Assessment\nof Linear and Cyclic Peptides’ Immobilization\nonto Cross-Linked, Poly(vinyl alcohol)/Cellulose Nanocrystal Nanofibers\nElectrospun over Quartz Crystal Microbalances with Dissipation Sensors

Immobilization of peptides onto nanofiber dressings holds\n significant\npotential for chronic wound treatment. However, it is necessary to\nunderstand the adsorptive capacity of the produced substrates and\nthe binding affinity of the peptides to determine the interface success.\nThis study aims at exploring for the first time the influence of electrospun\npoly(vinyl alcohol)-based nanofibers on the adsorption of a cyclic\npeptide, Tiger 17, and of a linear peptide, Pexiganan, using quartz\ncrystal microbalance with dissipation monitoring (QCM-D). PVA fibers\nreinforced with 0, 10, and 20% w/v cellulose nanocrystals (CNC) were\nelectrospun directly onto QCM-D sensors and, posteriorly, cross-linked\nby glutaraldehyde vapor. Adsorption levels of Pexiganan were the highest\n(∼7348 ng/cm<sup>2</sup>) on C80/20 PVA/CNC electrospun fibers,\nwhile the time to achieve equilibrium was the longest (∼235\nmin). In contrast, the adsorption mass with cyclic Tiger 17 was the\nhighest (∼3428 ng/cm<sup>2</sup>) on C100/0 PVA, reaching equilibrium\nafter nearly 123 min. In sequential deposition, the combination Tiger\n17 + Pexiganan on C100/0 fibers attained the highest number of bound\npeptide molecules, with ∼55% of Tiger 17 and ∼45% of\nPexiganan. Elastic shear modulus data on this peptide sequence, over\nthe C80/20 electrospun mats, reported 220 and 249 kPa for each peptide,\nrespectively, indicating the formation of stable bonds with the surface.\nThe results contributed to the understanding of the immobilization\nof linear and cyclic peptides, never studied in combination, and their\nmutual influence on polymeric substrates for engineering potential\nwound treatment strategies.