Nanotechnology, Science and Applications最新文献

The discovery of graphene, which has led to further research on other two-dimensional (2D) materials, has greatly enhanced the development of sustainable novel materials in the age of nanotechnology. The majority of elements in the periodic table are currently converted into 2D forms by researchers. Materials such as graphene and its derivatives, transition-metal dichalcogenides (TMDs), and transition-metal carbides (MXenes) have been extensively used because of their exceptional electronic and optical properties. While addressing synthesis challenges and stability issues, functionalization is one of the strategies used to overcome the difficulties related to the stability and large dimensions of 2D materials. This review provides detailed studies on MXene synthesis methods and their characteristic properties, emphasizing the importance of modifying MXenes for biosensing applications such as the detection of pathogenic viruses and bacteria, mycotoxins, hazardous pollutants, food contaminants, biomolecules, and cancer biomarkers. A review of the function of MXenes in hydrogen production highlights how well they improve charge transfer and lower reaction overpotentials. The future prospects of MXene-based biosensors as advanced diagnostic tools and hydrogen catalysts are also discussed, in addition to surface functionalization engineering and hybridization techniques.

The aging of skin is a multifaceted process influenced by internal factors and external influences. These factors contribute to the breakdown of skin structure, diminished skin resilience, and observable indications of aging. Conventional topical formulations often fail to deliver active chemicals adequately due to the skin's inherent barriers and the solubility and instability of numerous substances. Emerging nanotechnology-based technologies offer a viable solution to these restrictions. This paper analyzes the role of diverse organic and inorganic nanoparticle-based formulations as delivery systems in improving the distribution and efficacy of anti-aging agents. As part of its novelty, this article integrates findings on both synthetic and natural anti-aging compounds, providing a comprehensive comparison of their nano-enabled enhancements findings from in vitro and in vivo models, along with clinical studies. Comparative studies consistently demonstrate that nano-formulations surpass conventional approaches in enhancing antioxidant defense, stimulating collagen synthesis, and suppressing enzymes associated with skin aging.

Introduction: The growing demand for sensors capable of detecting hydrogen peroxide vapor (HPV) in industrial and medical applications has led to increased research activity in this field. Despite significant progress, there remains a strong need for the development of new HPV-sensitive materials as well as for improving the performance of existing sensor systems. This work presents a flexible hydrogen peroxide vapor sensor employing a ZnO/MWCNTs (multi-walled carbon nanotubes) thin film as the sensing layer and provides a detailed impedance-based analysis.

Methods: The frequency dependence of the real and imaginary components of the complex impedance was measured in air and under exposure to HPV at operating temperatures ranging from room temperature to 200 °C. The influence of ultraviolet (UV) irradiation on the impedance response of the ZnO/MWCNTs sensor was also examined. The structural, morphological, and compositional characteristics of the ZnO/MWCNTs composite were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS).

Results: Analysis of the impedance spectra enabled the proposal of an equivalent electrical circuit describing the sensor structure. The parameters of the circuit elements were determined, and the calculated impedance curves showed good agreement with the experimental data. A linear increase in sensor sensitivity was observed with increasing temperature up to 175 °C. Ultraviolet (UV) irradiation resulted in an approximately twofold enhancement of sensor sensitivity at room temperature.

Conclusion: It was demonstrated that the flexible polyimide substrate with platinum interdigitated electrodes makes a significant contribution to the overall impedance of the ZnO/MWCNTs sensor structure. In the equivalent circuit, this contribution is represented by a parallel parasitic capacitance (C₀ ≈ 1.67 × 10^-11 F). Exposure to hydrogen peroxide vapor mainly affects the resistance of the ZnO/MWCNTs sensing film. The validity of the proposed equivalent electrical circuit is confirmed by the close correspondence between the calculated Nyquist plots and the experimental impedance data.

Wound healing is a complex process involving hemostasis, inflammation, proliferation, and remodeling of tissues or cells. In chronic conditions, such as diabetic wounds, this process is often disrupted. Nanostructured lipid carriers (NLCs) are advantageous topical drug delivery systems because of their ability to improve stability, bioavailability, and controlled drug release. The incorporation of NLCs into a gel matrix (NLC-gel) enhances the formulation with bioadhesive properties, skin hydration, and drug retention in the wound area. This accelerates healing and reduces the risk of infections. While these findings highlight the potential of NLC-gel systems to improve local drug bioavailability and promote tissue regeneration, most available evidence is derived from in vitro and animal studies, and clinical data remain limited. This review critically summarizes recent advances in NLC-gel formulations for wound healing, with particular emphasis on the relationship between formulation strategies and biological mechanisms, including modulation of inflammation, angiogenesis, fibroblast and keratinocyte proliferation, collagen deposition, and antimicrobial and antioxidant activities. Additionally, translational considerations such as long-term safety, formulation scalability, and clinical prospects are discussed. Recent in vivo and in vitro studies have shown that NLC gels containing active ingredients, such as simvastatin, curcumin, quercetin, moxifloxacin, or other therapeutic proteins, can accelerate wound healing, particularly in wounds caused by metabolic disorders. These results suggest that NLC gels have great potential as therapeutic platforms for wound care. However, further research is required to optimize its formulation and clinical translation.

Cutaneous wound healing is a complex process regulated by molecular and cellular mechanisms. Conditions such as diabetes, obesity, and metabolic syndrome reduce this process, often leading to chronic wounds. These types of wounds remain a global health challenge due to prolonged healing, high infection risk, and poor response to conventional therapies. Zinc oxide nanoparticles (ZnO NPs) have gained attention in biomedical research because of their antimicrobial, anti-inflammatory, and antioxidant activities. While conventional synthesis methods often involve toxic reagents and high energy consumption, green synthesis using biological sources such as plants, fungi, and algae, offers safer and more sustainable alternatives. Furthermore, incorporating zinc oxide into biocompatible matrices enhances its therapeutic potential by promoting direct interaction with wound tissues. This review highlights recent advances in the green and biocompatible synthesis of ZnO NPs and explores their types and physical, chemical, and biological characteristics. Particular emphasis is placed on the use of green nanotechnology as a cost-effective and sustainable approach for developing next-generation wound healing materials reported the last five years in free-download through the literature.

Introduction: Sustainable nanotechnology requires synthesis approaches that are environmentally benign while maintaining high efficiency, yield, and functionality. Plant-mediated synthesis combined with advanced heating techniques offers a promising route to achieve these goals.

Methods: Phyto-copper oxide nanoparticles (Phy-CuO-NPs) were synthesized using Psidium guajava leaf extract under different pH conditions via two approaches: conventional heating (Series A) and microwave-assisted synthesis (Series B). The influence of pH and heating mode on nanoparticle formation was systematically evaluated. The synthesized nanoparticles were characterized using physicochemical and morphological techniques, and their antibacterial activity was assessed against Staphylococcus aureus and Pseudomonas aeruginosa.

Results: Microwave-assisted synthesis significantly altered pH-dependent nucleation pathways, resulting in nanoparticles with enhanced crystallinity, more uniform morphology, higher copper content, and improved colloidal stability, particularly under alkaline conditions. Series B nanoparticles showed a 34% increase in maximum yield (up to 80 mg/g) while achieving a 92% reduction in energy consumption compared to the conventional method. Antibacterial assays revealed strong inhibitory activity against both tested strains, with greater efficacy against Gram-negative bacteria.

Discussion: The improved antibacterial performance is attributed to the bio-capped nature of the nanoparticles, which facilitates cellular entry and promotes intracellular copper ion release, leading predominantly to reactive oxygen species generation rather than direct ionic toxicity. This study highlights the synergistic role of microwave irradiation and pH control in enhancing both sustainability and functionality.

Food safety remains a critical global challenge, particularly due to contamination by aflatoxins (AFs), highly toxic secondary metabolites produced primarily by Aspergillus flavus and A. parasiticus. This significant group of mycotoxins frequently contaminate staple food commodities, posing serious risks to public health, food security, and agricultural sustainability, thus the need for their detection in food. Conventional analytical methods, including chromatographic and immunochemical techniques, although highly accurate, are often time-consuming, resource-intensive, and dependent on sophisticated instrumentation and skilled personnel, thereby limiting their applicability in decentralized and resource-limited settings. Recent advances in detecting AFs in food matrices is nanoparticle-based, thus the focus in this systematic review. In this study, a systematic review that critically evaluates nanoparticle-based detection strategies for AFs in food, highlighting their potential to transform food safety monitoring was conducted in accordance with the Joanna Briggs Institute (JBI) guidelines. Data generated was subsequently reported following the Preferred Reporting Items for Systematic Reviews and PRISMA framework. Peer-reviewed articles published between January 1, 2010 and December 31, 2023 were systematically retrieved from multiple electronic databases. Study screening, eligibility assessment, and data extraction were independently performed using Covidence systematic review management software. A total of 38 studies met the inclusion criteria and were included in the qualitative synthesis. The findings demonstrate a strong predominance of gold nanoparticles (AuNPs), attributed to their high surface-to-volume ratio, tunable surface chemistry, and exceptional optical properties, which collectively enhance assay sensitivity and signal transduction in immunosensing platforms. Notably, gold-silica core-shell nanoparticle-based assays achieved the lowest reported limit of detection (LOD) for Aflatoxin B₁ (AFB₁) of 0.24 pg/mL. Other nanomaterials, including carbon-based nanostructures and polymeric nanoparticles, also exhibited robust analytical performance, with reported LOD ranging from 0.5 pg/mL to 2.7 ng/mL, depending on the food matrix, nanomaterial type, and assay design. Overall, this systematic review highlights key trends in nanoparticle applications for AF detection and underscores their potential for rapid, highly sensitive, and field-deployable food safety diagnostic testing. Despite substantial progress, critical challenges related to scalability, reproducibility, standardization, and regulatory approval remain. Addressing these barriers will be essential for translating nanotechnology-based AF detection platforms from laboratory research into routine food safety surveillance and regulatory practice.

Introduction: Pseudomonas aeruginosa produces pyocyanin, a phenazine antimicrobial agent against drug-resistant microorganisms. Multi-walled carbon nanotubes (MWCNTs) were shown to stimulate pyocyanin production. Since they are known for their conductivity, their stimulatory properties could be affected by electromagnetic fields (EMFs). Therefore, this study aimed to verify whether EMFs, alone or in combination with MWCNT, could serve as a process simulator for pyocyanin production, and whether the production process is optimizable.

Materials and methods: The Design of Experiment method was employed to optimize pyocyanin production by the cultures exposed to different types of EMFs alone or in combination with MWCNTs. This allowed for identifying the setup with the highest improvement in pyocyanin production. In this setup, additional assays, including conductivity, magnetic induction, ROS level, and membrane potential measurements, were performed. The antibacterial properties of the purified pigment were also assessed.

Results and discussion: The rotating magnetic field (RMF) combined with MWCNT was identified as the most effective setup for pyocyanin production (production improved by 143% compared to the control), which can be further enhanced by aeration. Significant changes in conductivity, magnetic induction, membrane potential, and ROS levels were observed. The purified pigment exhibited strong antibacterial properties, particularly against Staphylococcus aureus and Acinetobacter baumannii, which are often recognized as drug-resistant microorganisms.

Conclusion: This research proposes a novel approach to bioprocessing, where the production of the desired metabolite can be stimulated through a combination of stressors.

Introduction: Chronic and acute wounds remain difficult to manage due to the inability of conventional dressings to provide sustained delivery of poorly soluble bioactives such as α-mangostin. This study investigates the potential of α-mangostin (AMG)-loaded chitosan/collagen nanoparticles (AMG-Ch/Coll NPs) incorporated into a hydrogel system for enhanced topical wound healing.

Methods: Nanoparticles were prepared by ionic gelation and characterized for particle size, zeta potential, morphology (SEM), entrapment efficiency, and physicochemical interactions (FTIR, XRD, DSC). AMG solubility, including its apparent solubility in AMG-Ch NPs and AMG-Ch/Coll NPs was quantified. Subsequently, hydrogels incorporating AMG, AMG-Ch NPs, AMG-Ch/Coll NPs, and Ch-Coll NPs were formulated and evaluated for pH, spreadability, swelling ratio, and in vitro drug release. In vivo wound-healing efficacy was further assessed using a rat excision model.

Results: Mean particle size increased from 297.10 ± 11.64 nm (AMG-Ch NPs) to 317.66 ± 8.76 nm (AMG-Ch/Coll NPs) and 339.62 ± 6.43 nm (Ch-Coll NPs), indicating the influence of collagen on particle size. FTIR, XRD, and DSC analyses confirmed the successful formation of amorphous nanoparticles with strong intermolecular interactions, contributing to enhanced structural stability and solubility. A fourfold improvement in AMG solubility was observed in the nanoparticle formulations, which were subsequently incorporated into hydrogel matrices and evaluated for topical application. All hydrogel (HG) formulations exhibited acceptable pH values (6.50-6.98) suitable for skin application. AMG-Ch NPs-HG demonstrated superior spreadability, swelling ratio, and drug release profiles, followed by AMG-Ch/Coll NPs-HG. Sustained AMG release was achieved, supporting prolonged bioavailability. In vivo wound healing studies in rats revealed that AMG-Ch NPs-HG and AMG-Ch/Coll NPs-HG significantly accelerated wound closure (99.28 ± 3.59% and 98.13 ± 3.26%, respectively, on day 21), outperforming AMG-HG (89.12 ± 2.58%), Ch/Coll NPs-HG (88.95 ± 3.14%), and the control group (79.84 ± 2.25%).

Conclusion: Overall, these findings highlight the synergistic advantages of AMG-loaded Ch/Coll NPs in hydrogel formulations as a promising platform for enhanced topical wound healing.

Purpose: This study aimed to develop and evaluate core-shell electrospun orodispersible films (ODFs) containing lopinavir (LPV) and ritonavir (RTV) for pediatric HIV therapy. The investigation focused on the impact of fiber composition and storage conditions on film morphology, physicochemical stability, mechanical properties, disintegration time, and drug dissolution profiles.

Patients and methods: Core-shell ODFs were prepared via co-axial electrospinning using LPV and RTV solutions in Eudragit^® E100 and Kollidon^® VA64 matrices, respectively. Two configurations were tested, ie LPV in the core and RTV in the shell (LPV/RTV), and vice versa (RTV/LPV). Films were characterized using SEM, DSC, XRD, mechanical testing, disintegration and dissolution studies, and uniformity of content analysis. Stability was assessed under long-term (25 °C/60% RH) and accelerated (40 °C/75% RH) conditions over six months.

Results: LPV/RTV films were more homogeneous in their morphology and showed superior stability during storage compared to RTV/LPV films. SEM analysis revealed compact, well-aligned fibers in LPV/RTV mats, while RTV/LPV mats showed heterogeneous, ribbon-like structures. LPV/RTV films disintegrated within 100 ± 37s, meeting requirements of very fast disintegration, whereas RTV/LPV films remained intact for 180 s. Compared to RTV/LPV films, LPV/RTV films showed greater uniformity in API content and stability over time, while both formulations exhibited slight, non-significant shifts in LPV/RTV ratios during storage. Dissolution profiles indicated enhanced release from RTV/LPV films, though structural degradation limited their stability. After storage, for both types of films, partial recrystallization of API was observed. The LPV/RTV films maintained their dissolution performance, whereas the RTV/LPV films showed significant deterioration.

Conclusion: Core-shell electrospun ODFs with LPV in the core and RTV in the shell demonstrated more homogeneous and resistant to storage-related changes, although the release of the active ingredients was characterized by slower dissolution. These findings support the potential of co-axial electrospinning for developing pediatric-friendly antiretroviral formulations.