Carboxymethyl cotton and calcium alginates have ion exchange properties. The paper discusses a cation-exchange-based development of silver antimicrobial nonwovens from sodium salt of carboxymethylated cotton, and commercially available calcium alginate dressings that should be effective for burn wounds. We have prepared carboxymethylated cotton nonwovens by treating cotton nonwovens with caustic soda and monochloroacetic acid in 80/20 to 90/10 ethanol/water medium. Ethanol preserved the fibrous form of nonwovens, imparting the desired properties of improved moisture retention, high bound water, and high swellability. The presence of a functional group, methyl carboxyl (-CH2COONa) in carboxymethyl nonwovens enabled us to carry out further chemical modification to develop antimicrobial products. Antimicrobial nonwovens were prepared with silver nitrate and carboxymethylated cotton in a two-step reaction in an ethanol/water solution. Similarly, we also prepared antimicrobial calcium/sodium alginate nonwovens by treating alginates with silver nitrate in ethanol/water. By imparting antimicrobial properties to alginates that are used as moist wound dressings, we have expanded the functionality of the dressings. From the behavior of antimicrobial release and the suppression of bacterial proliferation, it was apparent that the dressings containing the silver antimicrobial agent would protect the wound surfaces from microbial invasion and effectively suppress bacterial proliferation. The antimicrobial activity of these products along with their untreated controls were evaluated as effective against both gram positive (Staphylococcous aureus) and gram negative microbes (Klebsiella pneuoniae) by North American Science Associates (NAMSA).
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