Redox-active nanomaterials for nanomedicine applications

A neoteric antibacterial ceria-silver nanozyme for abiotic surfaces

Community-associated and hospital-acquired infections caused by bacteria continue to yield major global challenges to human health. Bacterial contamination on abiotic surfaces is largely spread via high-touch surfaces and contemporary standard disinfection practices show limited efficacy, resulting in unsatisfactory therapeutic outcomes. New strategies that offer non-specific and broad protection are urgently needed. Herein, we report our novel ceria-silver nanozyme engineered at a molar ratio of 5:1 and with a higher trivalent (Ce3+) surface fraction. Our results reveal potent levels of surface catalytic activity on both wet and dry surfaces, with rapid, and complete eradication of Pseudomonas aeruginosa, Staphylococcus aureus, and methicillin resistant S. aureus, in both planktonic and biofilm form. Preferential electrostatic adherence of anionic bacteria to the cationic nanozyme surface leads to a catastrophic loss in both aerobic and anaerobic respiration, DNA damage, osmodysregulation, and finally, programmed bacterial lysis. Our data reveal several unique mechanistic avenues of synergistic ceria-Ag efficacy. Ag potentially increases the presence of Ce3+ sites at the ceria-Ag interface, thereby facilitating the formation of harmful H2O2, followed by likely permeation across the cell wall. Further, a weakened Ag-induced Ce-O bond may drive electron transfer from the Ec band to O2, thereby further facilitating the selective reduction of O2 toward H2O2 formation. Ag destabilizes the surface adsorption of molecular H2O2, potentially leading to higher concentrations of free H2O2 adjacent to bacteria. To this end, our results show that H2O2 and/or NO/NO2-/NO3- are the key liberators of antibacterial activity, with a limited immediate role being offered by nanozyme-induced ROS including O2•- and OH•, and likely other light-activated radicals. A mini-pilot proof-of-concept study performed in a pediatric dental clinic setting confirms residual, and continual nanozyme antibacterial efficacy over a 28-day period. These findings open a new approach to alleviate infections caused by bacteria for use on high-touch hard surfaces.

Reactive oxygen species-scavenging nanomaterials for the prevention and treatment of age-related diseases

With increasing proportion of the elderly in the population, age-related diseases (ARD) lead to a considerable healthcare burden to society. Prevention and treatment of ARD can decrease the negative impact of aging and the burden of disease. The aging rate is closely associated with the production of high levels of reactive oxygen species (ROS). ROS-mediated oxidative stress in aging triggers aging-related changes through lipid peroxidation, protein oxidation, and DNA oxidation. Antioxidants can control autoxidation by scavenging free radicals or inhibiting their formation, thereby reducing oxidative stress. Benefiting from significant advances in nanotechnology, a large number of nanomaterials with ROS-scavenging capabilities have been developed. ROS-scavenging nanomaterials can be divided into two categories: nanomaterials as carriers for delivering ROS-scavenging drugs, and nanomaterials themselves with ROS-scavenging activity. This study summarizes the current advances in ROS-scavenging nanomaterials for prevention and treatment of ARD, highlights the potential mechanisms of the nanomaterials used and discusses the challenges and prospects for their applications.

Unravelling the in vitro and in vivo potential of selenium nanoparticles in Alzheimer's disease: A bioanalytical review

Alzheimer's disease (AD) is a devastating neurodegenerative disorder characterized by progressive cognitive decline and the accumulation of beta-amyloid plaques and tau tangles in the brain. Current therapies have limited efficacy, prompting the search for novel treatments. Selenium nanoparticles (SeNPs) have emerged as promising candidates for AD therapy due to their unique physicochemical properties and potential therapeutic effects. This review provides an overview of SeNPs and their potential application in AD treatment, as well as the main bioanalytical techniques applied in this field. SeNPs possess antioxidant and anti-inflammatory properties, making them potential candidates to combat the oxidative stress and neuroinflammation associated with AD. Moreover, SeNPs have shown the ability to cross the blood-brain barrier (BBB), allowing them to target brain regions affected by AD pathology. Various methods for synthesizing SeNPs are explored, including chemical, physical and biological synthesis approaches. Based on the employment of algae, yeast, fungi, and plants, green methods offer a promising and biocompatible alternative for SeNPs production. In vitro studies have demonstrated the potential of SeNPs in reducing beta-amyloid aggregation and inhibiting tau hyperphosphorylation, providing evidence of their neuroprotective effects on neuronal cells. In vivo studies using transgenic mouse models and AD-induced symptoms have shown promising results, with SeNPs treatment leading to cognitive improvements and reduced amyloid plaque burden in the hippocampus. Looking ahead, future trends in SeNPs research involve developing innovative brain delivery strategies to enhance their therapeutic potential, exploring alternative animal models to complement traditional mouse studies, and investigating multi-targeted SeNPs formulations to address multiple aspects of AD pathology. Overall, SeNPs represent a promising avenue for AD treatment, and further research in this field may pave the way for effective and much-needed therapeutic interventions for individuals affected by this debilitating disease.

Natural polyphenols for drug delivery and tissue engineering construction: A review

Polyphenols, natural compounds rich in phenolic structures, are gaining prominence due to their antioxidant, anti-inflammatory, antibacterial, and anticancer properties, making them valuable in biomedical applications. Through covalent and noncovalent interactions, polyphenols can bind to biomaterials, enhancing their performance and compensating for their shortcomings. Such polyphenol-based biomaterials not only increase the efficacy of polyphenols but also improve drug stability, control release kinetics, and boost the therapeutic effects of drugs. They offer the potential for targeted drug delivery, reducing off-target impacts and enhancing therapeutic outcomes. In tissue engineering, polyphenols promote cell adhesion, proliferation, and differentiation, thus aiding in the formation of functional tissues. Additionally, they offer excellent biocompatibility and mechanical strength, essential in designing scaffolds. This review explores the significant roles of polyphenols in tissue engineering and drug delivery, emphasizing their potential in advancing biomedical research and healthcare.

Assessing the Redox Toxicity of 2D Nanosheets Based on Their Redox Effect on Cytochrome c in Microchannels

2D nanosheets (NSs) have been widely used in drug-related applications. However, a comprehensive investigation into the cytotoxicity mechanism linked to the redox activity is lacking. In this study, with cytochrome c (Cyt c) as the model biospecies, the cytotoxicity of 2D NSs was evaluated systematically based on their redox effect with microfluidic techniques. The interface interaction, dissolution, and redox effect of 2D NSs on Cyt c were monitored with pulsed streaming potential (SP) measurement and capillary electrophoresis (CE). The relationship between the redox activity of 2D NSs and the function of Cyt c was evaluated in vitro with Hela cells. The results indicated that the dissolution and redox activity of 2D NSs can be simultaneously monitored with CE under weak interface interactions and at low sample volumes. Both WS2 NSs and MoS2 NSs can reduce Cyt c without significant dissolution, with reduction rates measured at 6.24 × 10-5 M for WS2 NSs and 3.76 × 10-5 M for MoS2 NSs. Furthermore, exposure to 2D NSs exhibited heightened reducibility, which prompted more pronounced alterations associated with Cyt c dysfunction, encompassing ATP synthesis, modifications in mitochondrial membrane potential, and increased reactive oxygen species production. These observations suggest a positive correlation between the redox activity of 2D NSs and their redox toxicity in Hela cells. These findings provide valuable insight into the redox properties of 2D NSs regarding cytotoxicity and offer the possibility to modify the 2D NSs to reduce their redox toxicity for clinical applications.

Advanced materials foresight: research and innovation indicators related to advanced and smart nanomaterials

Background: Advanced materials are most likely to bring future economic, environmental and social benefits. At the same time, they may pose challenges regarding their safety and sustainability along the entire lifecycle. This needs to be timely addressed by the stakeholders (industry, research, policy, funding and regulatory bodies). As part of a larger foresight project, this study aimed to identify areas of scientific research and technological development related to advanced materials, in particular advanced nanomaterials and the sub-group of smart nanomaterials. The study identified and collected data to build relevant research and innovation indicators and analyse trends, impact and other implications. Methods: This study consisted of an iterative process including a documentation phase followed by the identification, description and development of a set of core research and innovation indicators regarding scientific publications, EU projects and patents. The data was extracted mainly from SCOPUS, CORDIS and PATSTAT databases using a predefined search string that included representative keywords. The trends, distributions and other aspects reflected in the final version of the indicators were analysed, e.g. the number of items in a period of time, geographical distribution, organisations involved, categories of journals, funding programmes, costs and technology areas. Results: Generally, for smart nanomaterials the data used represent around 3.5% of the advanced nanomaterials data, while for each field analysed, they represent 4.4% for publications, 13% for projects and 1.1% for patents. The study shows current trends for advanced nanomaterials at a top-level information that can be further extended with sub-indicators. Generally, the results indicated a significant growth in research into advanced nanomaterials, including smart nanomaterials, in the last decade, leading to an increased availability of information. Conclusion: These indicators identify trends regarding scientific and technological achievements and represent an important element when examining possible impacts on society and policy implications associated to these areas.

Multifunctional Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas9-Based Nanobomb against Carbapenem-Resistant Acinetobacter baumannii Infection through Cascade Reaction and Amplification Synergistic Effect

Carbapenems have been considered to be the preferred antibiotics against Acinetobacter baumannii thus far. However, carbapenem-resistant Acinetobacter baumannii (CRAB) has gradually escalated worldwide, and it frequently causes respiratory and bloodstream infections. Its resistance may lead to high mortality. Thus, there is an urgent need to develop antibacterial drugs. In our research, the pH-sensitive sgRNA-I/L@ZS nanosystem delivered imipenem and better released it in infected tissues to synergistically damage bacteria with nanoparticles. Gene editing of the CRISPR-Cas9 nanosystem amplified the synergistic effect by reversing the drug-resistance of imipenem. Nitric oxide, which l-arginine reacted with ROS to produce in cascade reaction and bacterial infection sites, was beneficial to heal the infected tissues and induce bacteria death for further enhancing antibacterial effects. In addition, this nanocomposite influenced host-bacteria interactions and restrained and destroyed biofilms. The sgRNA-I/L@ZS nanosystem, similar to a nanobomb, was a high-efficiency bactericide against CRAB. Eventually, in acute pneumonia and peritonitis mouse models, the sgRNA-I/L@ZS nanosystem could combat bacteria and protect tissues from infection. It had marked suppressive effects on inflammation and promoted healing and proliferation of infected tissues. This multifunctional nanosystem is expected to be an effective antibacterial agent in the clinic based on good biocompatibility and no toxic side effects. Therefore, developing the nanocomposites will take a favorable step toward solving intractable public health issues.

A pH-responsive ZC-QPP hydrogel for synergistic antibacterial and antioxidant treatment to enhance wound healing

The problems of bacterial resistance and high oxidation level severely limit wound healing. Therefore, we constructed a multifunctional platform of chitosan quaternary ammonium salts (QCS)/polyvinyl alcohol (PVA)/polyethylene glycol (PEG) hydrogels (QPP) loaded with ZnO@CeO2 (ZC-QPP). Firstly, the hydrogel was co-cross-linked by hydrogen and borate ester bonds, which allows easy adherence to a tissue surface for offering a protective barrier and moist environment for wounds. The chitosan quaternary ammonium salts due to their amino groups have inherent antibacterial properties to induce bacterial death. In response to the acidic conditions of the bacterial infection microenvironment, the borate ester bonds in the QPP hydrogel break and the ZC NCs dispersed in the hydrogel are released. The gradual dissociation of Zn2+ under acidic conditions can directly damage bacterial membranes. The wound site of bacterial infection always causes overexpression of reactive oxygen species (ROS) levels, often leading to inflammation and preventing rapid wound repair. CeO2 can eliminate excess ROS to reduce the inflammatory response. From in vitro and in vivo results, the high biosafety of the ZC-QPP hydrogel has demonstrated excellent antibacterial and antioxidant performance to enhance wound healing. Therefore, the ZC-QPP hydrogel opens a method to develop multifunctional synergistic therapeutic platforms combining enzyme-like nanomaterials with hydrogels for synergistic antibacterial and antioxidant treatment to promote wound healing.

Antioxidant Activities of Photoinduced Phycogenic Silver Nanoparticles and Their Potential Applications

While various methods exist for synthesizing silver nanoparticles (AgNPs), green synthesis has emerged as a promising approach due to its affordability, sustainability, and suitability for biomedical purposes. However, green synthesis is time-consuming, necessitating the development of efficient and cost-effective techniques to minimize reaction time. Consequently, researchers have turned their attention to photo-driven processes. In this study, we present the photoinduced bioreduction of silver nitrate (AgNO₃) to AgNPs using an aqueous extract of Ulva lactuca, an edible green seaweed. The phytochemicals found in the seaweed functioned as both reducing and capping agents, while light served as a catalyst for biosynthesis. We explored the effects of different light intensities and wavelengths, the initial pH of the reaction mixture, and the exposure time on the biosynthesis of AgNPs. Confirmation of AgNP formation was achieved through the observation of a surface plasmon resonance band at 428 nm using an ultraviolet-visible (UV-vis) spectrophotometer. Fourier transform infrared spectroscopy (FTIR) revealed the presence of algae-derived phytochemicals bound to the outer surface of the synthesized AgNPs. Additionally, high-resolution transmission electron microscopy (HRTEM) and atomic force microscopy (AFM) images demonstrated that the NPs possessed a nearly spherical shape, ranging in size from 5 nm to 40 nm. The crystalline nature of the NPs was confirmed by selected area electron diffraction (SAED) and X-ray diffraction (XRD), with Bragg's diffraction pattern revealing peaks at 2θ = 38°, 44°, 64°, and 77°, corresponding to the planes of silver 111, 200, 220, and 311 in the face-centered cubic crystal lattice of metallic silver. Energy-dispersive X-ray spectroscopy (EDX) results exhibited a prominent peak at 3 keV, indicating an Ag elemental configuration. The highly negative zeta potential values provided further confirmation of the stability of AgNPs. Moreover, the reduction kinetics observed via UV-vis spectrophotometry demonstrated superior photocatalytic activity in the degradation of hazardous pollutant dyes, such as rhodamine B, methylene orange, Congo red, acridine orange, and Coomassie brilliant blue G-250. Consequently, our biosynthesized AgNPs hold great potential for various biomedical redox reaction applications.

Bio-inspired nanoparticles mediated from plant extract biomolecules and their therapeutic application in cardiovascular diseases: A review

Nanoparticles (NPs) have gained recognition for diagnosis, drug delivery, and therapy in fatal diseases. This review focuses on the benefits of green synthesis of bioinspired NPs using various plant extract (containing various biomolecules such as sugars, proteins, and other phytochemical compounds) and their therapeutic application in cardiovascular diseases (CVDs). Multiple factors including inflammation, mitochondrial and cardiomyocyte mutations, endothelial cell apoptosis, and administration of non-cardiac drugs, can trigger the cause of cardiac disorders. Furthermore, the interruption of reactive oxygen species (ROS) synchronization from mitochondria causes oxidative stress in the cardiac system, leading to chronic diseases such as atherosclerosis and myocardial infarction. NPs can decrease the interaction with biomolecules and prevent the incitement of ROS. Understanding this mechanism can pave the way for using green synthesized elemental NPs to reduce the risk of CVD. This review delivers information on the different methods, classifications, mechanisms and benefits of using NPs, as well as the formation and progression of CVDs and their effects on the body.

Stimuli-responsive ultra-small vanadate prodrug nanoparticles with NIR photothermal properties to precisely inhibit Na/K-ATPase for enhanced cancer therapy

Inhibition of Na/K-ATPase is a promising cancer treatment owing to the essential role of Na/K-ATPase in maintaining various cellular functions. The potent Na/K-ATPase inhibitor, vanadate(V) (termed as V(V)), has exhibited efficient anticancer effects. However, nonspecific inhibition using V(V) results in serious side effects, which hinder its clinical application. Here, bovine serum albumin (BSA)-modified ultra-small vanadate prodrug nanoparticles (V(IV) NPs) were synthesized via a combined reduction-coordination strategy with a natural polyphenol tannic acid (TA). A lower systemic toxicity of V(IV) NPs is achieved by strong metal-polyphenol coordination interactions. An efficient V(V) activation is realized by reactive oxygen species (ROS) at the tumor site. Furthermore, V(IV) NPs show excellent photothermal properties in the near-infrared (NIR) region. By NIR irradiation at the tumor site for mild hyperthermia, selective enhancement of the interactions between V(V) and Na/K-ATPase achieves stronger inhibition of Na/K-ATPase for robust cell killing effect. Altogether, V(IV) NPs specifically inhibit Na/K-ATPase in cancer cells with negligible toxicity to normal tissues, thus making them a promising candidate for clinical applications of Na/K-ATPase inhibition.

MnOOH-Catalyzed Autoxidation of Glutathione for Reactive Oxygen Species Production and Nanocatalytic Tumor Innate Immunotherapy

The antioxidant system, signed with reduced glutathione (GSH) overexpression, is the key weapon for tumor to resist the attack by reactive oxygen species (ROS). Counteracting the ROS depletion by GSH is an effective strategy to guarantee the antitumor efficacy of nanocatalytic therapy. However, simply reducing the concentration of GSH does not sufficiently improve tumor response to nanocatalytic therapy intervention. Herein, a well-dispersed MnOOH nanocatalyst is developed to catalyze GSH autoxidation and peroxidase-like reaction concurrently and respectively to promote GSH depletion and H₂O₂ decomposition to produce abundant ROS such as hydroxyl radical (·OH), thereby generating a highly effective superadditive catalytic therapeutic efficacy. Such a therapeutic strategy that transforms endogenous "antioxidant" into "oxidant" may open a new avenue for the development of antitumor nanocatalytic medicine. Moreover, the released Mn²⁺ can activate and sensitize the cGAS-STING pathway to the damaged intratumoral DNA double-strands induced by the produced ROS to further promote macrophage maturation and M1-polarization, which will boost the innate immunotherapeutic efficacy. Resultantly, the developed simple MnOOH nanocatalytic medicine capable of simultaneously catalyzing GSH depletion and ROS generation, and mediating innate immune activation, holds great potential in the treatment of malignant tumors.

Engineering ROS-scavenging Prussian blue nanozymes for efficient atherosclerosis nanotherapy

Atherosclerosis (AS), characterized by a chronic inflammatory disease, is a top cause of morbidity and disability worldwide. During the pathogenesis of AS, the leading process of inflammation highly involves a secondary event of oxidative stress, but limited antioxidants are currently available clinically due to their nonspecific effects, poor biosafety, and rapid in vivo elimination and urinary excretion as well as short retention time within plaque lesions. In this work, Prussian blue nanozymes with a strong reactive oxygen species (ROS)-scavenging ability were rationally engineered for efficient AS nanotherapy. Specifically, the obtained nanozymes with high photothermal performance could behave as potent photoacoustic imaging agents for plaque detection. In addition, these nanozymes featuring multienzyme activities could reduce the cellular ROS level, exert cytoprotective effects against ROS-mediated macrophages apoptosis, and inhibit foam cell formation, significantly boycotting AS development. The underlying mechanism was further verified by transcriptome sequencing at the cellular level and a series of immunohistochemical staining of aortic sinus sections in apoE^-/- mice. Finally, the high biocompatibility and biosafety of the engineered Prussian blue nanozymes further guarantee their clinical translation potential for AS management.

Magnetically responsive nanoplatform targeting circRNA circ_0058051 inhibits hepatocellular carcinoma progression

Circular RNAs (circRNAs) are a class of highly stable and closed-loop noncoding RNA that are involved in the occurrence and development of hepatocellular carcinoma (HCC). However, little is known about the therapeutic role of circRNAs in HCC. We found that high circ_0058051 expression was negatively correlated with the prognosis of HCC patients. Circ_0058051 knockdown attenuated the proliferation and colony formation, meanwhile inhibited migration of HCC cells. Circ_0058051 may be used as a target for HCC gene therapy. We synthesized a novel small interfering RNA (siRNA) delivery system, PEG-PCL-PEI-C14-SPIONs (PPPCSs), based on superparamagnetic iron oxide nanoparticles (SPIONs). PPPCSs protected the siRNA of circ_0058051 from degradation in serum and effectively delivered siRNA into SMMC-7721 cells. Meanwhile, intravenous injection of the PPPCSs/siRNA complex could inhibit tumor growth in the subcutaneous tumor model. In addition, the nanocomposite is not toxic to the organs of nude mice. The above results show that PPPCSs/si-circ_0058051 complex may provide a novel and promising method of HCC treatment.

The progress of research on the application of redox nanomaterials in disease therapy

Redox imbalance can trigger cell dysfunction and damage and plays a vital role in the origin and progression of many diseases. Maintaining the balance between oxidants and antioxidants in vivo is a complicated and arduous task, leading to ongoing research into the construction of redox nanomaterials. Nanodrug platforms with redox characteristics can not only reduce the adverse effects of oxidative stress on tissues by removing excess oxidants from the body but also have multienzyme-like activity, which can play a cytotoxic role in tumor tissues through the catalytic oxidation of their substrates to produce harmful reactive oxygen species such as hydroxyl radicals. In this review, various redox nanomaterials currently used in disease therapy are discussed, emphasizing the treatment methods and their applications in tumors and other human tissues. Finally, the limitations of the current clinical application of redox nanomaterials are considered.

Mitogen-like Cerium-Based Nanoparticles Protect Schmidtea mediterranea against Severe Doses of X-rays

Novel radioprotectors are strongly demanded due to their numerous applications in radiobiology and biomedicine, e.g., for facilitating the remedy after cancer radiotherapy. Currently, cerium-containing nanomaterials are regarded as promising inorganic radioprotectors due to their unrivaled antioxidant activity based on their ability to mimic the action of natural redox enzymes like catalase and superoxide dismutase and to neutralize reactive oxygen species (ROS), which are by far the main damaging factors of ionizing radiation. The freshwater planarian flatworms are considered a promising system for testing new radioprotectors, due to the high regenerative potential of these species and an excessive amount of proliferating stem cells (neoblasts) in their bodies. Using planarian Schmidtea mediterranea, we tested CeO₂ nanoparticles, well known for their antioxidant activity, along with much less studied CeF₃ nanoparticles, for their radioprotective potential. In addition, both CeO₂ and CeF₃ nanoparticles improve planarian head blastema regeneration after ionizing irradiation by enhancing blastema growth, increasing the number of mitoses and neoblasts' survival, and modulating the expression of genes responsible for the proliferation and differentiation of neoblasts. The CeO₂ nanoparticles' action stems directly from their redox activity as ROS scavengers, while the CeF₃ nanoparticles' action is mediated by overexpression of "wound-induced genes" and neoblast- and stem cell-regulating genes.

Current Perspectives in Graphene Oxide-Based Electrochemical Biosensors for Cancer Diagnostics

Since the first commercial biosensor device for blood glucose measurement was introduced in the 1970s, many “biosensor types” have been developed, and this research area remains popular worldwide. In parallel with some global biosensor research reports published in the last decade, including a great deal of literature and industry statistics, it is predicted that biosensor design technologies, including handheld or wearable devices, will be preferred and highly valuable in many areas in the near future. Biosensors using nanoparticles still maintain their very important place in science and technology and are the subject of innovative research projects. Among the nanomaterials, carbon-based ones are considered to be one of the most valuable nanoparticles, especially in the field of electrochemical biosensors. In this context, graphene oxide, which has been used in recent years to increase the electrochemical analysis performance in biosensor designs, has been the subject of this review. In fact, graphene is already foreseen not only for biosensors but also as the nanomaterial of the future in many fields and is therefore drawing research attention. In this review, recent and prominent developments in biosensor technologies using graphene oxide (GO)-based nanomaterials in the field of cancer diagnosis are briefly summarized.

Assessment of the Potential Health Risk of Gold Nanoparticles Used in Nanomedicine

Due to unique properties, nanoparticles (NPs) have become a preferred material in biomedicine. The benefits of their use are indisputable, but their safety and potential toxicity are becoming more and more important. Especially, excessive production of reactive oxygen species (ROS) induced by the strong oxidation potential of metal NPs could evoke adverse effects associated with damage to nucleic acids, proteins and lipids. Our study gives a view on the potential cytotoxicity of gold NPs (Au NPs) of different size from the perspective of the redox state of healthy (HEK 293 T) and cancer (A375 and A594) cell lines. These cells were incubated in the presence of two concentrations of Au NPs for 24 h or 72 h and total antioxidant capacity, 8-isoprostane, and protein carbonyl levels were determined. Furthermore, the activity of antioxidant enzymes such as superoxide dismutase, glutathione peroxidase, and catalase was detected in cell lysates. Our results compared to the results of other laboratories are very contradictory. The outcomes also differ between healthy and cancer cell lines. However, there are certainly changes in the activities of antioxidant enzymes, as well as the damage to biological molecules due to increased NP-induced oxidative stress. But the final decision of the effect of Au NPs on the oxidative state of selected cell lines requires further research.

Systematic and mechanistic analysis of AuNP-induced nanotoxicity for risk assessment of nanomedicine

For decades, nanoparticles (NPs) have been widely implemented in various biomedical fields due to their unique optical, thermal, and tunable properties. Particularly, gold nanoparticles (AuNPs) have opened new frontiers in sensing, targeted drug delivery, imaging, and photodynamic therapy, showing promising results for the treatment of various intractable diseases that affect quality of life and longevity. Despite the tremendous achievements of AuNPs-based approaches in biomedical applications, few AuNP-based nanomedicines have been evaluated in clinical trials, which is likely due to a shortage of understanding of the biological and pathological effects of AuNPs. The biological fate of AuNPs is tightly related to a variety of physicochemical parameters including size, shape, chemical structure of ligands, charge, and protein corona, and therefore evaluating the effects of these parameters on specific biological interactions is a major ongoing challenge. Therefore, this review focuses on ongoing nanotoxicology studies that aim to characterize the effect of various AuNP characteristics on AuNP-induced toxicity. Specifically, we focus on understanding how each parameter alters the specific biological interactions of AuNPs via mechanistic analysis of nano-bio interactions. We also discuss different cellular functions affected by AuNP treatment (e.g., cell motility, ROS generation, interaction with DNA, and immune response) to understand their potential human health risks. The information discussed herein could contribute to the safe usage of nanomedicine by providing a basis for appropriate risk assessment and for the development of nano-QSAR models.

Gold Nanoparticle-Based Therapy for Muscle Inflammation and Oxidative Stress

Proinflammatory cytokines and reactive oxygen species are released after muscle damage, and although they are necessary for the muscle regeneration process, an excess of these substances leads to the destruction of biomolecules and impairment of the repair system. Several drugs have emerged in recent years to control the muscle inflammatory response, and studies have shown that gold nanoparticles (AuNPs) have anti-inflammatory and antioxidant properties. This review reveals the effects of AuNPs on the inflammatory and redox mechanisms of muscles. We assessed the results of several studies published in different journals over the last 20 years, with a focus on the effects of AuNPs on possible aspects of muscle regeneration or recovery, namely, inflammatory processes and redox system mechanisms. A systematic database search was conducted using PubMed, Medline, Bireme, Web of Science, and Google Scholar to identify peer-reviewed studies from the 2000s. Combinations of keywords related to muscle damage, regeneration or repair, AuNPs, oxidative stress, and antioxidants were used in the search. This review did not address other variables, such as specific diseases or other biological effects; however, these variables should be considered for a complete understanding of the effects of AuNPs on skeletal muscles.

N-Doped Carbon Nanorods from Biomass as a Potential Antidiabetic Nanomedicine

Insufficient glucose control remains a critical challenge for type 2 diabetes mellitus (T2DM) patients with currently used therapeutic drugs, which can also have detrimental side effects. The facile synthesis of nitrogen-doped carbon nanorods (N-CNRs) as therapeutic agents in a T2DM transgenic db/db mouse model is reported herein. N-CNRs are synthesized from silkworm powder without the assistance of any template and possess a hollow graphitic nature, rough surface, and good aqueous solubility, which make them ideal candidates for fabricating nanomedicines. N-CNRs are employed to reduce fasting blood glucose and ameliorate serum biomarker levels linked to oxidative stress and inflammation. Interestingly, through the downregulation of enhanced expression of glutathione peroxidase, superoxide dismutase, and catalase as well as inflammatory responses, N-CNRs reverse pancreatic dysfunction and normalize the secretory functions of pancreatic cells. Moreover, hepatic steatosis is attenuated by downregulating lipogenesis and increasing fatty acid oxidation. This finding may help in designing novel therapeutics for T2DM treatment.

Unravelling Micro and Nano vesicular System in Intranasal Drug Delivery for Epilepsy

BACKGROUND

Epilepsy is one of the major neurological disorders, affecting about 50 million people globally. Oral, intravenous, and rectal delivery systems are available for the management of epileptic seizures. However, intranasal delivery serves beneficial for delivering anti-epileptic drugs owing to the advantages it offers.

OBJECTIVE

Various approaches have been developed over the years aiming to attain either a safer or faster brain delivery; a nasal delivery system proposes significant outcomes. The non-invasiveness and high vascularity contribute to the high permeability of the nasal mucosa, allowing rapid drug absorption. This review highlights some of the promising novel approaches delivering antiepileptic drugs efficiently employing the nasal route.

METHODS

The method includes a collection of data from different search engines like PubMed, ScienceDirect, SciFinder for obtaining appropriate and relevant literature regarding epilepsy, intranasal delivery of antiepileptic agents, and novel therapeutics.

RESULTS

The present review underlines the majority of work related to intranasal delivery in the treatment of epilepsy, aiming to draw the attention of the researchers towards the easiest and efficient ways of formulation for the delivery of antiepileptics during seizures.

CONCLUSION

This review intends to provide understanding about the delivery aspects of anti-epileptic drugs, the benefits of intranasal delivery, and the novel approaches employed for the treatment of epilepsy.

Safe- and sustainable-by-design: The case of Smart Nanomaterials. A perspective based on a European workshop

The European Commission's Green Deal is a major policy initiative aiming to achieve a climate-neutral, zero-pollution, sustainable, circular and inclusive economy, driving both the New Industrial Strategy for Europe and the Chemicals Strategy for Sustainability. Innovative materials can help to reach these policy goals, but they need to be safe and sustainable themselves. Thus, one aim is to shift the development of chemicals to Safe- and Sustainable-by-Design, and define a new systems approach and criteria for sustainability to achieve this. An online workshop was organised in September 2020 by the Joint Research Centre and the Directorate-General Research and Innovation of the European Commission, with participants from academia, non-governmental organisations, industry and regulatory bodies. The aims were to introduce the concept of Safe- and Sustainable-by-Design, to identify industrial and regulatory challenges in achieving safer and more sustainable Smart Nanomaterials as an example of innovative materials, and to deliver recommendations for directions and actions necessary to meet these challenges. The following needs were identified: (i) an agreed terminology, (ii) a common understanding of the principles of Safe- and Sustainable-by-Design, iii) criteria, assessment tools and incentives to achieve a transition from Safe-by-Design to Safe- and Sustainable-by-Design, and (iv) preparedness of regulators and legislation for innovative chemicals/nanomaterials. This paper presents the authors' view on the state of the art as well as the needs for future activities, based on discussions at the workshop and further considerations. The case of Smart Nanomaterials is used to illustrate the Safe- and Sustainable-by-Design concept and challenges for its implementation. Most of the considerations can be extended to other advanced materials and to chemicals and products in general.

Anticancer Therapeutic Effects of Cerium Oxide Nanoparticles: Known and Unknown Molecular Mechanisms

Cerium-based nanoparticles (CeNPs), particularly cerium oxide (CeO2), have been studied extensively for their antioxidant and prooxidant properties. However, their complete redox and enzyme-mimetic mechanisms of therapeutic action at the molecular...

Polyphenol derived bioactive carbon quantum dots incorporated multifunctional hydrogel as oxidative stress attenuator for antiaging and in vivo wound-healing applications

Upregulation of certain enzymes, such as collagenase, tyrosinase, and elastase, is triggered by several extrinsic environmental factors, such as temperature, UV radiation, humidity, and stress, and leads to elasticity loss...

Commercial utilities and future perspective of nanomedicines

The present review aims to describe the commercial utilities and future perspectives of nanomedicines. Nanomedicines are intended to increase precision medicine and decrease the adverse effects on the patient. Nanomedicines are produced, engineered, and industrialized at the cellular, chemical, and macromolecular levels. This study describes the various aspects of nanomedicine such as governing outlooks over high use of nanomedicine, regulatory advancements for nanomedicines, standards, and guidelines for nanomedicines as per Therapeutic Goods Administration (TGA). This review also focuses on the patents and clinical trials based on nanoformulation, along with nanomedicines utilization as drug therapy and their market value. The present study concludes that nanomedicines are of high importance in biomedical and pharmaceutical production and offer better therapeutic effects especially in the case of drugs that possess low aqueous solubility. The factual data presented in this study will assist the researchers and health care professionals in understanding the applications of nanomedicine for better diagnosis and effective treatment of a disease.

Biomedical Applications of Carbon Nanomaterials: Fullerenes, Quantum Dots, Nanotubes, Nanofibers, and Graphene

Carbon nanomaterials (CNMs) have received tremendous interest in the area of nanotechnology due to their unique properties and flexible dimensional structure. CNMs have excellent electrical, thermal, and optical properties that make them promising materials for drug delivery, bioimaging, biosensing, and tissue engineering applications. Currently, there are many types of CNMs, such as quantum dots, nanotubes, nanosheets, and nanoribbons; and there are many others in development that promise exciting applications in the future. The surface functionalization of CNMs modifies their chemical and physical properties, which enhances their drug loading/release capacity, their ability to target drug delivery to specific sites, and their dispersibility and suitability in biological systems. Thus, CNMs have been effectively used in different biomedical systems. This review explores the unique physical, chemical, and biological properties that allow CNMs to improve on the state of the art materials currently used in different biomedical applications. The discussion also embraces the emerging biomedical applications of CNMs, including targeted drug delivery, medical implants, tissue engineering, wound healing, biosensing, bioimaging, vaccination, and photodynamic therapy.

Reactive oxygen species-based nanomaterials for the treatment of myocardial ischemia reperfusion injuries

Interventional coronary reperfusion strategies are widely adopted to treat acute myocardial infarction, but morbidity and mortality of acute myocardial infarction are still high. Reperfusion injuries are inevitable due to the generation of reactive oxygen species (ROS) and apoptosis of cardiac muscle cells. However, many antioxidant and anti-inflammatory drugs are largely limited by pharmacokinetics and route of administration, such as short half-life, low stability, low bioavailability, and side effects for treatment myocardial ischemia reperfusion injury. Therefore, it is necessary to develop effective drugs and technologies to address this issue. Fortunately, nanotherapies have demonstrated great opportunities for treating myocardial ischemia reperfusion injury. Compared with traditional drugs, nanodrugs can effectively increase the therapeutic effect and reduces side effects by improving pharmacokinetic and pharmacodynamic properties due to nanodrugs’ size, shape, and material characteristics. In this review, the biology of ROS and molecular mechanisms of myocardial ischemia reperfusion injury are discussed. Furthermore, we summarized the applications of ROS-based nanoparticles, highlighting the latest achievements of nanotechnology researches for the treatment of myocardial ischemia reperfusion injury.

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Cardiovascular diseases are the leading cause of death worldwide. Researches of the myocardial infarction pathology and development of new treatments have very important scientific significance in the biomedical field.

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Many nanomaterials have shown amazing therapeutic effects to reduce myocardial damage by eliminating ROS.

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Nanomaterials effectively reduced myocardial damage through eliminating ROS from NOXs, M-ETC, M-Ca²⁺, M-mPTP, and RIRR.

Understanding the interactions between inorganic-based nanomaterials and biological membranes

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

Engineering the Multi-Enzymatic Activity of Cerium Oxide Nanoparticle Coatings for the Antioxidant Protection of Implants

Imbalance of oxidants is a universal contributor to the failure of implanted devices and tissues. A sustained oxidative environment leads to cytotoxicity, prolonged inflammation, and ultimately host rejection of implanted devices/grafts. The incorporation of antioxidant materials can inhibit this redox/inflammatory cycle and enhance implant efficacy. Cerium oxide nanoparticles (CONP) is a highly promising agent that exhibits potent, ubiquitous, and self-renewable antioxidant properties. Integrating CONP as surface coatings provides ease in translating antioxidant properties to various implants/grafts. Herein, we describe the formation of CONP coatings, generated via the sequential deposition of CONP and alginate, and the impact of coating properties, pH, and polymer molecular weight, on their resulting redox profile. Investigation of CONP deposition, layer formation, and coating uniformity/thickness on their resulting oxidant scavenging activity identified key parameters for customizing global antioxidant properties. Results found lower molecular weight alginates and physiological pH shift CONP activity to a higher H2O2 to O2 --scavenging capability. The antioxidant properties measured for these various coatings translated to distinct antioxidant protection to the underlying encapsulated cells. Information gained from this work can be leveraged to tailor coatings towards specific oxidant-scavenging applications and prolong the function of medical devices and cellular implants.

Green synthesis of gold nanoparticles for immune response regulation: Mechanisms, applications, and perspectives

Immune responses are involved in the pathogenesis of many diseases, including cancer, autoimmune diseases, and chronic inflammation. These responses are attributed to immune cells that produce cytokines, mediate cytotoxicity, and synthesize antibodies. Gold nanoparticles (GNPs) are novel agents that intervene with immune responses because of their unique physical-chemical properties. In particular, GNPs enhance anti-tumour activity during immunotherapy and eliminate excessive inflammation in autoimmune diseases. However, GNPs synthesized by conventional methods are toxic to living organisms. Green biosynthesis provides a safe and eco-friendly method to obtain GNPs from microbes or plant extracts. In this review, we describe several patterns for green GNP biosynthesis. The applications of GNPs to target immune cells and modulate the immune response are summarized. In particular, we elaborate on how GNPs regulate innate immunity and adaptive immunity, including inflammatory signaling and immune cell differentiation. Finally, perspectives and challenges in utilizing green biosynthesized GNPs for novel therapeutic approaches are discussed.

Antioxidants: Classification, Natural Sources, Activity/Capacity Measurements, and Usefulness for the Synthesis of Nanoparticles

Natural extracts are the source of many antioxidant substances. They have proven useful not only as supplements preventing diseases caused by oxidative stress and food additives preventing oxidation but also as system components for the production of metallic nanoparticles by the so-called green synthesis. This is important given the drastically increased demand for nanomaterials in biomedical fields. The source of ecological technology for producing nanoparticles can be plants or microorganisms (yeast, algae, cyanobacteria, fungi, and bacteria). This review presents recently published research on the green synthesis of nanoparticles. The conditions of biosynthesis and possible mechanisms of nanoparticle formation with the participation of bacteria are presented. The potential of natural extracts for biogenic synthesis depends on the content of reducing substances. The assessment of the antioxidant activity of extracts as multicomponent mixtures is still a challenge for analytical chemistry. There is still no universal test for measuring total antioxidant capacity (TAC). There are many in vitro chemical tests that quantify the antioxidant scavenging activity of free radicals and their ability to chelate metals and that reduce free radical damage. This paper presents the classification of antioxidants and non-enzymatic methods of testing antioxidant capacity in vitro, with particular emphasis on methods based on nanoparticles. Examples of recent studies on the antioxidant activity of natural extracts obtained from different species such as plants, fungi, bacteria, algae, lichens, actinomycetes were collected, giving evaluation methods, reference antioxidants, and details on the preparation of extracts.

Recent perspectives of nanotechnology in burn wounds management: a review

OBJECTIVE

The burden of the management of problematic skin wounds characterised by a compromised skin barrier is growing rapidly. Almost six million patients are affected in the US alone, with an estimated market of $25 billion annually. There is an urgent requirement for efficient mechanism-based treatments and more efficacious drug delivery systems. Novel strategies are needed for faster healing by reducing infection, moisturising the wound, stimulating the healing mechanisms, speeding up wound closure and reducing scar formation.

METHODS

A systematic review of qualitative studies was conducted on the recent perspectives of nanotechnology in burn wounds management. Pubmed, Scopus, EMBASE, CINAHL and PsychINFO databases were all systematically searched. Authors independently rated the reporting of the qualitative studies included. A comprehensive literature search was conducted covering various resources up to 2018-2019. Traditional techniques aim to simply cover the wound without playing any active role in wound healing. However, nanotechnology-based solutions are being used to create multipurpose biomaterials, not only for regeneration and repair, but also for on-demand delivery of specific molecules. The chronic nature and associated complications of nonhealing wounds have led to the emergence of nanotechnology-based therapies that aim at facilitating the healing process and ultimately repairing the injured tissue.

CONCLUSION

Nanotechnology-based therapy is in the forefront of next-generation therapy that is able to advance wound healing of hard-to-heal wounds. In this review, we will highlight the developed nanotechnology-based therapeutic agents and assess the viability and efficacy of each treatment. Herein we will explore the unmet needs and future directions of current technologies, while discussing promising strategies that can advance the wound-healing field.

Combining secondary ion mass spectrometry image depth profiling and single particle inductively coupled plasma mass spectrometry to investigate the uptake and biodistribution of gold nanoparticles in Caenorhabditis elegans

Analytical techniques capable of determining the spatial distribution and quantity (mass and/or particle number) of engineered nanomaterials in organisms are essential for characterizing nano-bio interactions and for nanomaterial risk assessments. Here, we combine the use of dynamic secondary ion mass spectrometry (dynamic SIMS) and single particle inductively coupled mass spectrometry (spICP-MS) techniques to determine the biodistribution and quantity of gold nanoparticles (AuNPs) ingested by Caenorhabditis elegans. We report the application of SIMS in image depth profiling mode for visualizing, identifying, and characterizing the biodistribution of AuNPs ingested by nematodes in both the lateral and z (depth) dimensions. In parallel, conventional- and sp-ICP-MS quantified the mean number of AuNPs within the nematode, ranging from 2 to 36 NPs depending on the size of AuNP. The complementary data from both SIMS image depth profiling and spICP-MS provides a complete view of the uptake, translocation, and size distribution of ingested NPs within Caenorhabditis elegans.

An integrated approach for assessing the in vitro and in vivo redox-related effects of nanomaterials

Over the last few decades, nanotechnology has risen to the forefront of both the research and industrial interest, resulting in the manufacture and utilization of various nanomaterials, as well as in their integration into a wide range of fields. However, the consequent elevated exposure to such materials raises serious concerns regarding their effects on human health and safety. Existing scientific data indicate that the induction of oxidative stress, through the excessive generation of Reactive Oxygen Species (ROS), might be the principal mechanism of exerting their toxicity. Meanwhile, a number of nanomaterials exhibit antioxidant properties, either intrinsic or resulting from their functionalization with conventional antioxidants. Considering that their redox properties are implicated in the manifestation of their biological effects, we propose an integrated approach for the assessment of the redox-related activities of nanomaterials at three biological levels (in vitro-cell free systems, cell cultures, in vivo). Towards this direction, a battery of translational biomarkers is recommended, and a series of reliable protocols are presented in detail. The aim of the present approach is to acquire a better understanding with respect to the biological actions of nanomaterials in the interrelated fields of Redox Biology and Toxicology.

Redox Buffering Capacity of Nanomaterials as an Index of ROS-Based Therapeutics and Toxicity: A Preclinical Animal Study

Precise control of intracellular redox status, i.e., maintenance of the physiological level of reactive oxygen species (ROS) for mediating normal cellular functions (oxidative eustress) while evading the excess ROS stress (distress), is central to the concept of redox medicine. In this regard, engineered nanoparticles with unique ROS generation, transition, and depletion functions have the potential to be the choice of redox therapeutics. However, it is always challenging to estimate whether ROS-induced intracellular events are beneficial or deleterious to the cell. Here, we propose the concept of redox buffering capacity as a therapeutic index of engineered nanomaterials. As a steady redox state is maintained for normal functioning cells, we hypothesize that the ability of a nanomaterial to preserve this homeostatic condition will dictate its therapeutic efficacy. Additionally, the redox buffering capacity is expected to provide information about the nanoparticle toxicity. Here, using citrate-functionalized trimanganese tetroxide nanoparticles (C-Mn₃O₄ NPs) as a model nanosystem, we explored its redox buffering capacity in erythrocytes. Furthermore, we went on to study the chronic toxic effect (if any) of this nanomaterial in the animal model to co-relate with the experimentally estimated redox buffering capacity. This study could function as a framework for assessing the capability of a nanomaterial as redox medicine (whether maintains eustress or damages by creating distress), thus orienting its application and safety for clinical use.

Complexity of the Nano-Bio Interface and the Tortuous Path of Metal Oxides in Biological Systems

Metal oxide nanoparticles (NPs) have received a great deal of attention as potential theranostic agents. Despite extensive work on a wide variety of metal oxide NPs, few chemically active metal oxide NPs have received Food and Drug Administration (FDA) clearance. The clinical translation of metal oxide NP activity, which often looks so promising in preclinical studies, has not progressed as rapidly as one might expect. The lack of FDA approval for metal oxide NPs appears to be a consequence of the complex transformation of NP chemistry as any given NP passes through multiple extra- and intracellular environments and interacts with a variety of proteins and transport processes that may degrade or transform the chemical properties of the metal oxide NP. Moreover, the translational models frequently used to study these materials do not represent the final therapeutic environment well, and studies in reduced preparations have, all too frequently, predicted fundamentally different physico-chemical properties from the biological activity observed in intact organisms. Understanding the evolving pharmacology of metal oxide NPs as they interact with biological systems is critical to establish translational test systems that effectively predict future theranostic activity.

Functional Transdermal Nanoethosomes Enhance Photodynamic Therapy of Hypertrophic Scars via Self-Generating Oxygen

Photodynamic therapy (PDT) is a new therapeutic strategy for hypertrophic scars (HSs), and nanoethosomes (ES) have attracted considerable attention as an efficient transdermal delivery system for PDT of HSs (HS-PDT). However, the delivery of photosensitizers and the hypoxic microenvironment of HSs limit HS-PDT efficacy. Consequently, functional transdermal ES (A/A-ES) that are loaded with the photosensitizer, 5-aminolevulinic acid (ALA), and immobilized nanoenzyme Au nanoclusters (ANCs) within the ES surface have been developed that exhibit superior co-delivery characteristics and produce catalase that enhances HS-PDT efficacy. The unique structure of A/A-ES enables them to co-deliver ALA and ANCs into the HS tissue and to efficiently decompose the endogenous hydrogen peroxide in the HS to generate oxygen. The findings from in vitro and in vivo experiments demonstrated that A/A-ES efficiently co-delivered ALA and ANCs into the HS tissue and that they improved the hypoxic microenvironment of the HS. Systematic assessments reveal that A/A-ES enhance HS-PDT efficacy and that they are highly effective at improving the morphology and promoting HS fibroblast apoptosis and the rearrangement of collagen. These works give rise to an effective treatment option for HSs that integrates the transdermal co-delivery of ALA and nanoenzymes, thereby enabling them to exert their respective beneficial effects, and they highlight the enhancement of HS-PDT efficacy via self-generating oxygen.

pH-Responsive Redox Nanoparticles Protect SH-SY5Y Cells at Lowered pH in a Cellular Model of Parkinson's Disease

The damage to SH-SY5Y cells by 6-hydroxydopamine (6-OHDA) is an established cellular model of Parkinson's disease (PD). Redox nanoparticles are a promising tool for therapy, including neurodegenerative diseases. As pH of the brain tissue at sites affected by PD is lowered down to 6.5, we studied the effect of pH-responsive redox nanoparticles (poly(ethylene glycol)-b-poly[4-(2,2,6,6-tetramethylpiperidine-1-oxyl)aminomethylstyrene]), which change their structure in a pH-dependent manner and become active below pH 7 (NRNPs pH), on the viability of SH-SY5Y cells treated with 6-OHDA at pH 6.5 and 7.4. Pretreatment of the cells with NRNPs pH (15-75 μM) prior to the 6-OHDA treatment increased their survival in a concentration-dependent manner at pH 6.5, but not at pH 7.4. Among several parameters studied (ATP and GSH content, the level of reactive oxygen species, mitochondrial potential, mitochondrial mass), only the mitochondrial mass was dose-dependently protected by NRNPs pH at pH 6.5, but not at pH 7.4. These results indicate that the action of NRNPs pH on mitochondria underlies their protective effect in this cellular model of PD. These results may have potential importance for future applications of NRNPs pH in preclinical and perhaps clinical studies.

Cotreatment of Small Gold Nanoparticles Protects Against the Increase in Cerebral Acetylcholinesterase Activity and Oxidative Stress Induced by Acute Ethanol Exposure in the Zebrafish

Gold nanoparticles (GNP) have emerged as an alternative to biomaterials in biomedical applications. Research has clearly demonstrated the relative safety and low toxicity of these molecules. However, the possible neuroprotective effect of GNP on the central nervous system (CNS) and its relationship with neurological and psychiatric disorders remain unclear. Zebrafish is a reliable model to investigate the impact of ethanol (EtOH) consumption on the CNS, including reward signaling such as the cholinergic neurotransmission system. Here, we investigated whether cotreatment or pretreatment with GNP prevented EtOH-induced changes in acetylcholinesterase activity and oxidative stress in the brain of zebrafish. We exposed adult zebrafish to 2.5 mg·L^-1 GNP 1 h prior to EtOH (1% v/v) treatment for 1 h, and cotreated adult zebrafish simultaneously with both substances for 1 h. Pretreatment with GNP did not prevent EtOH-induced increase in the acetylcholinesterase activity, whereas cotreatment with 2.5 mg·L^-1 GNP and EtOH protected against this increase. The results also suggested similar protective effect on oxidative stress parameters in the zebrafish pretreated with GNP at 2.5 mg·L^-1. GNP significantly decreased the levels of thiobarbituric acid reactive species and dihydrodichlorofluorescein levels when cotreated with EtOH. GNP also prevented EtOH-induced increase in superoxide dismutase and catalase activities, suggesting a modulatory role of GNP in enzymatic antioxidant defenses. Our results showed that GNP was able to modulate the disruption of cholinergic and oxidative homeostasis in the brain of zebrafish. These findings indicate for the first time that zebrafish is an interesting perspective to investigate nanoparticles against disorders related to alcohol abuse.

Synergistic antibacterial activity of surfactant free Ag-GO nanocomposites

Graphene oxide–silver (Ag–GO) nanocomposite has emerged as a vital antibacterial agent very recently. In this work, we report a facile one step route of Ag–GO nanocomposite formation excluding the aid of surfactants and reductants and was successfully applied to negative Escherichia Coli (E coli) to investigate antibacterial activity by varying doze concentration. The successful formation of Ag–GO nanocomposite via facile one step route was confirmed using Fourier transform infrared spectroscopy (FTIR) and Raman Spectroscopy. The absorption spectra (peak ~ 300 nm) for GO and the (peak ~ 420 nm) for silver nanoparticles were observed. XRD study confirmed the formation of Ag–GO nanocomposite while atomic force microscopy (AFM) showed crumbled GO sheets decorated with Ag nanoparticles. It was observed that the functional groups of GO facilitated the binding of Ag nanoparticles to GO network and enhanced the antibacterial activity of the nanocomposite.

Engineered Nanomaterials: The Challenges and Opportunities for Nanomedicines

The emergence of nanotechnology as a key enabling technology over the past years has opened avenues for new and innovative applications in nanomedicine. From the business aspect, the nanomedicine market was estimated to worth USD 293.1 billion by 2022 with a perception of market growth to USD 350.8 billion in 2025. Despite these opportunities, the underlying challenges for the future of engineered nanomaterials (ENMs) in nanomedicine research became a significant obstacle in bringing ENMs into clinical stages. These challenges include the capability to design bias-free methods in evaluating ENMs' toxicity due to the lack of suitable detection and inconsistent characterization techniques. Therefore, in this literature review, the state-of-the-art of engineered nanomaterials in nanomedicine, their toxicology issues, the working framework in developing a toxicology benchmark and technical characterization techniques in determining the toxicity of ENMs from the reported literature are explored.

Recent advances in graphene-family nanomaterials for effective drug delivery and phototherapy

INTRODUCTION

Owing to the unique properties of graphene, including large specific surface area, excellent thermal conductivity, and optical absorption, graphene-family nanomaterials (GFNs) have attracted extensive attention in biomedical applications, particularly in drug delivery and phototherapy.

AREAS COVERED

In this review, we point out several challenges involved in the clinical application of GFNs. Then, we provide an overview of the most recent publications about GFNs in biomedical applications, including diverse strategies for improving the biocompatibility, specific targeting and stimuli-responsiveness of GFNs for drug delivery, codelivery of drug and gene, photothermal therapy, photodynamic therapy, and multimodal combination therapy.

EXPERT OPINION

Although the application of GFNs is still in the preclinical stage, rational modification of GFNs with functional elements or making full use of GFNs-based multimodal combination therapy might show great potential in biomedicine for clinical application.

Light-triggered redox activity of GdYVO4:Eu3+ nanoparticles

Light-triggered redox activity of small (d = 2 nm) GdYVO₄:Eu³⁺ nanoparticles (NPs) in aqueous solutions and lipid suspensions is reported. It has been revealed that depending on pre-treatment conditions (exposure to UV light or storage in the dark) the same NPs exhibit pro- or anti-oxidant properties. Pro-/anti-oxidant activity in aqueous solutions was evaluated by UV-vis spectroscopy using probe molecules for hydroxyl radicals (·OH) and superoxide anions (O₂^•-). Lipid oxidation under the effect of NPs has been also analyzed. Multi-functional GdYVO₄:Eu³⁺ NPs are assumed to be a new theranostic agent in cancer therapy, which exhibit fluorescent properties, triggered redox activity and drug-carrier ability.

Carbonaceous Nanomaterials-Mediated Defense Against Oxidative Stress

The concept of nanoscale materials and their applications in industrial technologies, consumer goods, as well as in novel medical therapies has rapidly escalated in the last several years. Consequently, there is a critical need to understand the mechanisms that drive nanomaterials biocompatibility or toxicity to human cells and tissues. The ability of nanomaterials to initiate cellular pathways resulting in oxidative stress has emerged as a leading hypothesis in nanotoxicology. Nevertheless, there are a few examples revealing another face of nanomaterials - they can alleviate oxidative stress via decreasing the level of reactive oxygen species. The fundamental structural and physicochemical properties of carbonaceous nanomaterials that govern these anti-oxidative effects are discussed in this article. The signaling pathways influenced by these unique nanomaterials, as well as examples of their applications in the biomedical field, e.g. cell culture, cell-based therapies or drug delivery, are presented. We anticipate this emerging knowledge of intrinsic anti-oxidative properties of carbon nanomaterials to facilitate the use of tailored nanoparticles in vivo.

Measurement and standardization challenges for extracellular vesicle therapeutic delivery vectors

Extracellular vesicles (EVs), such as exosomes and microvesicles, are nonreplicating lipid bilayer particles shed by most cell types which have the potential to revolutionize the development and efficient delivery of clinical therapeutics. This article provides an introduction to the landscape of EV-based vectors under development for the delivery of protein- and nucleic acid-based therapeutics. We highlight some of the most pressing measurement and standardization challenges that limit the translation of EVs to the clinic. Current challenges limiting development of EVs for drug delivery are the lack of: standardized cell-based platforms for the production of EV-based therapeutics; EV reference materials that allow researchers/manufacturers to validate EV measurements and standardized measurement systems for determining the molecular composition of EVs.

Fullerene nanoparticles: a promising candidate for the alleviation of silicosis-associated pulmonary inflammation

Chronic exposure to crystalline silica causes the development of silicosis, which is one of the most important occupational diseases worldwide. In the early stage of silicosis, inhaled silica crystals initiate oxidative stress, a cycle of persistent inflammation and lung injury. And it is crucial to prevent the deteriorative progression in the onset of the disease. Herein, we present a promising candidate for the treatment of crystalline silica-induced pulmonary inflammation, using a silicosis mouse model caused by intratracheal instillation based on local administration of β-alanine and hydroxyl functionalized C70 fullerene nanoparticles (FNs). The results demonstrate that FNs could significantly alleviate inflammatory cells infiltration, lower the secretion of pro-inflammatory cytokines, and reduce the destruction of lung architecture stimulated by crystalline silica. Further investigations reveal that FNs could effectively inhibit the activation of NLRP3 (NACHT, LRR and PYD domains-containing protein 3) inflammasome, and thus prevent the secretion of mature IL-1β and neutrophil influx, deriving from the superior ROS scavenging capability. Importantly, FNs could not cause any obvious toxicity after pulmonary administration.