t and 69,591 t, respectively. Emissions of heavy metals from these industries cause increased cancer risk, estimated to range from 1461 % to 50,752 %. Five crystalline compounds (ZnO, PbSO4, Mn3O4, Fe3O4, Fe2O3) that can indicate specific industrial sources are identified. Global annual emissions of these toxic compounds in fine PM from the industrial sources are estimated to be 78,635 t. The Global South displayed higher emissions than the Global North. These results are significant for recognizing regional health risks of industrial emissions.

Impact of conjugation to different lipids on the lymphatic uptake and biodistribution of brush PEG polymers

Delivery to peripheral lymphatics can be achieved following interstitial administration of nano-sized delivery systems (nanoparticles, liposomes, dendrimers etc) or molecules that hitchhike on endogenous nano-sized carriers (such as albumin). The published work concerning the hitchhiking approach has mostly focussed on the lymphatic uptake of vaccines conjugated directly to albumin binding moieties (ABMs such as lipids, Evans blue dye derivatives or peptides) and their subsequent trafficking into draining lymph nodes. The mechanisms underpinning access and transport of these constructs into lymph fluid, including potential interaction with other endogenous nanocarriers such as lipoproteins, have largely been ignored. Recently, we described a series of brush polyethylene glycol (PEG) polymers containing end terminal short-chain or medium-chain hydrocarbon tails (1C2 or 1C12, respectively), cholesterol moiety (Cho), or medium-chain or long-chain diacylglycerols (2C12 or 2C18, respectively). We evaluated the association of these materials with albumin and lipoprotein in rat plasma, and their intravenous (IV) and subcutaneous (SC) pharmacokinetic profiles. Here we fully detail the association of this suite of polymers with albumin and lipoproteins in rat lymph, which is expected to facilitate lymph transport of the materials from the SC injection site. Additionally, we characterise the thoracic lymph uptake, tissue and lymph node biodistribution of the lipidated brush PEG polymers following SC administration to thoracic lymph cannulated rats. All polymers had moderate lymphatic uptake in rats following SC dosing with the lymph uptake higher for 1C2-PEG, 2C12-PEG and 2C18-PEG (5.8%, 5.9% and 6.7% dose in lymph, respectively) compared with 1C12-PEG and Cho-PEG (both 1.5% dose in lymph). The enhanced lymph uptake of 1C2-PEG, 2C12-PEG and 2C18-PEG appeared related to their association profile with different lipoproteins. The five polymers displayed different biodistribution patterns in major organs and tissues in mice. All polymers reached immune cells deep within the inguinal lymph nodes of mice following SC dosing. The ability to access these immune cells suggests the potential of the polymers as platforms for the delivery of vaccines and immunotherapies. Future studies will focus on evaluating the lymphatic targeting and therapeutic potential of drug or vaccine-loaded polymers in pre-clinical disease models.

Targeted Thrombolysis with Magnetic Nanotherapeutics: A Translational Assessment

Plasminogen activators, such as recombinant tissue-type plasminogen activators (rtPAs), while effective in treating thromboembolic diseases, often induce hemorrhagic complications due to non-specific enzyme activities in the systemic circulation. This study evaluated the targeting efficiency, efficacy, biodistribution, and potential toxicity of a rtPA covalently attached to chitosan-coated magnetic nanoparticles (chitosan-MNP-rtPA). The thrombolytic activity of a chitosan-MNP-rtPA was preserved by protection from an endogenous plasminogen activator inhibitor-1 (PAI-1) in whole blood and after circulation in vivo, as examined by thromboelastometry. Single-photon emission computed tomography (SPECT) demonstrated real-time retention of a 99mTc-MNP-rtPA induced by magnet application in a rat embolic model; an 80% reduction in rtPA dosage for a chitosan-MNP-rtPA with magnetic guidance was shown to restore blood flow. After treatment, iron deposition was observed in the reticuloendothelial systems, with portal edema and neutrophil infiltration in the liver at a ten-fold higher dose but not the regular dose. Nevertheless, no liver or renal toxicity was observed at this higher dose. In conclusion, the liver may still be the major deposit site of rtPA nanocomposites after targeted delivery; chitosan-coated MNPs are potentially amenable to target therapeutics with parenteral administration.

Encapsulating In Vitro Transcribed circRNA into Lipid Nanoparticles Via Microfluidic Mixing

This chapter serves as a guide for researchers embarking on circular RNA-based translational studies. It provides a foundation for the successful encapsulation of circular RNA into lipid nanoparticles (LNPs) and facilitates progress in this emerging field. Crucial scientific methods and techniques involved in the formulation process, particle characterization, and downstream processing of circ-LNPs are covered. The production of in vitro transcribed circular RNA-containing LNPs based on a commercially available lipid mix is provided, in addition to the fundamentals for successful encapsulation based on lipid mixes composed of single components. Furthermore, the transfection and validation protocols for the identification of a functional and potentially therapeutic circRNA candidate for initial in vitro verification, before subsequent LNP studies, are explained.

Copper oxide nanoparticles: In vitro and in vivo toxicity, mechanisms of action and factors influencing their toxicology

Copper oxide nanoparticles (CuO NPs) have received increasing interest due to their distinctive properties, including small particle size, high surface area, and reactivity. Due to these properties, their applications have been expanded rapidly in various areas such as biomedical properties, industrial catalysts, gas sensors, electronic materials, and environmental remediation. However, because of these widespread uses, there is now an increased risk of human exposure, which could lead to short- and long-term toxicity. This review addresses the underlying toxicity mechanisms of CuO NPs in cells which include reactive oxygen species generation, leaching of Cu ion, coordination effects, non-homeostasis effect, autophagy, and inflammation. In addition, different key factors responsible for toxicity, characterization, surface modification, dissolution, NPs dose, exposure pathways and environment are discussed to understand the toxicological impact of CuO NPs. In vitro and in vivo studies have shown that CuO NPs cause oxidative stress, cytotoxicity, genotoxicity, immunotoxicity, neurotoxicity, and inflammation in bacterial, algal, fish, rodents, and human cell lines. Therefore, to make CuO NPs a more suitable candidate for various applications, it is essential to address their potential toxic effects, and hence, more studies should be done on the long-term and chronic impacts of CuO NPs at different concentrations to assure the safe usage of CuO NPs.

Influence of ionic cerium and cerium oxide nanoparticles on Zea mays seedlings grown with and without cadmium

Cerium (Ce⁴⁺) and cerium oxide nanoparticles (CeO₂-NPs) have diversified reported effects on plants. Once dispersed in the environment their fate is not well understood, especially in co-existence with other pollutants like cadmium (Cd). The effect of co-application of Ce and Cd are reported in various studies, but the role of Ce source (ionic or bulk) and nanoparticle size is still unknown in cereal plants like maize (Zea mays). To better understand the synergistic effects of Ce and Cd, 500 mg kg^-1 Ce coming from ionic (Ce⁴⁺ as CeSO₄) and CeO₂ nano sources (10 nm, 50 nm, and 100 nm) alone and in combination with 0.5 mg Cd kg^-1 sand were applied to maize seedlings. Growth, physiology, root structure, anatomy, and ionic homeostasis in maize were measured. The results revealed that Ce⁴⁺ resulted in overall decrease in seedling growth, biomass and resulted in higher heavy metal (in control sets) and Cd (in Cd spiked sets) uptake in maize seedlings' root and shoot. The effects of CeO₂-NPs were found to be dependent on particle size; in fact, under Cd-0 (non-Cd spiked sets) CeO₂-100 nm showed beneficial effects compared to the control. While under co-application with Cd, CeO₂-50 nm showed net beneficial effects on maize seedling growth parameters. The Ce alone, and in combination with Cd, altered the root suberin barrier formation. Both ionic and nano Ce sources alone and in co-existence with Cd behaved differently for tissue elemental concentrations (Ce, Cd, micronutrients like B, Mn, Ni, Cu, Zn, Mo, Fe and elements Co, Si) suggesting a strong influence of Cd-Ce coexistence on the element's uptake and translocation in maize.

Nanotechnology for Targeted Drug Delivery to Treat Osteoporosis

Bone diseases such as rheumatoid arthritis, Paget's disease, and osteoporosis cause mortality and mobility limits. Nanomedicine and nano delivery systems have been utilised to deliver active drug moiety to the precisely targeted site in a controlled manner, and it serves as a means of diagnostic tools. The utilisation of nanomedicine is expanding vigorously for assured targeting and efficient drug delivery. Nanotechnology offers various advantages, such as site-specific targeting, precise drug release kinetics, and improved bone mineral density. Recent medications available for osteoporosis are not viable due to the adverse effects associated with them and low patient compliance. There is an urgent need to develop biocompatible and appropriate drug delivery nanocarriers such as nanoparticles, liposomes, hydrogels, dendrimers, micelles, mesoporous particles, etc. These carriers enhance drug delivery and therapeutic effectiveness in bone tissues. The use of nanotechnology is also associated with toxicity. This article presents the review of various reports on nanocarrier systems and biologics for the treatment of osteoporosis. It aims to provide researchers with a clue for inventing a new drug delivery system with site-specific targeting for the treatment of osteoporosis.

Nanoparticles for Topical Application in the Treatment of Skin Dysfunctions-An Overview of Dermo-Cosmetic and Dermatological Products

Nanomaterials (NM) arouse interest in various fields of science and industry due to their composition-tunable properties and the ease of modification. They appear currently as components of many consumer products such as sunscreen, dressings, sports clothes, surface-cleaning agents, computer devices, paints, as well as pharmaceutical and cosmetics formulations. The use of NPs in products for topical applications improves the permeation/penetration of the bioactive compounds into deeper layers of the skin, providing a depot effect with sustained drug release and specific cellular and subcellular targeting. Nanocarriers provide advances in dermatology and systemic treatments. Examples are a non-invasive method of vaccination, advanced diagnostic techniques, and transdermal drug delivery. The mechanism of action of NPs, efficiency of skin penetration, and potential threat to human health are still open and not fully explained. This review gives a brief outline of the latest nanotechnology achievements in products used in topical applications to prevent and treat skin diseases. We highlighted aspects such as the penetration of NPs through the skin (influence of physical-chemical properties of NPs, the experimental models for skin penetration, methods applied to improve the penetration of NPs through the skin, and methods applied to investigate the skin penetration by NPs). The review summarizes various therapies using NPs to diagnose and treat skin diseases (melanoma, acne, alopecia, vitiligo, psoriasis) and anti-aging and UV-protectant nano-cosmetics.

Morphology-Controlled Green Synthesis of Magnetic Nanoparticles Using Extracts of 'Hairy' Roots: Environmental Application and Toxicity Evaluation

Magnetic nanoparticles (MNPs) were "green" synthesized from a FeCl3/FeSO4/CoCl2 mixture using ethanolic extracts of Artemisia tilesii Ledeb 'hairy' roots. The effect of chemical composition and reducing power of ethanolic extracts on the morphology, size destribution and other features of obtained MNPs was evaluated. Depending on the extract properties, nanosized magnetic materials of spherical (8-11 nm), nanorod-like (15-24 nm) and cubic (14-24 nm) shapes were obtained via self-assembly. Microspherical MNPs composed of nanoclusters were observed when using extract of the control root line in the synthesis. Polyhedral magnetic nanoparticles with an average size of ~30 nm were formed using 'hairy' root ethanolic extract without any additive. Studied samples manifested excellent magnetic characteristics. Field-dependent magnetic measurements of most MNPs demonstrated a saturation magnetization of 42.0-72.9 emu/g with negligible coercivity (∼0.02-0.29 emu/g), indicating superparamagnetic behaviour only for solids with a magnetite phase. The synthesized MNPs were minimally aggregated and well-dispersed in aqueous medium, probably due to their stabilization by bioactive compounds in the initial extract. The nanoparticles were tested for magnetic solid-phase extraction of copper (Cu), cadmium (Cd) and arsenic (As) pollutants in aqueous solution, followed by ICP-OES analysis. The magnetic oxides, mainly magnetite, showed high adsorption capacity and effectively removed arsenic ions at pH 6.7. The maximum adsorption capacity was ~150 mg/g for As(III, V) on the selected MNPs with cubic morphology, which is higher than that of previously reported adsorbents. The best adsorption was achieved using Fe3O4-based nanomaterials with low crystallinity, non-spherical form and a large number of surface-localized organic molecules. The phytotoxicity of the obtained MNPs was estimated in vitro using lettuce and chicory as model plants. The obtained MNPs did not exhibit inhibitory activity. This work provides novel insights on the morphology of "green" synthesized magnetic nanoparticles that can be used for applications in adsorption technologies.

Effect of water-soluble fullerenes on macrophage surface ultrastructure revealed by scanning ion conductance microscopy

C₆₀-fullerenes have unique potential in antiviral, drug delivery, photodynamic therapy and other biomedical applications. However, little is known about their effects on macrophage surface morphology and ultrastructure. Here by using contact-free scanning ion conductance microscopy (SICM), we investigated the effects of two water-soluble fullerenes on the surface ultrastructure and function of macrophages. The results showed that these fullerenes would be a promising phagocytosis inhibitor and SICM would be an excellent tool to study the morphological information of adhesive and fragile samples.

Nanoscale morphological changes of macrophages characterized by contact-free SICM and their relationship with phagocytosis after C₆₀-fullerene treatment demonstrate they are a potential phagocytosis inhibitor.

The Future of Tissue-Targeted Lipid Nanoparticle-Mediated Nucleic Acid Delivery

The earliest example of in vivo expression of exogenous mRNA is by direct intramuscular injection in mice without the aid of a delivery vehicle. The current state of the art for therapeutic nucleic acid delivery is lipid nanoparticles (LNP), which are composed of cholesterol, a helper lipid, a PEGylated lipid and an ionizable amine-containing lipid. The liver is the primary organ of LNP accumulation following intravenous administration and is also observed to varying degrees following intramuscular and subcutaneous routes. Delivery of nucleic acid to hepatocytes by LNP has therapeutic potential, but there are many disease indications that would benefit from non-hepatic LNP tissue and cell population targeting, such as cancer, and neurological, cardiovascular and infectious diseases. This review will concentrate on the current efforts to develop the next generation of tissue-targeted LNP constructs for therapeutic nucleic acids.

Think like a Virus: Toward Improving Nanovaccine Development against SARS-CoV-2

There is no doubt that infectious diseases present global impact on the economy, society, health, mental state, and even political aspects, causing a long-lasting dent, and the situation will surely worsen if and when the viral spread becomes out of control, as seen during the still ongoing coronavirus disease 2019 (COVID-19) pandemic. Despite the considerable achievements made in viral prevention and treatment, there are still significant challenges that can be overcome through careful understanding of the viral mechanism of action to establish common ground for innovating new preventative and treatment strategies. Viruses can be regarded as devil nanomachines, and one innovative approach to face and stop the spread of viral infections is the development of nanoparticles that can act similar to them as drug/vaccine carriers. Moreover, we can use the properties that different viruses have in designing nanoparticles that reassemble the virus conformational structures but that do not present the detrimental threats to human health that native viruses possess. This review discusses the current preventative strategies (i.e., vaccination) used in facing viral infections and the associated limitations, highlighting the importance of innovating new approaches to face viral infectious diseases and discussing the current nanoapplications in vaccine development and the challenges that still face the nanovaccine field.

Time course of pulmonary inflammation and trace element biodistribution during and after sub-acute inhalation exposure to copper oxide nanoparticles in a murine model

Background

It has been shown that copper oxide nanoparticles (CuO NPs) induce pulmonary toxicity after acute or sub-acute inhalation exposures. However, little is known about the biodistribution and elimination kinetics of inhaled CuO NPs from the respiratory tract. The purposes of this study were to observe the kinetics of pulmonary inflammation during and after CuO NP sub-acute inhalation exposure and to investigate copper (Cu) biodistribution and clearance rate from the exposure site and homeostasis of selected trace elements in secondary organs of BALB/c mice.

Results

Sub-acute inhalation exposure to CuO NPs led to pulmonary inflammation represented by increases in lactate dehydrogenase, total cell counts, neutrophils, macrophages, inflammatory cytokines, iron levels in bronchoalveolar lavage (BAL) fluid, and lung weight changes. Dosimetry analysis in lung tissues and BAL fluid showed Cu concentration increased steadily during exposure and gradually declined after exposure. Cu elimination from the lung showed first-order kinetics with a half-life of 6.5 days. Total Cu levels were significantly increased in whole blood and heart indicating that inhaled Cu could be translocated into the bloodstream and heart tissue, and potentially have adverse effects on the kidneys and spleen as there were significant changes in the weights of these organs; increase in the kidneys and decrease in the spleen. Furthermore, concentrations of selenium in kidneys and iron in spleen were decreased, pointing to disruption of trace element homeostasis.

Conclusions

Sub-acute inhalation exposure of CuO NPs induced pulmonary inflammation, which was correlated to Cu concentrations in the lungs and started to resolve once exposure ended. Dosimetry analysis showed that Cu in the lungs was translocated into the bloodstream and heart tissue. Secondary organs affected by CuO NPs exposure were kidneys and spleen as they showed the disruption of trace element homeostasis and organ weight changes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12989-022-00480-z.

Nanoliposomes as drug delivery systems: safety concerns

The review highlights the safety issues of drug delivery systems based on liposomes. Due to their small sizes (about 80-120 nm, sometimes even smaller), phospholipid nanoparticles interact intensively with living systems during parenteral administration. This interaction significantly affects both their transport role and safety; therefore, special attention is paid to these issues. The review summarises the data on the basic factors affecting the safety of nanoliposomes: composition, size, surface charge, stability, the release of an incorporated drug, penetration into tissues, interaction with the complement system. Attention is paid to the authors' own research of unique phospholipid nanoparticles with a diameter of 20-30 nm. The influence of technological processes of nanoliposome production on their properties is considered. The article also discusses the modern safety assessment criteria contained in the preliminary regulatory documents of the manufacturing countries for new nanoliposome-based drugs being developed or used in the clinic.

Effect of Nanostructures on the Properties of Glass Ionomer Dental Restoratives/Cements: A Comprehensive Narrative Review

Overall perspective of nanotechnology and reinforcement of dental biomaterials by nanoparticles has been reported in the literature. However, the literature regarding the reinforcement of dental biomaterials after incorporating various nanostructures is sparse. The present review addresses current developments of glass ionomer cements (GICs) after incorporating various metallic, polymeric, inorganic and carbon-based nanostructures. In addition, types, applications, and implications of various nanostructures incorporated in GICs are discussed. Most of the attempts by researchers are based on the laboratory-based studies; hence, it warrants long-term clinical trials to aid the development of suitable materials for the load bearing posterior dentition. Nevertheless, a few meaningful conclusions are drawn from this substantial piece of work; they are as follows: (1) most of the nanostructures are likely to enhance the mechanical strength of GICs; (2) certain nanostructures improve the antibacterial activity of GICs against the cariogenic bacteria; (3) clinical translation of these promising outcomes are completely missing, and (4) the nanostructured modified GICs could perform better than their conventional counterparts in the load bearing posterior dentition.

Safety Evaluation of Nanotechnology Products

Nanomaterials are now being used in a wide variety of biomedical applications. Medical and health-related issues, however, have raised major concerns, in view of the potential risks of these materials against tissue, cells, and/or organs and these are still poorly understood. These particles are able to interact with the body in countless ways, and they can cause unexpected and hazardous toxicities, especially at cellular levels. Therefore, undertaking in vitro and in vivo experiments is vital to establish their toxicity with natural tissues. In this review, we discuss the underlying mechanisms of nanotoxicity and provide an overview on in vitro characterizations and cytotoxicity assays, as well as in vivo studies that emphasize blood circulation and the in vivo fate of nanomaterials. Our focus is on understanding the role that the physicochemical properties of nanomaterials play in determining their toxicity.

Metal Oxide Nanoparticles: Evidence of Adverse Effects on the Male Reproductive System

Metal oxide nanoparticles (MONPs) are inorganic materials that have become a valuable tool for many industrial sectors, especially in healthcare, due to their versatility, unique intrinsic properties, and relatively inexpensive production cost. As a consequence of their wide applications, human exposure to MONPs has increased dramatically. More recently, their use has become somehow controversial. On one hand, MONPs can interact with cellular macromolecules, which makes them useful platforms for diagnostic and therapeutic interventions. On the other hand, research suggests that these MONPs can cross the blood–testis barrier and accumulate in the testis. Although it has been demonstrated that some MONPs have protective effects on male germ cells, contradictory reports suggest that these nanoparticles compromise male fertility by interfering with spermatogenesis. In fact, in vitro and in vivo studies indicate that exposure to MONPs could induce the overproduction of reactive oxygen species, resulting in oxidative stress, which is the main suggested molecular mechanism that leads to germ cells’ toxicity. The latter results in subsequent damage to proteins, cell membranes, and DNA, which ultimately may lead to the impairment of the male reproductive system. The present manuscript overviews the therapeutic potential of MONPs and their biomedical applications, followed by a critical view of their potential risks in mammalian male fertility, as suggested by recent scientific literature.

Insight into the substrate-dependent anti-aflatoxigenic effects of nanosized ZnO film: Electron transfer directed oxidative stress mechanisms

Exploring new anti-aflatoxigenic materials and their mechanisms are critical to reduce the prevalence of drug-resistant fungi and the contamination of aflatoxins. Zinc oxide nanoparticles (ZnONPs) are promising antifungal candidates but supporting substrates generally affect their antifungal activities. In this study, ZnONPs with a three-dimensional flower-like hierarchical microstructure bound to different substrates as anti-aflatoxigenic composites were prepared using a facile deposition method. It was found that ZnO nanocomposites showed the substrate-dependent anti-aflatoxigenic activities. The antifungal activities of ZnO films toward A. flavus growth and aflatoxin B₁ production decreased significantly in the order ZnO@Zn＞ZnO@Sn＞ZnO@Steel＞ZnO@Glass. The electrical conductivity of the substrate should play an important role for antifungal response. When compared with ZnO@Sn and ZnO@Steel, the conductivity value of ZnO@Zn was 2.07-fold and 14.84-fold of them, respectively. The higher the electrical conductivity of the substrate, the better the anti-aflatoxigenic efficiency of the composite. Such anti-aflatoxigenic activity was also due to ROS generation through electron transfer between fungi and the ZnO-substrate system, which could provoke the strength of intracellular oxidative stress. This mechanism was further confirmed using several assays such as hyphal morphology analysis, Zn²⁺ release, ROS evaluation, lipid peroxidation and antioxidant response. Collectively, improvement in knowledge regarding anti-aflatoxigenic performance of ZnONPs can help develop novel and effective strategies to reduce fungi growth and aflatoxin contamination in the food field.

Focal therapy for localized cancer: a patent review

INTRODUCTION

Conventional cancer treatments such as radical surgery and systemic therapy targeting the organ or organ system might have side effects because of damage to the surrounding tissue. For this reason, there is a need for new instruments that focally treat cancer.

AREAS COVERED

This review provides a comprehensive overview of the patent literature on minimally and noninvasive focal therapy instruments to treat localized cancer. The medical section of the Google Patents database was scanned, and 128 patents on focal therapy instruments published in the last two decades (2000-2021) were retrieved and classified. The classification is based on the treatment target (cancer cell or network of cancer cells), treatment purpose (destroy the cancerous structure or disable its function), and treatment means (energy, matter, or a combination of both).

EXPERT OPINION

We found patents describing instruments for all groups, except for the instruments that destroy a cancer cell network structure by applying matter (e.g. particles) to the network. The description of the different treatment types may serve as a source of inspiration for new focal therapy instruments to treat localized cancer.

Fabrication of Chitosan-coated Mesoporous Silica Nanoparticles Bearing Rosuvastatin as Drug Delivery System

AIM

In this work, to improve the solubility and bioavailability of the rosuvastatin (RSV) drug, chitosan-coated mesoporous silica nanoparticles (CS-MSNs) as drug delivery systems were fabricated.

METHODS

To do this, first MSNs with a maximum specific surface area were synthesized from sodium silicate as silica source and different molar ratios of cethyl trimethylammonium bromide (CTAB) and pluronics (P123, PEO20PPO17PEO20) as surfactants via the sol-gel process. Then, the synthesized MSNs were coated by CS polymer with the help of (3-glycidoxypropyl)methyldiethoxysilane (GPTMS) as a linker between MSNs and CS. Subsequently, the RSV drug was loaded into the synthesized CS-coated MSNs. The products were characterized by different techniques, including X-ray diffraction (XRD), the Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), dynamic light scattering (DLS), and Fourier-transform infrared spectroscopy (FTIR). The in vitro drug release profile of the fabricated DDS was evaluated in a typical phosphate-buffered saline (PBS) solution at different pH values (i.e., 4, 6, and 7.4) for 48 h. To assess the cytotoxicity, the viability of the human fibroblast cells exposed to the fabricated DDS was also examined.

RESULTS

The results showed that at an optimal molar ratio of P123/CTAB, the amorphous MSNs with a specific surface area of about 1080 m2/g, a pore diameter of 4 nm, a pore volume of 1.1 cm3/g, and an average size of about 30 nm were synthesized. Also, the presence of all the components, including the CS coating and the RSV drug, was confirmed in the structure of the fabricated DDS by FTIR analysis. Due to the pH-responsive feature of the CS coating, the RSV drug release from the fabricated DDS showed a reasonable environmental response; as the pH value of the PBS solution decreased, the degree of drug release increased.

CONCLUSION

The CS coating enhanced the cytotoxicity of the fabricated DDS and led to sustainable drug release behavior, which would provide a beneficial approach for drug delivery technology.

Mechanical cues protect against silica nanoparticle exposure in SH-SY5Y neuroblastoma

The increasing appearance of engineered nanomaterials in broad biomedical and industrial sectors poses an escalating health concern from unintended exposure with unknown consequences. Routine in vitro assessments of nanomaterial toxicity are a vital component to addressing these mounting health concerns; however, despite the known role of cell-cell and cell-matrix contacts in governing cell survival, these physical interactions are generally ignored. Herein, we demonstrate that exposure to amorphous silica particles destabilizes mitochondrial membrane potential, stimulates reactive oxygen species (ROS) production and promotes cytotoxicity in SH-SY5Y human neuroblastoma through mechanisms that are potently matrix dependent, with SH-SY5Y cells plated on the softest matrix displaying a near complete recovery in viability compared to dose-matched cells plated on tissue-culture plastic. Cells on the softest matrix (3 kPa) further displayed a 50% reduction in ROS production and preserved mitochondrial membrane potential. The actin cytoskeleton is mechanosensitive and closely related to ROS production. SH-SY5Y cells exposed to a 100 μg/mL dose of 50 nm silica particles displayed distinct cytoskeletal aberrations and a 70% increase in cell stiffness. Overall, this study establishes that the mechanical environment can significantly impact silica nanoparticle toxicity in SH-SY5Y cells. The mechanobiochemical mechanisms behind this regulation, which are initiated at the cell-matrix interface to adjust cytoskeletal structure and intracellular tension, demand specific attention for a comprehensive understanding of nanotoxicity.

Possible Mechanisms of Liver Injury Induced by Cadmium Sulfide Nanoparticles in Rat

Cadmium is primarily utilized in the construction of particles known as quantum dots. Hepatotoxicity caused by microparticles of cadmium is very well known; however, toxicity of nanoparticles of cadmium is not well understood. The present study describes the toxicity of cadmium sulfide nanoparticles (CdSNPs) in the liver of rat. Adult Wistar rats were administered CdSNPs (10 mg/kg) on alternate days for 45 days. Serum enzymes (ALT, AST, ALP), biomarkers of lipid peroxidation (MDA, H₂O₂, and NO), and metallothionein concentration were determined. Histopathological and TEM observations were also made to record morphological changes. CdSNPs (10 mg/kg) induced significant changes in the structure and function of liver. Values of serum enzymes and reactive species increased significantly in rats treated with CdSNPs in comparison to CdS-treated rats. Histopathological observations showed extensive parenchymal degeneration. Ultrastructural studies exhibited proliferation of endoplasmic reticulum, microsomes, and lysosomes. It is concluded that NP-membrane interaction leads to the generation of reactive species that alter membrane integrity and induce oxidative stress. These events may activate cell death pathways in hepatocytes.

In vitro cytotoxicity of co-exposure to superparamagnetic iron oxide and solid lipid nanoparticles

Increased production and use of different types of nanoparticles (NPs) in the last decades has led to increased environmental release of these NPs with potential detrimental effects on both the environment and public health. Information is scarce in the literature on the cytotoxic effect of co-exposure to many NPs as this concern is relatively recent. Thus, in this study, we hypothesized scenarios of cell's co-exposure to two kinds of NPs, solid lipid nanoparticles (SLNs) and superparamagnetic iron oxide nanoparticles (SPIONs), to assess the potential cytotoxicity of exposure to NPs combination. Cytotoxicity of SPIONs, SLNs, and their 1:1 mixture (MIX) in six tumor and six non-tumor cell lines was investigated. The mechanisms underlining the induced cytotoxicity were studied through cell cycle analysis, detection of reactive oxygen species (ROS), and alterations in mitochondrial membrane potential (ΔΨM). Double staining with acridine orange and ethidium bromide was also used to confirm cell morphology alterations. The results showed that SPIONs induced low cytotoxicity compared to SLNs. However, the mixture of SPIONs and SLNs showed synergistic, antagonistic, and additive effects based on distinct tests such as viability assay, ROS generation, ΔΨM, and DNA damage, depending on the cell line. Apoptosis triggered by ROS and disturbances in ΔΨM are the most probable related mechanisms of action. As was postulated, there is possible cytotoxic interaction between the two kinds of NPs.

Prospective Protective Effect of Ellagic Acid as a SIRT1 Activator in Iron Oxide Nanoparticle-Induced Renal Damage in Rats

Despite the wide application of iron oxide nanoparticles (IONPs), little is known about the specific mechanism of their nephrotoxic effect. We aimed to evaluate the nephrotoxic effects of iron oxide nanoparticles (IONPs) in vivo and the protective effect of ellagic acid (EA) as a silent information regulator sirtuin 1 (SIRT1) activator against the induced nephrotoxicity. Forty male albino Wistar rats were randomly distributed into four equal groups (10 rats each): the control group (oral saline for 30 days), ellagic acid (EA) group (10 mg/kg b.w. EA, orally for 30 days), IONP group (20 mg/kg b.w. IONP I/P injection at the 24th-30th day), and EA + IONP group (10 mg/kg b.w./day EA for 30 days + 20 mg/kg b.w. IONPs at the 24th-30th day). In the present study, the potent antioxidant and antiapoptotic effects of EA were indicated by the significant overexpression of SIRT1 in renal tissues that leads to significant decreases in renal MDA content, P53 protein level and forkhead-box transcription factor1 (FOXO1) expression, and significant increases in renal GSH level, catalase activity, growth arrest and DNA damage-inducible protein 45 alpha (GADDα45), and renal inhibition of apoptosis protein (KIAP) gene expression levels in the EA + IONP-treated group. These results were confirmed by the improved histopathological renal features with EA administration. In conclusion, the present study provides the first evidence for the usefulness of EA as a sirtuin1 activator in the prevention or treatment of renal damage. Thus, EA could be used as a promising therapy for the prevention of IONP-induced nephrotoxicity.

Deciphering the mechanism of hafnium oxide nanoparticles perturbation in the bio-physiological microenvironment of catalase

Nanoparticles (NPs) are extensively being used in state-of-the-art nano-based therapies, modern electronics, and consumer products, so can be released into the environment with enhancement interaction with humans. Hence, the exposures to these multifunctional NPs lead to changes in protein structure and functionality, raising serious health issues. This study thoroughly investigated the interaction and adsorption of catalase (CAT) with HfO2-NPs by circular dichroism (CD), Fourier transform infrared (FTIR), absorption, and fluorescence spectroscopic techniques. The results indicate that HfO2 NPs cause fluorescence quenching in CAT by a static quenching mechanism. The negative values of Vant Hoff thermodynamic expressions (ΔH o , ΔS o , and ΔG o ) corroborate the spontaneity and exothermic nature of static quenching driven by van der Waals forces and hydrogen bonding. Also, FTIR, UV-CD, and UV–visible spectroscopy techniques confirmed that HfO2 NPs binding could induce microenvironment perturbations leading to secondary and tertiary conformation changes in CAT. Furthermore, synchronous fluorescence spectroscopy confirmed the significant changes in the microenvironment around tryptophan (Trp) residue caused by HfO2 NPs. The time depending denaturing of CAT biochemistry through HfO2-NPs was investigated by assaying catalase activity elucidates the potential toxic action of HfO2-NPs at the macromolecular level. Briefly, this provides an empathetic knowledge of the nanotoxicity and likely health effects of HfO2 NPs exposure.

Toxicity of copper oxide nanoparticles: a review study

Copper oxide nanoparticles (CuO NPs) use has exponentially increased in various applications (such as industrial catalyst, gas sensors, electronic materials, biomedicines, environmental remediation) due to their flexible properties, i.e. large surface area to volume ratio. These broad applications, however, have increased human exposure and thus the potential risk related to their short- and long-term toxicity. Their release in environment has drawn considerable attention which has become an eminent area of research and development. To understand the toxicological impact of CuO NPs, this review summarises the in-vitro and in-vivo toxicity of CuO NPs subjected to species (bacterial, algae, fish, rats, human cell lines) used for toxicological hazard assessment. The key factors that influence the toxicity of CuO NPs such as particle shape, size, surface functionalisation, time-dose interaction and animal and cell models are elaborated. The literature evidences that the CuO NPs exposure to the living systems results in reactive oxygen species generation, oxidative stress, inflammation, cytotoxicity, genotoxicity and immunotoxicity. However, the physio-chemical characteristics of CuO NPs, concentration, mode of exposure, animal model and assessment characteristics are the main perspectives that define toxicology of CuO NPs.

Nanoparticles and Vaccine Development

In spite of the progress of conventional vaccines, improvements are required due to concerns about the low immunogenicity of the toxicity, instability, and the need for multiple administrations of the vaccines. To overcome the mentioned problems, nanotechnology has recently been incorporated into vaccine development. Nanotechnology increasingly plays an important role in vaccine development nanocarrier-based delivery systems that offer an opportunity to increase the cellular and humoral immune responses. The use of nanoparticles in vaccine formulations allows not only enhanced immunogenicity and stability of antigen, but also targeted delivery and slow release. Over the past decade, nanoscale size materials such as virus-like particles, liposomes, ISCOMs, polymeric, inorganic nanoparticles and emulsions have gained attention as potential delivery vehicles for vaccine antigens, which can both stabilize vaccine antigens and act as adjuvants. This advantage is attributable to the nanoscale particle size, which facilitates uptake by Antigen- Presenting Cells (APCs), then leading to efficient antigen recognition and presentation. Modifying the surfaces of nanoparticles with different targeting moieties permits the delivery of antigens to specific receptors on the cell surface, thereby stimulating selective and specific immune responses. This review provides an overview of recent advances in nanovaccinology.

Developmental toxicity of carbon nanoparticles during embryogenesis in chicken

Nanoparticles (NPs) are very small particles present in a wide range of materials. There is a dearth of knowledge regarding their potential secondary effects on the health of living organisms and the environment. Increasing research attention, however, has been directed toward determining the effects on humans exposed to NPs in the environment. Although the majority of studies focus on adult animals or populations, embryos of various species are considered more susceptible to environmental effects and pollutants. Hence, research studies dealing mainly with the impacts of NPs on embryogenesis have emerged recently, as this has become a major concern. Chicken embryos occupy a special place among animal models used in toxicity and developmental investigations and have also contributed significantly to the fields of genetics, virology, immunology, cell biology, and cancer. Their rapid development and easy accessibility for experimental observance and manipulation are just a few of the advantages that have made them the vertebrate model of choice for more than two millennia. The early stages of chicken embryogenesis, which are characterized by rapid embryonic growth, provide a sensitive model for studying the possible toxic effects on organ development, body weight, and oxidative stress. The objective of this review was to evaluate the toxicity of various types of carbon black nanomaterials administered at the beginning of embryogenesis in a chicken embryo model. In addition, the effects of diamond and graphene NPs and carbon nanotubes are reviewed.

Mesoporous silica induces hippocampal neurons cell autophagy through AMPK/mTOR/P70S6K signaling pathway

Mesoporous silica is a drug carrier with strong targeting, large loading capacity, and easy modification of its surface while its toxicity draws increasing attention recently. In this study, we evaluated the impact of SBA-15 nanomaterials on hippocampal neurons. We found that SBA-15 induces oxidative damage to hippocampal neurons HT22, which further activates autophagy. Treatment with the mammalian target of rapamycin (mTOR) inhibitor AZD8055, the phosphorylation level of mTOR and P70S6K reduced and increased levels of p-AMPK meaning that the adenosine-activated protein kinase (AMPK)/mTOR/P70S6K pathway is involved in SBA-15 induced autophagy of HT22. These results suggested that mesoporous silica material SBA-15 might affect central nervous cells via oxidative stress activation of the AMPK/mTOR/P70S6K pathway, which provides a theoretical basis for safe administration of such materials in patients.

The effects of functionalization of carbon nanotubes on toxicological parameters in mice

Carbon nanotubes (CNTs) have emerged as a new class of multifunctional nanoparticles in biomedicine, but their multiple in vivo effects remain unclear. Also, the impact of various functionalization types and duration of exposures are still unidentified. Herein, we report a complete toxicological study to evaluate the effects of single- and multiwalled carbon nanotubes (SWCNTs and MWCNTs) with either amine or carboxylic acid (COOH) surface functional groups. The results showed that significant oxidative stress and the subsequent cell apoptosis could be resulted in both acute and, mainly, in chronic intravenous administrations. Also, male reproductive parameters were altered during these exposures. The amino-functionalized CNTs had more toxic properties compared with the COOH functionalized group, and also, in some groups, the multiwalled nanotubes were more active in eliciting cytotoxicity than the single-walled nanotubes. Interestingly, the SWCNTs-COOH had the least alterations in most of the parameters. Evidently, it is concluded that the toxicity of CNTs in specific organs can be minimized through particular surface functionalizations.

Bioprinting for Human Respiratory and Gastrointestinal In Vitro Models

Increasing ethical and biological concerns require a paradigm shift toward animal-free testing strategies for drug testing and hazard assessments. To this end, the application of bioprinting technology in the field of biomedicine is driving a rapid progress in tissue engineering. In particular, standardized and reproducible in vitro models produced by three-dimensional (3D) bioprinting technique represent a possible alternative to animal models, enabling in vitro studies relevant to in vivo conditions. The innovative approach of 3D bioprinting allows a spatially controlled deposition of cells and biomaterial in a layer-by-layer fashion providing a platform for engineering reproducible models. However, despite the promising and revolutionizing character of 3D bioprinting technology, standardized protocols providing detailed instructions are lacking. Here, we provide a protocol for the automatized printing of simple alveolar, bronchial, and intestine epithelial cell layers as the basis for more complex respiratory and gastrointestinal tissue models. Such systems will be useful for high-throughput toxicity screening and drug efficacy evaluation.

Longitudinal follow-up of health effects among workers handling engineered nanomaterials: a panel study

BACKGROUND

Although no human illness to date is confirmed to be attributed to engineered nanoparticles, occupational epidemiological studies are needed to verify the health effects of nanoparticles. This study used a repeated measures design to explore the potential adverse health effects of workers handling nanomaterials.

METHODS

Study population was 206 nanomaterial-handling workers and 108 unexposed controls, who were recruited from 14 nanotechnology plants. They were followed up no less than two times in four years. A questionnaire was used to collect potential confounders and detailed work conditions. Control banding was adopted to categorize risk level for each participant as a surrogate marker of exposure. Health hazard markers include cardiopulmonary dysfunction markers, inflammation and oxidative damage markers, antioxidant enzymes activity, and genotoxicity markers. The Generalized Estimating Equation model was applied to analyze repeated measurements.

RESULTS

In comparison to the controls, a significant dose-dependent increase on risk levels for the change of superoxide dismutase (p<0.01) and a significant increase of glutathione peroxidase change in risk level 1 was found for nanomaterial-handling workers. However, the change of cardiovascular dysfunction, lung damages, inflammation, oxidative damages, neurobehavioral and genotoxic markers were not found to be significantly associated with nanomaterials handling in this panel study.

CONCLUSIONS

This repeated measurement study suggests that there was no evidence of potential adverse health effects under the existing workplace exposure levels among nanomaterials handling workers, except for the increase of antioxidant enzymes.

Host immune response to anti-cancer camptothecin conjugated cyclodextrin-based polymers

Introduction

Efficacy and safety are critical concerns when designing drug carriers. Nanoparticles are a particular type of carrier that has gained recent attention in cancer therapeutics.

Methods

In this study, we assess the safety profile of IT-101, a nanoparticle formed by self-assembly of camptothecin (CPT) conjugated cyclodextrin-based polymers. IT-101 delivers CPT to target cancer cells in animal models of numerous human cancers and in humans. Previous data from preclinical and clinical trials indicate that IT-101 has no notable immunological side effects. However, there have been no published studies focused on evaluating the effects of IT-101 on host immune systems.

Results

In this work, we demonstrate that IT-101 diminished initial host immune response following first injection of the nanopharmaceutical and induced NK cell activation and T cell proliferation upon further IT-101 exposure. Additionally, IT-101 could attenuate tumor growth more efficiently than CPT treatment only.

Conclusions

Drugs administration in whole-body circulation may lead to poorly bioavailable in central nervous system and often has toxic effects on peripheral tissues. Conjugated with cyclodextrin-based polymers not only reduce adverse effects but also modulate the immune responses to elevate drug efficacy. These immune responses may potentially facilitate actions of immune blockage, such as PD1/PDL1 in cancer treatment.

Study on the therapeutic index and synergistic effect of Chitosan-zinc oxide nanomicellar composites for drug-resistant bacterial biofilm inhibition

The synergistic effectiveness of chitosan with zinc oxide nanomicelles (CZNPs) on broad spectrum of multidrug resistance (MDR) was previously evidenced in our labs, requiring elucidation of the therapeutic index (TI) for safe in vivo use. This in vitro assessment estimated the effective dose (ED₅₀) of micellar CZNPs for eradication of the MDR Enterococcus faecium 1449 model and the corresponding cytotoxic dose (LD₅₀) against rat small intestinal epithelial cells as functions of TI. In order to visually determine the mechanistic effects of micellar CZNPs on bacterial biofilm size reduction, LIVE/DEAD viability assay was used in conjunction with advanced fluorescence imaging and 3D confocal microscopy. Biofilm quantification was performed through the measure of the fluorescence intensity, using the Biotek Synergy Neo2 for calculating the ED₅₀. To generate the LD₅₀, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cytotoxicity assay was implemented. Quantification results revealed, at the same concentration (200 µg/mL), micellar CZNPs had average biofilm reduction of approximately 50.22% at 24 h (ED₅₀ = 199.13 µg/mL, LD₅₀ = 240.20 µg/mL, TI = 1.2062), compared to chitosan (15.66%) and ZnO (13.94%) alone. Conclusively, the ED₅₀ of micellar CZNPs on MDR bacterial biofilms (199.13 µg/mL) as a function of TI reveals a promising nanotherapeutic agent in comparison to either Chitosan or ZnO alone.

Sensitive colorimetric detection of CN− and AcO− anions in a semi-aqueous environment through a coumarin–naphthalene conjugate azo dye

An efficient colorimetric chemosensor to detect anions in an aqueous medium.

The Plasma Bioavailability of Coenzyme Q10 Absorbed from the Gut and the Oral Mucosa

Coenzyme Q₁₀ (CoQ₁₀) has a central role in the generation of cellular bioenergy and its regulation. The hydrophobicity exhibited by the CoQ₁₀ molecule leads to reports of poor absorption profiles, therefore, the optimization of formulations and modes of delivery is an ever-evolving therapeutic goal. The aim of this study was to investigate different CoQ₁₀ formulations. The article summarizes the findings from an Australian comparative study involving adults administered CoQ₁₀ through different oral delivery platforms. A total of 11 participants (six males and five females) voluntarily participated in a comparative clinical study of three different CoQ₁₀ formulations across a six-week period, completing 198 person-hours of cumulative contribution equivalent to n = 33 participation. All of the eligible participants (n = 11) administered the three formulations blinded from who the commercial supplier of the formulation was and from what the chemical form of the CoQ₁₀ was that was being administered. The dosing between the CoQ₁₀ preparations were dispensed sequentially and were administered following three-week washouts. Three commercial preparations were tested, which included the following: formulations with capsules each containing ubiquinol and ubiquinone (150 mg/capsule), and a liposome ubiquinone formulation (40 mg/mL at 2 actuations of the pump). A significant inter-subject variation in the plasma level of CoQ₁₀ at baseline that was observed to increase with an increase in age. This trend persisted in the post administration of the different formulations. Furthermore, it was observed that the intestinal absorption and bioavailability of CoQ₁₀ varied significantly in the plasma between subjects, irrespective of whether the ubiquinol or ubiquinone forms were administered. The administration of CoQ₁₀ as a liposome for preparation showed the poorest response in bioavailability. Although the ubiquinol capsule form of CoQ₁₀ was observed to have increased in the plasma versus the ubiquinone capsules and the ubiquinol liposome at the two-hour interval, the inter-subject variation was such that the difference was not significant (p > 0.05). All of the CoQ₁₀ formulations showed no further increases in their plasma levels over the remaining study period (i.e., four hours). This study further concluded that the intestinal absorption of CoQ₁₀ is highly variable and is independent of the molecular form administered. Furthermore, it also concludes that liposomes are not an effective vehicle for the oral administration of CoQ₁₀, and as such, did not improve the oral mucosal/sublingual absorption and bioavailability of the molecule. Of interest was the observation that with the increasing subject age, there was an observed increase in the baseline plasma CoQ₁₀ levels in the participants prior to dosing. It was posited that the increase in the baseline plasma levels of CoQ₁₀ with an increase in age could be due to the loss of skeletal muscle mass, a result that still needs to be verified.

Inhaled nanomaterials and the respiratory microbiome: clinical, immunological and toxicological perspectives

Our development and usage of engineered nanomaterials has grown exponentially despite concerns about their unfavourable cardiorespiratory consequence, one that parallels ambient ultrafine particle exposure from vehicle emissions. Most research in the field has so far focused on airway inflammation in response to nanoparticle inhalation, however, little is known about nanoparticle-microbiome interaction in the human airway and the environment. Emerging evidence illustrates that the airway, even in its healthy state, is not sterile. The resident human airway microbiome is further altered in chronic inflammatory respiratory disease however little is known about the impact of nanoparticle inhalation on this airway microbiome. The composition of the airway microbiome, which is involved in the development and progression of respiratory disease is dynamic, adding further complexity to understanding microbiota-host interaction in the lung, particularly in the context of nanoparticle exposure. This article reviews the size-dependent properties of nanomaterials, their body deposition after inhalation and factors that influence their fate. We evaluate what is currently known about nanoparticle-microbiome interactions in the human airway and summarise the known clinical, immunological and toxicological consequences of this relationship. While associations between inhaled ambient ultrafine particles and host immune-inflammatory response are known, the airway and environmental microbiomes likely act as intermediaries and facilitate individual susceptibility to inhaled nanoparticles and toxicants. Characterising the precise interaction between the environment and airway microbiomes, inhaled nanoparticles and the host immune system is therefore critical and will provide insight into mechanisms promoting nanoparticle induced airway damage.

Zinc Oxide Nanoparticle as a Novel Class of Antifungal Agents: Current Advances and Future Perspectives

Certain types of nanoparticles, especially zinc oxide nanoparticles (ZnONPs), are widely reported to be capable of the inhibition of harmful bacteria, yeasts, and filamentous fungi. The unique physicochemical and biological properties of ZnONPs also make them attractive to the food industry for use as a promising antifungal agent. This Review thoroughly introduces the preparation methods and antifungal properties of ZnONPs and analyzes their possible antifungal mechanisms. The applicability of ZnONPs in food packaging and nutritional supplements and as an antimicrobial additive is also documented. Moreover, evaluations for biological safety of ZnONPs are objectively reviewed in this paper. The discussions addressed in this Review not only have theoretical significance but also are conducive to the development of food safety, nutrition, and human health. The summarized knowledge and future perspectives outlined here are expected to promote and guide new research toward developing and optimizing the application of ZnONPs as a novel class of antifungal agents to help improve food quality as well as food safety in the near future.