Antibacterial Powder Research Articles

Fabricating Antibacterial Powders from Olive Oil-In Water Emulsions Stabilized by Sour Cherry-Derived Hemicellulose and Pectin Crystalline Structures

Fabricating Antibacterial Powders from Olive Oil-In Water Emulsions Stabilized by Sour Cherry-Derived Hemicellulose and Pectin Crystalline Structures

Multiscale modeling-driven synthesis of Cu40Zn24Ni24Ag8Hg4 high entropy alloy with antibacterial properties

High-entropy alloys (HEAs) are promising materials across various sectors, yet their potential as antibacterial powders remain underexplored. In this study, we synthesized a novel Cu-Zn-Ni-Ag-Hg-based HEA using CALPHAD and DFT methods coupled with mechanical alloying. The HEA's antibacterial efficacy against Staphylococcus aureus (S. aureus) and Escherichia coli (E. Coli) was systematically evaluated. Computational and experimental analyses confirmed the HEA's single-phase FCC structure. Mechanical alloying for 8 h facilitated the formation of the single-phase HEA, with Ni and Cu initially dissolving into each other, followed by Zn, Ag, and Hg. Antibacterial testing demonstrated minimum inhibitory concentrations of 400 µg/mL for S. aureus and 600 µg/mL for E. coli, highlighting the broad-spectrum antibacterial properties of the synthesized HEA. These results underscore the potential of HEAs in advancing antibacterial materials for biomedical applications.

Effect of Carrier Materials for Active Silver in Antibacterial Powder Coatings

Environmentally friendly powder coatings which have the advantages of being VOC-free, low-cost, and high-efficiency with a high recovery rate have been attracting increasing research attention. The introduction of antibacterial agents into the powder coatings endows them with a capacity to kill bacteria and viruses on the surface of objects; additionally, this enables them to inhibit the indirect transmission of pathogenic microorganisms. Silver, possessing broad-spectrum, strong, and stable antibacterial properties, is considered to be a promising antibacterial material for use in coating applications. Carrier materials for active silver play an important role in its activity and stability. However, there is a lack of systematic studies on the effects of different types of carriers in such coating systems, especially in green powder coating systems. In this paper, we investigated two types of carriers for active silver agents: zeolite, i.e., Linde type A (LTA) zeolite and Y-type zeolite; clay-based materials, i.e., montmorillonite and vermiculite. All the agents showed high antibacterial activity, with antibacterial rates of over 99% as compared to commercial agents. Among the four agents, the Ag-LTA zeolite antimicrobial agent showed a reduction rate of over 99.99%; additionally, it maintained a reduction rate of 99% after seven washing cycles. Thus, this agent was demonstrated to have the highest effectiveness and high durability; these features can be attributed to the high silver content and small particle size. The LTA zeolite also provides a protective effect for silver ions, protecting them from reduction, due to the restriction of elemental silver formation within the confined interior space of the α-cage structure. The Y-type zeolite antimicrobial agent exhibited a slightly lower antimicrobial performance due to its higher silicon-to-aluminum ratio and its lower cation exchange capacity. Comparatively, antimicrobial agents utilizing clay-based carriers have lower cation exchange capacity, resulting in poorer antimicrobial effectiveness than zeolite carriers. In addition, silver loaded on clay-based materials is prone to detach from the carrier and undergo a reduction reaction, making the coating yellowish in color. This study first provides information on the roles of different types of carriers in powder coating systems; then, this information guides the selection of carriers for active silver for the development of efficient antimicrobial agents and coatings.

Ag-doped NiS nanocubes: Tailoring properties for optimal antibacterial performance

This study explores the synthesis of silver-doped nickel sulfide nano-cubes (Ni1-xAgxS: x= 0.00, 0.04, and 0.08) through a cost-effective hydrothermal process. X-ray diffraction analysis assured the presence of hexagonal NiS nanoparticles with fine crystallinity, with an estimated crystallite size of Ag-doped NiS ranges from 21.19 to 15.69 nm. A reduction in crystallite size was observed while including Ag ions along with enhancement in lattice constants for ‘a’ and ‘b’ from 3.416 Å to 3.424 Å and ‘c’ from 5.280 to 5.286 Å. The scanning electron microscopic images displayed cubic shaped agglomerated particles, that seemed quite suitable for antibacterial activity. The materials exhibit semiconducting behavior, as evidenced by increased direct current electrical conductivity with the rise in temperature. With increased silver content, the direct current electrical conductivity rises, and activation energy decreases from 0.246 to 0.213 eV. Dielectric characteristics, including dielectric constant, dielectric loss, and AC electrical conductivity, show a positive correlation with temperature, and all the aforementioned values elevates with systematic variation in Ag doping. The Agar well-diffusion method evaluates the antibacterial activity of un-doped and Ag-doped NiS nano-cubes against various pathogens, such as Gram-positive bacteria (M. luteus and S. aureus) and Gram-negative bacteria (E. coli and S. enterica), and significant inhibitory zones against all tested microbes, confirming the potential antibacterial efficacy. The Ag-doped NiS exhibited enhanced antibacterial efficiency. This research highlights Ag-doped NiS nano-cubes attributed with multifaceted functionalities, making them promising candidates for particular usage such as targeted drug delivery systems, antibacterial powder, wastewater treatment and pharmaceutical applications.

Treatment of wound anaerobic infection in great horned animals: clinical example in a cow

External mechanical problems contribute to a wider problem in the surgical field in dairy cattle. The frequency of early injuries is highest in the limbs, and the lowest in the posterior and tail area. Most often, cows have puncture wounds that are susceptible to infection. Infectious complications of injuries and improper care in the aggregate lead to a decrease in productivity, premature culling of animals, and even to their death. Therefore, the analysis of medical methods and their effectiveness in great horned cattle for the aggravation of a accidental wound with anaerobic infection is also relevant. We looked at the clinical episode of a cow of the 1st or 2nd lactation, which had a puncture wound in the sub-breast area, right next to the subscapular area. The cow tried to overcome the fence and was injured by the end of the rebar. The treatment protocol will first help to stop bleeding, wash the cavity of wound with an antiseptic, add antibacterial powder to it and close it with sutures, internally administer ceftioclene. After the development of infectious-flammable structure in the wound and bacteriological investigation, treatment included washing with H2O2, drainage with Levosin and Nitacid ointment, metronidozole, bicilin 3, and granulation with the granulation of wounds: hydrophobic ointments. This is the basis for the use of systemic antibacterial therapy, rational surgical tactics and drainage, local treatment of active pharmacological agents with antibacterial, analgesic and hyperosmodic agents. Key words: cow injuries, wounds, purulent inflammation, ointments on hydrophilic bases.

Antibacterial Activity and Mechanism of GO/Cu2O/ZnO Coating on Ultrafine Glass Fiber.

A GO (graphene oxide)/ZnO/Cu2O antibacterial coating was successfully sprayed on the ultrafine glass fibers using room temperature hydrothermal synthesis and air spraying techniques. The microstructures of the antibacterial coating were characterized, and the results showed that the Cu2ONPs (nano particles)/ZnONPs were uniformly dispersed on the surface of GO. Then, the antibacterial properties of the GO/ZnO/Cu2O (GZC) antibacterial coating were evaluated using the disc diffusion test. It was found that the coating exhibits excellent antibacterial properties and stability against E. coli and S. aureus, and the antibacterial rate of each group of antibacterial powder against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) was 100%. To explore the antibacterial mechanism of the GZC antibacterial powder on the ultrafine glass fibers based on the photocatalysis/oxidative stress method, the photoelectric coupling synergistic effect between GZC antibacterial coating was analyzed deeply. The results all showed that the photochemical activity of GZC antibacterial powder was significantly improved compared with pure component materials. The enhancement of its photochemical activity is beneficial to the generation of ROS (including hydroxyl radicals, superoxide anion radicals, etc.), which further confirms the speculation of the photocatalytic/oxidative stress mechanism.

Ultrasonochemically Modified Ag@TiO2 Nanocomposites as Potent Antibacterial Agent in the Paint Formulation for Surface Disinfection

AbstractAdvanced visible active antibacterial paint was developed by ultrasonochemically treated Ag@TiO2 NCs with varying content of Ag (1 wt. % to 5 wt. %) as a photoactive agent for antibacterial paint formulation for surface disinfection. Initially, the existence of the Ag@TiO2 NCs in the paint formulation and their impact with varying content of Ag in wt. % was studied through various spectroscopic studies. XRD analysis confirms the good crystalline nature of the Ag@TiO2 NCs after the paint formulation. UV visible spectroscopic study reveals the visible active properties of the antibacterial paint. Contact angle measurement study shows hydrophobic nature of the paint. Thereafter, Ag@TiO2 NCs with varying the content of Ag were used as a photoactive additive for the formulation of antibacterial powder paint through an industrial process. Finally, the 3 wt. % of Ag in the Ag@TiO2 NCs as an additive in the paint exhibits higher antibacterial activity against E. coli as compared with S. aureus bacteria's in the presence of visible light irradiation. It also confirmed after 72 hrs. that there was no leaching of the antibacterial paint on the coated substrates. Therefore, such nanocomposite based visible active antibacterial paint is efficient to use in healthcare for reducing hospital‐acquired infections.

Evaluation of fluorinated hydroxyapatite nanoparticles as an antibacterial material for catheter coating

BackgroundCatheter-related infection of peritoneal dialysis (PD) is one of the serious factors of peritonitis. However, an antibacterial PD catheter has not been commercially available in Japan yet. From an infection control viewpoint, it is necessary to develop an antibacterial coating material for catheters with a long-term effectiveness.MethodsFluorinated hydroxyapatite (F-HAp) nanoparticles were prepared by a wet chemical process. F-HAps with different F substitution contents were prepared by adjusting the feed ratio of F ions versus sites of OH groups in HAp structures. The characterization and evaluation of F-HAps were conducted using several analytical equipment and an antibacterial powder assay.ResultsThe F-HAp nanoparticles possessed highly crystalline and dispersibility. The F-HAps were named as F(30)-HAp, F(50)-HAp, and F(100)-HAp and were 24, 52, and 84% of the actual F substitution content, respectively. The nanomaterials showed acidic resistance, i.e., chemical stability, compared to normal HAp. In an antibacterial assay of F(100)-HAp with 50 mg in 0.2 mL of NaCl aqueous solution, four types of causative bacteria of catheter-related infections, Pseudomonas aeruginosa, Staphylococcus aureus, Enterobacter aerogenes, and Klebsiella pneumoniae were used. The antibacterial activities of F(100)-HAp showed 50–60% against the microorganisms. F ions were gradually released and finally plateaued at 24 weeks.ConclusionsThe retention possibility of the antibacterial effect of F(100)-HAp potentially lasted for 24 weeks based on the F ions release behavior. It is expected that the antibacterial performance can be improved by the precise control of material engineering technology, although the duration of the effect has not yet been satisfactory for a PD catheter.

Antibacterial powder coatings using single and binary ion-exchanged zeolite A from local kaolin

Antibacterial powder coatings using single and binary ion-exchanged zeolite A from local kaolin

Development of antibacterial powder coatings using single and binary ion-exchanged zeolite A prepared from local kaolin

Antibacterial electrostatic powder paint coating with intended esthetic criteria was specially formulated for industrial applications using single (Ag+) and binary exchanged (Ag+ and Zn2+) zeolite A, which was prepared from local kaolin resources. Optimization studies on reaction parameters were conducted to obtain the most crystalline zeolite A from kaolin. The Ag+ and Zn2+ exchanged zeolite A samples prepared from kaolin were introduced as filler into the paint matrix during the electrostatic powder coating process. The antibacterial efficacy of the coatings was evaluated against E. coli and S. aureus based on Japanese Industrial Standard JIS Z 2801 method. Color analysis was also performed on these coatings in order to meet the least discoloration criteria, which is relevant to judge the quality of the coatings for industrial use. Single ion-exchanged coatings with Ag+ resulted in discoloring effect, which was diminished by adding Zn2+. The results indicated that the coatings containing both 2 wt% Ag+ and 12 wt% Zn2+ exchanged zeolite A exhibited 99.99% and 99.96% reduction for E. coli and S. aureus, respectively. This was of special interest for zeolite A samples that were prepared from local kaolin resources with more significant discoloration due to using natural kaolin as raw material. In conclusion, a low cost and antibacterial powder paint formulation with desired esthetic criteria using zeolites was achieved for the first time using a combination of Ag+ and Zn2+ ions.

Functionally Modified Zeolite Powders for Delivering Antibacterial Performance to Cellulosic Paper

Zeolite powders were first treated with hydrochloric acid, then reacted with sodium chloride, and sodium zeolite (Na-Zeolite) powders were obtained. Further Antibacterial zeolite powders were prepared by loading metal ions such as, Ag+ and Zn2+, Ag+ and Cu2+, Zn2+and Cu2+, Ag+ and Cu2+and Zn2+, through ion exchange. The powders were characterized by minimum Inhibitory concentration (MIC), SEM/EDXA and XRD. Antibacterial paper with antibacterial zeolite powders as filler was fabricated. The results demonstrated that MIC of loading (Ag++Zn2+) zeolite was 125ppm against Staphylococcus aureus and Escherichia coli . MIC of loading (Ag++Cu2++Zn2+) zeolite was 62.5ppm against Candida albicans and Aspergillus Niger. By adding 6% of (Ag++Zn2+), (Ag++Cu2+), and (Ag++Cu2++Zn2+) antibacterial zeolite powders, respectively, antibacterial paper were prepared; and the antibacterial rate of these papers against Staphylococcus aureus, Escherichia coli, Candida albicans and Aspergillus Niger for 4h is close to 100%.

<b>Effect of feeding Thymolina<sup>®</sup> powder on the carcass characteristics and morphology of small intestine in ross 308 broiler chickens

In the present experiment, 320 one day old Ross 308 broiler chickens were used completely randomized design with 4 treatments, 4 replicates, and each replicate contained 20 broiler chickens. Experimental treatments include control, 0.5, 1, and 2% of Thymolina powder in chickens’ diet. Thymolina ® is an anti-bacterial powder drug which is made by composing 4 medicinal plants. A significant difference observed between treatments in each parameter of the Intestinal morphology (villus height, villus width, crypt depth and epithelial thickness). Goblet cells number was not affected. Our findings indicated that using Thymolina ® in the diet of broiler chickens causes improvements in carcass characteristics. Therefore, it may improve the carcass characteristics and morphology of small intestine in broiler chickens.

Optimised preparation and characterisation of silver-neodymium inorganic antibacterial material through response surface methodology

A novel silver-neodymium antibacterial white carbon black was successfully synthesised via a sol–gel method and used as an excellent antibacterial material for production. The central composite design of response surface methodology was used to optimise the preparation of antibacterial powder materials. Statistical analysis of results showed that the bulk density of Nd-Ag antibacterial white carbon black was significantly affected by the Nd ion concentration, reaction time and reaction temperature. The optimum Nd ion concentration, reaction temperature and reaction time were 0.001 mol L−1, 94.92 °C and 75 min, respectively. The antibacterial material was characterised by Fourier transform infrared spectroscopy, X-ray diffraction, energy dispersive spectroscopy and scanning electron microscopy. The antibacterial properties of Nd-Ag antibacterial white carbon black on Escherichia coli. were also investigated. Nd-Ag antibacterial white carbon black was higher than that of the general Ag antibacterial white carbon black (without containing yttrium). The bacteriostatic rate of Nd-Ag antibacterial white carbon black was >99%.

Preparation of Three Modified Natural Zeolite Powders and Antibacterial Properties of Antibacterial Paper Prepared Using them as Fillers

Natural zeolite powders, 600 meshes in size, were pretreated with three strong acids , then reacted with sodium chloride, sodium sulfate, sodium nitrate, respectively, and yielded sodium zeolite. The samples were loaded Ag++Zn2+, Ag++Cu2+, Zn2++Cu2+, and Ag++Cu2++Zn2+ ions through ion exchange to prepare the antibacterial zeolite powders. The powders were tested by MIC, SEM/EDXA and XRD. The results demonstrated that the pretreatment of zeolite powder with nitric acid could achieve a larger loading amount of metal ions compared to hydrochloric acid and sulfuric acid, and the samples loaded with Ag++Zn2+, Ag++Cu2+,Ag++Cu2++Zn2+ could attain excellent antibacterial properties with an MIC of 8 μg/ml to S. aureus Adding 5% of the aforementioned antibacterial zeolite powders to paper as filler resulted in an impressive antibacterial effect against S. aureus, as the inhibitory rate could reach to almost 100% in 1 h.

Synthesis and characterization of an antibacterial powder based on the covalent bonding of aminosilane-stabilized silver nanoparticles to a colloidal silica

Stable dispersions of silver nanoparticles (Ag NPs) were synthesized employing glycerol as both a solvent and reducing agent, and 3-aminopropyl trimethoxysilane (APTMS) as a stabilizer. Average sizes varied between 13 and 55 nm, depending on the molar ratio of APTMS/Ag. Terminal alkoxysilanes reacted with OH groups of glycerol leading to the covalent bonding of glycerol moieties to the chain ends of the stabilizer. This produced extremely stable colloidal dispersions from which NPs could not be extracted with solvents immiscible with glycerol (as THF). Ag NPs were covalently bonded to the surface of a colloidal silica by hydrolysis/condensation of terminal Si–O–C bonds of the stabilizer with superficial SiOH bonds of silica. TEM images revealed the presence of individual NPs and small clusters of NPs attached to the silica surface. These clusters were presumably generated by intermolecular reactions among chain ends of the stabilizer producing Si–O–Si bonds. The antibacterial properties of the resulting powder were confirmed by conventional tests employing a culture of Escherichia Coli.

Antibacterial properties of nano silver-containing orthodontic cements in the rat caries disease model

The purpose of this study was to evaluate the antibacterial properties of experimental nano silver-containing cements (NSCs) using rat caries disease model. Nano silver base inorganic antibacterial powder was added to the reinforced glass ionomer cement at three different weight ratios to obtain a series of nano silver-containing cements, then two orthodontic cement products and three NSC samples were implanted into rat caries disease model, and their antibacterial properties were evaluated by the scanning electron microscope(SEM). Moreover, the rat caries disease model were established by inoculating cariogenic bacteria S mutans into antibiotics treated rat mouths and feeding with cariogenic diet. The tested materials were bonded on the surface of the buccal half crowns of the upper first premolar, and then fixed under the rats’front teeth lingual side to acquire enough retention. The SEM results indicated that the growth of streptococcus mutans was very active in group of Transbond XT. One month later, S mutans scattered on the GC Fuji ORTHO LC surface, and then the number significantly increased and arranged in chains after three months. In groups of NSC2, NSC3 and NSC4, the number of S mutans presented the downward trend and tended to disperse individually with the increase of silver nanoparticle content. We may conclude that the incorporation of silver nanoparticle enhanced GC Fuji ORTHO LC the adhesion restrain and killing effect to S mutans.

Study on the antibacterial mechanism of copper ion- and neodymium ion-modified α-zirconium phosphate with better antibacterial activity and lower cytotoxicity

To improve the antibacterial activity of Cu2+, a series of Cu2+ and/or Nd3+-modified layered α-zirconium phosphate (ZrP) was prepared and characterized, and the antibacterial activities of the prepared Cu2+ and/or Nd3+-modified ZrP on Gram-negative Escherichia coli were investigated. The results showed that the basal spacing of ZrP was not obviously affected by the incorporation of Cu2+, but the basal spacing of the modified ZrP changed into an amorphous state with increasing additions of Nd3+. An antibacterial mechanism showed that Cu2+ and Nd3+ could enter into E. coli cells, leading to changes in ion concentrations and leakage of DNA, RNA and protein. The Cu2+- and Nd3+-modified ZrP, combining the advantages of Cu2+ and Nd3+, displayed excellent additive antibacterial activity and lower cytotoxicity, suggesting the great potential application as an antibacterial powder for microbial control.

Adsorption of nisin on raw montmorillonite

The aim of the present work was to develop food-grade materials capable of releasing antimicrobial agents. Montmorillonite (Mt), a raw, abundant inexpensive clay mineral approved as a food additive, was used as support material. The immobilized antimicrobial agent was pure nisin (Danisco, UK). A series of antibacterial compounds were prepared, and the antimicrobial activity of the resultant montmorillonite–nisin (MtNis) immobilized systems was determined against Enterococcus faecium C1. The characterization of the antimicrobial powders showed evidences of nisin adsorption on by means of a “frustrated intercalation” model with a nisin loading (NL) saturation value close to 0.24CEC (cation exchange capacity) of Mt. The antibacterial powders with NL above this value completely inhibited E. faecium C1 during 24h of contact. These results are encouraging for the development of nisin-based bioprotectors immobilized on raw Mt.

Fabrication and Properties of Silver-Doped Acrylonitrile Butadiene Styrene (ABS) Composites

In this work, a kind of silver-containing inorganic antibacterial powder was doped into acrylonitrile butadiene styrene (ABS) using an injection molding process. The results showed that the doping process could bring out a uniform distribution of antibacterial powder in the ABS matrix. An initially high (and later sustained) silver release rate into de-ionized water was obtained during an immersion test. High-efficiency and authoritative antibacterial abilities against Escherichia coli and Staphylococcus aureus were observed during antibacterial tests. The mechanical tests showed that the doping of this kind of antibacterial powder did not affect the composite's mechanical properties too significantly.

Long-term antibacterial properties and bond strength of experimental nano silver-containing orthodontic cements

The purpose of this study was to evaluate the long time antibacterial properties and shear bond strength of experimental nano silver-containing cements (NSC). Nano silver base inorganic antibacterial powder was added to the reinforced glass ionomer cement at five different weight ratios to obtain a series of nano silver-containing cements, then the antibacterial properties of three orthodontic cement products and five NSC samples were evaluated by the direct contact test (DCT) and the agar diffusion test (ADT). The DCT, which was based on turbidness determination of bacterial growth in 96-well microtiter plates, was performed in both fresh and aged for 1 day, 1 week, 2 weeks, 3 weeks, 4 weeks, 6 weeks, and 8 weeks tested materials. The shear bond strengthes of three orthodontic cement products and five NSC samples were examined using a universal testing machine. The ADT results indicated that there were no significant differences between NSCs and ORTHO LC fresh specimens. In the DCT experiment, all fresh silver nanoparticles-containing tested samples presented powerful antibacterial properties, but they gradually lost the effective antimicrobial agents with the extension of aging time. Finally, none of the tested materials maintained its antibacterial property after aging for 8 weeks. A gradually decreasing trend of bond strength presented with the increasing incorporation of nano silver base inorganic antibacterial powder into the glass ionomer cement, even though all the tested material specimens reached the ideal bond strength range. We may conclude that NSCs can contribute to decrease the demineralization rate around brackets without compromising bond strength.