Silver ion rapidly kills microbes by blocking the cell respiration pathway or breaking outer cell wall, almost instantly once the silver reaches the microbe. Wound dressing with silver kills bacteria effectively, but also kills critical cells of wounds. An innovative solution to wound dressing which kills bacteria effectively without killing critical cells of wounds has been developed. The Department of Chemical & Biological Engineering of University of Wisconsin, USA has developed a new method to modify just the surface of wound dressing. One square inch contains just 0.4% of the silver that is found in the silver-treated antibacterial bandages used in medicine. The concentration is low, since higher concentration of silver kills critical cells that help in healing of the wound along with bacteria of the wound. The required dose of silver can also be reduced because the new material would be designed to stay in close contact with the wound. The system is so sensitive that increasing the silver dose from 0.4% to 1% of the level used in a commercial dressing severely damages the fibroblasts. To kill bacteria, silver must take the form of charged particles, or ions, and the tiny silver nanoparticles that are embedded in the sandwich can be designed to release ions for days or weeks as needed. The basis of this technology is a nanometer-thick polyelectrolyte multilayer film composed of alternating layers of two different, oppositely charged polymers held together by electrostatic interactions. To make the sandwich, the team alternately dips a glass plate in two solutions of oppositely charged polymers, and finally adds a precise dose of silver. This architecture is very easily tuned to different applications because it allows exact control of such factors as thickness, porosity and silver content. The final sandwich may range from a few nanometers to several hundred nanometers in thickness. Through the team’s method, the amount of silver impregnated in the films can be precisely monitored by controlling the assembly conditions of the films. Thus, these films can also be integrated into existing wound-care products as antibacterial coatings on their surface. This technology would immobilize and localize silver on the surface of the wound bed where antimicrobial protection is needed. The result is very effective because immobilization permits precise delivery and minimal loading of silver onto the wound bed. It does not have any adverse cytotoxic consequences. This technique requires a significantly smaller concentration of silver to give effective healing without damage the mammalian cells like fibroblasts that are involved in wound repair. This dressing is of particular interest for burn injuries as well as diabetics, for whom wound healing is a particular problem, as poor blood supply inhibits healing can require amputations. Some burn surgeons avoid silver dressings despite their constant concern with infection - this could change with the new dressing.