Assessment of Linear and Cyclic Peptides’ Immobilization onto Cross-Linked, Poly(vinyl alcohol)/Cellulose Nanocrystal Nanofibers Electrospun over Quartz Crystal Microbalances with Dissipation Sensors

Immobilization of peptides onto nanofiber dressings holds significant potential for chronic wound treatment. However, it is necessary to understand the adsorptive capacity of the produced substrates and the binding affinity of the peptides to determine the interface success. This study aims at exploring for the first time the influence of electrospun poly(vinyl alcohol)-based nanofibers on the adsorption of a cyclic peptide, Tiger 17, and of a linear peptide, Pexiganan, using quartz crystal microbalance with dissipation monitoring (QCM-D). PVA fibers reinforced with 0, 10, and 20% w/v cellulose nanocrystals (CNC) were electrospun directly onto QCM-D sensors and, posteriorly, cross-linked by glutaraldehyde vapor. Adsorption levels of Pexiganan were the highest (∼7348 ng/cm²) on C80/20 PVA/CNC electrospun fibers, while the time to achieve equilibrium was the longest (∼235 min). In contrast, the adsorption mass with cyclic Tiger 17 was the highest (∼3428 ng/cm²) on C100/0 PVA, reaching equilibrium after nearly 123 min. In sequential deposition, the combination Tiger 17 + Pexiganan on C100/0 fibers attained the highest number of bound peptide molecules, with ∼55% of Tiger 17 and ∼45% of Pexiganan. Elastic shear modulus data on this peptide sequence, over the C80/20 electrospun mats, reported 220 and 249 kPa for each peptide, respectively, indicating the formation of stable bonds with the surface. The results contributed to the understanding of the immobilization of linear and cyclic peptides, never studied in combination, and their mutual influence on polymeric substrates for engineering potential wound treatment strategies.