(LR-015) Natural Zinc ion based Non-Skin Irritation Nylon Technology for Permanent Antimicrobial Activity and Biofilm Resistance

Nylons are versatile materials with the ability to easily tune properties from molecular level to tackle challenges for wound care and compression devices. An easily scalable embedded Zinc ions-based nylon was reported which demonstrated good antibacterial efficacy. In a recent review article,¹ skin irritation and allergic skin reaction were reported to be more common adverse events for compression devices. Additionally, about 65% of microbial infections and 80% of chronic infections are a result of biofilm as per the National Institutes of Health (NIH).² Thus, investigation of potential for dermal irritation/sensitization and biofilm resistance properties of this technology are important.   

Methods:

A spunbond nonwoven structure (SB), 34 gsm, was formed using melt spinning directly from the polymer and circular knit (CK) was produced by standard textile manufacturing process using 100% of the yarn from this new polymer. Three independent Repeat Insult Patch Test (RIPT) were conducted for these materials on 183 humans (male - 30, female – 153) subjects. This procedure was repeated until a series of nine consecutive 24-hour exposures and had been made three times a week for three consecutive weeks. Prior to each reapplication, the test sites were evaluated by trained laboratory personnel. To assess the biofilm resistance, ASTM E3151 was used for these substrates. This test method can assess the population of microorganisms that survive in planktonic state as well as in an adherent/biofilm state. Polypropylene spunbond (25 gsm) was used as control. Test specimens were tested against the control with a known biofilm-producing strain of Staphylococcus epidermidis.

Results:

100% of subjects scored 0, which is negative or no reaction according to the international Contact Dermatitis Research Group scoring scale. Under the conditions of this study, there was no indication of potential to elicit dermal irritation or sensitization (contact allergy) noted.  Biofilm resistance was found to be 99.89% and 100% reduction for SB and CK, respectively.    

Discussion:

In conclusion, this natural Zinc ion-based nylon technology was found to be non-skin irritant while effective against biofilm formation. This is a scalable and permanent antibacterial solution that can be incorporated to design advanced wound dressings and medical devices. 

Trademarked Items:

References: 1. Rabe, et al. Phlebology, 2020, 35(7), 447-460.
2. J Chin Med Assoc. 2018; 81(1): 7-11.