In the field of wound care, nanofibers represent a promising biomaterial, particularly in the form of advanced dressings. Due to their nanoscale structure, high network porosity, and similarity of nanofiber morphology to the structural elements of the extracellular matrix, they create a favorable microenvironment for cell adhesion, proliferation, and tissue regeneration. Furthermore, they enable efficient incorporation of bioactive compounds and their targeted and controlled release, which further increases their applicability in tissue engineering and wound management.
In this study, we developed electrospun nanofibers based on polyethylene oxide and sodium alginate (1:1, w/w) for use in wound care. To increase nanofiber stability, 0,5–2 % (w/v) calcium chloride solution was added to the base polymer solution so that its proportion in the final electrospinning solution was 1,5 % (w/w). We found that the polymer solution containing 1,5 % (w/v) calcium chloride was still processable and allowed the formation of morphologically correct nanofibers, whereas at 2 % (w/v) calcium chloride solution, the electrospun product did not exhibit the characteristic fibrous structure.
Nanofiber stability in aqueous environments depended on the degree of fiber crosslinking. Nanofibers without calcium chloride or with low calcium chloride content rapidly lost their fibrous morphology upon contact with water, whereas nanofibers with 1 % or 1,5 % (w/v) calcium chloride solution partially retained their structure upon exposure to an aqueous medium (one droplet). After prolonged exposure to aqueous medium, no nanofiber sample preserved its morphology, indicating the limited stability of nanofibers in water.
The efficiency of drug incorporation was high in non-crosslinked nanofibers (~100 %), while in crosslinked nanofibers it was slightly lower (~70 %) and more variable. Drug release from non-crosslinked nanofibers was faster, as most of the active compound was released within the first 30 minutes (~87 %), after which the released fraction stabilized. In crosslinked nanofibers, release was slower and gradually increased from 67,9 % at 5 minutes to 82,6 % at 120 minutes. Crosslinking with 1,5 % (w/v) calcium chloride solution slightly slowed the initial drug release, but the cumulative fraction released after 120 minutes remained high (82,6 %), indicating the need for further formulation optimization to achieve prolonged release of the incorporated drug.
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