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Section
III Continued . . .
SILVER
DELIVERY SYSTEM (ACTICOAT)
Scanning
Electron Micrographs (SEM)
Normal
Silver Coated Membrane
When Silver is sputtered under
typical physical vapour deposition conditions, the resulting
film, as shown here, is very dense with virtually no pores
allowing limited access to water and to silver release. The
crystals are smooth with crystal boundaries being the
predominate feature. Crystal sizes range from 100 nm to
greater than 400 nm with an average size of about 250 nm.
The structure of the Silvery Delivery (Acticoat) coating is
evident in this SEM. The physical vapour deposition process
creates a material which is very porous and consists of
equiaxed nanocrystals which allow for rapid exposure to water
and subsequent silver release. These crystals are generally
organized as aggregates in a columnar structure. The crystals
range in size from about 10nm to 22 nm with an average size of
15 nm and rapidly release silver ion (radicals) when exposed
to water.
Note: The release of silver with the nano
crystalline pure silver delivery system is constant for over
48 hours when exposed to water. The silver concentration on
the wound surface is 20-30 times greater than the
concentration required to kill microbes.
(The concentration of Ag+ required to kill pseudomonas is
comparable to that required for killing of other microbes)
This constant silver release is unique and quite different
from the Ag+ release initial pulse release of silver from
other products.
  
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