Antimicrobials silver nitrate

The first record of the medicinal but not antimicrobial use can be found in writings around 750 AD. An early scientific paper by Crede has already been alluded to [4] it involved the use of silver in the treatment of inflammation of the eyes (ophthalmia neonatorum) in new-born infants. In a further paper [8], silver was advocated as an internal antiseptic. During the following years, silver nitrate, citrate, lactate and proteinate have appeared in pharmacopoeias and formularies around the world. A silver nitrate lotion appeared in older editions of the British National Formulary. In the latest issues, however (no. 26, 1993 onwards [9]) only silver sulphadiazine is to be found. The USP XXII [10] lists silver sulphadiazine (used as a cream) and silver nitrate (used as an ophthalmic solution). 

The antimicrobial properties of silver and its salts have been discussed in various books [14, 16-18] and particular reference must be made to Grier s review in 1983 [15]. Ag usually used in the form of silver nitrate, is bacteriostatic or bactericidal [19-29], antifungal [30-32], protozoicidal [33] and lethal to herpes simplex virus [34]. However, bacterial spores [19], cysts of Entamoeba histolytica [19] and mycobacteria [35] are not killed by Ag. Brown and Anderson [20] observed a non-linear order of death in Pseudomonas aeruginosa exposed to Ag, whereas Ricketts et al. [22] reported a rapid bactericidal action of Ag in water, but not in broth, at concentrations of silver nitrate of 0.5 and 1 pg/ml (2.9 x 10 and 5.8 x 10 M, respectively) with inactivation at concentrations above 1 p.g/ml being too fast for measurement. 

Studies of the antimicrobial and therapeutic properties of silver and its derivatives have yielded an extensive scientific literature, ranging from clinically- to biochemically-based papers. The latter area includes studies in enzymatic and other macromolecular interactions to silver resistance encompassing plasmid-mediated patterns. The reduction to one silver compound (AgSD) in the current British National Formulary and to two compounds (AgSD and silver nitrate ophthalmic solution) in USP XXII may not be a true reflection of the use of silver in health care today. Silver compounds also find use in non-clinical situations, for example, as water disinfectants and, not considered in this review, as silver staining techniques for microscopy. 

The use of 1% silver nitrate eye-drops in prophylaxis of ophthalmia neonatorum has been periodically reviewed and compared with other prophylactic measures. There seems to be no case in which permanent damage to the eye was actually proven to have been caused by a single application of a correctly used 1 % silver nitrate solution (23). However, silver nitrate has largely been replaced by antimicrobial drugs. 

The preparation of rrltrafine antimicrobial cellnlose acetate (CA) fibres with silver nanoparticles by direct electrospinning of a CA solution containing low levels of silver nitrate and characterised by viscosity, strrface tension and conductivity, followed by photoreduction using UV irradiation, is described. The fibres were characterised by SEM, TEM, XPS arrd artfirrticrobial activity and the resrrlts are discussed. 24 refs. 

Can embedding nanoparticles of silver into a polymer give the polymer antimicrobial properties Researchers tested the antimicrobial properties of a new composite material- the polymer poly(4-vinyl-N-hexylpyridinium bromide), known as NPVP, which attracts cations. It is known that silver ions from silver bromide and silver nitrate exhibit antimicrobial activity. Silver bromide was embedded into the NPVP polymer. Scientists tested the antimicrobial properties of the composite material. Their results, illustrated in the graph, show the growth of E. coli bacteria over a period of approximately four hours. Each line represents the E. coli population in response to the introduction of a particular substance. 

The nurse is discussing the application of silver nitrate, an antimicrobial agent, to a client with a partial-thickness burn to the left leg. Which information should the nurse teach the client when discussing how to apply this medication after discharge ... 

On the other hand, layer-by-layer (LbL) assemblies have demonstrated their importance in a variety of biomedical applications. Polyelectrolyte multilayers have also been prepared using silver nitrate and/or cetrimide as the antimicrobial agents [44]. The substitution of cetrimide for silver dramatically enhances the antimicrobial efficacy of these films, as evidenced by the ZOI data. Furthermore, cetrimide is not susceptible to reduction as is ionic silver, resulting in highly transparent, colourless films. 

The use of antimicrobial finishes prevents the growth of microorganisms such as bacteria and fungi on the fibre/filter surface. These treatments include the application of halogens, alcohols, and metals, for example silver nitrate, to the filtration materials. Water-repellent finishes are also employed to form a barrier, which lowers the critical tension of the fibre surface. The repellency can be achieved by using chemical finishes, including chrome complexes, silicones, and fluorochemicals. 

Yoksan and Chirachanchai (2010) used y-ray irradiation reduction of silver nitrate in a chitosan solution to obtain Ag-NP with the objective of incorporating them into a starch-based matrix. TEM images showed that after the synthesis, silver nanoparticles presented a spherical shape with size between 20 and 25 nm. y-ray irradiated chitosan solution containing Ag-NP exhibited an important antimicrobial activity against E. coli, S. aureus and B. cereus. When color was evaluated, matrix resulted transparent and slightiy yellowish, while composites were pale brown and the color difference of the film increased with the concentration of Ag-NP. Physicochemical behavior of these composites was not the most desired... 

Silver and its compounds, including silver sulfadiazine and silver nitrate, have long been used as antimicrobial agents (Russell and Hugo, 1994). Some studies indicate that the incorporation of silver into paints and coatings for use in industrial water systems and in medical devices seems to be suitable to impair adhesion and delay biofilm formation, while in other studies no protective effect of silver has been observed. 

The use of silver nitrate and colloidal silver in wounds dates from the mid-nineteenth century and the term oligodynamic was applied to the antimicrobial action of heavy metals diluted in water [9]. Over the years, attempts to put silver in contact with wounds produced a number of electrolytic methods [9] as well as use of solutions of silver nitrate, in this case as late as 1965 [16]. However, the imbalance of sodium, potassium and chloride caused by silver nitrate in these cases was unsatisfactory due to the number of resulting side effects. These include in some cases methemoglobinemia from reduction of nitrate to nitrite. In 1968, a complex (AgSD) formed from a sulfonamide and silver was introduced in attempts to combine the oligodynamic action of the heavy metal with the antibacterial effect of the sulfonamide [17]. The insoluble product, which is used as a 1% cream, has suitable properties and excellent wide spectrum antibacterial activity, and is used worldwide for burn prophylaxis and other infectious skin conditions [9]. Side effects are few, the major one being leukopenia. The properties and mode of action of AgSD have been reviewed [9,18]. 

Yin et al. compared the antimicrobial activity of Acticoat with silver nitrate, silver sulfadiazine, and mafenide acetate to determine their minimum inhibitory concentration... 

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