Modification of Electrospun PI Membranes with Active Chlorine for Antimicrobial Skin Patches Applications

• Successful modification of PI patches with sodium hypochlorite (NaOCl). • Chlorination of the membranes changes their hydrophobic character to hydrophilic. • Decreased zeta potential of the patches is beneficial for antimicrobial activity. • Chlorinated PI patches inhibit bacteria growth, both gram-positive and gram-negative. Atopic dermatitis (AD) is a common andcomplex disorder caused by many inherently intractable factors. One of the symptoms is an increased amount of Staphylococcus aureus on the skin surface. These bacteria trigger, accelerate, and exacerbate AD. In order to reduce inflammation, we designed antimicrobial patches, which inhibit bacterial growth. Using electrospinning, we produced polyimide (PI) nanofibers collected in the form of porous membranes. These PI membranes were modified with sodium hypochlorite (NaOCl). The active chlorine content was confirmed with scanning electron microscopy (SEM) with secondary electrons (SE) mode, backscattered electrons (BSE) mode, and energy-dispersive X-ray (EDX) spectroscopy, with Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). Moreover, we evaluated the wettability and zeta potential of the patches. Finally, we performed an antimicrobial efficacy assay against the Gram-positive model organism S. aureus and the Gram-negative model, Escherichia coli . We observed that the chlorinated PI patches demonstrate effective bacterial killing, making them excellent material for antimicrobial skin patches applications.