Characterization of peptide coatings adhered to synthetic fibers: A versatile model for peptide nucleic acids

Peptide nucleic acids (PNAs) are an emerging family of biomaterials designed to specifically target and treat diseased cells, most commonly in the antimicrobial-resistant bacteria MRSA. While PNAs offer great promise for the elimination of these bacteria, they are significantly more expensive than traditional peptides and often do not provide functionality for analysis. In this work, a model peptide (KFFCCQ) was developed to evaluate peptide coatings adhered to fibrous surfaces with multiple functional handles, i.e. the presence of a sulfur atom in cysteine and an aromatic ring in phenylalanine, to predict the durability of PNA coatings on 50/50 nylon/cotton blends (NyCo), which are commonly used in clothing such as combat and medical attire. Following elemental analysis through XPS and EDX-SEM, rinses were performed on the fabrics and the subsequent release of peptide was evaluated with UV-vis. As expected, elevated temperature and increased time resulted in higher KFFCCQ release levels from the NyCo fibers. Finally, EDX-SEM examined the presence of KFFCCQ following rinse cycles, revealing that a higher level of KFFCCQ released from nylon fibers compared to cotton fibers. This evaluation proves the utility of KFFCCQ as a preliminary model to evaluate adhesion and release of peptides from nylon and cotton fibrous surfaces.