Human and environmental impacts of nanoparticles: a scoping review of the current literature

Serum protein albumin and chromium: Mechanistic insights into the interaction between ions, nanoparticles, and protein

The interaction of human proteins and metal species, both ions and nanoparticles, is poorly understood despite their growing importance. These materials are the by-products of corrosion processes and are of relevance for food and drug manufacturing, nanomedicine, and biomedical implant corrosion. Here, we study the interaction of Cr(III) ions and chromium oxide nanoparticles with bovine serum albumin in physiological conditions. This study combined electrophoretic mobility measurements, spectroscopy, and time-of-flight secondary ion mass spectrometry with principal component analysis. It was determined that neither metal species resulted in global albumin unfolding. The Cr(III) ions interacted strongly with amino acids found in previously discovered metal binding sites, but also were most strongly implicated in the interaction with negatively charged acid residues, suggesting an electrostatic interaction. Bovine serum albumin (BSA) was found to bind to the Cr2O3 nanoparticles in a preferential orientation, due to electrostatic interactions between the positive amino acid residues and the negative chromium oxide nanoparticle surface. These findings ameliorate our understanding of the interaction between trivalent chromium ions and nanoparticles, and biological macromolecules.

Advances in Regenerative and Reconstructive Medicine in the Prevention and Treatment of Bone Infections

Reconstructive and regenerative medicine are critical disciplines dedicated to restoring tissues and organs affected by injury, disease, or congenital anomalies. These fields rely on biomaterials like synthetic polymers, metals, ceramics, and biological tissues to create substitutes that integrate seamlessly with the body. Personalized implants and prosthetics, designed using advanced imaging and computer-assisted techniques, ensure optimal functionality and fit. Regenerative medicine focuses on stimulating natural healing mechanisms through cellular therapies and biomaterial scaffolds, enhancing tissue regeneration. In bone repair, addressing defects requires advanced solutions such as bone grafts, essential in medical and dental practices worldwide. Bovine bone scaffolds offer advantages over autogenous grafts, reducing surgical risks and costs. Incorporating antimicrobial properties into bone substitutes, particularly with metals like zinc, copper, and silver, shows promise in preventing infections associated with graft procedures. Silver nanoparticles exhibit robust antimicrobial efficacy, while zinc nanoparticles aid in infection prevention and support bone healing; 3D printing technology facilitates the production of customized implants and scaffolds, revolutionizing treatment approaches across medical disciplines. In this review, we discuss the primary biomaterials and their association with antimicrobial agents.

Nanomedicine and voltage-gated sodium channel blockers in pain management: a game changer or a lost cause?

Pain, a complex and debilitating condition affecting millions globally, is a significant concern, especially in the context of post-operative recovery. This comprehensive review explores the complexity of pain and its global impact, emphasizing the modulation of voltage-gated sodium channels (VGSC or NaV channels) as a promising avenue for pain management with the aim of reducing reliance on opioids. The article delves into the role of specific NaV isoforms, particularly NaV 1.7, NaV 1.8, and NaV 1.9, in pain process and discusses the development of sodium channel blockers to target these isoforms precisely. Traditional local anesthetics and selective NaV isoform inhibitors, despite showing varying efficacy in pain management, face challenges in systemic distribution and potential side effects. The review highlights the potential of nanomedicine in improving the delivery of local anesthetics, toxins and selective NaV isoform inhibitors for a targeted and sustained release at the site of pain. This innovative strategy seeks to improve drug bioavailability, minimize systemic exposure, and optimize therapeutic outcomes, holding significant promise for secure pain management and enhancing the quality of life for individuals recovering from surgical procedures or suffering from chronic pain.

Co-exposure to cadmium and triazophos induces variations at enzymatic and transcriptional levels in Opsariichthys bidens

Heavy metals and pesticides are significant pollutants in aquatic environments, often leading to combined pollution and exerting toxic effects on aquatic organisms. With the rapid growth of modern industry and agriculture, heavy metal cadmium (Cd) and pesticide triazophos (TRI) are frequently detected together in various water bodies, particularly in agricultural watersheds. However, the combined toxic mechanisms of these pollutants on fish remain poorly understood. This experiment involved a 21-day co-exposure of Cd and TRI to the hook snout carp Opsariichthys bidens to investigate the toxic effects on liver tissues at both enzymatic and transcriptional levels. Biochemical analysis revealed that both individual and combined exposures significantly increased the content or activity of caspase-3 (CASP-3) and malondialdehyde (MDA). Moreover, the impact on these parameters was greater in the combined exposure groups compared to the corresponding individual exposure groups. These findings suggested that both individual and combined exposures could induce mitochondrial dysfunction and lipid peroxidation damage, with combined exposure exacerbating the toxicological effects of each individual pollutant. Furthermore, at the molecular level, both individual and combined exposures upregulated the expression levels of cu-sod, cat, and erβ, while downregulating the expression of il-1. Similar to the patterns observed in the biochemical parameters, the combined exposure group exhibited a greater impact on the expression of these genes compared to the individual exposure groups. These results indicated that exposure to Cd, TRI, and their combination induced oxidative stress, endocrine disruption, and immunosuppression in fish livers, with more severe effects observed in the combined exposure group. Overall, the interaction between Cd and TRI appeared to be synergistic, shedding light on the toxic mechanisms by which fish livers responded to these pollutants. These findings contributed to the understanding of mixture risk assessment of pollutants and were valuable for the conservation of aquatic resources.

Nanomaterials in the environment and their pragmatic voyage at various trophic levels in an ecosystem

In the development of nanotechnology, nanomaterials (NMs) have a huge credential in advancing the existing follow-ups of analytical and diagnosis techniques, drug designing, agricultural science, electronics, cosmetics, sports, textiles and water purification. However, NMs have also grasped attention of researchers onto their toxicity. In the present review, initially the development of notable NMs such as metal and metal-oxide nanoparticles (NPs), magnetic NPs, carbon-based NMs and quantum dots intended to be commercialized along with their applications are discussed. This is followed by the current scenario of NMs in the environment to widen the outlook on the concentration of NPs in the environmental compartments and the frequency of organism exposed to NPs at varied trophic levels. In order to understand the physiochemical and morphological significance of NPs in exhibiting toxicity, fate of NPs in the environment is briefly deliberated. This is further geared-up to glance in-sightedly on the organisms starting from primary producer to primary consumer, secondary consumer, tertiary consumer and decomposers encountering NPs in their habitual niche. The state of NPs to which organisms are exposed, mechanism of NP uptake and toxicity, anomalies faced at each trophic level, concentration of NPs that is liable to cause toxicity and, biotransfer of NPs to the next generation and trophic level are detailed. Finally, the future prospects on bioaccumulation and biomagnification of NP-based products are conversed. Thus, the review would be noteworthy in unveiling the significance of NPs in forthcoming years combined with threat towards each organism in an ecosystem.

Engineering the protein corona: Strategies, effects, and future directions in nanoparticle therapeutics

Nanoparticles (NPs) serve as versatile delivery systems for anticancer, antibacterial, and antioxidant agents. The manipulation of protein-NP interactions within biological systems is crucial to the application of NPs in drug delivery and cancer nanotherapeutics. The protein corona (PC) that forms on the surface of NPs is the interface between biomacromolecules and NPs and significantly influences their pharmacokinetics and pharmacodynamics. Upon encountering proteins, NPs undergo surface alterations that facilitate their clearance from circulation by the mononuclear phagocytic system (MPS). PC behavior depends largely on the biological microenvironment and the physicochemical properties of the NPs. This review describes various strategies employed to engineer PC compositions on NP surfaces. The effects of NP characteristics such as size, shape, surface modification and protein precoating on PC performance were explored. In addition, this study addresses these challenges and guides the future directions of this evolving field.

Advancing in vivo reprogramming with synthetic biology

Reprogramming cells will play a fundamental role in shaping the future of cell therapies by developing new strategies to engineer cells for improved performance and higher-order physiological functions. Approaches in synthetic biology harness cells' natural ability to sense diverse signals, integrate environmental inputs to make decisions, and execute complex behaviors based on the health of the organism or tissue. In this review, we highlight strategies in synthetic biology to reprogram cells, and discuss how recent approaches in the delivery of modified mRNA have created new opportunities to alter cell function in vivo. Finally, we discuss how combining concepts from synthetic biology and the delivery of mRNA in vivo could provide a platform for innovation to advance in vivo cellular reprogramming.

Zinc oxide nanoparticles damage the prefrontal lobe in mouse: Behavioral impacts and key mechanisms

Zinc Oxide nanoparticles (ZnO NPs) have dualistic properties due to their advantage and toxicity. However, the impact and mechanisms of ZnO NPs on the prefrontal lobe have limited research. This study investigates the behavioral changes following exposure to ZnO NPs (34 mg/kg, 30 days), integrating multiple behaviors and bioinformatics analysis to identify critical factors and regulatory mechanisms. The essential differentially expressed genes (DEGs) were identified, including ORC1, DSP, AADAT, SLITRK6, and STEAP1. Analysis of the DEGs based on fold change reveals that ZnO NPs primarily regulate cell survival, proliferation, and apoptosis in neural cells, damaging the prefrontal lobe. Moreover, disruption of cell communication, mineral absorption, and immune pathways occurs. Gene set enrichment analysis (GSEA) further shows enrichment of behavior, neuromuscular process, signal transduction in function, synapses-related, cAMP signaling, and immune pathways. Furthermore, alternative splicing (AS) genes highlight synaptic structure/function, synaptic signal transduction, immune responses, cell proliferation, and communication.

Review of Prodrug and Nanodelivery Strategies to Improve the Treatment of Colorectal Cancer with Fluoropyrimidine Drugs

Fluoropyrimidine (FP) drugs are central components of combination chemotherapy regimens for the treatment of colorectal cancer (CRC). FP-based chemotherapy has improved survival outcomes over the last several decades with much of the therapeutic benefit derived from the optimization of dose and delivery. To provide further advances in therapeutic efficacy, next-generation prodrugs and nanodelivery systems for FPs are being developed. This review focuses on recent innovative nanodelivery approaches for FP drugs that display therapeutic promise. We summarize established, clinically useful FP prodrug strategies, including capecitabine, which exploit tumor-specific enzyme expression for optimal anticancer activity. We then describe the use of FP DNA-based polymers (e.g., CF10) for the delivery of activated FP nucleotides as a nanodelivery approach with proven activity in pre-clinical models and with clinical potential. Multiple nanodelivery systems for FP delivery show promise in CRC pre-clinical models and we review advances in albumin-mediated FP delivery, the development of mesoporous silica nanoparticles, emulsion-based nanoparticles, metal nanoparticles, hydrogel-based delivery, and liposomes and lipid nanoparticles that display particular promise for therapeutic development. Nanodelivery of FPs is anticipated to impact CRC treatment in the coming years and to improve survival for cancer patients.

Expanding the Horizons of Machine Learning in Nanomaterials to Chiral Nanostructures

Machine learning holds significant research potential in the field of nanotechnology, enabling nanomaterial structure and property predictions, facilitating materials design and discovery, and reducing the need for time-consuming and labor-intensive experiments and simulations. In contrast to their achiral counterparts, the application of machine learning for chiral nanomaterials is still in its infancy, with a limited number of publications to date. This is despite the great potential of machine learning to advance the development of new sustainable chiral materials with high values of optical activity, circularly polarized luminescence, and enantioselectivity, as well as for the analysis of structural chirality by electron microscopy. In this review, an analysis of machine learning methods used for studying achiral nanomaterials is provided, subsequently offering guidance on adapting and extending this work to chiral nanomaterials. An overview of chiral nanomaterials within the framework of synthesis-structure-property-application relationships is presented and insights on how to leverage machine learning for the study of these highly complex relationships are provided. Some key recent publications are reviewed and discussed on the application of machine learning for chiral nanomaterials. Finally, the review captures the key achievements, ongoing challenges, and the prospective outlook for this very important research field.

Unlocking the nanoparticle emission potential: a study of varied filaments in 3D printing

This study investigates nanoparticle emission during 3D printing processes, assessing various filament materials' impact on air quality. Commonly used 3D printers, including both filament and resin-based types, were examined. The study's scope encompasses diverse filament materials like ABS (acrylonitrile butadiene styrene), PLA (polylactic acid), PETG (polyethylene terephthalate glycol), ASA (acrylonitrile styrene acrylate), TPU (thermoplastic polyurethane), PP (polypropylene), nylon, and wood-based variants, alongside three types of resins. The research delves into the relationship between the type of material and nanoparticle emissions, emphasizing temperature's pivotal role. Measurement instruments were employed for nanoparticle quantification, including an engine exhaust particle sizer spectrometer, condensation particle counter, and nanozen dust counters. Notably, results reveal substantial variations in nanoparticle emissions among different filament materials, with ASA, TPU, PP, and ABS showing considerably elevated emission levels and characteristic particle size distribution patterns. The findings prompt practical recommendations for reducing nanoparticle exposure, emphasizing printer confinement, material selection, and adequate ventilation. This study offers insights into potential health risks associated with 3D printing emissions and provides a basis for adopting preventive measures.

Microorganism-mediated biodegradation for effective management and/or removal of micro-plastics from the environment: a comprehensive review

Micro- plastics (MPs) pose significant global threats, requiring an environment-friendly mode of decomposition. Microbial-mediated biodegradation and biodeterioration of micro-plastics (MPs) have been widely known for their cost-effectiveness, and environment-friendly techniques for removing MPs. MPs resistance to various biocidal microbes has also been reported by various studies. The biocidal resistance degree of biodegradability and/or microbiological susceptibility of MPs can be determined by defacement, structural deformation, erosion, degree of plasticizer degradation, metabolization, and/or solubilization of MPs. The degradation of microplastics involves microbial organisms like bacteria, mold, yeast, algae, and associated enzymes. Analytical and microbiological techniques monitor microplastic biodegradation, but no microbial organism can eliminate microplastics. MPs can pose environmental risks to aquatic and human life. Micro-plastic biodegradation involves fragmentation, assimilation, and mineralization, influenced by abiotic and biotic factors. Environmental factors and pre-treatment agents can naturally degrade large polymers or induce bio-fragmentation, which may impact their efficiency. A clear understanding of MPs pollution and the microbial degradation process is crucial for mitigating its effects. The study aimed to identify deteriogenic microorganism species that contribute to the biodegradation of micro-plastics (MPs). This knowledge is crucial for designing novel biodeterioration and biodegradation formulations, both lab-scale and industrial, that exhibit MPs-cidal actions, potentially predicting MPs-free aquatic and atmospheric environments. The study emphasizes the urgent need for global cooperation, research advancements, and public involvement to reduce micro-plastic contamination through policy proposals and improved waste management practices.

Exploring vismodegib: A non-surgical breakthrough in the management of advanced periocular basal cell carcinoma

The management of periocular basal cell carcinoma (BCC) is challenging due to its proximity to the eyeball. Vismodegib, a Hedgehog pathway inhibitor, has emerged as a therapeutic option for locally advanced and metastatic BCC. To critically appraise the relevant evidence, we conducted a systematic review of observational and experimental studies assessing the efficacy and safety of vismodegib for periocular BCC. Thirty-seven trials, including 435 patients, were eligible. No randomized trials were retrieved. Complete and overall clinical response rates were 20-88 % and 68-100 %, respectively. Disease progression was observed at a maximum rate of 14 %. Recurrence rates varied between 0 % and 31 %. The most common side effects were muscle cramps, dysgeusia, weight loss and alopecia. Treatment with vismodegib improved health-related quality of life. In conclusion, vismodegib represents an important novel treatment for advanced periocular BCC, with good response rates and acceptable tolerability profile. Nevertheless, its full potential needs clarification through randomized controlled trials.

Ecotoxicity Assessment of Nanomaterials: Latest Advances and Prospects

In the fast-evolving landscape of nanotechnology, the widespread applications of engineered nanomaterials (ENMs) have undoubtedly revolutionized various industries, ranging from healthcare and electronics to agriculture and environmental remediation [...].

Antiviral action of a functionalized plastic surface against human coronaviruses

Viruses may persist on solid surfaces for long periods, which may contribute to indirect transmission. Thus, it is imperative to develop functionalized surfaces that will lower the infectious viral load in everyday life. Here, we have tested a plastic surface functionalized with tall oil rosin against the seasonal human coronavirus OC43 as well as severe acute respiratory syndrome coronavirus 2. All tested non-functionalized plastic surfaces showed virus persistence up to 48 h. In contrast, the functionalized plastic showed good antiviral action already within 15 min of contact and excellent efficacy after 30 min over 90% humidity. Excellent antiviral effects were also observed at lower humidities of 20% and 40%. Despite the hydrophilic nature of the functionalized plastic, viruses did not adhere strongly to it. According to helium ion microscopy, viruses appeared flatter on the rosin-functionalized surface, but after flushing away from the rosin-functionalized surface, they showed no apparent structural changes when imaged by transmission electron microscopy of cryogenic or negatively stained specimens or by atomic force microscopy. Flushed viruses were able to bind to their host cell surface and enter endosomes, suggesting that the fusion with the endosomal membrane was halted. The eluted rosin from the functionalized surface demonstrated its ability to inactivate viruses, indicating that the antiviral efficacy relied on the active leaching of the antiviral substances, which acted on the viruses coming into contact. The rosin-functionalized plastic thus serves as a promising candidate as an antiviral surface for enveloped viruses.IMPORTANCEDuring seasonal and viral outbreaks, the implementation of antiviral plastics can serve as a proactive strategy to limit the spread of viruses from contaminated surfaces, complementing existing hygiene practices. In this study, we show the efficacy of a rosin-functionalized plastic surface that kills the viral infectivity of human coronaviruses within 15 min of contact time, irrespective of the humidity levels. In contrast, non-functionalized plastic surfaces retain viral infectivity for an extended period of up to 48 h. The transient attachment on the surface or the leached active components do not cause major structural changes in the virus or prevent receptor binding; instead, they effectively block viral infection at the endosomal stage.

Effect of Zinc Oxide Nanoparticles on Liver Functions in Albino Mice

BACKGROUND

An alarming number of zinc oxide nanoparticles (ZnO-NPs) have leaked into the environment, endangering the tissues of many living creatures, due to the recent surge in their use in several items. Through intra-peritoneal injection, this research intends to examine the impact of ZnO-NPs on the hepatic and gastrointestinal structures of male albino mice.

METHOD

For seven and 14 days, animals were given 0.1 ml of 100 and 200 mg kg-1 of 50 nm-size ZnO-NPs, respectively. In contrast, those in the control group were given only water and food.

RESULT

The results demonstrated that the treated mice's livers underwent functional changes and histological damage. After seven and 14 days, there was a notable rise in the average levels of the glutamate-oxaloacetate transaminase and glutamate-pyruvate transaminase enzymes in comparison to the control group (p≤0.05). Concentration time determines the magnitude of this impact. When enzyme levels vary, it means the liver isn't working properly. Histological changes in the liver, such as necrosis, destruction of hepatocyte membranes, widening of sinusoidal spaces and vacuolation of their cytoplasm, vascular congestion, and an increased number of Kupffer cells, were induced in mice treated with ZnO-NPs at two studied concentrations (100 and 200 mg/kg) for seven and 14 days, respectively. These effects were time-dose-dependent, according to the results of hematoxylin-eosin staining of liver tissue images.

Comprehensive Assessment of Graphene Oxide Nanoparticles: Effects on Liver Enzymes and Cardiovascular System in Animal Models and Skeletal Muscle Cells

The growing interest in graphene oxide (GO) for different biomedical applications requires thoroughly examining its safety. Therefore, there is an urgent need for reliable data on how GO nanoparticles affect healthy cells and organs. In the current work, we adopted a comprehensive approach to assess the influence of GO and its polyethylene glycol-modified form (GO-PEG) under near-infrared (NIR) exposure on several biological aspects. We evaluated the contractility of isolated frog hearts, the activity of two rat liver enzymes-mitochondrial ATPase and diamine oxidase (DAO), and the production of reactive oxygen species (ROS) in C2C12 skeletal muscle cells following direct exposure to GO nanoparticles. The aim was to study the influence of GO nanoparticles at multiple levels-organ; cellular; and subcellular-to provide a broader understanding of their effects. Our data demonstrated that GO and GO-PEG negatively affect heart contractility in frogs, inducing stronger arrhythmic contractions. They increased ROS production in C2C12 myoblasts, whose effects diminished after NIR irradiation. Both nanoparticles in the rat liver significantly stimulated DAO activity, with amplification of this effect after NIR irradiation. GO did not uncouple intact rat liver mitochondria but caused a concentration-dependent decline in ATPase activity in freeze/thaw mitochondria. This multifaceted investigation provides crucial insights into GOs potential for diverse implications in biological systems.

Impact of NQO1 dysregulation in CNS disorders

NAD(P)H Quinone Dehydrogenase 1 (NQO1) plays a pivotal role in the regulation of neuronal function and synaptic plasticity, cellular adaptation to oxidative stress, neuroinflammatory and degenerative processes, and tumorigenesis in the central nervous system (CNS). Impairment of the NQO1 activity in the CNS can result in abnormal neurotransmitter release and clearance, increased oxidative stress, and aggravated cellular injury/death. Furthermore, it can cause disturbances in neural circuit function and synaptic neurotransmission. The abnormalities of NQO1 enzyme activity have been linked to the pathophysiological mechanisms of multiple neurological disorders, including Parkinson's disease, Alzheimer's disease, epilepsy, multiple sclerosis, cerebrovascular disease, traumatic brain injury, and brain malignancy. NQO1 contributes to various dimensions of tumorigenesis and treatment response in various brain tumors. The precise mechanisms through which abnormalities in NQO1 function contribute to these neurological disorders continue to be a subject of ongoing research. Building upon the existing knowledge, the present study reviews current investigations describing the role of NQO1 dysregulations in various neurological disorders. This study emphasizes the potential of NQO1 as a biomarker in diagnostic and prognostic approaches, as well as its suitability as a target for drug development strategies in neurological disorders.

Silver Shell Thickness-Dependent Conductivity of Coatings Based on Ni@Ag Core@shell Nanoparticles

Introductions

Ink based on metallic nanoparticles has been widely used so far for the fabrication of electronic circuits and devices using printing technology. This study aimed at the analysis of the effect of the silver shell thickness of nickel@silver core@shell (Ni@Ag) nanoparticles (NPs) on the fabrication and conductive properties of deposited coatings.

Methods

The process of the synthesis of Ni@Ag NPs with various silver shell thicknesses was developed. The physicochemical properties (size, stability against aggregation process) of synthesized Ni@Ag nanoparticles were analyzed. The films based on ink containing Ni@Ag NPs with different silver shell thicknesses were fabricated and sintered in a temperature range of 120-300 °C and at times from 15 to 90 min. The dependence of their conductive properties on the applied temperature and time as well as silver shell thickness was evaluated.

Results

Ni NPs were coated with 10, 20, 30, 35, 45, and 55 nm silver shell thickness. The resistivity of coatings based on obtained NPs depends on the thickness of the Ag shell and the sintering temperature. After sintering at 300 °C, the highest decrease in its value (at an optimal sintering time of 60 min) from about 100 µΩ·cm to 9 µΩ·cm was observed when the thickness of the shell increased from 10 to 55 nm. At the lowest sintering temperature (120 °C) the highest conductivity (about 50% of that for bulk nickel) was obtained for films based on Ni@Ag NPs with 45 and 55 nm of the silver shell thickness.

Discussions

The analysis of the resistivity of the sintered films showed that higher conductivity was obtained for the coatings formed from Ni@Ag NPs with the thicker Ag shell; moreover, thicker shells allowed a lowering of sintering temperature due to higher conductivity and a lower melting point of silver in comparison to nickel NPs.

Cationic cellulose filter papers modified with ZnO/Ag/GO nanocomposite as point of use gravity-driven filters for bacterial removal from water

The surface modification of filters with large pore sizes for the development of low-cost gravity-driven point-of-use (POU) technologies for water disinfection can be an effective strategy to empower people to access safe water instantly, especially in low- and middle-income countries. In this study, the surface of commercial cellulose filter papers, as cheap and bio-based filters, was modified with polydopamine (PDA), polyethyleneimine (PEI) and ZnO/Ag/GO nanocomposite (ZnO/Ag/GO@PDA/PEI papers) for bacterial removal from water. PDA/PEI incorporation introduced a cationic functional layer, which can entrap negative bacteria and make a stable chemical bond with the nanocomposite. ZnO/Ag/GO exhibited promising synergistic antibacterial activities (30 times stronger than ZnO). As a result, 3 sheets of ZnO/Ag/GO@PDA/PEI papers showed a 99.98% bacterial reduction (E. coli), which met the WHO standards. Moreover, the leached zinc and silver in the filtrate were far below the WHO's limits (380 and 10 ppb, respectively). The results showed that the modified papers could be reused multiple times. After six times of reuse, the flow rate dropped slightly (below 20%) and the bacterial removal efficiency was more than 99.9%. This study is valuable for developing filters for treating bacterial-contaminated water on-site with no need for energy, which is a demand in many countries.

Engineered nanomaterials for carbon capture and bioenergy production in microbial electrochemical technologies: A review

The mounting threat of global warming, fuelled by industrialization and anthropogenic activities, is undeniable. In 2017, atmospheric carbon dioxide (CO2), the primary greenhouse gas, exceeded 410 ppm for the first time. Shockingly, on April 28, 2023, this figure surged even higher, reaching an alarming 425 ppm. Even though extensive research has been conducted on developing efficient carbon capture and storage technologies, most suffer from high costs, short lifespans, and significant environmental impacts. Recently, the use of engineered nanomaterials (ENM), particularly in microbial electrochemical technologies (METs), has gained momentum owing to their appropriate physicochemical properties and catalytic activity. By implementing ENM, the MET variants like microbial electrosynthesis (MES) and photosynthetic microbial fuel cells (pMFC) can enhance carbon capture efficiency with simultaneous bioenergy production and wastewater treatment. This review provides an overview of ENMs' role in carbon capture within MES and pMFC, highlighting advancements and charting future research directions.

Magnesium oxide nanoparticles alleviate arsenic toxicity, reduce oxidative stress and arsenic accumulation in rice (Oryza sativa L.)

Magnesium oxide nanoparticles (MgO NPs) have been attracted by the scientific community for their combating action against heavy metal stress in plants. However, their role towards the mitigation of arsenic (As) induced toxicity is still obscure. In the present study, MgO NPs were synthesized through the green route and assessed their efficacy towards the reduction of As accumulation and phytotoxicity in As-stressed rice cultivar MTU-1010 under laboratory conditions. Initially, rice seedlings were grown under separate and combined applications of As (10 mg/L) and MgO NPs (0, 10, 50, and 100 mg/L) and further analyzed plant growth attributes and As accumulation in rice seedlings. Characterization of biosynthesized MgO NPs by UV-Vis spectrophotometer, transmission electron microscopy (TEM), scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDX), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analysis showed the cubic in shape, and crystalline nature (73.10%) with average size ranges from 17-23 nm. The growth experiment showed a significant (p < 0.05) increase in seed germination, seedling growth, photosynthetic and other pigments content, and biomass accumulation in rice seedlings under the combined application of As (10 mg/L) and MgO NPs (50 mg/L) as compared to only As (10 mg/L) treatment. Additionally, As exposure resulted in declined primary metabolites such as soluble sugars and protein. However, the application of MgO NPs exhibited the alleviation of As toxicity through significant (p < 0.05) reduction of As accumulation by 34 and 53% in roots and 44 and 62% in shoots of rice seedlings under 50 and 100 mg/L MgO NPs supplementations, respectively and restored the accumulation of the primary metabolites. Furthermore, MgO NPs demonstrated the ability to scavenge reactive oxygen species (ROS) like hydrogen peroxide (H2O2) and superoxide anion (O2•-), through significant (p < 0.05) promotion of non-enzymatic (carotenoid, anthocyanin, flavonoid, and proline) and enzymatic (CAT, POD, and SOD) antioxidant defence under As stress. These findings highlighted the potential of green synthesized MgO NPs towards the mitigation of As contamination in rice plants. However, future study is necessary to unfold the actual mechanisms responsible for the protective effects of MgO NPs and to screen out the optimal dose to be used to formulate a potent nanofertilizer for sustainable rice production in metal-contaminated soils.

Antimicrobial and antioxidant potential of the silver nanoparticles synthesized using aqueous extracts of coconut meat (Cocos nucifera L)

Human pathogenic fungi and bacteria pose a huge threat to human life, accounting for high rates of mortality every year. Unfortunately, the past few years have seen an upsurge in multidrug resistance pathogens. Consequently, finding an effective alternative antimicrobial agent is of utmost importance. Hence, this study aimed to phytofabricate silver nanoparticles (AgNPs) using aqueous extracts of the solid endosperm of Cocos nucifera L, also known as coconut meat (Cm). Green synthesis is a facile, cost-effective and eco-friendly methods which has several benefits over other physical and chemical methods. The synthesized nanoparticles were characterized by UV-Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and dynamic light scattering (DLS). The Cm-AgNPs showed a UV-Vis peak at 435 nm and were crystalline and quasi-spherical, with an average size of 15 nm. The FTIR spectrum displayed functional groups of phenols, alkaloids, sugars, amines, and carbonyl compounds, which are vital in the reduction and capping of NPs. The antibacterial and anticandidal efficacy of the Cm-AgNPs was assessed by the agar-well diffusion method and expressed as a zone of inhibition (ZOI). Amongst all the test isolates, Staphylococcus epidermidis, Candida auris, and methicillin-resistant Staphylococcus epidermidis were more susceptible to the NPs with a ZOI of 26.33 ± 0.57 mm, 19.33 ± 0.57 mm, and 18 ± 0.76 mm. The MIC and MFC values for Candida spp. were higher than the bacterial test isolates. Scanning electron microscopic studies of all the test isolates at their MIC concentrations showed drastically altered cell morphology, indicating that the NPs could successfully cross the cell barrier and damage the cell integrity, causing cell death. This study reports the efficacy of Cm-AgNPs against several Candida and bacterial strains, which had not been reported in earlier studies. Furthermore, the synthesized AgNPs exhibited significant antioxidant activity. Thus, the findings of this study strongly imply that the Cm-AgNPs can serve as promising candidates for therapeutic applications, especially against multidrug-resistant isolates of Candida and bacteria. However, further investigation is needed to understand the mode of action and biosafety.