Search Results (280)

Non-stoichiometric copper sulfide (Cu_2-xS) nanomaterials are promising antibacterial agents, but the role of morphology in regulating their bactericidal performance remains poorly understood. Herein, we rationally design two types of Cu_2-xS nanostructures, namely nanoplates (NPs) and superparticles (SPs). Both materials were prepared via a ligand-directed synthesis method with the comparable sizes, surface ligands, and crystal phase. The antibacterial behaviors of Cu_2-xS NPs and Cu_2-xS SPs against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were investigated under dark and 808 nm near-infrared (NIR) light irradiation. The results showed that under NIR light irradiation, Cu_2-xS SPs exhibit a markedly higher bactericidal efficiency against both E. coli and S. aureus than Cu_2-xS NPs, leading to almost complete eradication of bacterial colonies. Notably, S. aureus shows more sensitive than E. coli, and significant growth inhibition is observed even in the absence of laser irradiation. Mechanistic investigations reveal that hierarchical assembly of primary nanoparticles in SPs can promote multiple internal light scatterings, thereby significantly enhancing light harvesting efficiency and further improving the photothermal conversion efficiency. In addition, the SPs exhibited higher peroxidase-like activity, resulting in enhanced reactive oxygen species (ROS) generation and aggravated oxidative damage, and the accelerated Cu²⁺ release kinetics strengthens ionic toxicity. Full article

Tumor-associated macrophages (TAMs) are pivotal in shaping the immunosuppressive tumor microenvironment (TME). Reprogramming TAMs towards an anti-tumor M1 phenotype represents a promising strategy to enhance anti-tumor immunity. While Fe₃O₄ nanoparticles (NPs) possess immunomodulatory potential, the influence of NP size on macrophage polarization and the underlying mechanisms remain unclear. This study aims to systematically investigate the size-dependent immunomodulatory effects of Fe₃O₄ NPs and elucidate their mechanisms. We synthesized a series of Fe₃O₄ NPs of controlled sizes (5 nm, 10 nm, 30 nm, and 100 nm) via the polyol method. Among these, the 10 nm NPs demonstrated superior cellular uptake efficiency in macrophages. This enhanced uptake induced a significant increase in intracellular reactive oxygen species (ROS) levels. Subsequently, the elevated ROS activated the NF-κB signaling pathway, promoting M1 macrophage polarization. This polarization was evidenced by enhanced CD86 expression, increased nitric oxide (NO) release, and elevated secretion of pro-inflammatory cytokines. This study identifies 10 nm as the optimal size for Fe₃O₄ NPs to elicit their maximal immunomodulatory effects. Our findings establish a crucial size-design principle for the rational development of nano-immunotherapeutic agents and identify 10 nm Fe₃O₄ NPs as a promising candidate for TAM-targeted cancer therapy. Full article

This study focuses on the production and characterization of polyvinyl alcohol (PVA)-chitosan (CS)-based nanoparticles loaded with vitamin E (VitE) and ephedrine (Ep) via electrospraying for intranasal drug delivery in narcolepsy treatment. The nanoparticles were successfully synthesized using optimized parameters (15.5 kV voltage, 0.3 mL/h flow rate, 25 G needle size, and 14 cm distance). Scanning electron microscopy (SEM) analysis confirmed the formation of spherical particles with an average size of 350–500 nm, while energy-dispersive X-ray spectroscopy (EDS) mapping revealed a homogeneous elemental distribution with oxygen (51.74%), silicon (24.48%), carbon (6.47%), zinc (6.08%), and aluminum (3.82%). Fourier-transform infrared (FTIR) spectra demonstrated the successful encapsulation of VitE and Ep through characteristic peaks at 3285 cm⁻¹ (OH stretching), 1731 cm⁻¹ (C=O stretching), and 1086 cm⁻¹ (C-O-C stretching). In vitro drug release analysis indicated a controlled and sustained release profile, with cumulative VitE and Ep release reaching 78.6% and 84.3%, respectively, over 48 h in phosphate-buffered saline (PBS, pH 7.4). Antioxidant activity assessment using the DPPH assay confirmed an R² value of 18.84 µg/mL, demonstrating significant free radical scavenging potential. The antibacterial activity, tested via the disk diffusion method, exhibited inhibition zones of 18.31 ± 5.8 mm (E. coli) and 21.51 ± 1.57 mm (S. aureus), confirming strong antimicrobial properties. These findings suggest that the developed electrosprayed PVA/CS nanoparticles loaded with VitE and Ep offer a promising intranasal delivery system with enhanced bioavailability, controlled release, antioxidant capacity, and antibacterial properties, making them a viable candidate for narcolepsy treatment. Full article

Calcium peroxide nanoparticles (CaO₂ NPs) have recently attracted increasing attention as oxygen-generating nanomaterials with potential biomedical applications. Their ability to release molecular oxygen and reactive oxygen species (ROS) in aqueous environments enables modulation of hypoxic and oxidative microenvironments, which play critical roles in infection control, tumor progression, and tissue regeneration. Despite growing interest in oxygen-releasing biomaterials, the literature specifically addressing CaO₂ nanomaterials remains comparatively limited and fragmented, particularly when compared with the extensive body of work on calcium oxide-based systems. This review provides a comprehensive overview of CaO₂ nanoparticles, focusing on synthesis strategies, physicochemical properties, and emerging biomedical applications. Conventional bottom-up synthesis routes based on calcium salts, calcium hydroxide, and calcium oxide are critically compared, highlighting the influence of reaction parameters and stabilizing agents on particle size, morphology, crystallinity, and colloidal stability. Surface modification strategies, including polyethylene glycol, polyvinylpyrrolidone, and hyaluronic acid, are also discussed for their role in improving nanoparticle stability, regulating decomposition kinetics, and enhancing biocompatibility. The mechanisms governing oxygen and ROS generation are analysed in relation to antibacterial activity, hypoxia alleviation in tumor microenvironments, and oxygen-supplying biomaterials for tissue engineering and wound healing. In addition, key challenges associated with oxidative stress responses are discussed. Finally, the review outlines current limitations and perspectives regarding the clinical translation of CaO₂-based nanotherapeutic systems. Overall, this work aims to consolidate the currently dispersed knowledge on CaO₂ nanoparticles and provide a critical framework to guide future research in oxygen-releasing nanomedicine. Full article

Over the past decade, antibacterial materials have become a promising strategy to address both antibiotic-resistant and biomaterial-associated infections in clinical settings. Despite substantial progress, a gap remains between promising antibacterial performance in vitro and limited therapeutic outcomes in vivo. Herein, we present a mechanistic framework for understanding formulation-dependent antibacterial performance across five representative formulation architectures: nanoparticle-based systems, nanofibrous scaffolds, hydrogel matrices, surface coatings, and vesicular or microencapsulated carriers. We impart how structural organization and delivery dynamics regulate antibacterial mechanisms such as contact-mediated killing, controlled therapeutic release, and reactive oxygen species (ROS) generation and discuss their context-dependent suitability for diverse infection scenarios; these include acute wound infections, biofilm-associated implant infections, and chronic infected wounds. Particular emphasis is placed on factors contributing to the frequent failure of high in vitro log reduction efficacy translating into clinical success, including protein corona formation, biological barrier penetration, and dynamic host–pathogen interactions. Finally, we propose a comparative formulation-selection framework based on infection type, tissue environment, and therapeutic objectives to guide the rational design of next-generation antibacterial materials. This perspective bridges the gap between material innovation and clinical translation by highlighting formulation architecture as a central determinant of antibacterial performance in biomedical applications. Full article

Healing skin wounds is still difficult in many clinical situations, especially when the wounds are chronic or infected. These wounds often stay inflamed for long periods, and the risk of bacterial invasion is high. Oxidative stress tends to increase as well, while the formation of new blood vessels is often inadequate. Because of these factors, wound repair depends on the proper coordination of several biological events. These include basic antimicrobial activities, the control and resolution of inflammation, protection against oxidative damage, the rebuilding of collagen structures, and the development of new vascular networks. Traditional Chinese Medicine (TCM) provides many active compounds. These compounds work on many targets and through different pathways. They show good potential in wound treatment. But many TCM compounds have poor solubility in water. They are also unstable, have low bioavailability, and do not pass through the skin easily. These problems limit their use in clinical settings. Nanotechnology offers new ways to solve these problems. Nanodelivery systems can improve the solubility and stability of active compounds. They can also help the compounds enter the skin and stay in the wound area. Many types of nanocarriers have been developed, such as liposomes, polymer nanoparticles, nanogels, and inorganic nanomaterials. These systems can also provide controlled release or release that responds to the wound environment. This can make the treatment more accurate. In this review, we summarize how major TCM-derived compounds support wound repair and describe the biological mechanisms behind their effects. We also discuss recent nanodelivery approaches that aim to strengthen these therapeutic actions. These combinations can improve antibacterial performance, shape the immune response, reduce reactive oxygen species, and help the skin close more quickly. We also point out several challenges, such as concerns about material safety, the need for more consistent herbal extraction methods, gaps in mechanistic understanding, and the difficulty of producing these formulations on a large scale. Taken together, these points suggest that nanodelivery approaches using TCM-derived compounds still need more careful study and steady improvement before they can be used more widely in wound care. Full article

Foodborne pathogens cause hundreds of millions of illnesses annually, underscoring the urgent need for advanced antimicrobial food packaging materials. The objective of this study was to develop a crosslinked cyclodextrin metal–organic framework, loaded with gold nanoparticles (CL-AuNPs@CD-MOF) and integrated into a PLA-Zein composite film with humidity-responsive antimicrobial release, as a sustainable and high-performance packaging solution to address the critical limitations of conventional materials in controlling microbial contamination during food storage. Therefore, gold nanoparticles (AuNPs) were synthesized via a green approach using CD-MOFs as stabilizers and p-coumaric acid as a natural reducing agent, then crosslinked with diphenyl carbonate (DPC) to produce CL-AuNPs@CD-MOF. Crosslinking conditions were optimized to a CD-MOF:DPC ratio of 1:1, 1080 min reaction time, and 80 °C, preserving the cubic morphology and crystalline structure while transforming burst release into sustained antimicrobial activity against E. coli and S. aureus over 7 days. Then, the incorporation of CL-AuNPs@CD-MOF into PLA-Zein films yielded a composite packaging material with favorable mechanical and barrier properties, including a water vapor transmission rate of 539.44 g/m²·24 h and an oxygen permeability of 235.90 cm³/m²·24 h·0.1 MPa. Progressive elimination of E. coli, S. aureus, and L. monocytogenes over 7 days was confirmed, with antimicrobial efficacy originating exclusively from the CL-AuNPs@CD-MOF component. Application on Agaricus bisporus over 12 days of refrigerated storage demonstrated superior preservation performance: mushrooms inoculated with L. monocytogenes and packaged with CL-AuNPs@CD-MOF/PLA-Zein exhibited a weight loss of only 6.20 ± 2.06%, compared to 17.74 ± 3.15% for PLA-Zein and 41.50 ± 3.01% for PE controls. Color stability was equally improved, with lightness values of 71.46 ± 1.47 retained under CL-AuNPs@CD-MOF/PLA-Zein packaging, versus 58.37 ± 0.86 for PLA-Zein and 23.34 ± 2.34 for PE. Mushrooms inoculated with E. coli and S. aureus followed consistent trends. These results establish CL-AuNPs@CD-MOF/PLA-Zein as a promising multifunctional antimicrobial packaging platform for sustainable food preservation. Full article

Nanomaterials are emerging versatile platforms for therapeutic delivery, as they offer precise control over drug, antioxidant, and genetic payload transport across biological barriers. Inorganic, organic, hybrid, and biomimetic systems are the major classes of nanomaterials, which all have different physicochemical properties such as size, surface charge, and surface functionalization. These properties collectively influence stability, biodistribution, cellular uptake, and release kinetics. Engineering strategies are increasingly using stimuli-responsive designs that are triggered by pH, reactive oxygen species (ROS), and intracellular redox gradients to perform spatially and temporally controlled delivery. Antioxidant and redox-modulating nanocarriers are of great importance as they overcome the limited bioavailability and nonspecific activity of conventional antioxidants by improving stability, targeting oxidative microenvironments, and allowing for regulated release. Improvements in lipid, polymeric, and inorganic nanoplatforms have also developed gene delivery applications, including siRNA, mRNA, and CRISPR/Cas systems, to provide better cytosolic release and precise therapeutics. When diagnostic imaging is integrated with therapy through theranostic nanoparticles, real-time monitoring and personalized intervention are possible. Safety, scalable manufacturing, and regulatory alignment are some challenges that show the need for standardization and translational procedures to utilize the potential of theranostic nanomedicine. Full article

Pneumonia, an acute inflammatory condition of the lung tissue, imposes a significant burden on global health and is characterized by a high rate of illness and death. The pathogenesis of the disease extends beyond infection to breakdown of redox hemostasis, where the excessive reactive oxygen species produced during the immune response inflict damage on the alveolar tissues and hence promote varying complications. This dual role of oxygen and oxidative mechanisms makes the management of pneumonia challenging, as the very oxygen that is vital for host defense, when not regulated, imposes severe lung damage. Antioxidant administration and oxygen therapy offer limited efficacy, mostly due to their non-specific action and iatrogenic harm from oxygen oversupply. These limitations are overcome by the use of emerging therapeutic strategies, which primarily focus on precision-targeted approaches. These include inhalable antioxidants, nanoparticle-based systems and biomaterials that are engineered to respond to local ROS concentrations, which aim to deliver the therapeutic agent directly to the inflamed regions of the lung. Calcium peroxide- and manganese dioxide-incorporating materials are being designed to modulate the oxygen levels, either by releasing it in hypoxic zones or scavenging it in hyperoxic microenvironments. This approach simultaneously addresses hypoxia and oxidative stress. Despite showing promising results in experimental and preclinical studies, complications related to product stability, regulatory compliance, and manufacturing scalability need to be addressed. Personalized treatment protocols, guided by biomarkers, involve the future generation of treatments, aiming to achieve a delicate recalibration of the lung’s oxidative environment for improved patient outcomes. Full article

This study presents a comprehensive comparative analysis of the performance, combustion, and emission characteristics of a single-cylinder, four-stroke spark-ignition engine fueled by commercial gasoline and raw biogas enhanced with cerium oxide (CeO₂) nanoparticles. Raw biogas containing 58% methane was tested without carbon dioxide removal to reflect practical rural applications, while CeO₂ nanoparticles were ultrasonically dispersed in the fuel to promote homogeneous suspension and catalytic activity. Experiments were conducted under wide-open and part-throttle conditions across a range of engine speeds, with simultaneous measurement of brake thermal efficiency, brake-specific fuel consumption, volumetric efficiency, in-cylinder pressure, heat release rate, combustion phasing, and regulated emissions. The results showed that while gasoline consistently outperformed biogas in torque and power due to its higher heating value and flame speed, the addition of CeO₂ significantly reduced the performance gap. For the biogas mode, CeO₂ addition increased brake thermal efficiency by up to 5%, lowered brake-specific fuel consumption by up to 8%, and shifted the start of main combustion to earlier crank angles, indicating faster and more complete combustion, particularly at high loads where higher temperatures activate CeO₂’s catalytic behavior. Emission analysis revealed that CeO₂-blended biogas reduced carbon monoxide emissions by approximately 25% and unburned hydrocarbons by up to 55% compared with gasoline, while nitrogen oxide emissions were consistently 15–22% lower. These reductions were observed across both wide-open and part-throttle conditions, confirming improved combustion completeness and lower peak flame temperatures. These improvements are attributed to CeO₂’s oxygen-storage capability, catalytic oxidation activity, and enhanced thermal conductivity, which collectively strengthen combustion completeness and cyclic stability. The findings demonstrate that nanoparticle-enhanced biogas can substantially improve the environmental and operational viability of spark-ignition engines, offering a practical pathway for integrating renewable gaseous fuels into existing transportation systems. Full article

Cow’s milk allergy (CMA) is characterized by an exaggerated immune response where dendritic cells (DCs) play a crucial role. Additionally, extracellular vesicles (EVs) can be released by immune cells, modulating this allergic response. Moreover, eosinophils also contribute to tissue damage and perpetuate inflammation in allergic reactions. Therefore, the aim of this work was to study the role of EVs from monocyte-derived dendritic cells (moDCs) on eosinophil and lymphocytes in CMA. Sixteen infants with IgE-mediated cow’s milk allergy (CMAIE) and three non-allergic controls were recruited. Peripheral blood monocytes were purified and differentiated to moDCs. EVs were obtained from the culture supernatant by ultracentrifugation and characterized by nanoparticle tracking analysis and Western blot. Interaction among EVs, eosinophils and peripheral blood mononuclear cells (PBMCs) were analyzed with confocal microscopy. Additionally, these cells were incubated with EVs to assess lymphocyte proliferation, as well as eosinophil migration and reactive oxygen species (ROS) production by flow cytometry. Moreover, multiplex analysis was performed to evaluate the cytokines released by PBMCs following stimulation with EVs. Proteins characteristic of EVs were identified (CD9, CD63, CD81 and Alix). Furthermore, the size of the nanovesicles was ~185 nm, which is consistent with previously published reports. Confocal microscopy revealed that EVs internalized and localized in the cytoplasm of eosinophils, while in PBMCs, EVs were located in the perinuclear region. A proliferation assay revealed an increase in the proliferation of Th1 and Th2 lymphocytes, with higher levels of IL-4. Moreover, EVs were able to significantly increase eosinophil ROS production and migration. However, these effects were not observed after stimulation with EVs from non-allergic controls. This exploratory study shows that EVs from the moDCs of children with CMAIE could induce chemotactic and stimulatory functions on eosinophils and lymphocytes, which could perpetuate inflammation and contribute to tissue damage in this type of allergy. Full article

Microbial spoilage and foodborne pathogens remain central challenges in food safety, driven by the metabolic resilience and ecological adaptability of bacteria, yeasts, and molds across diverse food matrices. Active antimicrobial packaging has emerged as a biologically informed strategy that directly targets microbial physiology through controlled release or contact-mediated mechanisms. These systems employ natural antimicrobials, bacteriocins, essential oils, and metal nanoparticles to disrupt cell membranes, inhibit enzymatic pathways, generate reactive oxygen species, or interfere with quorum sensing, resulting in substantial reductions in microorganisms such as Listeria monocytogenes, Salmonella spp., E. coli O157:H7, Pseudomonas spp., Brochothrix thermosphacta, and spoilage fungi. In real food environments, these interventions achieve multi-log reductions and attenuate microbial metabolism, though efficacy varies with pH, water activity, fat content, and storage temperature. Oxygen scavengers further reshape microbial ecology by suppressing aerobic spoilage organisms while inadvertently favoring anaerobic competitors. Despite promising outcomes, concerns regarding nanoparticle migration, microbial resistance potential, and matrix-dependent performance highlight the need for deeper microbiological validation. Future progress will require integrative research linking microbial ecology, packaging material science, and mechanistic toxicology. By aligning with microbial behavior at the cellular and ecosystem levels, active antimicrobial packaging represents a powerful, biologically grounded approach to mitigating foodborne risks. Full article

Biogenic copper-based nanoparticles have attracted attention as potent antimicrobial agents synthesised via environmentally sustainable routes using plants, microorganisms, and biological waste. Green synthesis leverages phytochemicals, enzymes, and proteins as natural reducing and stabilising agents, enabling nanoparticle formation under mild, non-toxic conditions without hazardous reagents. The resulting nanoparticles are typically spherical, <100 nm in size, and enriched with bioactive surface functionalities that contribute to broad-spectrum antimicrobial activity against bacteria, fungi, and biofilms. Their antimicrobial effects arise from interconnected mechanisms, including the generation of reactive oxygen species, the release of Cu² ions, membrane disruption, and interference with vital metabolic and genetic processes. Hybrid systems such as Ag–Cu, Zn–CuO, and CuS nanoparticles further enhance efficacy through synergistic redox and photothermal effects. These properties support applications in medical coatings, wound dressings, food packaging, aquaculture disease management, and sustainable crop protection. However, toxicity is highly context-dependent, influenced by factors such as nanoparticle size, shape, surface chemistry, capping agent, concentration, exposure medium, and the biological system. Small or weakly capped NPs can induce cytotoxicity, hemolysis, developmental defects, or growth inhibition, whereas functionalization or capping can improve selectivity and biocompatibility. Standardised physicochemical characterisation, harmonised toxicity testing, and mechanistic understanding are critical for the safe translation of biogenic CuNPs into regulatory-approved applications. This review summarises recent advances (2015–2025) in the biogenic synthesis of copper-based nanoparticles, highlighting how biological systems govern nanoparticle morphology, stability, and antimicrobial efficiency. It integrates mechanistic insights, compares monometallic and hybrid systems, and evaluates emerging applications in medicine, agriculture, aquaculture, and food safety. The review also identifies current limitations and future directions for standardisation, toxicity evaluation, and regulatory approval. Full article

Hypoxia and nutrient-deprived microenvironments pose significant challenges to the survival of transplanted human umbilical cord mesenchymal stem cells (UC-MSCs), necessitating the development of controllable oxygen delivery strategies. In this study, we engineered fluorosurfactant-coated oxygen nanobubbles (Tivida^®-stabilized; TONBs) and assessed their cytoprotective effects in a two-dimensional (2D) ischemia-mimetic model (1% O₂ and 1% FBS). The TONBs were characterized by nanoparticle tracking analysis and zeta potential, while dissolved oxygen (DO) release was quantified in DMEM culture media. TONBs formed stable sub-200 nm populations with high colloidal stability (−58 mV) and demonstrated elevated DO levels up to ~18 ppm, compared to DMEM control (~ 8 ppm). Under hypoxic stress, TONB treatment preserved metabolic activity and viability, reduced mitochondrial ROS levels by ~20% and resulted in an ~8–9 fold downregulation of HIF-1α expression relative to untreated hypoxic controls. These results indicate that TONBs provide oxygen buffering to mitigate hypoxia-driven metabolic stress, supporting their potential as an oxygen delivery adjunct for regenerative medicine applications and tissue engineering applications. Full article

Silver nanoparticles (AgNPs) possess distinct physicochemical characteristics and demonstrate high antibacterial potential that highlights them as promising alternatives against a wide range of pathogens. The immense antibacterial potential of AgNPs is primarily attributed to the release of silver ions that lead to the disruption of bacterial cell membrane, generation of reactive oxygen species (ROS), inhibition of protein synthesis and interference with DNA replication. Variations in AgNPs’ shape, size, and surface characteristics are also considered key factors determining their effectivity as well as specificity. AgNPs are considered potent antibacterial agents, including against antibiotic- and drug-resistant strains. However, inappropriate dosages or unoptimized application of may result in potential toxicity, consisting one of the main drawbacks of the AgNPs’ safer administration. This article reviews the recent literature on the antibacterial potential of AgNPs, focusing on their broad mechanisms of action, applicability, especially in agriculture, biomedical and environmental fields, toxicity and future perspectives. Full article