Nanotechnology, Science and Applications最新文献

Purpose: As bacterial resistance to antibiotics increases, there is an urgent need to identify alternative antibacterial agents and improve antibacterial materials. One is the controlled transport of antibacterial agents that prevents infection with drug-resistant bacteria, especially in the treatment of difficult-to-heal wounds.

Methods: This work presents the use of electrospun PLCL/PVP (poly(L-lactide-co-ε-caprolactone/polyvinylpyrrolidone) nanofibers modified with two agents with antibacterial properties but with different mechanisms of action, that is, dendritic silver nanoparticles (Dend-AgNPs) and endolysin.

Results: The nanomat prepared in this manner showed significant antibacterial activity against antibiotic-resistant Pseudomonas aeruginosa strains, inhibiting their growth and production of key pigments and virulence factors. Moreover, the use of nanofibers as carriers of the selected factors significantly reduced their cytotoxicity towards human fibroblasts.

Conclusion: The results confirmed the possibility of using the presented product as an innovative dressing material, opening new perspectives for the treatment of wounds and combating bacterial infections with drug-resistant bacteria.

Purpose: Studying the role of nanoparticles in plant cryopreservation is essential for developing innovative methods to conserve plant genetic resources amid environmental challenges. This research investigated the effects of gold (AuNPs), silver (AgNPs), and zinc oxide (ZnONPs) nanoparticles on the structural integrity, genetic stability, and metabolic activity of cryopreserved plant materials with medicinal properties.

Methods: Shoot tips from two bleeding heart (Lamprocapnos spectabilis (L). Fukuhara) cultivars, 'Gold Heart' and 'Valentine', were cryopreserved using the encapsulation-vitrification technique, with nanoparticles added at concentrations of 5 or 15 ppm during either the preculture phase or the alginate bead matrix formation. Post-recovery, the plants underwent histological, molecular, and biochemical analyses.

Results: Electron microscopy observations of LN-derived plant material confirmed the production of micro-morpho-structurally stable cells. It was found that nanoparticles could penetrate the cell and accumulate in its various compartments, including the nucleus. As for the genetic analysis, SCoT markers identified polymorphisms in 11.5% of 'Gold Heart' plants, while RAPDs detected mutations in 1.9% of 'Valentine' specimens. Analysis of Molecular Variance (AMOVA) indicated that in the 'Valentine' cultivar, all genetic variation detected was within populations and not significantly affected by nanoparticle treatments. In 'Gold Heart', the majority (94%) of genetic variation detected was within populations, while 6% was attributed to nanoparticle treatments (mostly the application of 15 ppm ZnONPs). The application of nanoparticles significantly influenced the metabolic profile of bleeding heart plants, particularly affecting the synthesis of phenolic acids and aldehydes, as well as the antioxidant mechanisms in both 'Gold Heart' and 'Valentine' cultivars. The content of proteins was altered in 'Gold Heart' plants but not in 'Valentine'.

Conclusion: The results suggest that different types and concentrations of NPs have varying effects on the production of specific metabolites, which could be harnessed to modulate plant secondary metabolism for desired pharmacological outcomes.

Introduction: Trace elements such as manganese (Mn) are essential for various biological processes, including enzyme activation, metabolic pathways, and antioxidant defences. Given its involvement in these critical processes, maintaining adequate Mn levels is crucial for overall health.

Methods: The experimental design involved 24 male Wistar rats divided into three groups (n=8 per group): a control group receiving standard Mn supplementation (65 mg/kg), an Mn-deficient group, and a group supplemented with Mn₂O₃ nanoparticles (65 mg/kg). The 12-week feeding trial assessed selected physiological parameters, tissue composition, caecal health, and biochemical markers.

Results: Body and major organ weights were not significantly affected across groups (p=0.083 to p=0.579). However, significant differences were observed in fat tissue percentage (p=0.016) and lean tissue percentage (p<0.001). Caecal parameters showed higher ammonia levels (p=0.030) and increased pH (p=0.031) in the nano-Mn group. In turn, total SCFA concentrations were highest in the control group, followed by the Mn-deficient and nano-Mn groups (p<0.001). Enzymatic activities of caecal bacteria differed significantly between the groups, with reduced activity in the nano-Mn group (p<0.001). Blood plasma analysis revealed significantly lower insulin (p<0.001) and neurotransmitter levels, including dopamine and serotonin, in the Mn-deficient and nano-Mn groups compared to controls.

Discussion: Our findings suggest that both Mn supplementation and deficiency can lead to physiological and biochemical alterations, affecting fat metabolism, gut health and microbial enzymatic activity or neurotransmitter levels highlighting the critical role of Mn in maintaining metabolic homeostasis or its potential implications for nutritional and pharmaceutical interventions.

Purpose: Improving drug solubility is crucial in formulating poorly water-soluble drugs, especially for oral administration. The incorporation of drugs into mesoporous silica nanoparticles (MSN) is widely used in the pharmaceutical industry to improve physical stability and solubility. Therefore, this study aimed to elucidate the mechanism of poorly water-soluble drugs within MSN, as well as evaluate the impact on the dissolution and physical stability.

Methods: Alpha mangostin (AM) was adopted as a model of a poorly water-soluble drug, while MSN with the pore size of 45 Å (MSN45) and 120 Å (MSN120) were used as Mesoporous materials. AM-loaded MSN (AM/MSN45 and AM/MSN120) was prepared by solvent evaporation method.

Results: The amorphization of AM/MSN45 and AM/MSN120 was confirmed by the halo pattern observed in the powder X-ray diffraction pattern and the absence of the melting peak and the glass transition of AM in the DSC curves. This signified the successful incorporation of AM into MSN. FT-IR measurements suggested the formation of hydrogen bond interaction between the carbonyl group of AM and the silica surface of MSN. In the dissolution test, the presence of the AM within MSN improved the dissolution rate and generated the supersaturation of AM. However, the difference of pores size of MSN could affect the dissolution profile of AM within MSN. Additionally, it retained the X-ray halo patterns after 30 d of storage at 25 ^oC and 0% RH.

Conclusion: In conclusion, AM-loaded mesoporous silica significantly improved the dissolution and physical stability.

Purpose: Biofilms are one of the main threats related to bacteria. Owing to their complex structure, in which bacteria are embedded in the extracellular matrix, they are extremely challenging to eradicate, especially since they can inhabit both biotic and abiotic surfaces. This study aimed to create an effective antibiofilm nanofilm based on graphene oxide-metal nanoparticles (GOM-NPs).

Methods: To create nanofilms, physicochemical analysis was performed, including zeta potential (Zp) (and the nanocomposites stability in time) and size distribution measurements, scanning transmission electron microscopy (STEM), energy dispersive X-ray analysis (EDX), and atomic force microscopy (AFM) of the nanofilm surfaces. During biological analysis, reactive oxygen species (ROS) and antioxidant capacity were measured in planktonic cells treated with the nanocomposites. Thereafter, biofilm formation was checked via crystal violet staining, biofilm thickness was assessed by confocal microscopy using double fluorescent staining, and biofilm structure was analyzed by scanning electron microscopy.

Results: The results showed that two of the three nanocomposites were effective in reducing biofilm formation (GOAg and GOZnO), although the nanofilms were characterized by the roughest surface, indicating that high surface roughness is unfavorable for biofilm formation by the tested bacterial species (Staphylococcus aureus (ATCC 25923), Salmonella enterica (ATCC 13076), Pseudomonas aeruginosa (ATCC 27853)).

Conclusion: The performed analysis indicated that graphene oxide may be a platform for metal nanoparticles that enhances their properties (eg colloidal stability, which is maintained over time). Nanocomposites based on graphene oxide with silver nanoparticles and other types of nanocomposites with zinc oxide were effective against biofilms, contributing to changes throughout the biofilm structure, causing a significant reduction in the thickness of the structure, and affecting cell distribution. A nanocomposite consisting of graphene oxide with copper nanoparticles inhibited the biofilm, but to a lesser extent.

Purpose: This study investigates the impact of various mixing parameters and surfactant combinations on the physical characteristics of nanoemulsions produced using high-speed homogenization. Nanoemulsions are explored for their capacity to enhance transdermal drug delivery in pharmaceutical and cosmetic contexts.

Methods: Employing a standard high-speed homogenizer typical in the cosmetic industry, we tested different combinations of Polysorbate (Tween®) and Sorbitan ester (Span®) surfactants under single and intermittent process configurations. Key parameters assessed included particle size, size distribution, Oswald ripening, and creaming index.

Results: Nanoemulsions synthesized had particle sizes below 200 nm and appeared as white liquids with slight creaming. Extended mixing times were associated with smaller droplet sizes and reduced creaming. Both processing methods yielded similar nanoemulsion properties, indicating minimal impact from the type of process used. The nanoemulsions exhibited polydispersity indices ranging from 0.3 to 0.5, suggesting a uniform size distribution, and showed negligible Oswald ripening, which indicates stable droplet sizes over time.

Conclusion: The study confirms that precise control of mixing parameters and the selection of appropriate surfactant pairs are more critical than the choice of process in producing stable nanoemulsions. With efficient use of standard high-speed homogenizers, stable nanoemulsions suitable for large-scale production can be achieved, providing a cost-effective method for pharmaceutical and cosmetic industries.

Introduction: The rapid growth of flexible and wearable electronics has created a need for materials that offer both mechanical durability and high conductivity. Textile electronics, which integrate electronic pathways into fabrics, are pivotal in this field but face challenges in maintaining stable electrical performance under mechanical strain. This study develops highly stretchable silver multi-walled carbon nanotube (Ag-MWCNT) composites, tailored for screen printing and heat-transfer methods, to address these challenges.

Methods: Silver flakes dispersed in a thermoplastic polyurethane (TPU) matrix formed the base composite, which was initially evaluated under tensile and cyclic stretching conditions. Resistance drift observed in these tests prompted the incorporation of multi-walled carbon nanotubes (MWCNTs). Leveraging their high aspect ratio and conductivity, MWCNTs were homogenized into the composite at varying concentrations. The resulting Ag-MWCNT composites were assessed through cyclic stretching and thermal shock tests to evaluate electrical and mechanical performance.

Results: Incorporating MWCNTs improved composite performance, reducing resistance change amplitude by 40% and stabilizing resistance within 2-8 Ohms under mechanical stress. These materials demonstrated superior electrical stability and durability, maintaining consistent performance over extended use compared to Ag/TPU alone.

Discussion: This study highlights the critical role of MWCNTs in enhancing the reliability of conductive composites for textile electronics. By addressing resistance drift and stabilizing electrical properties, these advancements enable more robust and long-lasting wearable technologies. The demonstrated feasibility of combining screen-printing and heat-transfer techniques provides a scalable approach for manufacturing flexible electronics, paving the way for further innovation in industrial applications.

Introduction: Since the population of Europe is rapidly aging, the number of cases of neurodegenerative diseases sharply increases. One of the most significant limitations of current neurodegenerative disease treatment is the inefficient delivery of neuroprotective drugs to the affected part of the brain. One of the promising methods to improve the pharmacokinetic and pharmacodynamic properties of antioxidants is their encapsulation in nanocarriers.

Materials and methods: Encapsulation of carnosic acid into a chitosan-based nanoparticle system with ultrasound-assisted emulsification process was developed. The physicochemical properties (size, stability, concentration of nanoparticles) of obtained nanocapsules were analyzed. Also, the cytotoxicity and neuroprotective effect in SH-SY5Y cells exposed to toxic concentration of H₂O₂ of the obtained nanoparticles were evaluated in vitro.

Results and discussion: The capsules with diameters between 90 and 150 nm and long-term stability were obtained. Cytotoxicity tests of empty capsules indicate that observed toxic effects were concentration dependent and lower concentrations (dilution above 500×) can be considered as safe for tested cells. Our study also indicates that encapsulation of carnosic acid decreased the cytotoxicity of empty nanocapsules and can efficiently protect SH-SY5Y cells from factors causing cell destruction. In addition, the neuroprotective efficacy of carnosic acid loaded nanocapsules was also demonstrated in SH-SY5Y cells exposed to toxic concentration of H₂O₂. The designed nanoparticles appear to possess sufficient biocompatibility to deserve their further evaluation in in vivo models.