The Role of Reactive Oxygen Species (ROS) in the Biological Activities of Metallic Nanoparticles

A review on the green synthesis of metal (Ag, Cu, and Au) and metal oxide (ZnO, MgO, Co3O4, and TiO2) nanoparticles using plant extracts for developing antimicrobial properties

Green synthesis (GS) is a vital method for producing metal nanoparticles with antimicrobial properties. Unlike traditional methods, green synthesis utilizes natural substances, such as plant extracts, microorganisms, etc., to create nanoparticles. This eco-friendly approach results in non-toxic and biocompatible nanoparticles with superior antimicrobial activity. This paper reviews the prospects of green synthesis of metal nanoparticles of silver (Ag), copper (Cu), gold (Au) and metal oxide nanoparticles of zinc (ZnO), magnesium (MgO), cobalt (Co3O4), and titanium (TiO2) using plant extracts from tissues of leaves, barks, roots, etc., antibacterial mechanisms of metal and metal oxide nanoparticles, and obstacles and factors that need to be considered to overcome the limitations of the green synthesis process. The clean surfaces and minimal chemical residues of these nanoparticles contribute to their effectiveness. Certain metals exhibit enhanced antibacterial properties only in GS methods due to the presence of bioactive compounds from natural reducing agents such as Au and MgO. GS improves TiO2 antibacterial properties under visible light, while it would be impossible without UV activation. These nanoparticles have important antimicrobial properties for treating microbial infections and combating antibiotic resistance against bacteria, fungi, and viruses by disrupting microbial membranes, generating ROS, and interfering with DNA and protein synthesis. Nanoscale size and large surface area make them critical for developing advanced antimicrobial treatments. They are effective antibacterial agents for treating infections, suitable in water purification systems, and fostering innovation by creating green, economically viable antibacterial materials. Therefore, green synthesis of metal and metal oxide nanoparticles for antibacterial agents supports several United Nations Sustainable Development Goals (SDGs), including health improvement, sustainability, and innovation.

The nano-paradox: addressing nanotoxicity for sustainable agriculture, circular economy and SDGs

Engineered nanomaterials (ENMs) have aroused extensive interest in agricultural, industrial, and medical applications. The integration of ENMs into the agricultural systems aligns with the principles of United Nations' sustainable development goals (SDGs), circular economy (CE) and bio-economy (BE) principles. This approach offers excellent opportunities to enhance productivity and address global climate change challenges. The revelation of the adverse effects of nanomaterials (NMs) on various organisms and ecosystems, however, has fueled the debate on 'Nano-paradox' leading to emergence of a new research domain 'Nanotoxicology'. ENMs have shown different interactions with biological and environmental systems as compared to their bulk counterparts. They bioaccumulate in organisms, soils, and other environmental matrices, move through food chains and reach higher trophic levels including humans ultimately resulting in oxidative stress and cellular damage. Understanding nano-bio interactions, the mechanism of gene- and cytotoxicity, and associated potential hazards, is therefore, essential to mitigate their toxicological outputs. This review comprehensively examines the cyto- and genotoxicity mechanisms of ENMs in biological systems, covering aspects such as their entry, uptake, cellular responses, dynamic interactions in biological environments their long-term effects and environmental risk assessment (ERA). It also discusses toxicological assessment methods, regulatory policies, strategies for toxicity management/mitigation and future research directions in nanotechnology, all within the context of SDGs, CE, promoting resource efficiency and sustainability. Navigating the nano-paradox involves balancing the benefits of nanomaterials with concerns about nanotoxicity. Prioritizing thorough research on above facets can ensure sustainability and safety, enabling responsible harnessing of nanotechnology's transformative potential in various applications including mitigating global climate change and enhancing agricultural productivity.

Synthesis of carbon dots from spent coffee grounds: transforming waste into potential biomedical tools

Carbon dots (CDs) are small-sized, spherical nanoparticles presenting amorphous carbon cores with nanocrystalline regions of a graphitic structure. They show unique properties such as high aqueous solubility, robust chemical inertness, and non-toxicity and can be manufactured at a relatively low cost. They are also well known for outstanding fluorescence tunability and resistance to photobleaching. Together, these properties boost their potential to act as drug delivery systems (DDSs). This work presents a low-cost synthesis of CDs by upcycling spent coffee grounds (SCGs) and transforming them into value-added products. This synthetic route eliminates the use of highly toxic heavy metals, high energy-consuming reactions and long reaction times, which can improve biocompatibility while benefiting the environment. A series of physico-chemical characterisation techniques demonstrated that these SCG-derived CDs are small-sized nanoparticles with tunable fluorescence. In vitro studies with 120 h of incubation of SCG-derived CDs demonstrated their specific antiproliferative effect on the breast cancer CAL-51 cell line, accompanied by increased reactive oxygen species (ROS) production. Importantly, no impact was observed on healthy breast, kidney, and liver cells. Confocal laser scanning microscopy confirmed the intracellular accumulation of SCG-derived CDs. Furthermore, the drug efflux pumps P-glycoprotein (P-gp) and the breast cancer resistance protein (BCRP) did not impact CD accumulation in the cancer cells.

Cellular strategies for surviving the alpine extremes: methylerythritol phosphate pathway-driven isoprenoid biosynthesis and stress resilience

High altitude conditions pose a significant challenge to all earth's inhabitants including flora. Low atmospheric pressure (thin air), intense ultraviolet (UV) light, and ultra-low temperatures combine to cause oxidative stress in plants. In these abiotic stress conditions, plants exhibit various ecophysiological, morphological, and biochemical adaptations to cope with stress. Morphologically, plants may develop smaller, thicker leaves with protective trichomes or waxy cuticles against intense UV radiation, and minimize water loss in the thin, dry air. However biochemically, plants increase the production of UV-absorbing compounds like flavonoids and phenolic acids along with antioxidant enzymes for neutralizing reactive oxygen species (ROS). To protect against these stress conditions plants start producing specialized metabolites, i.e., isoprenoids, phenolic acids, flavonoids, sterols, carotenoids, etc. The production of these specialized metabolites occurs through MEP (methylerythritol phosphate) and MVA (mevalonic acid) pathways. Although, this article aims to review the scientific complexities of high-altitude plants by providing an in-depth explanation of the MEP pathway, including its regulation, sources and causes of oxidative stress in plants, functions and roles of isoprenoids in stress tolerance, and the adaptation strategies that support alpine plant survival and acclimation. The MEP pathway's products, several carotenoids, viz., phytoene, lycopene, β-carotene, etc., and terpenoids, viz., geraniol, citral, phytol, etc., act as potent scavengers of ROS, providing defense against oxidative damage. Also, phytohormones, viz., abscisic acid, salicylic acid, and jasmonic acid play crucial roles in modulating plant responses to oxidative stress. To date, little scientific literature is available specifically on high-altitude plants with respect to MEP pathway and oxidative stress management. Understanding the interaction between the MEP pathway and oxidative stress in high-altitude plants can provide insight into the implications for improving crop resilience and producing bioactive chemicals with potential human health benefits.

Ecotoxicity of fungal-synthesized silver nanoparticles: mechanisms, impacts, and sustainable mitigation strategies

The review investigates the ecotoxicological implications of fungal-synthesized silver nanoparticles (AgNPs), focusing on their behavior, transformations, and impacts across aquatic and terrestrial ecosystems. Advanced techniques, such as Single-Particle ICP-MS and Nanoparticle Tracking Analysis, reveal the persistence and biotransformation of AgNPs, including silver ion (Ag⁺) release and reactive oxygen species (ROS) generation. The review highlights species-specific bio-accumulation pathways in algae, soil microbes, invertebrates, and vertebrates, along with the limited biomagnification potential within trophic levels. Long-term exposure to AgNPs leads to reduced soil fertility, altered microbial communities, and inhibited plant growth, raising significant ecological concerns. Sustainable mitigation strategies, including bioremediation and advanced filtration systems, are proposed to reduce the environmental risks of AgNPs. This comprehensive analysis provides a framework for future ecological studies and regulatory measures, balancing the technological benefits of fungal-synthesized AgNPs with their environmental safety.

Preparation and Characterization of Polyphenol-Functionalized Chitooligosaccharide Pyridinium Salts with Antioxidant Activity

As a kind of eco-friendly material with wide application prospects, chitooligosaccharide (COS) has attracted increasing attention because of its unique bioactivities. In this study, novel polyphenol-functionalized COS pyridinium salts were designed and synthesized. The structural characteristics of the desired derivatives were confirmed by FT-IR and 1H NMR spectroscopy. Their antioxidant activities were evaluated in vitro by DPPH radical scavenging assay, superoxide anion radical scavenging assay, and reducing power assay. The solubility assay in common solvents and cytotoxicity assay against L929 cells using the MTT method in vitro were also performed. The antioxidant assay results showed that the compounds functionalized by polyphenol displayed improved antioxidant activities, which were enhanced with the increase of sample concentration and the number of phenolic hydroxyl groups. The solubility assay indicated that the prepared derivatives had good water solubility. Besides, the modified products were non-toxic to the cells tested. In short, the polyphenol-functionalized COS pyridinium salts with enhanced antioxidant activity and good biocompatibility could be employed as newly safe antioxidant in the fields of biomedicine and food.

Unlocking the potential of fishery waste: exploring diverse applications of fish protein hydrolysates in food and nonfood sectors

Fish and their byproducts play a pivotal role as protein sources. With the global population increasing, urbanization on the rise and increased affluence, efficient utilization of available protein resources is becoming increasingly critical. Additionally, the need for sustainable protein sources is gaining recognition. By 2050, the world's protein demand is expected to double, driven not only by population growth but also by heightened awareness of protein's role in maintaining health. The fishery industry has experienced continuous growth over the last decade. However, this growth comes with a significant challenge: inadequate waste management. The fisheries industry discards 35% to 70% of their production as waste, including fillet remains, skin, fins, bones, heads, viscera and scales. Despite the importance of these byproducts as protein sources, their effective utilization remains a hurdle. Various strategies have been proposed to address this issue. Among them, the production of protein hydrolysates stands out as an efficient method for value addition. Protein hydrolysis breaks down proteins into smaller peptides with diverse functional and bioactive properties. Therefore, fish protein hydrolysates have applications in both the food and nonfood sectors. Utilizing fishery byproducts and waste represents a sustainable approach toward waste valorization and resource optimization in the fishery industry. This approach offers promising opportunities for innovation and economic growth across multiple sectors. This comprehensive review explores fish protein hydrolysates derived from fishery byproducts and wastes, focusing on their applications in both the food and nonfood sectors.

Assessment of Potential Toxicity of Hyaluronic Acid-Coated Magnetic Nanoparticles on Maize (Zea mays) at Early Development Stages

The effectiveness of iron oxide nanoparticles in enhancing crop plant development depends on their stabilization. In this study, the effect of hyaluronic acid (HA), used both as a stabilizer for iron oxide nanoparticles (HA-MNP) and independently, was evaluated in maize seedlings. Different concentrations of HA-MNP (0.625-7.5 mg/L) were tested alongside a 0.01% HA solution. Growth parameters, antioxidant enzyme activities (peroxidase and polyphenol oxidase), photosynthetic pigments (chlorophyll and carotenoids), phenolic content, and genotoxicity were analyzed. While HA alone led to slight decreases in seedling length, pigment content, and polyphenol levels compared to the control, it increased peroxidase activity and mitotic index. Lower concentrations of HA-MNP (below 2.5 mg/L) enhanced seedling growth, likely due to improved iron uptake, whereas higher concentrations reduced pigment and phenolic content. All HA-MNP concentrations induced genotoxic effects, which was proven by an increased mitotic index and chromosomal aberrations, indicating both positive and defensive plant responses to oxidative stress. These findings suggest a complex interaction between HA, HA-MNP, and maize seedlings, where HA concentrations play a significant role in modulating growth and stress response, while higher concentrations may induce toxicity.

The use of silver nanoparticles in pigs - An invited review

Silver nanoparticles (AgNPs) have attracted significant interest in veterinary medicine due to their unique properties, including enhanced stability, greater antimicrobial efficacy, and reduced toxicity compared to traditional silver salts. Their applications span various areas of veterinary practice, such as dermatology, wound management, infection prevention, drug delivery, and disinfection. This review explores their use in pigs, highlighting their role as feed additives to prevent diarrhoea, as antibacterial agents in semen extenders, and veterinary dermatology. AgNPs possess broad-spectrum antibacterial activity against both Gram-positive and Gram-negative bacteria, positioning them as a promising alternative to antibiotics in addressing antibiotic resistance. Additionally, AgNPs have shown antiviral potential, though the exact mechanism of action remains unclear. The review examines the antibacterial and antiviral properties of AgNPs, their utility in facility sanitation, and their potential toxicity to pigs. While AgNPs offer significant benefits in veterinary applications, concerns about their toxicity persist. Efforts to reduce this toxicity, such as surface modifications or combining AgNPs with other substances, are under investigation. Further research is essential to fully understand the potential applications and safety of AgNPs in pig medicine.

"Harnessing green synthesized zinc oxide nanoparticles for dual action in wound management: Antibiotic delivery and healing Promotion"

Wound infections are characterized by the invasion of microorganisms into bodily tissues, leading to inflammation and potentially affecting any type of wound, including surgical incisions and chronic ulcers. If left untreated, they can delay recovery and cause tissue damage. Healthcare providers face challenges in treating these infections, which necessitate efficient treatment plans involving microbiological testing and clinical evaluation. The effectiveness of conventional treatments like antibiotics is limited by resistance. Various forms of nanotechnology have been developed, each exhibiting unique properties that address particular issues with conventional therapies. Among all the Nanocarriers, zinc oxide nanoparticles (ZnO NPs), offer promising treatments for persistent wound infections. ZnO NPs possess strong antibacterial, antioxidant, anti-inflammatory, and anti-diabetic properties, making them suitable for wound care applications. These nanoparticles can be produced economically and environmentally using green synthesis techniques that minimize toxicity and are biocompatible. While chemical and physical techniques offer precise control over nanoparticle characteristics, they often involve hazardous substances and energy-intensive procedures. The antibacterial qualities, low toxicity, and biological compatibility of green-synthesized ZnO NPs make them a promising treatment for wound infections. Their use in scaffolds, drug delivery systems, and wound dressings provides a viable approach to combat antibiotic resistance and enhance wound treatment outcomes. Furthermore research is necessary to fully realize the benefits of ZnO NPs in clinical practice.

Multifunctional Hydrogel with Photothermal ROS Scavenging and Antibacterial Activity Accelerates Diabetic Wound Healing

Poor diabetic wound healing poses a critical threat to human health. Excessive oxidative stress and increased susceptibility to bacterial infection are key issues that impede diabetic wound healing. Cerium oxide nanoparticles (CeO2 NPs) have attracted increasing attention because of their unique antioxidant and antimicrobial properties. Here, this work designs a near-infrared (NIR) light-responsive gelatin methacryloyl (GelMA)/CeO2/polydopamine (PDA) hydrogel with antibacterial and antioxidant effects. The hydrogel exhibits a stable, efficient, and controllable photothermal conversion capacity under NIR stimulation. The hydrogel can be used to construct a local microenvironment conducive to chronic diabetic wound healing. Significant antibacterial effects of the NIR-responsive GelMA/CeO2/PDA hydrogel on both Escherichia coli (E.coli) and methicillin-resistant Staphylococcus aureus (MRSA) are demonstrated by counting colony-forming units (CFUs) and in bacterial live/dead staining experiments. The strong antioxidant activity of hydrogels is demonstrated by measuring the level of reactive oxygen species (ROS). The effect of the NIR-responsive GelMA/CeO2/PDA hydrogel in terms of promoting diabetic wound healing is validated in full-thickness cutaneous wounds of diabetic rat models. Additionally, this work describes the mechanism by which the NIR-responsive GelMA/CeO2/PDA hydrogel promotes diabetic wound healing; the hydrogel inhibits the interleukin (IL)-17 signaling pathway. This NIR-responsive, multifunctional hydrogel dressing provides a targeted approach to diabetic wound healing.

Nanopesticides for managing primary and secondary stored product pests: Current status and future directions

The preservation of agricultural commodities during storage is critical for ensuring food security and minimizing post-harvest losses. Both primary storage pests such as Callosobruchus maculatus, Callosobruchus chinensis, Sitophilus weevils, Rhyzopertha dominica, and Trogoderma granarium, and secondary storage pests like Tribolium castaneum cause significant damage to stored products, resulting in substantial economic losses. Traditional pest control methods, including chemical insecticides, face limitations due to environmental concerns and pest resistance. Consequently, nanoparticle-based insecticides are being extensively suggested as a promising alternative. This review analyzes the available literature on the efficacy of nanoparticles (NPs) against primary and some secondary storage pests. Green synthesis methods using plant extracts and other biological sources are highlighted for the production of environmentally friendly NPs. Studies demonstrate that NPs of alumina, carbon, silica, silver, copper, zinc oxide, nickel oxide, titanium dioxide, nano zeolite, as well as chitosan and polymers exhibit significant insecticidal activity against a variety of pests, in some cases surpassing mortality rates caused by traditional insecticides at recommended dosages. Structural, biochemical and molecular studies reveal that NPs induce oxidative stress, disrupt cellular homeostasis, and cause structural damage in pests. Histopathological evaluations indicate specific organ-related toxicity, emphasizing the need for comprehensive biosafety assessments. Additionally, the integration of NPs with conventional insecticides shows enhanced pest control efficiency, although challenges remain in standardizing synthesis methods and evaluating long-term environmental impacts. This review highlights the potential of NPs in sustainable pest management and underlines the importance of ongoing research to optimize specific formulations for specific groups of pests and ensure safety.

Insights into the fungal secretomes and their roles in the formation and stabilization of the biogenic silver nanoparticles

The biosynthesis of silver nanoparticles (AgNPs) using biological systems has emerged as a promising alternative to traditional chemical methods, providing eco-friendly solutions in nanotechnology. This study investigates the secretomes of two strains of Fusarium oxysporum (VR039 and 07SD) to synthesize AgNPs (AgNP@Fo VR039 and AgNP@Fo 07SD), characterized by similar sizes of 35.4 ± 12.4 nm and 28.6 ± 9.5 nm, respectively. We conducted proteomic analysis via mass spectrometry on both secretomes and nanoparticles, identifying proteins involved in the biosynthesis, stabilization, and antimicrobial activity of the nanoparticles. Our results indicate notable similarities in the proteomes of both nanoparticles and their respective secretomes, correlating with similar antimicrobial efficacy against Staphylococcus aureus and Escherichia coli, as demonstrated through bacterial growth inhibition assays. The presence of redox proteins, such as glyceraldehyde reductase and FAD-oxidoreductase, suggests a potential mechanism for the generation of reactive oxygen species (ROS) and oxidative stress in bacterial cells, further validated by fluorescence microscopy to differentiate viable from non-viable cells. Unlike previous studies that have focused separately on metal ion reduction or nanoparticle stabilization, our findings reveal a coordinated biosynthetic process where the same proteins mediate both functions. This overlap between the secretome and nanoparticle proteome provides new insights into fungal-mediated nanoparticle synthesis, highlighting the multifunctionality of fungal proteins in bionanotechnology. By demonstrating how secreted enzymes directly contribute to nanoparticle formation, this study paves the way for more efficient, scalable, and environmentally sustainable approaches to biogenic nanoparticle production.

Gadolinium (Gd)-based nanostructures as dual-armoured materials for microbial therapy and cancer theranostics

Gadolinium (Gd) nanoparticles hold significant promise in medical theranostics due to their unique properties. This review outlines the synthesis, characterisation, and applications of Gd nanostructures in combating microbial threats and advancing cancer theragnostic strategies. Synthesis methods such as co-precipitation, microemulsion, and laser ablation are discussed, alongside TEM, SEM, and magnetic characterisation. The antimicrobial efficacy of Gd nanostructures, their potential in combination therapy, and promising anticancer mechanisms are explored. Biocompatibility, toxicity, and regulatory considerations are also evaluated. Challenges, future perspectives, and emerging trends in Gd nanostructure research are highlighted, emphasising their transformative potential in medical applications.

Antifungal efficacy of Citrusfusion mediated silver nanoparticles in Candida species

BACKGROUND

Candida species are commensal fungi that can become opportunistic pathogens under specific host and environmental conditions. The emergence of multidrug-resistant Candida strains poses a significant challenge. Nanotechnology represents a cutting-edge field offering precise and targeted delivery systems for combating fungal infections, leveraging the unique properties of plant-derived bioactive compounds. This investigation employed a biogenic approach utilizing polyherbal leaf extracts from Citrus limon and Citrus medica, known for their abundant Citral content.

RESULTS

Citrus sp. extracts were used to synthesize Citrusfusion silver nanoparticles (CitAgNPs) through a green synthesis method. Characterization of CitAgNPs was carried out using advanced analytical methods ensuring the quality, uniformity, size, and charge. The synthesized CitAgNPs exhibited non toxic effect when tested on Vigna radiata and Danio rerio, highlighting their potential for sustainability and safe therapeutic use. Antifungal assays demonstrated the potent efficacy of CitAgNPs in various Candida strains, with low MIC and MFC. CitAgNPs exhibited remarkable biofilm inhibition capabilities and elucidated specific mechanisms of action in Candida species, surpassing the performance of fluconazole.

CONCLUSION

This study underscores the immense potential of nanotechnology-driven approaches harnessing Citrus leaf extract for synthesizing highly effective antifungal nanoparticles. The fusion of biogenic nanoparticles with Citrus bioactive compounds presents a sustainable strategy for addressing the escalating challenge of azole-resistant Candida infections. The research outcomes suggest that CitAgNPs have promising applications in inhibiting Candida biofilms, offering potential solutions for infections caused by diaper rashes and onychomycosis, providing safe and effective alternatives to antifungal therapies.

HPPE Activates NRF2 Signaling by Liberating Heavy Metal Stores

The Cap'n'collar transcription factor BACH1 represses the transcription of gene products involved in oxidative stress protection. Accordingly, agents capable of inhibiting the activity of BACH1 would be of keen interest in treating several autoimmune and age-related diseases. Here, we report that a previously annotated BACH1 inhibitor, HPPE, does not inhibit BACH1 but instead activates a NRF2 driven transcription program that is dependent on the canonical cysteine sensors of NRF2 inhibitory protein KEAP1. Mechanistically, HPPE acts as an ionophore, liberating cellular Zn2+ stores and inducing non-lethal levels of reactive oxygen species, resulting in KEAP1 inactivation. These data provide a surprising mechanism by which HPPE acts in cells and suggest that inducing small amounts of cellular stress may be a viable mechanism for activating NRF2 therapeutically.

Potential Antibiotic Resurgence: Consecutive Silver Nanoparticle Applications Gradually Increase Bacterial Susceptibility to Antibiotics

The increasing prevalence of resistant bacteria has emerged as a critical public health concern due to their ability to resist multiple antibiotics. This study aimed to investigate whether repeated treatments with silver nanoparticles (AgNPs) could gradually decrease bacterial resistance to antibiotics. The methodology involved three consecutive applications of AgNPs on six bacterial strains, followed by assessing their susceptibility to 38 different antibiotics. To our knowledge, the following three phenomena were observed for the first time. (1) During three consecutive AgNP applications, it was revealed that all the studied bacteria gradually became more susceptible to 38 antibiotics; by the end of the treatments, susceptibility had doubled for five bacteria and tripled for Klebsiella pneumoniae compared to the susceptibility before the first AgNP application. (2) Three consecutive AgNP treatments led to 27-47% restoration of bacterial susceptibility to antibiotics, which had already completely lost their activity before the initial AgNP application. (3) Unlike previous studies, we discovered a novel effect: the repeated AgNP applications increased the susceptibility of Salmonella enteritidis and Staphylococcus aureus to AgNPs themselves. Obtained results suggest that AgNP treatments may offer a new promising strategy to combat antibiotic resistance.

Gelation of Polyisocyanurate Xerogel Composites Induced by Silver Nanoparticles and Their Electrospun Fibers with Biocompatible and Antibacterial Properties for Biomedical Applications

We report the in situ synthesis of silver-containing polyisocyanurate (Ag-PI) gels via the self-polymerization of isocyanate-containing organic molecules (Desmodur N75) catalyzed by silver nitrate (AgNO3) in N,N'-dimethylformamide, which acts as both the solvent and reducing agent. Fourier transform infrared spectroscopy and X-ray diffraction confirmed the formation of polyisocyanurate and metallic silver nanoparticles. Gelation occurred in 30 min at 30 °C for Ag-PI, compared to 24 h for the uncatalyzed system, demonstrating AgNO3's catalytic role. Ag-PI gels exhibited superior compressive strength (up to ∼30 MPa with 74.3% bearing nature) compared to bare polyurea (∼6 MPa). Electrospun fibers (500-750 nm) and xerogels demonstrated excellent antibacterial activity against "Staphylococcus aureus" and "Escherichia coli" and were nontoxic to MG 63 cells, making them promising for tissue engineering applications.

Methionine-Derived Fluorescent Probes Targeting Mitochondria: A Tool for Real-Time Oxidative Stress Monitoring in Live Cells

Reactive oxygen species (ROS) play crucial roles in both cell signaling and defense mechanisms. Hypochlorous acid (HOCl), a strong oxidant, aids the immune response by damaging pathogens. In this study, we developed two pyridinium-based fluorophores PSSM and PSSE for selective hypochlorite detection. Out of these two fluorescent probes, PSSM shows a strong turn-on emission via a photoinduced electron transfer (PeT) mechanism, excellent mitochondrial localization, and rapid response to HOCl with high selectivity among reactive oxygen species by achieving a detection limit of 2.41 μM. It successfully detects both exogenous and endogenous HOCl in live cells, enabling the study of HOCl's role at the organelle level. Structural analysis of PSSM via thioether oxidation confirmed by HPLC, NMR and HRMS further supports its specificity. Confocal imaging and flow cytometry studies further highlights its utility in investigating oxidative stress, positioning this fluorophore as a valuable tool for monitoring HOCl imbalances in biological systems.

Investigation on the Interaction of Dendritic Core Multi-Shell Nanoparticles with Human Red Blood Cells

The use of nanoparticles is becoming increasingly apparent in a growing number of medical fields. To exploit the full potential of these particles, it is essential to examine their behavior in the blood and their possible interactions with blood cells. Dendritic core multi-shell DendroSol™ nanoparticles (DS-NPs) are able to penetrate into viable layers of human skin, but nothing is known about their interaction with blood cells. In the present study, we analyze the effect of DS-NPs on red blood cells (RBCs) using confocal laser scanning microscopy (CLSM), flow cytometry, sedimentation rate analysis, spectrophotometry, and hemolysis assays. DS-NPs labeled with Nile red (NR) were added to RBC suspensions and their accumulation in the area of the RBC membranes was demonstrated by CLSM as well as by flow cytometry. In the presence of DS-NPs, the RBCs show an increased sedimentation rate, which also confirms the binding of the NPs to the cells. Interestingly, in the presence of DS-NPs, the RBCs are stabilized against hypotonic hemolysis as well as against the hemolytic action of Triton X-100. This proven anti-hemolytic effect could be utilized to enhance the circulation time of RBCs loaded with drugs for prolonged sustained release and drug delivery with enhanced bioavailability.

Nanoparticle-Doped Antibacterial and Antifungal Coatings

Antimicrobial polymeric coatings rely not only on their surface functionalities but also on nanoparticles (NPs). Antimicrobial coatings gain their properties from the addition of NPs into a polymeric matrix. NPs that have been used include metal-based NPs, metal oxide NPs, carbon-based nanomaterials, and organic NPs. Copper NPs and silver NPs exhibit antibacterial and antifungal properties. So, when present in coatings, they will release metal ions with the combined effect of having bacteriostatic/bactericidal properties, preventing the growth of pathogens on surfaces covered by these nano-enhanced films. In addition, metal oxide NPs such as titanium dioxide NPs (TiO2 NPs) and zinc oxide NPs (ZnONPs) are used as NPs in antimicrobial polymeric coatings. Under UV irradiation, these NPs show photocatalytic properties that lead to the production of reactive oxygen species (ROS) when exposed to UV radiation. After various forms of nano-carbon materials were successfully developed over the past decade, they and their derivatives from graphite/nanotubes, and composite sheets have been receiving more attention because they share an extremely large surface area, excellent mechanical strength, etc. These NPs not only show the ability to cause oxidative stress but also have the ability to release antimicrobial chemicals under control, resulting in long-lasting antibacterial action. The effectiveness and life spans of the antifouling performance of a variety of polymeric materials have been improved by adding nano-sized particles to those coatings.

Blue-LED assisted Photodegradation kinetics of rhodamine-6G dye, enhanced anticancer activity and cleavage of plasmids using Au-ZnO nanocomposite

The plasmonic metal doping on the UV-active metal oxide nanoparticle turns the resultant plasmonic metal-metal oxide (PMMO) into visible light active and upon exogenous illumination the photogenerated energetic charge carriers and the in situ generated reactive oxygen species (ROS, e.g. ·OH and O2 -·) authoritatively enhances its biological and catalytic activity. Herein, a hexagonal rod-shaped ZnO nanoparticles (NP) precursor was prepared using the sol-gel method, which in the presence of varying concentrations of gold (0.005M, 0.01M, and 0.015M) via a greener citrate reduction method afforded a nanocrystalline Au-ZnO nanocomposite. Using which, the visible-light driven photo-degradation kinetics investigation of rhodamine-6G (R6G) dye under blue LED irradiation were carried out. The use of 20 mg 0.015-Au-ZnO completes the degradation of R6G (97.0 %, k = 6.5 X 10-3s-1 at pH 7) within 55 min while 50 mg of 0.015-Au-ZnO catalyst improves the rate of R6G degradation (15 min 97.8 %, k = 14.8 × 10-3 s-1) and it is reusable up to three cycles. The LC-MS spectra of the remains of R6G (after 15 min) identified various low molecular ions (up m/z = 65). Further, the blue-LED assisted anti-cancer studies (MTT assay) using 0.015-Au-ZnO towards human lung cancer cells (A549), breast cancer cells (SKBr3) show high anti-proliferation rate and low cytotoxicity against healthy human embryonic kidney cells (HEK-293) with an IC50 value of 65, 53 and 124 μg/mL respectively. Also, the AO-EB dual staining and DCFH-DA analysis of SKBr3 and A549 cells revealed ROS-mediated cell death via apoptosis. Moreover, plasmid cleavage studies against supercoiled pBR322 DNA result in single-stranded linear DNA without traversing the nicked circular form, suggesting the possible DNA targeting activity of Au-ZnO nanozyme. Thus, the synthesized Au-ZnO nanocomposite shows excellent photocatalytic and biological activity.

Reactive oxygen species-scavenging biomaterials for neural regenerative medicine

Reactive oxygen species (ROS) are natural by-products of oxygen metabolism. As signaling molecules, ROS can regulate various physiological processes in the body. However excessive ROS may be a major cause of inflammatory diseases. In the field of neurological diseases, ROS cause neuronal apoptosis and neurodegeneration, which severely impede neuroregeneration. Currently, ROS-scavenging biomaterials are considered as a promising therapeutic strategy for neurological injuries due to their ability to scavenge excessive ROS at defects and modulate the oxidative stress microenvironment. This review provides an overview of the generation and sources of ROS, briefly describes the dangers of generating excessive ROS in nervous system diseases, and highlights the importance of scavenging excessive ROS for neuroregeneration. We have classified ROS-scavenging biomaterials into three categories based on the different mechanisms of ROS clearance. The applications of ROS-responsive biomaterials for neurological diseases, such as spinal cord injury, brain injury, and peripheral nerve injury, are also discussed. Our review contributes to the development of ROS-scavenging biomaterials in the field of neural regeneration.

Copper oxide nanoparticles induced reactive oxygen species generation: A systematic review and meta-analysis

Copper oxide nanoparticles (CuO NPs) are widely employed in various industrial and biomedical applications owing to their enhanced physicochemical characteristics. However, concerns regarding their adverse effects on biological systems upon entering the environment remain unexplored. The generation of reactive oxygen species (ROS) is one of the primary mechanisms in CuO NPs induced toxicity. This meta-analysis was conducted to assess the associative link between CuO NPs exposure and ROS generation. A literature survey was performed in PubMed, Web of Science, Scopus, and Google Scholar, following PRISMA guidelines. After comprehensive initial and primary screening, 28 in vitro studies were selected for meta-analysis. Overall, our results show a substantial increase of ROS in the experimental group when compared to control (SMD = 3.3; 95 % CI: 2.82-3.77, p = 0.00001), with substantial heterogeneity (82 %). Subgroup analysis revealed that larger-sized NPs, higher dosages, and longer exposure duration were associated with ROS generation. Meta-regression analysis identified size, and dosage as significant factors influencing ROS levels. Sensitivity analysis revealed an outlier study and the funnel plot results suggested potential publication bias. Overall, our results provide valuable insights of CuO NPs induced ROS generation, and the relation of variables such as size, dose, and duration in nanotoxicity assessments.

Titanium dioxide nanoparticles: a promising candidate for wound healing applications

Effective wound management and treatment are crucial in clinical practice, yet existing strategies often fall short in fully addressing the complexities of skin wound healing. Recent advancements in tissue engineering have introduced innovative approaches, particularly through the use of nanobiomaterials, to enhance the healing process. In this context, titanium dioxide nanoparticles (TiO2 NPs) have garnered attention due to their excellent biological properties, including antioxidant, anti-inflammatory, and antimicrobial properties. Furthermore, these nanoparticles can be modified to enhance their therapeutic benefits. Scaffolds and dressings containing TiO2 NPs have demonstrated promising outcomes in accelerating wound healing and enhancing tissue regeneration. This review paper covers the wound healing process, the biological properties of TiO2 NPs that make them suitable for promoting wound healing, methods for synthesizing TiO2 NPs, the use of scaffolds and dressings containing TiO2 NPs in wound healing, the application of modified TiO2 NPs in wound healing, and the potential toxicity of TiO2 NPs.

Supramolecular Conductive Hydrogels for Tissue Engineering Applications

Owing to their unique attributes, including reversibility, specificity, directionality, and tunability, supramolecular biomaterials have evolved as an excellent alternative to conventional biomaterials like polymers, ceramics, and metals. Supramolecular hydrogels, in particular, have garnered significant interest because their fibrous architecture, high water content, and interconnected 3D network resemble the extracellular matrix to some extent. Consequently, supramolecular hydrogels have been used to develop biomaterials for tissue engineering. Supramolecular conductive hydrogels combine the advantages of supramolecular soft materials with the electrical properties of metals, making them highly relevant for electrogenic tissue engineering. Given the versatile applications of these hydrogels, it is essential to periodically review high-quality research in this area. In this review, we focus on recent advances in supramolecular conductive hydrogels, particularly their applications in tissue engineering. We discuss the conductive components of these hydrogels and highlight notable reports on their use in cardiac, skin, and neural tissue engineering. Additionally, we outline potential future developments in this field.

Construction and Application of Fluorescent Probes with Imine Protective Groups for Hypochlorite Detection

Several fluorescent probes have been designed to detect ClO- in biological systems based on the isomerization mechanism of C = N bonds. Particularly, fluorescein has emerged as an important fluorophore for detecting ClO- because of its unique properties. Previously, we introduced the fluorescein analog F-1 with an active aldehyde group. In this study, two ClO- fluorescent sensors (F-2 and F-3) with imine groups were designed and synthesized using diaminomaleonitrile and 2-hydrazylbenzothiazole as amines. The electron cloud distribution of F-2 and F-3 in ground and excited states was explored via Gaussian calculations, reasonably explaining their photophysical properties. The fluorescence detection of ClO- in solution using the two probes (F-2 and F-3) was realized based on the mechanism of imine deprotection with ClO-. NaClO concentration titration demonstrated that the colorimetric detection of ClO- with the naked eye could be achieved using both F-2 and F-3. However, after adding ClO-, the fluorescence intensity of probe F-2 increased, whereas that of probe F-3 first decreased and then increased. Probes F-2 and F-3 exhibited good selectivity, anti-interference capability, and sensitivity, with the detection limits of 169.95 and 37.30 µM, respectively. Owing to their low cell toxicity, probes F-2 and F-3 can be applied to detect ClO- in vivo. The design approach adopted in this study will further advance the future development of ClO- chemical probes through the removal of C = N bond isomerization.

Nanoceria Anti-inflammatory and Antimicrobial Nanodrug: Cellular and Molecular Mechanism of Action

INTRODUCTION

Nanoceria is a well-known nanomaterial with various properties, including antioxidant, proangiogenic, and therapeutic effects. Despite its potential, there are still aspects that require further exploration, particularly its anti-inflammatory and antimicrobial activities.

METHODS

The global demand for novel anti-inflammatory and antimicrobial drugs underscores the significance of understanding nanoceria in both contexts. In this study, we evaluated the effect of nanoceria on macrophage polarization to better understand its anti-inflammatory effects. Additionally, we investigated the mechanism of action of nanoceria against Cryptococcus neoformans (ATCC 32045), Candida parapsilosis (ATCC 22019), Candida krusei (ATCC 6258), and Candida albicans.

RESULTS

The results demonstrated that nanoceria can polarize macrophages toward an anti-inflammatory profile, revealing the cellular mechanisms involved in the anti-inflammatory response. Concerning the antimicrobial effect, it was observed that nanoceria have a more pronounced impact on Candida parapsilosis, leading to the formation of pronounced pores on the surface of this species.

CONCLUSION

Finally, biochemical analysis revealed transitory alterations, mainly in liver enzymes. The data support the use of nanoceria as a potential anti-inflammatory and antimicrobial drug and elucidate some of the mechanisms involved, shedding light on the properties of this nanodrug.

Nano Revolution: Harnessing Nanoparticles to Combat Antibiotic-resistant Bacterial Infections

Nanoparticles, defined as particles ranging from 1 to 100 nanometers in size, are revolutionizing the approach to combating bacterial infections amid a backdrop of escalating antibiotic resistance. Bacterial infections remain a formidable global health challenge, causing millions of deaths annually and encompassing a spectrum from common illnesses like Strep throat to severe diseases such as tuberculosis and pneumonia. The misuse of antibiotics has precipitated the rise of resistant strains like methicillin-resistant Staphylococcus aureus (MRSA), multidrug-resistant Mycobacterium tuberculosis (MDR-TB), and carbapenem-resistant Enterobacteriaceae (CRE), underscoring the critical need for innovative therapeutic strategies. Nanotechnology offers a promising avenue in this crisis. Nanoparticles possess unique physical and chemical properties that distinguish them from traditional antibiotics. Their high surface area to volume ratio, ability to be functionalized with various molecules, and distinctive optical, electronic, and magnetic characteristics enable them to exert potent antibacterial effects. Mechanisms include physical disruption of bacterial membranes, generation of reactive oxygen species (ROS), and release of metal ions that disrupt bacterial metabolism. Moreover, nanoparticles penetrate biofilms and bacterial cell walls more effectively than conventional antibiotics and can be precisely targeted to minimize off-target effects. Crucially, nanoparticles mitigate the development of bacterial resistance by leveraging multiple simultaneous mechanisms of action, which make it challenging for bacteria to adapt through single genetic mutations. As research advances, nanotechnology holds immense promise in transforming antibacterial treatments, offering effective solutions that address current infections and combat antibiotic resistance globally. This review provides a comprehensive overview of nanoparticle applications in antibacterial therapies, highlighting their mechanisms, advantages over antibiotics, and future directions in healthcare innovation.

Nanocarrier-Mediated Dermal Drug Delivery System of Antimicrobial Agents for Targeting Skin and Soft Tissue Infections

Antimicrobial resistance in disease-causing microbes is seen as a severe problem that affects the entire world, makes therapy less effective, and raises mortality rates. Dermal antimicrobial therapy becomes a desirable choice in the management of infectious disorders since the rising resistance to systemic antimicrobial treatment frequently necessitates the use of more toxic drugs. Nanoparticulate systems such as nanobactericides, which have built-in antibacterial activity, and nanocarriers, which function as drug delivery systems for conventional antimicrobials, are just two examples of the treatment methods made feasible by nanotechnology. Silver nanoparticles, zinc oxide nanoparticles, and titanium dioxide nanoparticles are examples of inorganic nanoparticles that are efficient on sensitive and multidrug-resistant bacterial strains both as nanobactericides and nanocarriers. To stop the growth of microorganisms that are resistant to standard antimicrobials, various antimicrobials for dermal application are widely used. This review covers the most prevalent microbes responsible for skin and soft tissue infections, techniques to deliver dermal antimicrobials, topical antimicrobial safety concerns, current issues, challenges, and potential future developments. A thorough and methodical search of databases, such as Google Scholar, PubMed, Science Direct, and others, using specified keyword combinations, such as "antimicrobials," "dermal," "nanocarriers," and numerous others, was used to gather relevant literature for this work.

Green synthesized Zingiber officinale-ZnO nanoparticles: anticancer efficacy against 3D breast cancer model

Aim: ZnO NPs were prepared via green synthesis utilizing Zingiber Officinale.Methodology: Physical characterization and biological activity were performed against 2D, and 3D spheroids MCF-7 cell lines.Results: The NPs exhibited 188.9, 175.7 and 171.2 nm size with charge of -8.2, -11.7 and -9.7 mV for the 2%, 3% and 4% formulations. XRD confirmed a wurtzite hexagonal phase. FTIR spectra showed Zn-O stretching vibrations. The 2%, 3% and 4% formulations presented IC50 values of 14.7, 26.2 and 47 μg/ml, respectively, with complete destruction of MCF-7 spheroids. Elevated TNF-α levels suggested an inflammatory-mediated mechanism of action.Conclusion: 2% Zingiber officinale-derived ZnO NPs showed antitumor potential against deserving further mechanistic and in vivo explorations.

Utilizing nanomaterials for cancer treatment and diagnosis: an overview

Cancer is a deadly disease with complex pathophysiological nature and is the leading cause of death worldwide. Traditional diagnosis methods often detect cancer at a considerably critical stage and the conventional methods of treatment like chemotherapy, radiation therapy, targeted therapy, and immunotherapy have several limitations, multidrug resistance, cytotoxicity, and lack of specificity are a few examples. These pose substantial challenge for effective and favourable cancer treatment. The advent of nanotechnology has revolutionized the face of cancer diagnosis and treatment. Nanoparticles, which have a size range of 1-100 nm, are biocompatible and have special optical, magnetic, and electrical capabilities, less toxic, more stable, exhibit permeability and retention effect, and are used for precise targeting. There are several classes of nanoparticles each having their own sets of unique properties. NPs have played an important role in the drug delivery system, overcoming the multi-drug resistance, reducing the side-effects as seen in conventional therapeutic methods and hence able to solve the limitations of conventional methods of diagnosis and treatment. This review discusses the four major classes of nanoparticles (Lipid based NPs, Carbon NPs and Metallic NPs and Polymeric NPs): their discovery and introduction in medical field, unique properties and characteristics, advantages and disadvantages, sub-categories and characteristics of these categories, major area of application in Cancer diagnosis and treatment, and latest methodologies where these are used in cancer treatment.

Enhancing orthopaedic implant efficacy: the development of cerium-doped bioactive glass and polyvinylpyrrolidone composite coatings via MAPLE technique

This study investigates the potential of combining Cerium-doped bioactive glass (BBGi) with Polyvinylpyrrolidone (PVP) to enhance the properties of titanium (Ti) implant surfaces using the Matrix-Assisted Pulsed Laser Evaporation (MAPLE) technique. The primary focus is on improving osseointegration, corrosion resistance, and evaluating the cytotoxicity of the developed thin films towards host cells. The innovative approach involves synthesizing a composite thin film comprising BBGi and PVP, leveraging the distinct benefits of both materials: BBGi's biocompatibility and osteoinductive capabilities, and PVP's film-forming and biocompatible properties. Results demonstrate that the BBGi + PVP coatings significantly enhance hydrophilicity, indicating improved cell-material interaction potential. The electrochemical analysis reveals superior corrosion resistance of the BBGi + PVP films compared to BBGi alone, which is critical for long-term implant stability. The mechanical adherence tests confirm the robust attachment of the coatings to Ti substrates, surpassing the ISO standards for implant materials. Biocompatibility tests show promising cell viability and negligible cytotoxic effects, with a controlled inflammatory response, underscoring the potential of BBGi + PVP coatings for orthopedic applications. The study concludes that the synergistic combination of BBGi and PVP, applied through the MAPLE technique, offers a promising route to fabricate bioactive and corrosion-resistant coatings for Ti implants, potentially enhancing osseointegration and longevity in clinical settings.

Biogenic biocompatible silver nanoparticles: a promising antibacterial agent

The biogenic synthesis of silver nanoparticles (AgNPs) are gaining attention because they are eco-friendly, non-hazardous, economical and devoid of the drawbacks of physicochemical processes. Biogenic approaches for synthesizing nanoparticles (NPs) using plant leaves, seeds, bark, stems, fruits, roots and flowers are highly cost-effective compared to other methods. Silver (Ag) has been used since ancient times, but biogenic AgNPs have only been made in the last few decades. They have been employed primarily in the food and pharmaceutical industries as antimicrobials and antioxidants. Recent studies have confirmed that many molecules present in different bacteria, including Escherichia coli, Staphylococcus aureus, Citrobacter koseri, Bacillus cereus, Salmonella typhi, Klebsipneumoniaoniae, Vibrio parahaemolyticus, Pseudomonas Aeruginosa, are bound to the AgNPs and can be inhibited using multifaceted mechanisms like AgNPs inter inside the cells, free radicals, ROS generation and modulate transduction pathways. Recent breakthroughs in nanobiotechnology-based therapeutics have opened up new possibilities for fighting microorganisms. Thus, in particular, biogenic AgNPs as powerful antibacterial agents have gained much interest. Surface charge, colloidal state, shape, concentration and size are the most critical physicochemical characteristics that determine the antibacterial potential of AgNPs. Based on this review, it can be stated that AgNPs could be made better in terms of their potency, durability, accuracy, biosecurity and compatibility.

Constructing the cGAMP-Aluminum Nanoparticles as a Vaccine Adjuvant-Delivery System (VADS) for Developing the Efficient Pulmonary COVID-19 Subunit Vaccines

The cGAMP-aluminum nanoparticles (CAN) are engineered as a vaccine adjuvant-delivery system to carry mixed RBD (receptor-binding domain) of the original severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its new variant for developing bivalent pulmonary coronavirus disease 2019 (COVID-19) vaccines (biRBD-CAN). High phosphophilicity/adsorptivity made intrapulmonary CAN instantly form the pulmonary ingredient-coated CAN (piCAN) to possess biomimetic features enhancing biocompatibility. In vitro biRBD-CAN sparked APCs (antigen-presenting cells) to mature and make extra reactive oxygen species, engendered lysosome escape effects and enhanced proteasome activities. Through activating the intracellular stimulator of interferon genes (STING) and nucleotide-binding domain and leucine-rich repeat and pyrin domain containing proteins 3 (NALP3) inflammasome pathways to exert synergy between cGAMP and AN, biRBD-CAN stimulated APCs to secret cytokines favoring mixed Th1/Th2 immunoresponses. Mice bearing twice intrapulmonary biRBD-CAN produced high levels of mucosal antibodies, the long-lasting systemic antibodies, and potent cytotoxic T lymphocytes which efficiently erased cells displaying cognate epitopes. Notably, biRBD-CAN existed in mouse lungs and different lymph nodes for at least 48 h, unveiling their sustained immunostimulatory activity as the main mechanism underlying the long-lasting immunity and memory. Hamsters bearing twice intrapulmonary biRBD-CAN developed high resistance to pseudoviral challenges performed using different recombinant strains including the ones with distinct SARS-CoV-2-spike mutations. Thus, biRBD-CAN as a broad-spectrum pulmonary COVID-19 vaccine candidate may provide a tool for controlling the emerging SARS-CoV-2 variants.

Impact of metallic nanoparticles on gut microbiota modulation in colorectal cancer: A review

Colorectal cancer (CRC) is the third most prevalent cancer. Ongoing research aims to uncover the causes of CRC, with a growing focus on the role of gut microbiota (GM) in carcinogenesis. The GM influences CRC development, progression, treatment efficacy, and therapeutic toxicities. For example, Fusobacterium nucleatum and Escherichia coli can regulate microbial gene expression through the incorporation of human small noncode RNA and potentially contribute to cancer progression. Metallic nanoparticles (MNPs) have both negative and positive impacts on GM, depending on their type. Several studies state that titanium dioxide may increase the diversity, richness, and abundance of probiotics bacteria, whereas other studies demonstrate dose-dependent GM dysbiosis. The MNPs offer cytotoxicity through the modulation of MAPK signaling pathways, NF-kB signaling pathways, PI3K/Akt signaling pathways, extrinsic signaling pathways, intrinsic apoptosis, and cell cycle arrest at G1, G2, or M phase. MNPs enhance drug delivery, enable targeted therapy, and may restore GM. However, there is a need to conduct well-designed clinical trials to assess the toxicity, safety, and effectiveness of MNPs-based CRC therapies.

Recent advances in targeted drug delivery systems for multiple myeloma

Despite significant therapeutic advances, multiple myeloma (MM) remains a challenging, incurable, hematological malignancy. The efficacy of traditional chemotherapy and currently available anti-MM agents is in part limited by their adverse effects, which restrict their therapeutic potential. Nanotherapeutics is an emerging field of cancer therapy that can overcome the biological and chemical barriers of existing anticancer drugs. This review presents an overview of recent advancements in nanoparticle- and immunotherapy-based drug delivery systems for MM treatment. It further delves into the targeting strategies, mechanism of controlled drug release, and challenges associated with the development of drug delivery systems for the treatment of MM.

Miniature Robots for Battling Bacterial Infection

Micro/nanorobots have shown great promise for minimally invasive bacterial infection therapy. However, bacterial infections usually form biofilms inside the body by aggregation and adhesion, preventing antibiotic penetration and increasing the likelihood of recurrence. Moreover, a substantial portion of the infection happens in those hard-to-access regions, making delivery of antibiotics to infected sites or tissues difficult and exacerbating the challenge of addressing bacterial infections. Micro/nanorobots feature exceptional mobility and controllability, are able to deliver drugs to specific sites (targeted delivery), and enhance drug penetration. In particular, the emergence of bioinspired microrobot surface design strategies have provided effective alternatives for treating infections, thereby preventing the possible development of bacterial resistance. In this paper, we review the recent advances in design, mechanism, and actuation modalities of micro/nanorobots with exceptional antimicrobial features, highlighting active therapy strategies for bacterial infections and derived complications at various organs, from the laboratory bench to in vivo applications. The current challenges and future research directions in this field are summarized. Those breakthroughs in micro/nanorobots offer a huge potential for clinical translation for bacterial infection therapy.

Exosomal therapy mitigates silver nanoparticles-induced neurotoxicity in rats

INTRODUCTION

Our investigation aims to appraise the neuroprotective impact of Bone Marrow-Mesenchymal Stem Cells (BM-MSCs) derived exosomes against Ag NPs-inducing neurotoxicity in rats.

MATERIALS AND METHODS

Twenty-four albino rats were divided into 3 groups. Group I (control negative), Group II (intraperitoneally injected with Ag NPs for 28 days, whereas Group III (intraperitoneally injected with Ag NP and BM-MSCs derived exosomes.

RESULTS

There was a marked elevation of Malondialdehyde (MDA) along with a reduction of brain antioxidants, Gamma-aminobutyric acid (GABA) and Monoamine Oxidase (MAO) in the Ag NPs receiving group. Ag NPs upregulated c-Jun N-terminal Kinases (JNK) genes and c-Myc and downregulated the tissue inhibitors of metalloproteinases (TIMP-1) and Histone deacetylase 1 (HDAC1) genes. Otherwise, the co-treatment of BM-MSCs derived exosomes with Ag NPs could markedly increase the rat's body weight, activity and learning while, decreasing anxiety, restoring all the toxicological parameters and improving the microscopic appearance of different brain areas.

CONCLUSION

BM-MSCs-derived exosomes downregulated both apoptotic and inflammatory mediators and upregulated the antiapoptotic genes. BM-MSCs-derived exosomes exhibit a great therapeutic effect against the neurotoxic effects of Ag NPs.

Unlocking the potential of biocompatible chitosan-hyaluronic acid nanogels labeled with fluorochromes: A promising step toward enhanced FRET bioimaging

Chitosan is a natural polysaccharide widely used in medical formulations as nanoparticles due to their special properties. Our work aimed to assess the biocompatibility of chitosan-hyaluronic acid nanogels labeled with fluorochromes for use in biomedical applications, based on the FRET effect. The preparation method included the ionic gelation, grafting rhodamine or fluorescein isothiocyanate molecules onto the chitosan backbone. To assess the potential applications as fluorescence imaging tools of chitosan-fluorophores conjugates in diagnostics and therapies, SVEC4-10 cells (simian virus 40-transformed mouse microvascular endothelial cell line) and RAW264.7 murine macrophages were used within this study. Good biocompatibility was observed after 6 and 24 h of incubation with nanogels, with no increase in cell death or membrane damage for concentrations up to 120 μg/mL. Both types of fluorescent nanogels presented the tendency to agglomerate on the cell membrane's surface, and few cells were internalized, especially at the periphery of cells. Molecular dynamics simulations showed that distances between fluorophores fitted at values close to those calculated based on FRET experiments. These formulations can further incorporate gadolinium for better nanomedicine tools.

Mechanistic Insights into Toxicity of Titanium Dioxide Nanoparticles at the Micro- and Macro-levels

Titanium oxide nanoparticles (TiO2 NPs) have been regarded as a legacy nanomaterial due to their widespread usage across multiple fields. The TiO2 NPs have been and are still extensively used as a food and cosmetic additive and in wastewater and sewage treatment, paints, and industrial catalysis as ultrafine TiO2. Recent developments in nanotechnology have catapulted it into a potent antibacterial and anticancer agent due to its excellent photocatalytic potential that generates substantial amounts of highly reactive oxygen radicals. The method of production, surface modifications, and especially size impact its toxicity in biological systems. The anatase form of TiO2 (<30 nm) has been found to exert better and more potent cytotoxicity in bacteria as well as cancer cells than other forms. However, owing to the very small size, anatase particles are able to penetrate deep tissue easily; hence, they have also been implicated in inflammatory reactions and even as a potent oncogenic substance. Additionally, TiO2 NPs have been investigated to assess their toxicity to large-scale ecosystems owing to their excellent reactive oxygen species (ROS)-generating potential compounded with widespread usage over decades. This review discusses in detail the mechanisms by which TiO2 NPs induce toxic effects on microorganisms, including bacteria and fungi, as well as in cancer cells. It also attempts to shed light on how and why it is so prevalent in our lives and by what mechanisms it could potentially affect the environment on a larger scale.

Nanomedicines as a cutting-edge solution to combat antimicrobial resistance

Antimicrobial resistance (AMR) poses a critical threat to global public health, necessitating the development of novel strategies. AMR occurs when bacteria, viruses, fungi, and parasites evolve to resist antimicrobial drugs, making infections difficult to treat and increasing the risk of disease spread, severe illness, and death. Over 70% of infection-causing microorganisms are estimated to be resistant to one or several antimicrobial drugs. AMR mechanisms include efflux pumps, target modifications (e.g., mutations in penicillin-binding proteins (PBPs), ribosomal subunits, or DNA gyrase), drug hydrolysis by enzymes (e.g., β-lactamase), and membrane alterations that reduce the antibiotic's binding affinity and entry. Microbes also resist antimicrobials through peptidoglycan precursor modification, ribosomal subunit methylation, and alterations in metabolic enzymes. Rapid development of new strategies is essential to curb the spread of AMR and microbial infections. Nanomedicines, with their small size and unique physicochemical properties, offer a promising solution by overcoming drug resistance mechanisms such as reduced drug uptake, increased efflux, biofilm formation, and intracellular bacterial persistence. They enhance the therapeutic efficacy of antimicrobial agents, reduce toxicity, and tackle microbial resistance effectively. Various nanomaterials, including polymeric-based, lipid-based, metal nanoparticles, carbohydrate-derived, nucleic acid-based, and hydrogels, provide efficient solutions for AMR. This review addresses the epidemiology of microbial resistance, outlines key resistance mechanisms, and explores how nanomedicines overcome these barriers. In conclusion, nanomaterials represent a versatile and powerful approach to combating the current antimicrobial crisis.

Food grade titanium dioxide (E171) interferes with monocyte-macrophage cell differentiation and their phagocytic capacity

Food grade titanium dioxide E171 has been used in products such as confectionery, doughs and flours to enhance organoleptic properties. The European Union has warned about adverse effects on humans due to oral consumption. After oral exposure, E171 reaches the bloodstream which raises the concern about effects on blood cells such as monocytes. One of the main functions of these cells is the differentiation of macrophages leading to the phagocytosis of foreign particles. The aim of this study was to evaluate the effect of E171 exposure on the phagocytic capacity and differentiation process of monocytes (THP-1) into macrophages. Physicochemical E171 properties were evaluated, and THP-1 monocytes were exposed to 4, 40 and 200 μg/ml. Cell viability, uptake capacity, cytokine release, the differentiation process, cytoskeletal arrangement and E171 internalization were assayed. Results showed that E171 particles had an amorphous shape with a mean of hydrodynamic size of ∼46 nm in cell culture media. Cell viability decreased until the 9th day of exposure, while the uptake capacity decreased up to 62% in a concentration dependent manner in monocytes. Additionally, the E171 exposure increased the proinflammatory cytokines release and decreased the cell differentiation by a 61% in macrophages. E171 induced changes in cytoskeletal arrangement and some of the E171 particles were located inside the nuclei. We conclude that E171 exposure in THP-1 monocytes induced an inflammatory response, impaired the phagocytic capacity, and interfered with cell differentiation from monocytes to macrophages.

Advancements of metallic nanoparticles: A promising frontier in cancer treatment

The incidence of cancer is increasing and evolving as a major source of mortality. Nanotechnology has garnered considerable scientific interest in recent decades and can offer a promising solution to the challenges encountered with traditional chemotherapy. Nanoparticle utilization holds promise in combating cancer and other diseases, offering exciting prospects for drug delivery systems and medicinal applications. Metallic nanoparticles exhibit remarkable physical and chemical properties, such as their minute size, chemical composition, structure, and extensive surface area, rendering them versatile and cost-effective. Research has demonstrated their significant and beneficial impact on cancer treatment, characterized by enhanced targeting abilities, gene activity suppression, and improved drug delivery efficiency. By incorporating targeting ligands, functionalized metal nanoparticles ensure precise energy deposition within tumors, thereby augmenting treatment accuracy. Moreover, beyond their therapeutic efficacy, metal nanoparticles serve as valuable tools for cancer cell visualization, contributing to diagnostic techniques. Utilizing metal nanoparticles in therapeutic systems allows for simultaneous cancer diagnosis and treatment, while also facilitating controlled drug release, thus revolutionizing cancer care. This narrative review investigates the advancements of metal nanoparticles in cancer treatment, types and mechanisms in targeting cancer cells, application in clinical scenarios, and potential toxicity in medicine.

Sex Influences the Safety and Therapeutic Efficacy of Cardiac Nanomedicine Technologies

Nanomedicine technologies are being developed for the prevention, diagnosis, and treatment of cardiovascular disease (CVD), which is the leading cause of death worldwide. Before delving into the nuances of cardiac nanomedicine, it is essential to comprehend the fundamental sex-specific differences in cardiovascular health. Traditionally, CVDs have been more prevalent in males, but it is increasingly evident that females also face significant risks, albeit with distinct characteristics. Females tend to develop CVDs at a later age, exhibit different clinical symptoms, and often experience worse outcomes compared to males. These differences indicate the need for sex-specific approaches in cardiac nanomedicine. This Perspective discusses the importance of considering sex in the safety and therapeutic efficacy of nanomedicine approaches for the prevention, diagnosis, and treatment of CVD.

Nanozymes and their biomolecular conjugates as next-generation antibacterial agents: A comprehensive review

Antimicrobial resistance (AMR), the ability of bacterial species to develop resistance against exposed antibiotics, has gained immense global attention in the past few years. Bacterial infections are serious health concerns affecting millions of people annually worldwide. Therefore, developing novel antibacterial agents that are highly effective and avoid resistance development is imperative. Among various strategies, recent developments in nanozyme technology have shown promising results as antibacterials in several antibiotic-sensitive and resistant bacterial species. Nanozymes offer several advantages over corresponding natural enzymes, such as inexpensive, stable, multifunctional, tunable catalytic properties, etc. Although the use of nanozymes as antibacterial agents has provided promising results, the specific biomolecule-conjugated nanozymes have shown further improvement in catalytic performance and associated antibacterial efficacy. The exclusive design of functional nanozymes with theranostic potential is found to simultaneously inhibit the growth and image of AMR bacterial species. This review comprehensively summarizes the history of nanozymes, their classification, biomolecules conjugated nanozyme, and their mechanism of enzyme-mimetic activity and associated antibacterial activity in antibiotic-sensitive and resistant species. The futureneeds to effectively engineer the existing or new nanozymes to curb AMR have also been discussed.

Designing antibacterial materials through simulation and theory

Antibacterial materials have a wide range of potential applications in bio-antimicrobial, environmental antimicrobial, and food antimicrobial fields due to their intrinsic antimicrobial properties, which can circumvent the development of drug resistance in bacteria. Understanding the intricate mechanisms and intrinsic nature of diverse antibacterial materials is significant for the formulation of guidelines for the design of materials with rapid and efficacious antimicrobial action and a high degree of biomedical material safety. Herein, this review highlights the recent advances in investigating antimicrobial mechanisms of different antibacterial materials with a particular focus on tailored computer simulations and theoretical analysis. From the view of structure and function, we summarize the characteristics and mechanisms of different antibacterial materials, introduce the latest advances of new antibacterial materials, and discuss the design concept and development direction of new materials. In addition, we underscore the significance of employing simulation and theoretical methodologies to elucidate the intrinsic antimicrobial mechanisms, which is crucial for a comprehensive comprehension of the control strategies, safer biomedical applications, and the management of health and environmental concerns associated with antibacterial materials. This review could potentially stimulate further endeavors in fundamental research and facilitate the extensive utilization of computational and theoretical approaches in the design of novel functional nanomaterials.

Antioxidant and Pro-Oxidant Properties of Selected Clinically Applied Antibiotics: Therapeutic Insights

BACKGROUND

The balance between antioxidants and pro-oxidants plays a significant role in the context of oxidative stress, influenced by both physiological and non-physiological factors.

OBJECTIVES

In this study, 18 prescribed antibiotics (including doxycycline hydrochloride, tigecycline, rifampicin, tebipenem, cefuroxime, cefixime, potassium clavulanate, colistin, ampicillin, amoxicillin, amikacin, nalidixic acid, azithromycin, pipemidic acid trihydrate, pivmecillinam, aztreonam, fosfomycin sodium, and ciprofloxacin) were subjected to simultaneous determination of antioxidant and pro-oxidant potential to assess if pro-oxidant activity is a dominant co-mechanism of antibacterial activity or if any antibiotic exhibits a balanced effect.

METHODS

This study presents a recently developed approach for the simultaneous assessment of antioxidant and pro-oxidant potential on a single microplate in situ, applied to prescribed antibiotics.

RESULTS

Ten antibiotics from eighteen showed lower antioxidant or pro-oxidant potential, while five exhibited only mild potential with DPPH50 values over 0.5 mM. The pro-oxidant antioxidant balance index (PABI) was also calculated to determine whether antioxidant or pro-oxidant activity was dominant for each antibiotic. Surprisingly, three antibiotics-doxycycline hydrochloride, tigecycline, and rifampicin-showed significant measures of both antioxidant and pro-oxidant activities. Especially notable was tebipenem, a broad-spectrum, orally administered carbapenem, showed a positive PABI index ratio, indicating a dominant antioxidant over pro-oxidant effect.

CONCLUSIONS

These findings could be significant for both therapy, where the antibacterial effect is enhanced by radical scavenging activity, and biotechnology, where substantial pro-oxidant activity might limit microbial viability in cultures and consequently affect yield.

Impact of Metal Ions on Cellular Functions: A Focus on Mesenchymal Stem/Stromal Cell Differentiation

Metals play a crucial role in the human body, especially as ions in metalloproteins. Essential metals, such as calcium, iron, and zinc are crucial for various physiological functions, but their interactions within biological networks are complex and not fully understood. Mesenchymal stem/stromal cells (MSCs) are essential for tissue regeneration due to their ability to differentiate into various cell types. This review article addresses the effects of physiological and unphysiological, but not directly toxic, metal ion concentrations, particularly concerning MSCs. Overloading or unbalancing of metal ion concentrations can significantly impair the function and differentiation capacity of MSCs. In addition, excessive or unbalanced metal ion concentrations can lead to oxidative stress, which can affect viability or inflammation. Data on the effects of metal ions on MSC differentiation are limited and often contradictory. Future research should, therefore, aim to clarify the mechanisms by which metal ions affect MSC differentiation, focusing on aspects such as metal ion interactions, ion concentrations, exposure duration, and other environmental conditions. Understanding these interactions could ultimately improve the design of biomaterials and implants to promote MSC-mediated tissue regeneration. It could also lead to the development of innovative therapeutic strategies in regenerative medicine.