Search Results (34)

This study evaluated two techniques for encapsulating Lactiplantibacillus plantarum using bovine lactoferrin and sodium alginate. The first method involved a layer-by-layer (LbL) coating of lactoferrin and alginate directly onto individual cells, using three layers of these electrolytes. The second method focused on encapsulating the probiotics in calcium alginate miniaturized beads, followed by a lactoferrin coating (AAcL). Encapsulation efficiency was measured at 52.7% for the LbL method and 32.6% for AAcL. Encapsulation was confirmed through zeta potential changes and scanning electron microscopy (SEM) micrographs. After freeze drying, the LbL technique showed a 2.67 log CFU decrease in survival rates, whereas the AAcL method resulted in a 3.77 log CFU decline. Nonencapsulated probiotics experienced a reduction of 5.8 log CFU. In storage at −20 °C, the LbL method led to a 32% decrease in survival after 30 days and 41% after 90 days, while the AAcL method showed a decline of 15% after 30 days and 28% after 90 days. Both techniques preserved 75% of the initial L. plantarum population under simulated gastrointestinal conditions. Overall, these methods effectively protected the probiotic from environmental stress. Full article

In this research, the high efficacy of Mentha spicata L. extract, commonly known as spearmint, as a corrosion inhibitor with an efficacy rate of 86.98% is highlighted. Analytical techniques, such as scanning electron microscopy (SEM) to obtain a detailed morphological view, Fourier transform infrared spectroscopy (FTIR) to identify the functional groups of flavonoids, and electrochemical impedance spectroscopy (EIS) and Tafel plots for a corrosion assessment, were employed. This study pioneers a greener alternative to traditional corrosion inhibition methods. The distinctive aspect of this research is the innovative spray coating application method used to deliver the spearmint extract onto structural steel. This method involves the strategic use of an airbrush for spray coating, ensuring the uniform and efficient deposition of the organic inhibitor, thus forming a protective barrier against corrosion. This spray coating technique is emerging as an innovative approach for the industrial application of natural corrosion inhibitors, demonstrating significant advances in the corrosion resistance of coated steel. The results not only corroborate the efficacy of natural inhibitors, but also highlight the critical role that sophisticated application techniques play in improving their industrial viability. This methodological innovation presents a pathway to sustainable practices in corrosion management, prioritizing environmental protection and ecological footprint reduction in the quest for corrosion mitigation. Full article

PEEK-based implant materials have gained increasing attention as an alternative to titanium due to their biocompatibility and bone-like elasticity. However, PEEK’s surface quality and wear resistance are lower than those of metals. This study aimed to enhance the bioactivity and surface quality of PEEK by coating it with silver and copper nanoparticles synthesized via a green method using Equisetum telmateia Ehrh. extract. PEEK samples (Ø 25 mm, 3 mm thick) were coated with single and double layers using spray (airbrush-spray) and drop-coating methods. Comprehensive analyses including SEM, EDX, FT-IR, UV-Vis, surface roughness, release studies, antioxidant and cytotoxicity activity, and antibacterial tests were conducted on the coated samples. The results demonstrated that AgNPs and CuNPs coatings significantly improved the surface quality of PEEK. SEM analysis revealed particle sizes ranging from 48 to 160 nm for AgNPs and 50–135 nm for CuNPs, with superior dispersion obtained using the airbrush-spray method. Surface roughness measurements showed a reduction of 17–33% for AgNPs-coated samples and 7–15% for CuNPs-coated samples compared to uncoated PEEK, with airbrush-spray coatings providing smoother surfaces. Antioxidant activity tests indicated that AgNPs provided 35% higher antioxidant activity compared to CuNPs. Additionally, antibacterial tests revealed that AgNPs exhibited a higher zone of inhibition (up to 14 mm for S. aureus and 18 mm for E. coli) compared to CuNPs, which exhibited zones of 8 mm and 10 mm, respectively. This study concludes that green-synthesized AgNPs, in particular, enhance the bioactivity and surface properties of PEEK, making it a promising material for biomedical applications such as infection-resistant implants. Full article

Some basic aspects of plant disease epidemiology remain largely unknown due to a lack of empirical study methods to experimentally manipulate the position of infections within a single plant or within a plant canopy and the dispersal behaviors of small insects that vector important plant diseases, for example. We present two methods using UV fluorescent particles that, when mixed in a 10% ethanol solution, can be used to create surrogate fungal infections on plant leaves and to field mark whiteflies in situ. When we used a custom-made experimental chamber to measure the velocity of falling particles, we found that the UV fluorescent particles had settlement velocities that overlapped with known fungal plant pathogen spores. In a separate experiment, field applied marks to whiteflies, Bemisia tabaci, were used to estimate straight-line insect vector displacement from source plants as a simple dispersal gradient over a limited distance in a 48 h period. The UV fluorescent particles and airbrushes were relatively inexpensive (USD < 100 total), easily sourced, and usable in a field setting. We believe that the approaches and methods shared in this manuscript can be used to design specific experiments that will fill important plant epidemiological knowledge gaps in future studies. Full article

Edible coatings are used to extend the shelf life of various fruit, including bananas (Musa from the Musaceae family). After harvest, bananas reach the ripening and subsequent senescence phase. During senescence, the quality of the fruit deteriorates as it takes on a brown color and the tissue becomes soft. To extend the shelf life of such a fruit, effective methods to delay ripening are required. In this study, an alginate-based emulsion, i.e., an oil-in-water emulsion of lemongrass essential oil in alginate, was used to combine the mechanical properties of hydrocolloids with the water barrier properties of the oil phase. The emulsion was sprayed onto the whole fruit with an airbrush, and calcium chloride was added to promote gelling of the alginate. Compared to the uncoated fruit, coated bananas remained uniform in appearance (peel color) for longer, showed less weight loss, had a delay in the formation of total soluble solids, and in the consumption of organic acids. The shelf life of the coated fruit was extended by up to 11 days, at least 5 days more than uncoated bananas. Overall, the proposed coating could be suitable for reducing the global amount of food waste. Full article

In this work, efficient hydrogen gas sensors based on multilayered p-type bare MoS₂ and Pd-decorated MoS₂ were fabricated. MoS₂ was deposited onto alumina transducers using an airbrushing technique to be used as a sensing material. Aerosol-assisted chemical vapor deposition (AACVD) was used to decorate layered MoS₂ with Pd nanoparticles at 250 °C. The bare and Pd-decorated MoS₂ was characterized using field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), and Raman spectroscopy. The characterization results reveal the multilayered crystalline structure of MoS₂ with successful Pd decoration. The size of the Pd nanoparticles ranges from 15 nm to 23 nm. Gas sensing studies reveal that a maximum response of 55% is achieved for Pd-decorated MoS₂ operated at 150 °C to 100 ppm of H₂, which is clearly below the explosive limit (4%) in air. The higher sensitivity due to Pd nanoparticle decoration was owed to a spillover effect. This study reveals that the sensitivity of the sensors is highly dependent on the amount of Pd decoration. Moreover, sensor responses increase slightly when exposed to 50% relative humidity (RH at 25 °C). Full article

The aim of the study was to assess the biocidal effectiveness and the effect of 80% and 90% ethanol applied in the form of mist on the surface of textile materials from historical A-BSM objects. The microorganisms used for the tests, namely, Cladosporium cladosporioides, Aspergillus niger and Penicillium chrysogenum, were isolated from the surface of textile objects in the A-BSM. Bacillus subtilis, Staphylococcus aureus, Aspergillus flavus and Aspergillus niger were also used from the American Type Culture Collection (ATCC). Fabric samples were inoculated with microorganisms at a concentration of 10⁵–10⁶ CFU/ml. Ethanol in the form of mist was applied in concentrations of 80% and 90%. Airbrushes VL 0819 and VE 0707 were used for this purpose, where the pressure was 0.2 MPa and the PA HEAD VLH-5 nozzle with a tip of 1.05 mm in diameter was used. In order to achieve more effective disinfection after applying the ethanol mist, samples were stored in PE foil in the conditions of 21 °C ± 1 °C for 22 ± 1 h. After applying the ethanol mist, changes in the properties of the materials were assessed using scanning electron microscopy (SEM). The reduction in the number of microorganisms on modern cotton fabric after the use of ethanol in the form of mist at concentrations of 80% and 90% ranged from 93.27% to 99.91% for fungi and from 94.96% to 100% for bacteria, except for 74.24% for B. subtillis. On the historical fabric, after the time of application of 90% ethanol was shortened to 4 s, the microorganisms were reduced by over 99.93% and S. aureus was completely eliminated. After applying the tested disinfection technique, no changes in fiber morphology were observed on the surface of the model and historical cotton. Full article

The general spray gun is used for industrial large-area spraying, and there is less demand for different pressures and the accuracy of spraying pressure, so mechanical pressure regulators are mostly used. However, as the demand for artistic innovation continues to grow, it promotes the advent of the micro spray gun. The micro spray gun is currently commonly known as an airbrush. The micro spray gun is mainly used for fine drawing, so it must provide different pressures with high precision pressures, but the existing mechanical regulators cannot meet this requirement. For these unmet requirements, this study proposed a solution for PID (proportional-integral-derivative) control micro spray gun system. The results showed that the PID control could effectively provide various stable output pressures of the micro spray gun. The pressure-varying range of 30 kPa could rapidly return to the target value in 10 s (the usual spraying time). The proposed solution then presents better spraying effects. Full article

Human tissues and disease models require well-defined biomimetic microenvironments. During the past decade, innovative developments in materials science, microfabrication, and polymer science have provided us with the ability to manipulate cellular microenvironments for regenerative medicine and tissue engineering applications. Solution blow spinning is a facile fiber fabricating method that requires a simple apparatus, a concentrated polymer solution within a volatile solvent, and a high-pressure gas source. Commercially available airbrushes, typically used for painting and cosmetic makeup, have successfully generated a range of nanofibers and films. Applications under investigation are similar to electrospinning and include enzyme immobilization, drug delivery, filtration, infection protection, tissue engineering, and wound healing. This review will discuss fiber fabrication methods before a more detailed discussion of the potential of blow-spinning in biomedical applications. Full article

In this work, the preparation and characterization of films based on polysulfone (PSF) filled with zinc oxide, ZnO, nanoparticles (NPs) are conducted. The novelty of this research mainly relies on two points: (i) the use of a commercial airbrush to prepare or modify materials, and (ii) the design of new materials (nanocomposites) for the consolidation and restoration of historical bones. To accomplish these objectives, free-standing thin films and ancient bone coatings of PSF/ZnO nanocomposites with different particle contents (0%, 1%, 2%, 5% and 10%, % wt) are prepared using a commercial airbrush. Mechanical characterization is carried out to correlate properties between free-standing thin films and coatings, thus understanding the final performance of the coatings as consolidants for ancient bones. Thin films of PSF/ZnO show that the elastic modulus (E) increases with particle content. The mechanical behavior of the surfaces of the treated and untreated bones is studied locally using Martens hardness measurements. Maximum values of Martens hardness are obtained for the bone samples treated with polysulfone filled with 1% ZnO nanoparticles (HM = 850 N·mm⁻²) or 2% ZnO (HM = 625 N·mm⁻²) compared to those treated just with neat PSF (HM = 282 N·mm⁻²) or untreated bone (HM = 140 N·mm⁻²), indicating there is a correspondence between rigidity of free-standing films and hardness of the corresponding coatings. In terms of mechanical performance, it is demonstrated the existence of a balance between nanoparticle concentration and probability of nanoparticle aggregation, which allows better material design for ancient bones consolidation. Full article

Copper thin films are intended to serve as a cover layer of photocathodes that are deposited by ablating copper targets in a high vacuum by temporally clean 600 fs laser pulses at 248 nm. The extremely forward-peaked plume produced by the ultrashort UV pulses of high-energy contrast ensures fast film growth. The deposition rate, defined as peak thickness per number of pulses, rises from 0.03 to 0.11 nm/pulse with an increasing ablated area while keeping the pulse energy constant. The material distribution over the surface-to-be-coated can also effectively be controlled by tuning the dimensions of the ablated area: surface patterning from airbrush-like to broad strokes is available. The well-adhering films of uniform surface morphology consist of densely packed lentil-like particles of several hundred nm in diameter and several ten nm in height. Task-optimized ultrashort UV laser deposition is thereby an effective approach for the production of thin film patterns of predetermined geometry, serving e.g., as critical parts of photocathodes. Full article

The present investigation was undertaken to evaluate the topographical and ultrastructural architecture of titanium plates coated with polylactic co-glycolic acid (PLGA), chitosan (CH), and/or meropenem (MEM) with or without Staphylococcus aureus (SA) or Pseudomonas aeruginosa (PA) bacteria. Single-hole segments of 0.4 mm thick, low-profile titanium plates were spray coated using an airbrush with polymeric carriers (PLGA or CH) loaded with MEM, in addition to the negative control group (uncoated titanium plates). The coated plates and the negative control group were subjected to bacterial biofilms through a cultivation process while being slowly stirred at 20 rpm for 24 h. The samples were fixed and processed for scanning electron microscopic study at 5, 10, and 20 k magnification. The data were statistically analyzed to compare within and between the different materials. Coating titanium plates with PLGA or CH with MEM appeared to enhance bacterial inhibition over uncoated plates, hindering biofilm formation and preventing bacterial proliferation. In the staphylococcus aureus group, the highest bacterial count was observed in the uncoated plates, whereas the lowest count was detected in meropenem-PLGA, followed by PLGA, chitosan, meropenem, and meropenem-chitosan, respectively. On the other hand, the Pseudomonas aeruginosa group with the uncoated plates had the highest bacterial count, whereas the lowest bacterial count was found related to CH, followed by PLGA, MP, MC, and MEM, respectively. Full article

Wounds result from different causes (e.g., trauma, surgeries, and diabetic ulcers), requiring even extended periods of intensive care for healing, according to the patient’s organism and treatment. Currently, wound dressings generated by polymeric fibers at micro and nanometric scales are promising for healing the injured area. They offer great surface area and porosity, mimicking the fibrous extracellular matrix structure, facilitating cell adhesion, migration, and proliferation, and accelerating the wound healing process. Such properties resulted in countless applications of these materials in biomedical and tissue engineering, also as drug delivery systems for bioactive molecules to help tissue regeneration. The techniques used to engineer these fibers include spinning methods (electro-, rotary jet-), airbrushing, and 3D printing. These techniques have important advantages, such as easy-handle procedure and process parameters variability (type of polymer), but encounter some scalability problems. RJS is described as a simple and low-cost technique resulting in high efficiency and yield for fiber production, also capable of bioactive agents’ incorporation to improve the healing potential of RJS wound dressings. This review addresses the use of RJS to produce polymeric fibers, describing the concept, type of configuration, comparison to other spinning techniques, most commonly used polymers, and the relevant parameters that influence the manufacture of the fibers, for the ultimate use in the development of wound dressings. Full article

A thin film of single-walled carbon nanotube (SWCNT) network field-effect transistor (FET) was fabricated by a simple, fast, and reliable deposition method for electronic applications. This study aims to develop a method for fabricating a thin film of random SWCNTs to be used as a transducer to detect human serum albumin (HSA) in biosensor applications. The random SWCNT network was deposited using the airbrush technique. The morphology of the CNT network was examined by utilising atomic force microscopy (AFM) and field-emission scanning electron microscopy (FESEM), while electrical characteristics were analysed using three-terminal IV measurements. The thin film (SWCNT network) was applied as a transducer to detect human serum albumin (HSA) based on its covalent interaction with antibodies. HSA plays a significant part in the physiological functions of the human body. The surface alteration of the SWCNTs was verified using Fourier transform infrared (FTIR) spectroscopy. Electrical current–voltage measurements validated the surface binding and HSA detection. The biosensor linearly recorded a 0.47 fg/mL limit of detection (LOD) and a high sensitivity of 3.44 μA (g/mL)⁻¹ between 1 fg/mL and 10 pg/mL. This device can also be used to identify a genuine HSA despite interference from other biomolecules (i.e., bovine serum albumin (BSA)), thus demonstrating the random SWCNT-FET immunosensor ability to quantify HSA in a complex biological environment. Full article

‘Silica-defective glasses’, combined with a silicone binder, have been already shown as a promising solution for the manufacturing of glass–ceramics with complex geometries. A fundamental advantage is the fact that, after holding glass powders together from room temperature up to the firing temperature, the binder does not completely disappear. More precisely, it converts into silica when heat-treated in air. A specified ‘target’ glass–ceramic formulation results from the interaction between glass powders and the binder-derived silica. The present paper is dedicated to the extension of the approach to the coating of titanium substrates (to be used for dental and orthopedic applications), with a bioactive wollastonite–diopside glass–ceramic layer, by the simple airbrushing of suspensions of glass powders in alcoholic silicone solutions. The interaction between glass and silica from the decomposition of the binder led to crack-free glass–ceramic coatings, upon firing in air; in argon, the glass/silicone mixtures yielded novel composite coatings, embedding pyrolytic carbon. The latter phase enabled the absorption of infrared radiation from the coating, which is useful for disinfection purposes. Full article