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IUCrData Mar 2024The structure of the title compound, [CHN)Ag](NO), contains subtle differences in ligand, metal, and counter-anion coordination. One quinoxaline ligand uses one of its...
The structure of the title compound, [CHN)Ag](NO), contains subtle differences in ligand, metal, and counter-anion coordination. One quinoxaline ligand uses one of its quinoxaline N atoms to bond to one silver cation. That silver cation is bound to a second quinoxaline which, in turn, is bound to a second silver atom; thereby using both of its quinoxaline N atoms. A nitrate group bonds with one of its O atoms to the first silver and uses the same oxygen to bond to a silver atom (related by symmetry to the second), thereby forming an extended network. The second nitrate group on the other silver bonds two nitrate O atoms; one silver cation therefore has a coordination number of three whereas the second has a coordination number of four. One of the quinoxaline ligands has a disordered ethyl group.
PubMed: 38586514
DOI: 10.1107/S2414314624002475 -
International Journal of Molecular... Oct 2023The healing properties of silver have been used since ancient times. The main aim of the study was to collect and review the literature on the clinical potential of... (Review)
Review
The healing properties of silver have been used since ancient times. The main aim of the study was to collect and review the literature on the clinical potential of silver, its salts and complex compounds. The second goal was to present an outline of the historical use of silver in medicine and pharmacy, taking into account the possibility of producing pharmaceutical drug forms on the premises of pharmacies. In the context of the growing resistance of microorganisms to available, widely used antibiotics, silver plays a key role. There is only one known case of bacterial resistance to silver-the strain, which naturally occurs in silver mines. The development of research in the field of coordination chemistry offers great opportunities in the design of new substances in which silver ions can be incorporated. These substances exhibit increased potency and often an extended antimicrobial spectrum. Silver-based compounds are, however, only limited to external applications, as opposed to their historic oral administration. Advanced studies of their physicochemical, microbiological, cytotoxic and genotoxic properties are ongoing and full of challenges. The improvement of the methods of synthesis gives the possibility of applying the newly synthesized compounds , as was the case with the complex of metronidazole with silver (I) nitrate. Some of these experimental efforts performed in vitro are followed with clinical trials. The third and final goal of this study was to present the possibility of obtaining an ointment under the conditions of an actual pharmacy using silver (I) salts and a ligand, both of which are active substances with antimicrobial properties.
Topics: Silver; Salts; Pharmacies; Anti-Infective Agents; Anti-Bacterial Agents; Silver Compounds; Pharmaceutical Preparations; Pharmacy
PubMed: 37958707
DOI: 10.3390/ijms242115723 -
International Dental Journal Apr 2024Silver metal and compounds have antibacterial properties, although their action's mechanisms are not fully understood. Scientists generally consider that silver disrupts... (Review)
Review
Silver metal and compounds have antibacterial properties, although their action's mechanisms are not fully understood. Scientists generally consider that silver disrupts the bacterial cell wall. It causes a structural change in the bacterial cell membrane and cytoplasm. It also stops deoxyribonucleic acid replication, resulting in inactivating enzymatic activity and cell death. The antimicrobial effect of silver-containing compounds relies on the release of bioactive silver ions. Hence, silver metal and compounds have been used in medicine to prevent infection for hundreds of years. Silver metal and compounds are also used as antibacterial agents in dentistry. Studies have shown that silver compounds are effective in the management of dental caries. Fluoride-containing silver compounds have been found in experiments to be beneficial at remineralising dental cavities. Silver diamine fluoride (SDF) can assist in preventing and arresting tooth cavities. The World Health Organization included SDF in its Model List of Essential Medicine for both adults and children in 2021. Clinicians also use SDF to manage dentine hypersensitivity as well as to inhibit growth of periodontal pathogens. However, traditional silver compounds cause tooth discolouration because of the silver-staining effect. These side effects of their applications depend on the amount applied and the frequency of application. Researchers are developing nanosilver fluoride and silver nanoparticles to overcome the staining. This review gives an overview of the antibacterial mechanism of silver compounds, namely silver nitrate, silver fluoride, SDF, silver nanoparticles, and nano silver fluoride for caries management. The outlook for the future development of silver compounds will be discussed.
Topics: Child; Humans; Cariostatic Agents; Fluorides; Dental Caries; Metal Nanoparticles; Dental Caries Susceptibility; Silver; Fluorides, Topical; Silver Compounds; Silver Nitrate; Quaternary Ammonium Compounds; Anti-Bacterial Agents
PubMed: 38008704
DOI: 10.1016/j.identj.2023.10.013 -
Cureus Nov 2023Calcium silicate-based types of cement have gained recognition in various dental applications due to their exceptional sealing capabilities, bioactivity, and minimal...
INTRODUCTION
Calcium silicate-based types of cement have gained recognition in various dental applications due to their exceptional sealing capabilities, bioactivity, and minimal adaptability. However, these materials have certain shortcomings that can lead to mechanical failures and premature degradation. The inclusion of metal ions into their structure is expected to promote their biological activity. This article focuses on the preparation and characterization of calcium silicate cement to enhance its fundamental material properties, by introducing zinc and silver while retaining its biomaterial characteristics.
AIM
This study aims to evaluate the biomedical potential of zinc and silver-impregnated bioactive calcium silicate cement.
MATERIALS AND METHODS
The calcium silicate powder was synthesized via the sol-gel method. Tetraethyl orthosilicate, calcium nitrate, silver nitrate, and zinc nitrate were sequentially added to create the bioactive calcium silicate material. The synthesized particles underwent physicochemical characterization using techniques such as scanning electron microscopy, X-ray diffraction, Raman spectroscopy, and biological characterization through in vitro hemocompatibility assays.
RESULTS
The study's results revealed the presence of multiple crystalline phases (AgSiO, ZnSiO, CaCO) as indicated by X-ray diffraction. Raman spectra displayed vibrations associated with Si-O-Si and Zn-O bonding in the zinc and silver-infused bioactive calcium silicate. Scanning electron microscopy confirmed a mixture of spherical and sheet-like morphologies, while energy dispersive spectra confirmed the presence of elements Ca, Si, Zn, Ag, O, and C. In vitro hemocompatibility testing affirmed the material's biocompatible nature.
CONCLUSION
In conclusion, the zinc and silver-infused calcium silicate cement was successfully synthesized through an in-house procedure and demonstrated biocompatibility. The inclusion of zinc and silver, known for their osteogenic and antimicrobial properties, is anticipated to enhance the cement's biological properties and broaden its utility in dentistry. Further in vitro and in vivo investigations are imperative to validate its clinical applications and elucidate the molecular mechanisms underlying its efficacy.
PubMed: 38054157
DOI: 10.7759/cureus.48243 -
Heliyon Jul 2023Ulvan is a polysaccharide from green algae that shows good hydrogel film dressing characteristics. Silver nanoparticles (AgNP) can be incorporated into the hydrogel film...
Ulvan is a polysaccharide from green algae that shows good hydrogel film dressing characteristics. Silver nanoparticles (AgNP) can be incorporated into the hydrogel film to improve antibacterial properties and provide a potential burn treatment. In this study, we developed a novel hydrogel film wound dressing composed of ulvan and silver nanoparticles. Two concentrations (0.5 mM and 1 mM) of silver nitrate were used to produce ulvan-silver nanoparticles hydrogel film (UHF-AgNP0.5 and UHF-AgNP1), respectively. The physicochemical characteristics of the hydrogel films were evaluated, including particle size, zeta potential, Fourier transform infrared (FTIR), X-ray diffractometry (XRD), scanning electron microscope and energy-dispersive X-ray (SEM-EDX). Furthermore, the in vitro antimicrobial activity, and second-degree burn wound healing test were evaluated. The UHF-AgNP0.5 showed the highest antimicrobial activity compared to UHF-AgNP1 and UHF film. Meanwhile, an in vivo study using Wistar rats induced second-degree burns showed that UHF-AgNP0.5 significantly accelerated the healing process by regulating the inflammatory process, increasing re-epithelialization, and improving the vascularization process. Ulvan-silver nanoparticle hydrogel films have the ability to accelerate the healing of second-degree burns and are potential candidates for wound dressings.
PubMed: 37483826
DOI: 10.1016/j.heliyon.2023.e18044 -
Research and Reports in Urology 2023Hemorrhagic cystitis (HC) can be one of the most challenging clinical scenarios for urologists to manage. It most commonly occurs as a toxicity of pelvic radiation... (Review)
Review
Hemorrhagic cystitis (HC) can be one of the most challenging clinical scenarios for urologists to manage. It most commonly occurs as a toxicity of pelvic radiation therapy or in patients treated with the oxazaphosphorine class of chemotherapy. Successful management of HC necessitates a stepwise approach with a thorough understanding of the various treatment options. Once ensuring hemodynamic stability, conservative management includes establishing bladder drainage, manual clot evacuation, and continuous bladder irrigation through a large-bore urethral catheter. If gross hematuria persists, operative cystoscopy with bladder clot evacuation is often required. There are multiple intravesical options for treating HC, including alum, aminocaproic acid, prostaglandins, silver nitrate, and formalin. Formalin is an intravesical option that has caustic effects on the bladder mucosa and is most often reserved as a last-line intravesical treatment. Non-intravesical management tools include hyperbaric oxygen therapy and oral pentosan polysulfate. If needed, nephrostomy tube placement or superselective angioembolization of the anterior division of the internal iliac artery can be performed. Finally, cystectomy with urinary diversion is a definitive, albeit invasive, treatment option for refractory HC. While there is no standardized algorithm, treatment modalities typically progress from less to more invasive. Clinical judgement and shared decision-making with the patient are required when choosing therapies for managing HC, as success rates are variable and some treatments may have significant or irreversible effects.
PubMed: 37404838
DOI: 10.2147/RRU.S320684 -
Burns : Journal of the International... Apr 2024Burns are a major global healthcare concern, often complicated by the presence of bacteria such as Pseudomonas aeruginosa in the wounds. Silver-based dressings are...
Burns are a major global healthcare concern, often complicated by the presence of bacteria such as Pseudomonas aeruginosa in the wounds. Silver-based dressings are commonly used in the treatment of burns but can cause skin irritation and delay healing time. Medical-grade honey (MGH) provides an interesting alternative. This study investigated the antimicrobial effects and possible cytotoxicity of L-Mesitran Soft (MGH-gel) and its individual components, Medihoney (Manuka), Flammazine (silver sulphadiazine), and silver nitrate (AgNO) in an ex vivo human burn wound model. Bacterial survival and wound healing parameters, including re-epithelialization and keratinocyte proliferation were assessed. L-Mesitran, Flammazine, and AgNO reduced P. aeruginosa numbers below detection levels. L-Mesitran Soft exhibited a significantly stronger antimicrobial effect compared to Medihoney. The individual components of L-Mesitran contributed significantly to its antibacterial efficacy, thus suggesting synergistic activities. Moreover, L-Mesitran, Flammazine, and AgNO slightly inhibited re-epithelialization while Medihoney treatment resulted in a complete lack of re-epithelialization and keratinocyte proliferation. Furthermore, clinical cases illustrated the effectiveness of MGH therapy in infected burns. Overall, L-Mesitran Soft had similar effects as silver-based products on bacterial load and epidermal regeneration, but outperformed Medihoney. Therefore, supplemented MGH could be used as an effective alternative to silver-based dressings for P. aeruginosa-infected burns.
Topics: Humans; Silver Sulfadiazine; Honey; Burns; Wound Healing; Anti-Bacterial Agents; Bacteria
PubMed: 37940425
DOI: 10.1016/j.burns.2023.10.009 -
Molecules (Basel, Switzerland) Sep 2023The widespread prevalence of infectious bacteria is one of the greatest threats to public health, and consequently, there is an urgent need for efficient and...
The widespread prevalence of infectious bacteria is one of the greatest threats to public health, and consequently, there is an urgent need for efficient and broad-spectrum antibacterial materials that are antibiotic-free. In this study, 2-pyridinecarboxaldehyde (PCA) was grafted onto chitosan (CS) and the modified CS coordinated with silver ions to prepare PCA-CS-Ag complexes with antibacterial activity. To obtain complexes with a high silver content, the preparation process was optimized using single-factor experiments and response surface methodology. Under the optimal preparation conditions (an additional amount of silver nitrate (58 mg), a solution pH of 3.9, and a reaction temperature of 69 °C), the silver content of the PCA-CS-Ag complex reached 13.27 mg/g. The structure of the PCA-CS-Ag complex was subsequently verified using ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, and thermogravimetric analysis. Furthermore, three possible complexation modes of the PCA-CS-Ag complex were proposed using molecular mechanics calculations. The results of the antibacterial assay in vitro showed that the PCA-CS-Ag complex exhibited strong antibacterial activity against both Gram-positive and Gram-negative bacteria, exerting the synergistic antibacterial effect of modified chitosan and silver ions. Therefore, the PCA-CS-Ag complex is expected to be developed as an effective antibacterial material with promising applications in food films, packaging, medical dressings, and other fields.
Topics: Anti-Bacterial Agents; Chitosan; Gram-Negative Bacteria; Gram-Positive Bacteria; Spectroscopy, Fourier Transform Infrared; Ions; Metal Nanoparticles; Microbial Sensitivity Tests
PubMed: 37836620
DOI: 10.3390/molecules28196777