Particles of silver that measure less than 100nm have been a major research focus in recent years because their antimicrobial effect is greatly enhanced due to their high ratio of surface area to volume. They also have unique optical, electrical, and thermal properties and are already used in photovoltaic systems and various sensors.

Current silver nanoparticle antimicrobial-based medical products include medical face masks, heart valves and other implants, wound dressings, and bandages.

The innovation is the combination of the particles with polymer hydrogels. Composites can be made with polyvinyl alcohol, polypyrrole, polyvinylidene fluoride, chitosan, and cellulose

"Many previous attempts to form polymer-silver nanocomposites have involved mixing of a nanoparticle solution into the polymerization mixture. However, this approach does not result in the uniform distribution of particles within the matrix," reports Bajpai and coauthors in a report published in the Society of Plastics Engineers Plastics Research online.

The Indian research team said they used an in situ approach to form AgNPs within a polymer matrix to overcome the problem.

Silver cations were loaded into a polymethacrylic acid hydrogel, a biocompatible polymer that is typically used in the fabrication of contact lenses. The silver cations were then chemically transformed into AgNPs, to yield a nanocomposite with uniform distribution of AgNPs within the polymer matrix, according to the research report.

Coauthors were Manika Mahendra and Navin Chand.