The evaluation of the antibacterial properties of SILVERLINING ® has been made at the Microbiology Laboratory of the Department of Biotechnologies and Biosciences of Milano-Bicocca University.
Two standard methods, elaborated and validated by “American Association of textile Chemists and Colorists, AATCC ” an association that develops methods for the quality control of the products in textile and tanning industries, have been used. Used methods are:
- AATCC 100, 2004 – Assessment of antibacterial finishes on textile materials
- ASTM E2149, 2001 – Standard method for determining the antimicrobial activity of immobilized antimicrobial agents under dynamic contact conditions.
The antibacterial activity has been estimated by analyzing the ability of Escherichia Coli and Staphylococcus aureus bacterial strains to adhere and colonize the surface of SILVERLINING ®in comparison with the same linings not treated with silver.
Numerous and repeated tests confirmed the antibacterial property of SILVERLINING ®; the antibacterial power has been valued of about 100% with both methods.
The data obtained by the tests performed on different productions of SILVERLINING ®, in different times, also examining the same sample in a period of time of nine months, proved that the treatment with silver is uniform, repeatable and lasting.
In both methods used to study the antibacterial power, different materials with known quantities of bacterial agent have been put in contact, and the residual bacterial charge has been counted progressively in time. Then three culture grounds with a known bacterial quantity are prepared.
- A first part is put in contact with SILVERLINING ®.
- A second one is put in contact with a classic lining.
- A third part is left as it is.
After periods of contact fixed by the trial methods, the count of residual bacteria is done.
In picture A, the turbidity of the three different samples shows the different bacterial quantity:
- Bottle n°1 is clear, most of the bacteria have been eliminated after the contact with SILVERLINING ®.
- Bottle n°2 is turbid, the bacterial charge after the contact with the classic lining is high.
- Bottle n°3 has a high bacterial level, it is the culture ground as it is.
Picture B shows the growth in “Petri” dish of the remaining bacteria after a new seeding on culture ground
- Sample 1 doesn’t show any bacterial growth, the contact with SILVERLINING ® removed most of the bacteria.
- Sample 2 shows a considerable bacterial quantity after the contact with the classic lining.
- Sample 3 shows a considerable bacterial quantity , it is the culture ground as it is.
In these laboratory trials the samples have been put in contact with a bacterial quantity definitely higher than the one present in the human sweat, and in the best condition for their development.
The antibacterial action of SILVERLINING ® has been proved to be excellent even in such extreme conditions.