Silver antibacterial properties

Metallic copper and silver both have antibacterial properties and Au thiol complexes have found increasing use in the treatment of rheumatoid arthritis, but only copper of this group has a biological role in sustaining life. It is widely distributed in the plant and animal worlds, and its redox chemistry is involved in a variety of... 

Mercury and silver have long been known to have antibacterial properties and preparations of these metals were among the earliest used antiseptics, but have been replaced by less toxic compounds. Other metals such as zinc, copper, aluminium and tin have weak antibacterial properties but are used in medicine for other functions, e.g. aluminium acetate and zinc sulphate are employed as astringents. 

Sulfonamides have been extensively used in medicine for their antibacterial properties. Silver sulfadiazene (Af-pyrimidin-2-ylsulfanilamide, 41), when applied topically, has proved effective in preventing infections in bums victims.335,336... 

Silver has long been known to exhibit antibacterial properties, which may have been an unwitting advantage to those who could afford silver vessels and tableware. Silver sulfadiazine is a widely used and very effective bum ointment, and silver-treated catheters greatly reduces the rate of infection associated with their use. The element is not known to be essential, although trace amounts (total body burden) are accumulated, with blood levels typically below lOpgL-. ... 

Topical 2% povidone iodine solution and 0.2% chlorhexidine gluconate solution have broad antimicrobial profiles and may be used as cheap spectrum and effective antifungal agents in equine ketomycosis, particularly where Fusarium spp. are involved. A1% dermatological cream formulation of silver sulfadiazine has both antifungal and antibacterial properties and is reasonably well tolerated topically in the horse eye. Its use is advocated where cost restraints exist or for prophylaxis in comeal injuries involving embedded plant material (Hamor Whelan 1999). 

Mercury and silver have long been known to have antibacterial properties and preparations of these metals were among the earliest used antiseptics however, they have been replaced by less toxic compounds. 

Guibal E., Cambe S., Bayle S., Taulemesse J.M., Vincent T. Silver/chitosan/cellulose fibers foam composites from S3mthesis to antibacterial properties. Journal of Colloid and Interface Science 2013 393 411-420. 

The antibacterial properties of silver/polymethyl methacrylate (PMMA) nanofibres against both Gram-negative Escherichia coli) and Gram-positive Staphylococcus... 

Hence, PP composites containing zinc oxide along with silver can further enhance the antimicrobial properties of this polymer. Antibacterial elastomer composites of silver zeolite/silicone could be a useful material to satisfy a range of requirements including good mechanical properties, due to the incorporation of zeolite, and good antibacterial properties. 

Li B, Liu X, Meng F, Chang J, Ding C. Preparation and antibacterial properties of plasma sprayed nano-titania/silver coatings. Mater Chem Phys 2009 118 99-104. 

The most popular methods of synthesizing silver nanoparticles, the antibacterial properties of silver nanoparticles, their interactions with microorganisms, and assessment of antibacterial activity are the most important issues which will be discussed here. 

In this section, the production of PP nanofibres containing silver nanoparticles using the above technique, together with their characterisations using X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis are presented. Additionally, the antibacterial properties of nanofibres are evaluated using the quantitative American Association of Textile Chemists and Colorists (AATCC) 100 test. The inclusion of nanosilver into polymers to form a nanocomposite has been demonstrated to have a profound effect on the crystallisation of the polymer, which in turn affects the properties of nanofibres, including their antibacterial properties. 

A quantitive test method (AATCC 100) was used to measure the antibacterial properties of the PP/silver nanofibres. The tests can be performed with one bacillus. Staphylococcus aureus (American Type Culture Collection No. 6538), as the grampositive organism. The degree of antibacterial effect can be presented as the percentage reduction in the original concentration of the bacteria. 

Table 3.3 shows the antibacterial performance of the samples. Considering the result, it can be said that even at a low silver nanoparticle content, the nanofibres produced exhibited excellent antibacterial properties. Additionally, it is stated that the antibacterial properties is enhanced as the fineness of the fibre is increased. This is due to the fact that as the fibre diameter decreases, the contact area between the nanoparticles and the bacteria is increased, thus bacterial propagation is severely restricted [7-13]. 

PP nanofibres containing silver nanoparticles exhibited excellent antibacterial properties, even at low silver content. 

To determine whether the inherent silver and silver coated thread samples would show antimicrobial activity when subjected to soaking wet conditions, the dynamic shake method, ASTM E2149, was performed. The log reduction results after 1 hour and 24 hours incubation at 37 "C (Table 3) show that under soaking wet conditions the inherent silver and silver coated thread samples do exhibit a reduction in bacterial growth. The untreated control samples show an increase in bacterial growth. From these results it would appear the antibacterial activity of inherent silver and silver coated thread samples require soaking wet conditions to exhibit dieir antibacterial properties. As with the AATCC 100 method, the carbonised bamboo sample showed no antimicrobial activity. 

Nanomaterials based on silver nanoparticles have received signihcant attention from various authors in different research helds, such as biomaterials, medical devices, and electronics. Apart from their unique wound heaUng ability, silver nanoparticles exhibit antibacterial properties that make them potential candidates for use in infection-resistant biomaterials (Jang 2006). To prepare silver polymer nanohbers, silver nanoparticles are deposited onto the electrospun polymer nanohbers by sputter coating or polymeric solutions containing silver ions are electrospun. 

Hou et al. assembled CU2O nanoctystals of 4 nm radius on RGO using poly-(sodium 4-styrensulfonate) as the intermediaiy between nanosheet and nanoparticle. The platform exhibits excellent water dispersibility with selective apoptotic capabilities towards cancer cell lines in vitro depending on the irradiation wavelength chosen. Fu and co-workers have introduced antibacterial properties to graphene by decorating it with silver nanoparticles of 50 nm radius. Similarly, Tan and co-workers have used silver nanoparticles on GO as an antibacterial agent for plants. Antiviral surfaces based on GO and GO derivatives [e.g. SO3 terminated GO) which reject attachment of herpes simplex HSV-1 have been reported. ... 

Matyjas-Zgondek E, Bacciarelli A, Rybicki E, Szynkowska MI, Kolodziejczyk M (2008) Antibacterial properties of silver-finished textiles. Fiber Text East Eur 16 101-107... 

H. Kong, J. Jang, Antibacterial properties of novel poly(methyl methacrylate) nanofiber containing silver nanoparticles, Langmuir 24 (2008) 2051-2056. 

A prominent FDA-approved chitin dressing is rapid deployment hemo-stat (RDH) (Marine Polymer Technologies) which costs 300 per dressing. One study shows that polymeric hber material based on P-NAG is more effective than alpha-chitin or chitosan, since these have a heterogeneous structure and are complexed with minerals and proteins. Moreover, the j3 structure (parallel orientation) of the hbers was found to be more effective than the a structure (antiparallel orientation). In another study, the hemostatic and antibacterial properties of chitosan dressings have been shown to be improved by the addition of polyphosphate polymers and silver nanoparticles respectively. One limiting factor is that all forms of chitin or chitosan bandages are not equally effective and the effectiveness varies from batch to batch. ... 

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