120 years of nanosilver history: implications for policy makers.

Nanosilver is one nanomaterial that is currently under a lot of scrutiny. Much of the discussion is based on the assumption that nanosilver is something new that has not been seen until recently and that the advances in nanotechnology opened completely new application areas for silver. However, we show in this analysis that nanosilver in the form of colloidal silver has been used for more than 100 years and has been registered as a biocidal material in the United States since 1954. Fifty-three percent of the EPA-registered biocidal silver products likely contain nanosilver. Most of these nanosilver applications are silver-impregnated water filters, algicides, and antimicrobial additives that do not claim to contain nanoparticles. Many human health standards for silver are based on an analysis of argyria occurrence (discoloration of the skin, a cosmetic condition) from the 1930s and include studies that considered nanosilver materials. The environmental standards on the other hand are based on ionic silver and may need to be re-evaluated based on recent findings that most silver in the environment, regardless of the original silver form, is present in the form of small clusters or nanoparticles. The implications of this analysis for policy of nanosilver is that it would be a mistake for regulators to ignore the accumulated knowledge of our scientific and regulatory heritage in a bid to declare nanosilver materials as new chemicals, with unknown properties and automatically harmful simply on the basis of a change in nomenclature to the term "nano".

Prospective randomized controlled study of Hydrofiber dressing containing ionic silver or calcium alginate dressings in non-ischaemic diabetic foot ulcers.

AIMS: Diabetic foot ulcers (DFUs) are at risk of infection and impaired healing, placing patients at risk of lower extremity amputation. DFU care requires debridement and dressings. A prospective, multicentre study compared clinical efficacy and safety of AQUACEL Hydrofiber dressings containing ionic silver (AQAg) with those of Algosteril calcium alginate (CA) dressings in managing out-patients with Type 1 or 2 diabetes mellitus and non-ischaemic Wagner Grade 1 or 2 DFUs. METHODS: Patients stratified by antibiotic use on enrolment were randomly assigned to similar protocols including off-loading, AQAg (n = 67) or CA (n = 67) primary dressings and secondary foam dressings for 8 weeks or until healing. Clinical efficacy measures were healing outcomes and primarily healing speed. Adverse events were recorded. RESULTS: AQAg and CA groups were comparable at baseline. All ulcer healing outcomes improved in both groups. The mean time to healing was 53 days for AQAg ulcers and 58 days for CA ulcers (P = 0.34). AQAg-treated ulcers reduced in depth nearly twice as much as CA-treated ulcers (0.25 cm vs. 0.13 cm; P = 0.04). There was more overall ulcer improvement and less deterioration in AQAg subjects (P = 0.058), particularly in the subset initially using antibiotics (P = 0.02). Safety profiles of both groups were similar. CONCLUSION: When added to standard care with appropriate off-loading, AQAg silver dressings were associated with favourable clinical outcomes compared with CA dressings, specifically in ulcer depth reduction and in infected ulcers requiring antibiotic treatment. This study reports the first significant clinical effects of a primary wound dressing containing silver on DFU healing.