Silver News

By Samuel Etris, Senior Technical Consultant to The Silver Institute

Worldwide concern about the spread of diseases, combined with the emergence of drug-resistant bacteria, has thrown the problem of sanitizing surfaces to inhibit the spread of disease onto an age-old bacteria fighter: silver.

With effective and virtually permanent performance, silver often becomes the agent of choice to sanitize surfaces ranging from concrete to tableware. As a permanent surface agent halting the spread of bacteria, silver is being applied to decontaminate surfaces in hospitals, food processing plants, public telephones, textiles, hospital bandages and more.

Some common silver delivery systems for bactericidal control are reviewed below.

JMAC:
Silver chloride deposited on inert titanium dioxide provides a powerful, almost permanent antimicrobial action based on research by Johnson Matthey, plc., UK. Studies showed significant activity against a wide variety of bacteria including E. coli and S. aureus, yeasts such as C. albicans, and molds such as Aspergillus niger.

This combination is finding wide application as coatings on catheters, internal feeding tubes, dental prostheses, sutures, wound dressings, drain tubing, products in contact with body fluids and products touched by many hands.

JMAC is marketed by Clarient Technologies, Royston, UK, (Tel: 44-1763-253-000).

Conval PAg-40TM:
The Tsinghua University, Beijing, developed the silver-bearing antibiotic, silver zircon phosphate. Extensive studies proved its action against Staphylococcus aureas, Candida albicans, and Bacilius entritidia. Toxicity tests showed no allergenic reactions to the skin.

Tsinghua’s silver-bearing antibiotic is certified by the Science and Technology Ministry of China as a “National Key New Product” as part of the Chinese Government’s program to improve health through sanitation of the environment. The silver-bearing antibiotic, “Conval PAg-40TM”, is marketed by the Tsinghua Pharmaceutical Co., Beijing, and in the USA by the Kotler Marketing Group, (www.kotlermarketing.com) Washington, DC.

X-Static: Silver-coated nylon thread, marketed as X-Static®, by Noble Fiber Technologies, (www.noblefiber.com) Scranton, PA, has had its bactericidal value established by laboratories at Pennsylvania State University. The study reported significant bacteri-cidal activity against E. coli, and the Pseudomonas, Klebsiella, Stapyhlococcus and Streptococcus species. At room temperature, bacteria in the vicinity of the thread shows a rapid decrease in sur-vival usually after about an hour, but in contact with the body at the normal tempera-ture of 98.6ºF, there was no delay in its bactericidal action. Experience with anti-bacterial textiles show they contribute to comfort and health. For example, athletes from 60 countries will be wearing X-Static® socks at the 2004 Olympic

Silverlon:
Silverlon® supplied by Argentum Medical LLC, (www.silverlon.com) Lakemont, GA, has been extensively tested and found to be effective in inhibiting bacterial growth by S. aureus (a gram positive bacterium) and P. aeruginosa (a gram negative bacterium) by 99.93 and 99.97 percent respectively within 24 hours.

A 60-patient randomized trial comparing Silverlon® post operative wound dressings with the typically-used surgical wound dressings after coronary bypass graft surgery was conducted at the Washington Regional Hospital in Fayetteville, AK. The study reported that Silverlon Post Operative Wound Dressings reduced the post operation infection rate by 50 percent.

The U.S. Cycling Team, achieving its fourth successive victory in the 2002 Tour de France last July 28, found Silverlon® reduced the effects of traumatic injury and promoted the recovery of the cyclist’s injuries while biking in the midst of competition. It controlled inflammation and minimized or eliminated the risk of infection, allowing the cyclist to participate while healing.

AgION:
AgION Technologies, (www.agion-tech.com) Wakefield, MA, has developed a silver/zinc-zeolite to provide a tough, adherent bactericidal surface to stainless and carbon steel sheet. AgION’s zeolite coating provides a continuous release of silver ions and in studies conducted by the University of Arizona showed marked reductions in populations of Salmonella, E. coli, Listeria, Legionella, and S. aureous within a few minutes and complete elimination within 3 hours.

The need to eliminate bacteria and biofilms from air conditioning ducts, water supply systems on shipboard, exterior and interior surfaces of refrigerators, humidifiers, ice dispensers, and machinery in feed and meat processing plants has been highlighted in the news. Suppliers of such systems have turned to AgION Technologies for solutions.

The facility for the City of Hope Helford Clinical Research Hospital, Duarte, CA, is being constructed with AK Steel’s AgION-coated steel. It will house the nation’s largest bone marrow transplant facility providing the nation’s most advanced treatment environment.

AK Steel Corp., Middletown, OH, produces AgION silver-coated steel and has distributed trial sheets to customers for prototype evaluation. AgION Technologies, (Tel: 781-224-7100; Fax: 781-246-3340).

Alagon™:
Alagon™ is a silver-containing alumina compatible with cement and concrete to provide them with bactericidal action. The silver provides biocidal, algeacidal, and fungicidal inhibition to concrete, plaster, and wall board providing nearly permanent sanitation for inactivating E. coli and other bacteria. Grouts compounded with Alagon™ have prevented mold growth even when molds are growing nearby.

Alagon™ incorporated in pool filters prevent colonization by algae and bacteria. It can be added to any formulated product including deodorants and cosmetics as neither the silver nor the alumina is toxic.

Alagon™, is supplied by Ames Goldsmith Corp., Glen Falls, NY,(Tel: 518-792-5808; Fax: 518-792-1034).

Tetrasil:
A departure from the single-charged silver based bactericide is Tetrasil, the trade name for tetrasilver tetroxide. Laboratory studies show small amounts (1.25 to 5 parts per million) of Tetrasil inactivate a broad variety of microorganisms as well as yeasts and molds.

Tetrasil is precipitated deep into the fibers of textiles to provide virtually permanent bactericidal action. Standard tests with hot water and detergent for 100 hours of laundering plus 600 hours of ultra violet exposure showed Tetracil-treated fabrics maintained their bactericidal activity undiminished.

Information about Tetrasil is supplied by Marantech Holding, LLC, East Providence, RI, (Tel: 401-223-3000).

Silver News - Second Quarter 2003