Nadya Markova

In this study, a hierarchical design strategy is introduced for tuning the release of rosmarinic acid (RA) from electrospun poly(L-lactide) (PLA) fibrous materials via surface engineering with chitosan/hyaluronic acid (Ch/HA) polyelectrolyte complexes (PECs). RA was selectively incorporated within the fiber bulk, the PEC coating, or both, enabling control over its spatial distribution. The PEC coating, formed by sequential dip coating, was shown to act as a diffusion-regulating layer with a dual role—either retarding RA release or promoting rapid initial release when functioning as a surface-associated reservoir. As a result, the release kinetics could be systematically tuned depending on the coating architecture and RA localization. Thorough characterization confirmed successful coating formation, enhanced surface hydrophilicity, and improved mechanical performance. All RA-loaded materials retained high antioxidant activity and exhibited pronounced antibacterial and antifungal effects against Staphylococcus aureus, Escherichia coli, and Candida albicans. This work introduces PEC-modified electrospun systems as a versatile platform for the rational design of multifunctional fibrous biomaterials with controlled release profiles, with potential applications in wound healing and drug delivery.

Novel multifunctional fibrous materials were prepared by simultaneous dual spinneret electrospinning of two separate solutions differing in composition. This technique allowed for the preparation of materials built of two types of fibers: fibers from poly(vinyl alcohol) (PVA), chitosan (Ch), and rosmarinic acid (RA), and poly(L-lactide) (PLA) fibers containing lidocaine hydrochloride (LHC). Confocal laser scanning microscopy (CLSM) analyses showed that both types of fibers are present on the surface and in the bulk of the new materials. The presence of all components and some interactions between them were proven by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. RA and LHC were in an amorphous state in the fibers, and their presence affected the temperature characteristics and the crystallinity, as detected by differential scanning calorimetry (DSC) and X-ray diffraction analyses (XRD). The presence of PVA/Ch/RA fibers enabled the hydrophilization of the surface of the multifunctional fibrous materials (the water contact angle value was 0°). The newly developed materials demonstrated adequate mechanical properties, making them suitable for use in wound dressing applications. The RA-containing fibrous mats possessed high radical-scavenging activity (ca. 93%), and the combining with LHC led to an enhancement of this effect (ca. 98.5%). RA-containing fibrous mats killed all the pathogenic bacteria S. aureus and E. coli and decreased the titer of fungi C. albicans by ca. 0.4 log for a contact time of 24 h. Therefore, the new materials are prospective as antibacterial and atraumatic functional wound dressings, as systems for local drug delivery, and in medical skincare.