scholarly journals Printable Resin Modified by Grafted Silver Nanoparticles for Preparation of Antifouling Microstructures with Antibacterial Effect

Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3838
Author(s):  
Hazem Idriss ◽  
Roman Elashnikov ◽  
Silvie Rimpelová ◽  
Barbora Vokatá ◽  
Petr Haušild ◽  
...  

The usage of three-dimensional (3D) printed materials in many bioapplications has been one of the fastest-growing sectors in the nanobiomaterial industry in the last couple of years. In this work, we present a chemical approach for grafting silver nanoparticles (AgNPs) into a resin matrix, which is convenient for 3D printing. In this way, the samples can be prepared and are able to release silver ions (Ag+) with excellent antibacterial effect against bacterial strains of E. coli and S. epidermidis. By the proposed process, the AgNPs are perfectly mixed and involved in the polymerization process and their distribution in the matrix is homogenous. It was also demonstrated that this approach does not affect the printing resolution and the resin is therefore suitable for the construction of microstructures enabling controlled silver ion release and antifouling properties. At the same time the physical properties of the material, such as viscosity and elasticity modulus are preserved. The described approach can be used for the fabrication of facile, low-cost 3D printed resin with antifouling-antibacterial properties with the possibility to control the release of Ag+ through microstructuring.

2020 ◽  
Vol 12 (4) ◽  
pp. 1484 ◽  
Author(s):  
M. Asimuddin ◽  
Mohammed Rafi Shaik ◽  
Neeshat Fathima ◽  
M. Shaistha Afreen ◽  
Syed Farooq Adil ◽  
...  

Due to their low cost and environmentally friendly nature, plant extracts based methods have gained significant popularity among researchers for the synthesis of metallic nanoparticles. Herein, green synthesis of silver nanoparticles was performed using the aqueous solution of Ziziphus mauritiana leaves extract (ZM-LE) as a bio-reducing agent. The as-obtained silver nanoparticles were characterized by using UV-Vis spectroscopy, XRD (X-ray diffraction), TEM (transmission electron microscopy), and FT-IR (Fourier-transform infrared spectroscopy). In addition, the effects of the concentrations of the leaves extract, silver nitrate, and the temperature on the preparation of nanoparticles were also investigated. In order to determine the nature of secondary metabolites present in leaves extract, a preliminary investigation of phytoconstituents was carried out using different methods including Folin-Ciocalteu and AlCl3 methods. The results have indicated the presence of a considerable amount of phenolic and flavonoid contents in the leaves extract, which are believed to be responsible for the reduction of silver ions and stabilization of resulting nanoparticles. Indeed, the FT-IR spectrum of silver nanoparticles also confirmed the presence of residual phytomolecules of leaves extract as stabilizing ligands on the surface of nanoparticles. The antibacterial properties of as-obtained silver nanoparticles were tested against various bacterial strains including Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Bacillus subtilis. The nanoparticles strongly inhibited the growth of S. aureus with a minimum inhibitory concentration (MIC) of 2.5 μg/ml and moderately inhibited the growth of E. coli with a MIC of 5 μg/ml.


Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 31
Author(s):  
Varvara Platania ◽  
Alexandra Kaldeli-Kerou ◽  
Theodora Karamanidou ◽  
Maria Kouki ◽  
Alexander Tsouknidas ◽  
...  

A lot of effort has been dedicated recently to provide a better insight into the mechanism of the antibacterial activity of silver nanoparticles (AgNPs) colloidal suspensions and their released silver ionic counterparts. However, there is no consistency regarding whether the antibacterial effect displayed at cellular level originates from the AgNPs or their ionic constitutes. To address this issue, three colloidal suspensions exhibiting different ratios of AgNPs/silver ions were synthesized by a wet chemistry method in conjunction with tangential flow filtration, and were characterized and evaluated for their antimicrobial properties against two gram-negative, Escherichia coli (E. coli) and Pseudomonas aeruginosa (P. aeruginosa), and two gram-positive, Staphylococcus aureus (S. aureus) and Staphylococcus epidermidis (S. epidermidis), bacterial strains. The produced samples contained 25% AgNPs and 75% Ag ions (AgNP_25), 50% AgNPs and 50% Ag ions (AgNP_50), and 100% AgNPs (AgNP_100). The sample AgNP_100 demonstrated the lowest minimum inhibitory concentration values ranging from 4.6 to 15.6 ppm for all four bacterial strains, while all three samples indicated minimum bactericidal concentration (MBC) values ranging from 16.6 ppm to 62.5 ppm against all strains. An increase in silver ions content results in higher bactericidal activity. All three samples were found to lead to a significant morphological damage by disruption of the bacterial cell membranes as analyzed by means of scanning electron microscopy (SEM). The growth kinetics demonstrated that all three samples were able to reduce the bacterial population at a concentration of 3.1 ppm. SEM and growth kinetic data underline that S. epidermidis is the most sensitive among all strains against the investigated samples. Our results showed that all three AgNPs colloidal suspensions exhibited strong antibacterial properties and, thus, they can be applied in medical devices and antimicrobial control systems.


2021 ◽  
Vol 892 ◽  
pp. 36-42
Author(s):  
Muhammad Iqbal Hidayat ◽  
Muhammad Adlim ◽  
Ilham Maulana ◽  
Muhammad Zulfajri

Silver nanoparticles (Ag0) have attracted the most attention due to their broad antimicrobial application and outstanding activity. The silver nanoparticles are usually in colloidal form, then immobilization the colloid onto solid support is still interesting to explore. In this work, a new method for silver colloidal nanoparticle immobilization on silica gel beads (SiG), which was then symbolized as Ag0-[chi-SiG] was conducted and characterized successfully. The finding proved that SiG must be coated with three chitosan film layers to give stable support for silver nanoparticles. This coating method caused the chitosan completely covered SiG, and the chitosan film provides coordination bonding for silver ions. The most appropriate solvent for silver ion impregnation on the surface of chi-SiG is methanol compared to other solvents. Tungsten lamp as the photo-irradiation, which is low cost and environmentally friendly has been proven effective for silver ion reduction, as shown by silver metal colloid UV-Vis surface plasmon resonance at 400-700 nm. Ag0-[chi-SiG] showed the antibacterial properties of inhibiting the growth Staphylococcus aureus and Escherichia coli; then it provides the potential application for antibacterial filter material. According to the weight comparison between antibacterial standard and Ag content, then Ag0-[chi-SiG] has two and five times higher of exhibiting zone for each bacteria.


Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 702
Author(s):  
F. Javier Gil ◽  
Eduardo Espinar-Escalona ◽  
Nuria Clusellas ◽  
Javier Fernandez-Bozal ◽  
Montserrat Artes-Ribas ◽  
...  

A potential new bactericide treatment for NiTi orthodontic archwires based in the electrodeposition of silver nanoparticles on the surface was studied. Twenty-five archwires were treated by electrodeposition, obtaining nanoparticles of silver embedded on the archwire surface. These were evaluated in order to investigate the possible changes on the superelastic characteristics (critical temperatures and stresses), the nickel ion release, and the bacteria culture behavior. The chemical composition was analyzed by Energy Dispersive X-Ray Spectroscopy-microanalysis; the singular temperatures of the martensitic transformation were obtained by a flow calorimeter. Induced martensitic transformation stresses were obtained by mechanical testing apparatus. Nickel ion release was analyzed by inductively coupled plasma-mass spectrometry (ICP-MS) equipment using artificial saliva solution at 37 °C. Bacterial tests were studied with the most used oral bacterial strains: Streptococcus sanguinis and Lactobacillus salivarius. NiTi samples were immersed in bacterial suspensions for 2 h at 37 °C. Adhered bacteria were separated and seeded on agar plates: Tood-Hewitt (TH) and Man-Rogosa-Sharpe (MRS) for S. sanguinis and for L.salivarius, respectively. These were then incubated at 37 °C for 1 day and the colonies were analyzed. The results showed that the transformation temperatures and the critical stresses have not statistically significant differences. Likewise, nickel ion release at different immersion times in saliva at 37 °C does not present changes between the original and treated with silver nanoparticles archwires. Bacteria culture results showed that the reduction of the bacteria due to the presence to the nanoparticles of silver is higher than 90%. Consequently, the new treatment with nanoparticles of silver could be a good candidate as bactericidic orthodontic archwire.


2020 ◽  
Author(s):  
Sara González-Fernández ◽  
Víctor Lozano-Iturbe ◽  
Beatriz García ◽  
Luis J. Andrés ◽  
Mª Fe Menéndez ◽  
...  

Abstract Background: The emergence and expansion of antibiotic resistance makes it necessary to have alternative anti-infective agents, among which silver nanoparticles (AgNPs) display especially interesting properties. AgNPs carry out their antibacterial action through various molecular mechanisms, and the magnitude of the observed effect is dependent on multiple, not fully understood, aspects, particle shape being one of the most important. In this article, we conduct a study of the antibacterial effect of a recently described type of AgNP: silver nanorings (AgNRs), making comparisons with other alternative types of AgNP synthesized in parallel using the same methodology. Results: When they act on planktonic forms, AgNRs produce a smaller effect on the viability of different bacteria than nanoparticles with other structures although their effect on growth is more intense over a longer period. When their action on biofilms is analyzed, AgNRs show a greater concentration-dependent effect. In both cases it was observed that the effect on inhibition depends on the microbial species, but not its Gram positive or negative nature. Growth patterns in silver-resistant Salmonella strains suggest that AgNRs work through different mechanisms to other AgNPs. The antibacterial effect is also produced to some extent by the conditioning of culture media or water by contact with AgNPs but, at least over short periods of time, this is not due to the release of Ag ions. Conclusions: AgNRs constitute a new type of AgNP, whose antibacterial properties depend on their shape, and is capable of acting efficiently on both planktonic bacteria and biofilms.


Author(s):  
Jsr Murthy ◽  
Venkata Kumar T ◽  
Narayana Rao V

Objective: Synthesis of varied sized and morphologically distinct silver nanoparticles (AgNPs) using callus/callus extract, and their promising antibacterial and cytotoxicity was reported from very few plant systems. Here, we investigated silver nanoparticle synthetic potential of Couroupita guianensis leaf callus extract and their antibacterial activity.Methods: synthesis of callus mediated silver nanoparticles and characterisation of physical, chemical, and antibacterial activity of AgNPs.Results: Callus extract rapidly reduced silver ions and stabilized nanoparticles have displayed characteristic maximum UV absorbance at 410 nm. SEM and AFM images revealed their spherical morphology and size variation, which is ranged from 30.38 nm to 88.32 nm and were in small aggregates. Capping of AgNPs by the phenolic compounds and proteins revealed from FTIR spectral peaks. Silver nanoparticles displayed significantly high antimicrobial activity against both Gram positive and negative bacterial strains compared to silver ions and gentamicin. This enhanced antimicrobial activity of AgNPs may due their small size leading to efficient molecular contact with cell surface, and uptake and interaction with vital biomolecules.Conclusions: Stable AgNPs were synthesized through reduction and capping of silver ions by polyphenols and proteins present in callus extract. Theenhanced antimicrobial activity of AgNPs may due to their small size leading to efficient molecular contact with the cell surface, penetration, andinteraction, and inactivation of vital biomolecules.KEY WORDS: Couroupita guianensis, callus extract, Silver nanoparticles (AgNPs), antibacterial activity


Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1529
Author(s):  
Yu-Hsuan Chen ◽  
Wei-Hsun Wang ◽  
Sheng-Hui Lin ◽  
Yuan-Ting Yang-Wang ◽  
Sung-Pin Tseng ◽  
...  

Acinetobacter baumannii (A. baumannii) is a common and challenging pathogen of nosocomial infections, due to its ability to survive on inanimate objects, desiccation tolerance, and resistance to disinfectants. In this study, we investigated an antibacterial strategy to combat A. baumannii via the combination of antibiotics and silver protein. This strategy used a functional platform consisting of silver nanoparticles (AgNPs) resurrected from silver-based calcium thiophosphate (SSCP) through casein and arginine. Then, the silver protein was combined with tigecycline, the first drug in glycylcycline antibiotic, to synergistically inhibit the viability of A. baumannii. The synergistic antibacterial activity was confirmed by the 96-well checkerboard method to determine their minimum inhibitory concentrations (MIC) and calculated for the combination index (CI). The MIC of the combination of silver protein and tigecycline (0.31 mg/mL, 0.16 µg/mL) was significantly lower than that of the individual MIC, and the CI was 0.59, which indicates a synergistic effect. Consequently, we integrated the detailed synergistic antibacterial properties when silver protein was combined with tigecycline. The result could make for a promising approach for the treatment of A. baumannii.


2012 ◽  
Vol 441 ◽  
pp. 356-359
Author(s):  
Jun Natsuki ◽  
Takao Abe

This paper describes a new method to prepare silver nanoparticles useful for printing electronic circuits. We have tried to develop a silver nitrate reduction method, with which a certain reducing agent has played an important role in the reduction of silver ions in an aqueous solution. The reduction has occurred rapidly at room temperature and the silver particles have been separated very easily from the solution in a short time. In this process, any organic solvent has not been used and separation of silver nanoparticles has not been complicated. All chemicals used in this study have been water-soluble. Small and relatively uniform particles of a diameter lower than 10 nm can be obtained with high purity and high yield. These can result in low cost, safe treatment and good for environment protection. This method of producing colloidal silver nanoparticles will find practical use in electronics applications.


2020 ◽  
Vol 16 ◽  
Author(s):  
Arfaa Sajid ◽  
Qaisar Manzoor ◽  
Anam Sajid ◽  
Muhammad Imran ◽  
Shanza Khalid ◽  
...  

Background:: Currently, developing methods for the formation of nanoparticles with antimicrobial properties based on green chemistry are the research hotspots. In this research green biosynthesis of Eriobotrya japonica extract loaded silver nanoparticles and their characterization were the main objectives to achieve. Methods:: Green synthesis of E. japonica leaves extract-loaded silver nanoparticles (AgNPs) was carried out and its effect on bacterial growth was examined. The reduction of silver ions in solution was observed using UV-Vis spectrophotometer. The properties of AgNPs were assessed using Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Also, their antibacterial effects were checked against Staphylococcus aureus and Escherichia coli. Results:: It was revealed that 5-50 nm sized spherical to elongated nanoparticles were synthesized that possessed comparatively better antibacterial potential against E. coli and S. aureus than conventional extract of the E. japonica leaves. Conclusions:: Green synthesis and effective utilization of Eriobotrya japonica extract loaded silver nanoparticles is a promising approach for nanoparticle production avoiding negative environmental impacts.


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