A Pharmacological and Toxicological Profile of Silver as an Antimicrobial Agent in Medical Devices

Abstract

Silver is used widely in wound dressings and medical devices as a broad-spectrum antibiotic. Metallic silver and most inorganic silver compounds ionise in moisture, body fluids, and secretions to release biologically active Ag+. The ion is absorbed into the systemic circulation from the diet and drinking water, by inhalation and through intraparenteral administration. Percutaneous absorption of Ag+ through intact or damaged skin is low. Ag+ binds strongly to metallothionein, albumins, and macroglobulins and is metabolised to all tissues other than the brain and the central nervous system. Silver sulphide or silver selenide precipitates, bound lysosomally in soft tissues, are inert and not associated with an irreversible toxic change. Argyria and argyrosis are the principle effects associated with heavy deposition of insoluble silver precipitates in the dermis and cornea/conjunctiva. Whilst these changes may be profoundly disfiguring and persistent, they are not associated with pathological damage in any tissue. The present paper discusses the mechanisms of absorption and metabolism of silver in the human body, presumed mechanisms of argyria and argyrosis, and the elimination of silver-protein complexes in the bile and urine. Minimum blood silver levels consistent with early signs of argyria or argyrosis are not known. Silver allergy does occur but the extent of the problem is not known. Reference values for silver exposure are discussed.

The Effectiveness and Safety of 1% Silver Sulfadiazine (Flammazine) Cream in Preventing Infection in Potentially Contaminated Traumatic Wounds among Pediatric Patients 2 To <18 Years Old: An Open-Label, Single-Arm Phase 3 Clinical Trial

“…The slow and steady reactions of silver sulfadiazine with sodium-chloride containing body fluids such as serum and exudate permit slow and sustained delivery of silver ions into the wound area [12,13].…”

“…Silver ions are active against a broad range of microorganisms: bacteria, fungi and viruses, including many antibiotic-resistant bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA) and Vancomycin-resistant Enterococci (VRE) [13].…”

Waste Minimization for the Safe Use of Nanosilver in Consumer Products - Its Impact on the Eco-Product Design for Public Health

“…Silver has long been used as an antimicrobial agent in medicine to keep wounds clean since the days of ancient Greece, Egypt, and Rome (Chen & Schluesener, 2008;Lansdown, 2010). This is because of the efficacy of thiol group reactions which inactivate bacterial enzymatic activity (Faunce & Watal, 2010).…”

Decreased bacterial growth on titanium nanoscale topographies created by ion beam assisted evaporation

“…Lorenzetti et al 11 used hydrothermal treatments to generate nanorough surfaces on titanium and found that macro-and microscale grooves (results of the initial material machining process) provided niches for bacteria to adhere and proliferate on, despite high roughness values. Silver is one of the most prominent non-small-molecule drugs used for antibacterial applications, 3,[17][18][19] but can be expensive and mildly toxic to surrounding mammalian cells. 20,21 Additionally, adding different materials to the surface may lead to imperfectly fused layers that may eventually wear or delaminate from the bulk implant.…”