Silver Nitrate Research Articles

Enhancing Dental Alginate with Syzygium aromaticum, Zingiber officinale and Green Silver Nanoparticles: A Nature-Enhanced Approach for Superior Infection Control.

The study addresses the challenge of cross-infection in dentistry, focusing on improving disinfection protocols for dental hydrocolloid gel materials. This research aimed to incorporate chlorhexidine, natural plant extracts, and green-synthesized silver nanoparticles (AgNPs) into dental alginate to enhance safety and hygiene standards in dental practices. Conventional dental alginate served as the control, with experimental groups including alginate modified with 0.2% chlorhexidine (CHX-group) and alginate incorporating AgNPs synthesized from Syzygium aromaticum (SA) and Zingiber officinale (ZO) extracts (SA + AgNPs and ZO + AgNPs groups). Plant extracts were analyzed via GC/MS to confirm their composition. UV-visible spectroscopy, SEM, and EDX characterized the synthesized AgNPs. Antimicrobial efficacy against Candida albicans, Streptococcus mutans, and methicillin-resistant and methicillin-sensitive Staphylococcus aureus was evaluated using agar well diffusion assays. The dimensional accuracy of alginate impressions was assessed according to ISO 21563:2021 standards. Chemical analysis of SA and ZO extracts identified 60 and 43 active compounds, respectively, supporting their use in AgNP synthesis. UV-visible spectroscopy, SEM, and EDX confirmed the formation of spherical AgNPs using SA and ZO extracts. Modified groups showed inhibitory activity against Streptococcus mutans and methicillin-resistant (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA), in contrast to the unmodified control. Both AgNP-modified groups demonstrated efficacy comparable to the CHX-group against MRSA and MSSA, with SA + AgNP showing superior performance against C. albicans. The dimensional accuracy of all groups was within clinically acceptable ranges as reported in the literature (0.027-0.083 mm). CHX, silver nitrate, and green-synthesized AgNPs present promising options for developing self-disinfecting alginate impression materials. Utilizing plant extracts in AgNP synthesis offers a safe, efficient, and synergistic approach between metal ions and phytotherapeutic agents. This approach could potentially enhance disinfection efficacy without compromising material performance, improving dental safety and hygiene.

Silver nanoparticles mediated apoptosis and cell cycle arrest in lung cancer A549.

The present study was aimed to synthesize the silver nanoparticles from Alangium salvifolium Wang. and evaluating its biomedical applications. The leaves of A. salvifolium collected and subjected for the standard procedure of Soxhlet extraction using distilled water as a solvent. With the help of an aqueous extract AgNPs were synthesized from silver nitrate using phyto-reduction method. Further, synthesized AgNPs were characterized using several analytical techniques such as UV, FTIR, SEM-EDX, XRD, particles size and zeta potential. Synthesized AgNPs were tested for antibacterial, antioxidant, anticancer for lung cancer cell line and flowcytometry-based pathway studies. The visual observation confirmed the formation of AgNPs from the aqueous extract by changing yellow to brown colour formation. Further, characterization techniques also confirmed the formation of AgNPs. Antibacterial activity results showed that the tested AgNPs were potent against bacterial pathogens with a higher zone of inhibition. Further, the antioxidant and anticancer activity of AgNPs revealed that the AgNPs have exhibited significant results with a good percentage of inhibition. Further, the flow cytometry studies confirmed that the AgNPs inducing apoptosis and cell cycle arrest in lung cancer. The phytochemicals of A. salvifolium plant have successfully synthesized AgNPs. In the case of performed biological activity, the synthesized silver nanoparticles exhibited potent activity. In future these AgNPs can be taken for molecular and in vivo studies to identify their efficacy using in vivo and molecular models.

Optimizing Titanium Carbide-Silver Oxide Nanostructures for Targeted Cancer Therapy: Synthesis, Functionalization, and In Vitro Evaluations.

Introduction Cancer remains a significant health challenge, and nanoparticles (NPs) are promising candidates for cancer treatment due to their unique physicochemical properties and ability to selectively target tumour cells. Two-dimensional (2D) nanomaterials, such as MXenes, have attracted interest due to their electronic structures, optical properties, catalytic abilities, and exceptional physicochemical attributes. MXenes are highly suitable for surface functionalization or modification, and their unique properties make them promising candidates for various applications in the biological field. Silver-based compounds have shown remarkable potential in biomedical fields, with silver oxide (Ag₂O) NPs finding applications in various domains. The fabrication of titanium carbide (Ti₃C₂)-Ag₂O heterostructures has been investigated for their anti-cancer properties by conducting cell viability assays on different cell lines. Aim To synthesize and characterize Ti₃C₂-Ag₂O, and to assess its in vitro anti-cancer activity. Materials and methods Ti₃C₂ synthesis begins by dissolving Ti₃AlC₂ powder in a 50% v/v hydrofluoric (HF) acid solution, allowing the aluminium to be etched away. This process should be conducted with continuous stirring for 24 to 48 hours at ambient temperature. Following this, filter the resulting suspension to eliminate aluminium particles and HF, and subsequently wash the Ti₃C₂ MXene with distilled water until a neutral pH is attained. The MXene should then be dispersed in ethanol, and sonication in deionized (DI) water or an alternative solvent should be employed to achieve exfoliation into monolayer or few-layer MXenes. To prepare Ag₂O NPs, dissolve silver nitrate (AgNO₃) in DI water to create a 0.1 M solution, and concurrently prepare a separate 0.1 M sodium hydroxide (NaOH) solution. Introduce the NaOH solution to the AgNO₃ while stirring until a precipitate is observed. The mixture should then be filtered, washed with distilled water, and the NPs dried at 60°C for 12 hours. To fabricate the MXene-Ag₂O composite, disperse the MXene nanoflakes in a solvent through sonication, incorporate the Ag₂O NPs, and stir the mixture for 24 hours. Finally, centrifuge the resultant mixture to isolate the composite, wash it with solvent, and dry it under vacuum conditions. Results The presence of Ag₂O particles on Ti₃C₂ nanosheets was observed, and the high crystallinity of the compound was confirmed through X-ray diffraction (XRD), energy-dispersive spectroscopy (EDS), and scanning electron microscopy (SEM) analyses. These tests verified that the compound was free of impurities and exhibited anti-cancer properties. Conclusion The synthesis of Ti₃C₂ MXenes and Ag₂O NPs was achieved and confirmed through structural characterization methods, including SEM, XRD, and EDS. SEM provided detailed insights into the morphology and distribution of the nanostructures, while XRD and EDS verified their phase purity and elemental composition. Functionalization strategies were employed to enhance the stability and bioactivity of the nanocomposites. In vitro evaluations demonstrated promising anti-cancer activity, indicating that the Ti₃C₂-Ag₂O composites effectively target and inhibit cancer cell growth.

Multipurpose Impacts of Silver Nitrate on Direct Organogenesis of Begonia rex cv. DS-EYWA via Transverse Thin Cell Layering (tTCL) Technique

Begonia rex cv. DS-EYWA is an important plant for indoor and outdoor cultivation, and cv. DS-EYWA is a rare unique cultivar with curly, colorful leaves. Due to their importance, applying plant tissue culture techniques for mass and healthy production in a short period of time without seasonal limitation is of immense economic value. Applying several concentrations of silver nitrate (AgNO3) in combination with varied concentrations of cytokinins including 6-benzylaminopurine (BAP), thidiazuron (TDZ) (0, 0.5, 1, 1.5 mgL−1), and 1-naphthaleneacetic acid (NAA) auxin (0, 0.5, 1 mgL−1) via focusing on transverse thin cell layer (tTCL) petiole explants for high-scale production was used to establish an efficient in vitro propagation protocol. Our results showed that even low concentrations (25 mgL−1) can control internal bacterial infection and increase shoot direct regeneration efficiency. A combination of 1.5 mgL−1 BAP, 0.5 mgL−1 NAA, and 25 mgL−1 AgNO3 was the best treatment to increase the number of direct regenerated shoots, and a lower concentration of BAP (0.5 mgL−1) can be suggested for shoot elongation. Elongated shoots were successfully rooted in MS basal medium and acclimatized in a 1:1 peat moss/perlite sterilized pot mixture.

Synergistic photocatalytic and antibacterial efficacies of Ag/rGO and Ag/Ag2O/rGO nanocomposites: The impact of oxide formation and ternary heterojunction

This study explores the efficient solvothermal integration of Ag/rGO and Ag/Ag2O/rGO nanocomposites using various solvents and employs thorough characterization procedures. The primary focus is on understanding the nuanced effects resulting from the combination of Ag nanoparticles with rGO nanosheets, particularly in the context of Ag2O formation. For a quantitative assessment of their photocatalytic and antibacterial properties, graphene oxide and silver nitrate (AgNO3) were introduced to create Ag/rGO and Ag/Ag2O/rGO nanocomposites. The results demonstrate a significant enhancement in photocatalytic performance for the Ag/Ag2O/rGO nanocomposite, achieving a rapid degradation of 99.99 % of methylene blue dye within 30 minutes under simulated solar light irradiation. This heightened efficiency is attributed to improved separation and transfer efficiency, as well as the substantial generation of photoinduced carriers due to the incorporation of visibly active Ag2O nanoparticles. Moreover, the Ag/Ag2O/rGO nanocomposite exhibits an enhanced antibacterial activity, reflected in Minimum Inhibitory Concentration (MIC) values of 50 μg/ml for Bacillus cereus and 300 μg/ml for Escherichia coli. The nanocomposite's higher antimicrobial activity against Gram-positive bacteria, particularly Bacillus cereus, is underscored, revealing its potential as an effective antibacterial agent. The formation of a ternary heterojunction in the Ag/Ag2O/rGO nanocomposite results in a notable increase in the production of free radicals, enhancing charge carrier migration and separation efficiency. This quantitative evidence emphasizes the versatile nature of the nanocomposite, highlighting its potential across diverse fields through augmented antibacterial and photocatalytic properties.

Fighting A New Front On An Old Battlefield: Examining the Development of Topical Antimicrobial Care to Control Burn Wound Sepsis.

Recognition of invasive burn wound sepsis as a major cause of morbidity and mortality in burn injured patients has profoundly changed the management of burn wounds and its associated complications. The development of effective topical antimicrobial therapy is one of the last major developments of modern burn care and has been driven by major world events and scientific breakthroughs. Topical antimicrobial burn care has evolved from the use of anecdotal remedies to scientific breakthroughs such as Moyer's successful dilution of silver nitrate solution, Fox's described benefit of silver sulfadiazine use in animal models, and Pruitt's dramatic improvement in post-burn mortality using topical mafenide acetate in burn wounds. The objective of this manuscript is to review the definition of burn wound sepsis and highlight the major developments and breakthroughs in topical burn wound care throughout history. This includes historical events like major wars or domestic fires that have influenced or impacted the understanding and treatment of burn wounds. Newer advances in topical antimicrobial care such as nanosilvers and dressing technologies that improve the morbidity and mortality associated with burn wound sepsis and novel approaches to management will also be discussed. To improve burn care, it is prudent to look to the past and learn from the experiences of those who contributed to the control of burn wound sepsis.

Developing a novel calcium silver zeolite for caries management

ObjectiveTo develop a novel calcium silver zeolite (Ca-Ag-Zeo) and assess its biocompatibility, physiochemical properties and antimicrobial effects.MethodsCa-Ag-Zeo was synthesized using ion-exchange method with calcium chloride, silver nitrate and Zeolite X (Zeo). Silver zeolite X (Ag-Zeo) and Zeo were set as control. The chemical structure, morphology, crystal structure and elemental composition of Ca-Ag-Zeo was characterized by X-ray diffraction spectrum, scanning electron microscopy, transmission electron microscopy and energy dispersive spectroscopy, respectively. Its biocompatibility on the human gingival fibroblasts was assessed by cell counting kit-8 assay. Its physiochemical properties were determined by the released calcium and silver ion using Inductive Coupled Plasma Emission Spectrometry for up to 12 weeks. The antimicrobial properties on Streptococcus mutans, Lactobacillus acidophilus, Lactobacillus casei, and Candida albicans were assessed by minimum bactericidal concentration (MBC) or minimum fungicidal concentration (MFC) assay.ResultsCa-Ag-Zeo with a hexagonal cage structure was synthesized. As for biocompatibility, the half-maximal inhibitory concentration (± SD in mg/mL) of Ca-Ag-Zeo, Ag-Zeo and Zeo in human gingival fibroblasts were 0.52 ± 0.05, 0.15 ± 0.01 and 3.35 ± 0.58, respectively (Zeo > Ca-Ag-Zeo > Ag-Zeo; p < 0.05). As for physiochemical properties, the accumulated ion release (± SD in mg) of Ca-Ag-Zeo, Ag-Zeo and Zeo were 0.011 ± 0.003, 0 and 0 for calcium ion, respectively (Ca-Ag-Zeo > Ag-Zeo, Zeo; p < 0.001), and 0.213 ± 0.032, 0.209 ± 0.019 and 0 for silver ion, respectively (Ca-Ag-Zeo, Ag-Zeo > Zeo; p < 0.001). As for anti-microbial ability, the MBC/MFC (mg/mL) of Ca-Ag-Zeo, Ag-Zeo and Zeo were 32, 16 and > 256 against Streptococcus mutans; 32, 16, > 256 against Lactobacillus acidophilus; 16, 16, and 256 against Lactobacillus casei; 0.25, 0.125; and 2, 1, > 256 against Candida albicans, respectively.ConclusionA novel Ca-Ag-Zeo was developed. It presented better biocompatibility compared to Ag-Zeo. It released calcium and silver ions sustainably, and it could inhibit the growth of common cariogenic microorganisms.

Screening of Lithium Substituted Ag-TiO2 Nanoparticle Coating for Antibiofilm Application.

Bacterial infections and biofilm growth are common mishaps associated with medical devices, and they contribute significantly to ill health and mortality. Removal of bacterial deposition from these devices is a major challenge, resulting in an immediate necessity for developing antibacterial coatings on the surfaces of medical implants. In this context, we developed an innovative coating strategy that can operate at low temperatures (80 °C) and preserve the devices' integrity and functionality. An innovative Ag-TiO2 based coating was developed by ion exchange between silver nitrate (AgNO3) and lithium titanate (Li4Ti5O12) on glass substrates for different periods, ranging from 10 to 60 min. The differently coated samples were tested for their antibacterial and antibiofilm efficacy.

Silver secnidazole nano-hybrid emulsion-based probiotics as a novel antifungal formula against multidrug-resistant vaginal pathogens.

This study presents a novel approach to manage vaginal infections due to Candidiasis, utilizing a novel silver secnidazole nano-hybrid emulsion (Ag-Secn-NHE)-based probiotics and free Ag-Secn-NHE. Ag-Secn-NHE was prepared by simple homogenization‒ultrasonication technique and validated by using a ultraviolet‒visible scan, dynamic light scattering, transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy, and zeta potential. Saccharomyces cerevisiae (RCMB 002Y001) is the most effective probiotic-producing organism that demonstrates significant effects when combined with Ag-Secn-NHE. Ag-Secn-NHE-based probiotics showed significant antifungal effect compared to free Ag-Secn-NHE, silver nitrate, silver nanoparticles, secnidazole, secnidazole nanoemulsion, and commercial vaginal wash against multidrug-resistant vaginal pathogens. The highest inhibitory effect was achieved with Ag-Secn-NHE-based probiotic against Candida auris, Candida albicans, and Cryptococcus neoformans with minimal inhibitory concentration (MIC) 0.625±0.002, 0.00625:1.25±0.012 and 0.00625:1.25±0.032mg/mL, respectively, in comparison with Ag-Secn-NHE that show MIC at 0.00625:1.25±0.612, 0.0125:2.5±0.812, and 0.0125:2.5±0.112mg/mL (Ag:Secn). Ag-Secn-NHE-based- probiotic show minimum fungicidal concentration (MFC) at range from 2.5 to 20mg/mL, wherever free Ag-Secn-NHE show MFC range from 5 to >20mg/mL. Additionally, Ag-Secn-NHE-based probiotics have 75% inhibition of biofilm formation against C. auris and 60% inhibition of biofilm formation against both Cryptococcus neoformans and C. albicans in comparison with free Ag-Secn-NHE. Time-kill curves showed that the antifungal effect of Ag-Secn-NHE-based probiotics was fungistatic at 2MIC value after 4h and after 16h for Ag-Secn-NHE. TEM photographs showed that C. auris cells treated with Ag-Secn-NHE-based probiotic formula revealed severe deformations and distored ultrastructural changes. furthermore, results indicated that the Gamma radiation up to 15kGy increases production of Ag-Secn-NHE in comparison with non-irradiated one.

Amplifying Fibre Optic Sensor Signals with Graphene Oxide-Silver Nanostars

This work presents a straightforward yet impactful method to enhance optical fibre sensor signals by integrating silver nanostars (AgNS) with graphene oxide (GO-AgNS) as a sensing material. AgNS were synthesized successfully via a one-step chemical reduction method using hydroxylamine as a reducing agent. The concentration of hydroxylamine was varied (7.2, 3.6, 1.8, and 0.9) x 10−4 %v/v to optimize AgNS formation, with the longest spike of the nanostar observed at lower hydroxylamine concentrations, as confirmed by transmission electron microscopy (TEM). UV-visible measurements revealed the highest peak absorption for AgNS synthesized using 0.9 x 10−4 %v/v hydroxylamine, 0.05 M sodium hydroxide, 0.8 mM silver nitrate, and 0.045 M sodium citrate, with an average length of 352.62 ± 59.72 nm measured from TEM images. GO was synthesized via a modified Hummer’s method and mixed with AgNS at varying ratios (1:5, 1:10, 1:15, and 1:20) to form GO-AgNS coatings for the fibre optic probe. The GO-AgNS coating at a ratio of 1:5 exhibited the highest light absorption intensity, enhancing optical signal by 218% compared to GO-coated and 174% compared to AgNS-coated fibre optic sensors. These findings demonstrate that embedding AgNS onto the GO matrix structure as a sensing material significantly improves sensor performance, suggesting promising applications for super-sensitive, cost-effective, and rapid detection in fibre optic-based sensors.

Synthesis of uniform spherical silver powder without dispersants in a confined impinging-jet reactor

Sliver powder is the most common and extensively utilized precious metal powder in electronics, primarily for electronic paste. Herein, micron-sized spherical silver powder was synthesized via a liquid phase reduction method employing silver nitrate as the source of silver and ascorbic acid as the reducing agent in a confined impinging jet reactor (CIJR). The impact of the molar ratio between silver nitrate and ascorbic acid, the flow rate, and the temperature on the particle size of silver powder was investigated. The optimal process conditions for silver powder are as follows: maintain a molar ratio of 1:1 and control the feeding rate at 10 ml/min while operating at 50 ° C. The confined impinging jet reactor offers enhanced control over reaction conditions during the synthesis of silver powder, surpassing the capabilities of traditional batch reactors. The aforementioned optimized methodology was employed to successfully synthesize uniform and spherical silver powder (with an aspect ratio approaching 1) in the low Reynolds number jet, resulting in an average particle size of d50 = 0.83 μm and a standard deviation of 0.07, without the addition of dispersant. The synthesis method presented here improves the performance of silver powder, simplifies the production process, reduces energy consumption, and minimizes waste generation. These advances yield significant environmental and economic benefits. In the future, with the continuous development and optimization of microreactor technology, this synthesis method is anticipated to play a more prominent role in the commercial-scale production and application of micrometer-sized silver powder.

Effectiveness of topical 25% silver nitrate solution followed by 5% fluoride varnish compared to 38% silver diamine fluoride in arresting and preventing dental caries among beta-thalassemia major patients: A randomized clinical trial

IntroductionThis is the first randomized non-inferiority clinical trial in the evidence literature to examine the effectiveness of topical 25% silver nitrate (SN) followed by 5% sodium fluoride (NaF) varnish is not much worse or acceptable to 38% silver diamine fluoride (SDF) in preventing and arresting dental caries among Beta-Thalassemia Major (BTM) patients. Method170 BTM participants aged 18 years and older with at least 1 or more active carious lesions were randomly allocated into 2 groups (1:1). 25% silver nitrate solution application followed by 5% NaF varnish was administered to Group I, and Group II received 38% SDF. The Nyvad criteria and DMFT index were used to assess caries arrest and prevention among both groups at 3- and 6-months interval. ResultsCaries arrest rate at 3 months was significantly higher in Group I (83.10%) when compared to Group II (76.16%) (p<0.05). While at 6 months, both the groups were comparable with arrest rate (76.16%) (p>0.05). The caries increment was comparable among both groups at 3 months, while at 6 months, caries increment was almost half in SN with NaF group compared to SDF group (p>0.05). Kaplan–Meir survival estimated the median survival time for caries increment was 17 and 39 weeks for Group I and 15 and 36 weeks for Group II at 3 and 6 months, respectively. ConclusionOne time application of 25% SN followed by 5% NaF is no worse than a 38% SDF in arresting and preventing dental caries among Thalassemia Major participants at 3 and 6 months. Clinical SignificanceThe study provides clinicians with a cost-effective, safer, readily available, non-invasive treatment option (25% SN followed by 5% NaF) for caries management.

Effects of exposure sequence and GGBS cement replacement on performance of concrete subjected to carbonation and chloride ingress

In a variety of applications, such as in tidal zones, abutments of bridges and concrete tunnel linings, reinforced concrete is exposed to both carbonation and chloride ingress. The exposure can be either simultaneous or sequential. However, durability design rarely considers synergistic effects due to carbonation and chloride ingress, even though this may have detrimental consequences for performance. Comparative implications of exposure sequence across different concrete compositions are also unknown. In this study, an experimental investigation on the effects of the sequence of carbonation and chloride ingress was conducted, using two concretes which differ by 50% cement replacement with ground granulated blast furnace slag (GGBS). Specimens were exposed to a combination of 10% CO2 accelerated carbonation and immersion in 3% sodium chloride solution, in either sequence, and compared with companion samples subjected to only one of these aggressive environments. The extent of carbonation was measured using phenolphthalein indicator solution, while silver nitrate and Rapid Chloride Testing provided indicators of the chloride ingress. For both concrete mixes, specimens with prior chloride ingress exhibited a decreased rate of carbonation when compared to specimens with no prior exposure. Conversely, specimens with prior carbonation displayed an increased rate of chloride ingress compared to non-carbonated counterparts and a step in the acid soluble chloride content in the region of the carbonation front. The concrete composition appeared to play a role since a greater increase in chloride diffusion coefficient due to prior carbonation was observed in the mix with 50% GGBS replacement than the mix without. These findings suggest that in concrete structures exposed to air and saline environments, the effects of sequential exposure should be characterised.

Efficacy of silver nanoparticle-modified bullfrog skin as an antimicrobial wound dressing

This research explores the synthesis of silver nanoparticles and their incorporation into bullfrog skin for potential use as a wound dressing. The study addresses the need for wound dressings that exhibit biocompatibility, low cytotoxicity, superior biodegradability, and antimicrobial activity. Silver nanoparticles were synthesized using silver nitrate and sodium citrate solutions and integrated into bullfrog skin at varying concentrations (0%, 0.5%, 1%, and 1.5%). The modified and unmodified bullfrog skin samples were characterized using dynamic light scattering(DLS), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy Dispersive Spectroscopy (EDS). Antimicrobial analyses were conducted to assess the efficacy of the modified skin against common pathogens, including Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans. The results demonstrated that samples containing 1% and 1.5% silver nanoparticles exhibited significant inhibitory effects on all tested microorganisms. This indicates that these concentrations are optimal for antimicrobial activity, suggesting the potential of silver nanoparticle-modified bullfrog skin as an innovative and effective wound dressing material.

THE PERSPECTIVITIES OF MICRICLONAL PROPAGATION OF ACER PLATANOIDES L. CRIMSON KING (ACEARCEAE JUSS.)

Clonal micropropagation – massive asexual propagation of plants from cell and tissue culture; the resulting plants are genetically identical to the original copy. The conservation of plants by tissue culture methods is of great interest and will probably become even more common in the future. The advantages of this method are numerous, but we find it most important that the initiation of cultivation requires only a single plant, a seed or a single explant (apex, meristem, bud, piece of leaf, stem etc.), thus, the available plant specimens (which can be only a few) will not be affected by harvesting them from their habitat. The state program “Developing of the scientific basis for the sustainable reproduction of valuable specimens of the botanical garden collection in in vitro culture” is being conducted in the laboratory of biotechnology of the Tashkent Botanical Garden of the Institute of Botany, Academy of Sciences of the Republic of Uzbekistan, directed at microclonal propagation of many valuable species presented in a single copy, as well as species in demand in urban greening programs. Acer platanoides L. Crimson King variety (Acearceae Juss.) is a deciduous, slow-growing tree, reaching 15 m with age. The crown shape is wide-round and even. The leaves are large, 5-7 lobed, deep purple, and do not change color throughout the growing season. The trunk is smooth, dark in color, with clearly defined longitudinal grooves. Because of its graceful shape, the Crimson King variety is extremely popular. It is actively planted in city yards, parks, and roadsides. Suitable for landscaping. Within this state program the protocol of microclonal propagation of A. platanoides Crimson King variety has been developed to propagate this species for Botanical Garden collection as well as for greening programs. Solutions of sodium hypochloride (4-6%), hydrogen peroxide (2-15%), silver nitrate (0.01%), Tween20, ethanol (70%), and some other sterilizing agents were tested for developing a protocol for sterilization of maple explants. “Belizna” solution, “Domestos” sterilizing soap, fungicides difenoconazole, mancoseb and metalaxyl, fludioxonil, propiconazole, antibiotics streptomycin, amoxicillin, gentamicin, and etc. were also implemented for explants sterilization. As a result of the studies, it was determined that the most optimal source of explants are branches with apical (10% regeneration) and lateral (100% regeneration) buds of the annual shoot of A. platanoides Crimson King variety. Plant growth environment is important in the success of in vitro propagation. Thus, explants obtained from trees growing in the arid areas of massive Kuylyuk in Tashkent, were characterized by low viability and a high degree of infection with fungal diseases in comparison with explants obtained from trees growing in Hastimom Square in Tashkent, where trees are watered daily. We found two ways of in vitro propagation of A. platanoides L. variety Crimson King: 1. With the use of microcuttings. 2. Indirect organogenesis with induction of callus. The best way for A. platanoides L. variety Crimson King became indirect organogenesis trough induction of the callus in the WPM - Wood Propagation Media, hormone free or with 6- benzilaminopurine in the media. The duration of the developing of a plant usually takes 6-9 months.

Enhancing virus inhibition in track-etched membranes through surface modification with silver nanoparticles and curcumin

The present work reports on the use of silver nanoparticles (AgNPs) and curcumin immobilized on the surface of microfiltration track-etched membranes (mTMs) as antiviral filtration materials. AgNPs were synthesized through the direct reduction of silver nitrate by sodium borohydride in the presence of a stabilizing agent. The synthesized nanoparticles and curcumin were immobilized on polyethyleneimine (PEI)-modified mTMs through a static sorption process. TEM, SEM, UV–vis. spectroscopy and luminescence measurements revealed a uniform distribution of AgNPs and confirmed the presence of curcumin on the membrane surface. The resulting TM-PEI-AgNPs-PVP and TM-PEI-Curcumin hybrid membranes were employed for the filtration of HSV-1, VSV, IAV, and EMCV viruses. While both membrane types exhibited insignificant inhibition for the latter two, they achieved 95 and 99 % inhibition for HSV-1 and VSV, respectively. These findings suggest that hybrid membranes with immobilized AgNPs and curcumin can have potential as antiviral filtration materials.

Impeding microbial biofilm formation and Pseudomonas aeruginosa virulence genes using biologically synthesized silver Carthamus nanoparticles

Long-term antibiotic treatment results in the increasing resistance of bacteria to antimicrobials drugs, so it is necessary to search for effective alternatives to prevent and treat pathogens that cause diseases. This study is aimed for biological synthesis of silver Carthamus nanoparticles (Ag-Carth-NPs) to combat microbial biofilm formation and Pseudomonas aeruginosa virulence genes. Ag-Carth-NPs are synthesized using Carthamus tenuis aqueous extract as environmentally friendly method has no harmful effect on environment. General factorial design is used to optimize Ag-Carth-NPs synthesis using three variables in three levels are Carthamus extract concentration, silver nitrate concentration and gamma radiation doses. Analysis of response data indicates gamma radiation has a significant effect on Ag-Carth-NPs production. Ag-Carth-NPs have sharp peak at λ max 425 nm, small and spherical particles with size 20.0 ± 1.22 nm, high stability up to 240 day with zeta potential around − 43 ± 0.12 mV, face centered cubic crystalline structure and FT-IR spectroscopy shows peak around 620 cm−1 that corresponding to AgNPs that stabilized by C. tenuis extract functional moiety. The antibacterial activity of Ag-Carth-NPs against pathogenic bacteria and fungi was determined using well diffusion method. The MIC values of Ag-Carth-NPs were (6.25, 6.25, 3.126, 25, 12.5, 12.5, 25 and 12.5 µg/ml), MBC values were (12.5, 12.5, 6.25, 50, 25, 25, 50 and 25 µg/ml) and biofilm inhibition% were (62.12, 68.25, 90.12, 69.51, 70.61, 71.12, 75.51 and 77.71%) against Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus, Staphylococcus epidermidis, Candida tropicalis and Candida albicans respectively. Ag-Carth-NPs has bactericidal efficacy and significantly reduced the swarming, swimming motility, pyocyanin and protease production of P. aeruginosa. Furthermore, P. aeruginosa ToxA gene expression was significantly down regulated by 81.5%, while exoU reduced by 78.1%, where lasR gene expression reduction was 68%, while the reduction in exoU was 66% and 60.1% decrease in lasB gene expression after treatment with Ag-Carth-NPs. This activity is attributed to effect of Ag-Carth-NPs on cell membrane integrity, down regulation of virulence gene expression, and induction of general and oxidative stress in P. aeruginosa. Ag-Carth-NPs have no significant cytotoxic effects on normal human cell (Hfb4) but have IC50 at 5.6µg/mL against of HepG-2 cells. Limitations of the study include studies with low risks of silver nanoparticles for in vitro antimicrobial effects and its toxicity.

Standardization of silver nanoparticle synthesis: Photocatalytic application (immobilized with chitosan complex) with textile dyes and antibacterial activity against Staphylococcus aureus using banana pseudo stem

The purpose of the study is to standardize the silver nanoparticle (BP-AgNPs) synthesis and its antibacterial activity and photocatalytic application with the selected dyes using the banana pseudo stem extract. “One-factor analysis (OFTA)” was carried out for the standardization of silver nanoparticle synthesis and nanoparticle-chitosan complex immobilization. The parameters were identified with plant quantity (20 g), silver nitrate concentration (1 mM), the ratio of plant extract and silver nitrate solution (2:8), pH (12), temperature (37 °C), dispersed light conditions, shaking conditions (120 rpm), and time (6 h) were analysed. The photocatalytic decolorization efficiency of the standardized BP-AgNPs (immobilized with chitosan complex) has shown 96.92% for methylene blue (10 ppm) at 3 h and 97.55% for safranin (100 ppm) at 15 h. The antibacterial activity for the synthesised BP-AgNPs was determined. MIC value of the BP-AgNPs was determined to be 15.62 μg. mL−1 for S. aureus. The synthesised BP-AgNPs treated with 0.5×, 1× and 2× MIC concentration (x = 15.62 μg. mL−1) showed decreased viable counts of S. aureus (99.6% at 2× concentration having viable count of 22.6 × 102 CFU. mL−1) at 24 h incubation when compared with the control culture. The structural characteristics of the BP-AgNPs were identified as spherical with SEM and the size was identified as 12.19 ± 1.62 nm with TEM and as 37.23 ± 17.89 nm with XRD. The parameters such as FTIR, Zeta potential, EDS further supports the nanoparticle synthesis with banana pseudostem extract. The current result suggested that, the silver nanoparticles (BP-AgNPs) synthesised using the extract of the banana pseudo stem could be used as an alternative source for dye decolorization and antibacterial activities.

Metallic nanoentities: Bio-engineered silver, gold, and silver/gold bimetallic nanoparticles for biomedical applications

This present study reports the biogenic synthesis of silver nanoparticles (AgNPs), gold nanoparticles (AuNPs) and Ag/Au bimetallic nanoparticles (BNPs) using bark extract of plant Tamarix aphylla (T.A). The bark extract contained total polyphenolic compounds and total flavonoids as 0.0362 mg/mg and 0.2928 mg/mg of the dried bark extract respectively. Silver nitrate (AgNO3) and hydrogen tetra chloroaurate trihydrate (HAuCl4.3H2O) were used as precursors while deionised water and methanol (CH3OH) were used as solvents. Synthesized nanoparticles were characterized through UV–visible spectroscopy, SEM (scanning electron microscopy), TEM (transmission electron microscopy) and FTIR (Fourier transform infrared) for their morphology, structure, and identification of different functional groups. The UV–visible spectra of AgNPs, AuNPs and Ag/Au BNPs showed peaks at 436, 532 and 527 nm respectively due to the excitation of Surface Plasmon Resonance. SEM and TEM images showed spherical and well distributed nanoparticles (NPs) with particle size as 29 nm (AgNPs), 13 nm (AuNPs) and 26 nm (Ag/Au BNPs). The synthesized NPs are significantly active against inhibition of free radicals, α-amylase, α-glucosidase and have anti inflammatory potential with AgNPs having the highest percent activity at 400 μg/ml, followed by Ag/Au BNPs. The same trend (AgNPs > Ag/AuBNPs > AuNPs) has been observed at all concentrations i.e. 100 μg/ml, 200 μg/ml and 400 μg/ml. AuNPs have shown lowest activity at all concentrations. So the current study strongly confirms use of T.A bark extract as reducing agent for synthesis of metal NPs and opens up a new possibility of using these green synthesized NPs as biomedicines. We also suggest further in vivo investigation to report any side effects if present.

Enhanced engineering and biocidal polypropylene filaments enabling melt reduction of AgNO3 through PVP agent: A scalable process for the defense industry with MEX additive manufacturing

This study focused on the production of polypropylene (PP)/silver (Ag) composites via additive manufacturing. This study aimed to enhance the quality of medical-grade PP in material extrusion (MEX) three-dimensional printing (3DP) by improving its mechanical properties while simultaneously adding antibacterial properties. The latter can find extremely important and versatile properties that are applicable in defense and security domains. PP/Ag nanocomposites were prepared using a novel method based on a reaction occurring while mixing appropriate quantities of the starting polymers and additives, namely polyvinylpyrrolidone (PVP) as the matrix material and silver nitrate (AgNO3) as the filler. This process produced three-dimensional (3D) printed filaments, which were then used to create specimens for a series of standardized tests. It was found that the mechanical properties of the nanocomposites were enhanced in relation to pristine PP, especially for the PP matrix with various loadings of AgNO3 and PVP, such as 5.0 wt% and 2.5 wt%, respectively. The voids, inclusions, and actual-to-nominal dimensions also showed improved results. The 3DP specimens exhibited a more effective biocidal performance against Staphylococcus aureus than Escherichia coli, which developed an inhibition zone only in the case of PP with filler loading percentages of AgNO3 and PVP at 10.0 wt% and 5.0 wt%, respectively Compounds possessing such properties can be beneficial for various applications requiring increased mechanical properties and biocidal capabilities, such as in the Defence or medical industries.