Investigation of chitosan-supported silver as a safe and effective broad-spectrum antimicrobial textile finish

PROJECT SUMMARY Maximum of 30 lines of textMinimum of ½” marginsFont size 11 pts or greater The overall research goal of the proposed work is to test the antimicrobial activity and durability of a chitosan-supported silver-based textile finish for incorporation into hospital privacy curtains. Furthermore, successful development of this textile finish for privacy curtains would set the foundation for development of additional antimicrobial textiles for incorporation in bed sheets, blankets, patient clothing, scrubs, and surgical sheets, for example. Antimicrobial textiles serve to combat hospital-acquired infections which affect approximately 2 million patients per year and incur annual direct medical costs of at least $28.4 billion in the U.S. In support of the overall research goal, Specific Aim 1 will determine the loading rate of the chitosan silver product on a variety of textiles relevant to the healthcare field given a manufacturing tolerance of 10%. The current chitosan silver product (1% chitosan and 0.15% silver) will be manufactured with a tolerance of 10% (0.9-1.1% chitosan and 0.14-0.16% silver) and used to finish cotton, polyester, spandex, and textile blends, with subsequent determination of the loading rate of the chitosan silver textile finish. Results of Specific Aim 1 will provde the basis for correlating antimicrobial activity with chitosan and silver concentrations on treated textiles. Specific Aim 2 will determine the antimicrobial activity of the textiles prepared in Specific Aim 1. Four organisms will be used in testing: a gram negative bacterium, a gram positive bacterium, a yeast, and a mold. Testing will determine the presence of diffusible antimicrobial agents, indicative of leaching of the chitosan silver finish, and further testing will determine contact inhibition of the treated textiles. Results of Specific Aim 2 will determine the primary mode of antimicrobial activity, which is anticipated to be via contact inhibition rather than leaching of the chitosan silver finish. Specific Aim 3 will demonstrate the durability of the textile finish during washing and disinfection. Textiles will be washed, with and without bleach, using typical cleaning conditions for healthcare textiles. Antimicrobial efficacy will be tested after 10, 50, and 100 washes using the same methods as described for Specific Aim 2. After each washing stage, silver remaining on the textile will be determined via nitric acid digestion and ICP-MS. Results of Specific Aim 3 will demonstrate the durability of the textile finish during typical cleaning procedures, and verify the retention of the chitosan silver finish. Specific Aim 4 is to determine how the chitosan silver textile finish alters textile properties, specifically, color, water repellency, and flammability. The treated textiles are anticipated to demonstrate minimal graying, no impact on water repellency, and reduced flammability. To demonstrate the utility of this chitosan silver finish for preparing antimicrobial textiles, the anticipated outcome is at least a 3-log reduction for all pathogens for all treated textiles, both unwashed and washed up to 50 times.