Applied Nanoscience最新文献

This study evaluates the antibacterial and antioxidant properties of sodium alginate (SA) gels loaded with polyphenol-rich extracts from Rubus occidentalis (black raspberry) leaves, targeting Streptococcus mutans and Lactobacillus acidophilus, two primary pathogens involved in dental caries. Extracts prepared using acetone, chloroform, and methanol were analyzed using HPLC and GC–MS, revealing that the methanol extract contained the highest levels of gallic acid (5.62 µg/mL), chlorogenic acid (17.24 µg/mL), and catechin (47.83 µg/mL). Antioxidant activity, assessed via DPPH assay, showed the methanol extract achieved the lowest IC₅₀ value (110.5 µg/mL), compared to acetone (400.5 µg/mL) and chloroform (238.0 µg/mL). The methanol extract showed the strongest effect in antibacterial assays, with minimum inhibitory concentrations (MICs) of 32 µg/mL for L. acidophilus and 125 µg/mL for S. mutans. When encapsulated in SA gel, the methanol extract formulation demonstrated the largest zones of inhibition (23 ± 2.14 mm for S. mutans and 25 ± 3.01 mm for L. acidophilus), along with superior antioxidant values (ABTS: 251.3 ± 4.32 µmol Trolox/g; FRAP: 118.62 ± 1.68 µmol Fe(II)/g). Results of confocal laser scanning microscopy examination confirmed a significant biofilm disruption. These findings highlight the potential of methanol-extracted polyphenols from R. occidentalis leaves, particularly when delivered via SA gel, as a natural therapeutic for oral infection control and dental biofilm inhibition.

The epoxy/CeO₂ nanocomposite was synthesised, where the nanoceria (CeO₂) were prepared via the hydrothermal method and the dopant with an average grain size of 18.1 nm was incorporated in the epoxy matrix. The corrosion inhibition of stainless steel rods in 1 M CH₃COOH and 0.5 M H₂SO₄ by EP/CeO₂ nanocomposite coverage has been investigated by Tafel polarisation technique and electrochemical impedance spectroscopy (EIS) at the corrosion potential. The study has been carried out at 298 K, where nano-CeO₂ acts as an excellent corrosion inhibitor. The obtained data were analysed and modelled to the appropriate Randles circuit. The sequel of UV–visible radiation on the EP/CeO₂ nanocomposite was interrogated through UV–visible spectroscopy. The highest absorption peak appeared around 402 nm for the sample with a larger inclusion of nanoceria. The dielectric properties of EP/CeO₂ nanocomposite were studied for different frequencies, and its dielectric permittivity and dielectric constant decreased with an increase in frequency. The FESEM graph details the homogeneous dispersion, the particle size distribution of nanoceria in the matrix, and its possibility of agglomeration for some concentrations.

This research work focuses on the influence of Nickel (Ni) (0–10 wt.%) doping on structural, surface, linear, and non-linear optical parameters of Tin oxide thin films. The above thin films were deposited on glass substrate using the spray pyrolysis technique. A crystalline thin film with tetragonal structure was confirmed from X-ray diffraction. Intensity of the prominent peak (110) decreased with increase in doping concentration. Both Scherrer and the W–H plot methods were considered to determine the crystallite size of Sn_1-xNi_xO₂ thin film. Formation of cluster-like structures was visible using the FESEM results. Confirmation of elemental composition was done using EDAX. A decrease of surface roughness with increasing doping concentration was detected. Doping on Nickel brought changes in the transmittance of the thin film from 84 to 80% for lower doping concentrations in the visible region. The PL studies depicted peaks due to contributions of both Sn⁴⁺ ions and oxygen vacancies. Near white light emission was observed due to the presence of the defects. Third-order non-linear studies were carried using the Z-Scan, and all the deposited samples showed non-linearity. Reverse saturable absorption (RSA) was observed in the deposited thin film. The third-order non-linear susceptibility were seen to range to be suitable for optical limiting applications. Hence, the spray pyrolysis-deposited thin films are found to be suitable for optical limiters.

Oil pollution in wastewater poses a significant environmental threat due to its toxicity to aquatic ecosystems and potential risks to human health. This study explores the use of ferric sulfate nanoparticles as an advanced coagulant for treating effluents from the Shiraz Petrochemical Complex. A two-stage reactor system was employed to optimize treatment conditions, focusing on mixing speed, coagulant dosage, and the use of coagulant aids (NaOH and Na₂CO₃). Optimal performance was observed at a mixing speed of 120 rpm in the primary reactor, reducing chemical and biological oxygen demand (COD and BOD) to 19 mg/L and 6.5 mg/L, respectively. Removal efficiencies for petroleum hydrocarbons, oily compounds, and aromatic substances improved with increased coagulant dosage, achieving up to 62.8%, 4%, and 5.2% improvement, respectively. Zeta potential analysis revealed decreased electrostatic repulsion at higher dosages, with values reaching − 13.4 mV. A second-order polynomial regression model demonstrated excellent predictive accuracy (R² = 0.9999), validating the experimental findings. These results underscore the potential of nano-enhanced coagulation for industrial wastewater treatment.

Psoriasis is a chronic inflammatory and T cell-mediated autoimmune dermal disorder and remains a therapeutic limitation due to its thickened epidermal growth, high keratinocyte differentiation, scaly patches, and dry skin, leading to the failure of conventional treatments. Nanomedicine has shown the potential to improve therapeutic efficacy in psoriatic skin. The metallic nanocarriers such as gold, selenium, silver, zinc, iron, titanium, and copper have currently emerged as promising and highly effective treatment options for psoriasis as they offer several advantages like favorable physicochemical properties, enhanced drug-loading, improved skin penetration, and permeation. Metallic nanocarriers can be functionalized and tailored to specific therapeutic needs, making them highly effective at delivering anti-psoriatic drugs directly to the targeted areas without causing any adverse effects. The gold nanoparticles are known for their high biocompatibility and anti-inflammatory properties, while silver nanoparticles exhibit strong antimicrobial effects that are beneficial in managing psoriatic skin infections. Selenium, zinc, and iron nanoparticles contribute antioxidant and anti-inflammatory benefits, which are essential in mitigating the reactive oxidative stress, suppressing cytokines, and interleukins inflammatory mediators associated with psoriasis. Through metallic nanoparticles, it is possible to achieve controlled release, which maintains a steady rate of drug diffusion and skin penetration and delivers drugs more precisely, lowering the risk of systemic toxicity and improving patient compliance. This review highlights the potential mechanism and combines recent research based on metallic nanoparticles in advancing psoriasis treatment, offering an effective treatment option over various conventional therapies due to their multifunctionality, safety, and therapeutic efficacy.

In this work, a titanium-incorporated metal–organic framework nanoadditive was used to study its efficiency in removing heavy metals and dyes from contaminated water. The use of MIL-125 (Ti) nanoadditive-incorporated polysulfone membranes has been tested for the elimination of heavy metals such as cadmium and lead as well as synthetic dyes, such as reactive black-5 (RB-5) and reactive orange -16 (RO-16). The incorporation of metal–organic frameworks (MOFs) into polysulfone matrices can increase the performance of the membrane for specific applications, such as dye removal and heavy metal rejection. The MIL-125 (Ti) is a well-known MOF with excellent chemical stability, large surface area, and adjustable pore size, making it suitable for membrane fabrication. This study fabricated membranes composed of MIL-125(Ti) and polysulfone (PSF) with MOF doses ranging from 0.5 to 3 wt %. Compared with the pristine PSF membrane, the pore-forming agent PVP was used at a 12% concentration, increasing the pore size and porosity. The hydrophilicity, water flux, and antifouling nature of the fabricated membrane were studied. The dye removal and heavy metal rejection experiments were carried out, and a dye removal efficiency of 90% for RB-5 and 47% for RO-16 was exhibited by the M-1 membrane. Furthermore, the M-2 membrane resulted in heavy metal rejection of 89.33% for Cd²⁺, and M-3 resulted in 68.81% for Pb²⁺ at a feed concentration of 500 ppm. Hence, the membranes showed good stability and efficiency with a high feed concentration of heavy metals. In the present study, metal ion rejection was studied without the use of any complexing agents.

Nanotechnology has provided an enabling platform for innovations in site-specific cancer therapy and personalized oncomedicine. One of the most important advances in this area is the creation of nanomedicines that target cancer cells, which facilitates the progress of precise therapeutic interventions. Efficient drug delivery into tumor cells remains one of the critical challenges in cancer therapy. However, cancer-cell-targeted nanomedicines that function within the intricate milieu of the tumor microenvironment have shown potential to improve therapeutic efficiency. Epigallocatechin gallate (EGCG), the major phytochemical in Phyllanthus emblica (amla), is known for its anticancer and anti-inflammatory properties. In this study, we developed pH-responsive calcium carbonate nanoparticles (CCNPs) as a nanocarrier for EGCG to enhance its intracellular delivery and therapeutic efficacy. EGCG was physically adsorbed onto the surface of CCNPs. The synthesized nanoparticles were characterized using UV–visible spectroscopy, scanning electron microscopy (SEM), dynamic light scattering (DLS), zeta potential analysis, Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). In-vitro drug release studies demonstrated a sustained and more prominent release of EGCG at the acidic pH (4.8) typical of the tumor microenvironment. The biological activity of EGCG-loaded CCNPs was evaluated using the MTT assay and apoptosis analysis. The results showed significant cytotoxicity against colorectal cancer cells (COLO-320 DM), while blank CCNPs exhibited low toxicity and high biocompatibility. Intracellular uptake studies further confirmed the preferential accumulation of nanoparticles within colorectal cancer cells. Flow cytometry-based apoptosis assays revealed that EGCG-conjugated CCNPs induced considerable cancer cell death. These findings suggest that EGCG-loaded calcium carbonate nanoparticles may serve as an effective and biocompatible drug delivery platform for targeted colorectal cancer therapy.

Bacterial biofilms pose significant challenges to wound-healing, and to achieve successful wound-healing, it is imperative to develop strategies to prevent and eliminate these biofilms. This study aims to explore the potential of using Aloe vera extract for the green synthesis of silver nanoparticles (AgNPs) and to evaluate their antibacterial properties and effectiveness in wound-healing. AgNPs were synthesized hydrothermally, employing Aloe vera as a natural reducing and stabilizing agent. The antibacterial activity of these AgNPs was tested against Escherichia coli and Staphylococcus aureus using zone inhibition and MTT assays. The wound-healing capabilities were assessed through a scratch assay on fibroblast cells. Results indicated that the AgNPs exhibited significant antibacterial activity, increasing effectiveness with higher concentrations of Aloe vera used in synthesis. AgNPs were characterized via UV–VIS spectroscopy, SEM, and DLS, showing spherical shapes ranging from 255.5 ± 5.02 nm to 749.47 ± 24.12 nm, decreasing with increasing Aloe vera concentration. Biocompatibility assessments on L929 cells showed low cytotoxicity, with over 70% cell viability at 10 mg/mL. Wound-healing assays indicated faster closure due to enhanced cell migration and matrix deposition, likely due to the synergistic effects of AgNPs and Aloe vera's bioactive components. The findings of this study highlight the significant potential of these silver nanoparticles in wound-healing applications, owing to their potent antibacterial properties and ability to enhance the wound-healing process.

The aim of this research was to create a nanoemulsion that contains expanded graphite (EG) and azelaic–benzalkonium chloride–montmorillonite (azelaic–BAC–MMT) to improve its antibacterial and bioavailability. Using FT-IR, DLS, XRD, and FE-SEM, the nanoemulsions’ stability and dispersibility were enhanced by the addition of EG. Significant antimicrobial activity was shown in biological assessments against strains of fungi, Gram-negative bacteria (Pseudomonas aeruginosa, Escherichia coli), and Gram-positive bacteria (Staphylococcus aureus, Streptococcus pyogenes). The combined effect of EG and azelaic–cetrimide–MMT resulted in increased antibacterial efficacy. The findings show that this new nanoemulsion has the potential to be a very effective antibacterial agent for use in environmental and medicinal applications. This study highlights a viable strategy for using material engineering and nanotechnology to take on microbial resistance.

This study reports the development of zinc oxide nanoparticles (ZnO NPs) through an eco-friendly, microwave-assisted method using Citrus × aurantiifolia (Christm.) Swingle fruit peel extract as a sustainable resource. Analysis of the produced ZnO NPs verified their spherical shape and hexagonal wurtzite crystal structure. Tests for biocompatibility demonstrated low toxicity to cells from mammals, indicating their potential safe use in biomedical applications. Evaluation of antibacterial properties revealed substantial inhibition of bacterial growth in uropathogenic strains, with minimum inhibitory concentrations (MICs) determined as 7.5 µg/mL for Acinetobacter sp., Enterobacter sp., and Klebsiella pneumoniae; 10 µg/mL for Proteus mirabilis; and 12.5 µg/mL for Escherichia coli. These results underscore the potential of ZnO NPs as effective antimicrobial agents, offering promising applications in combating urinary tract infections (UTIs) and addressing the critical issue of antimicrobial resistance.