Antimicrobial hydrogel scaffolds from Barba de Viejo microfibers, alginate and Ag^o nanoparticles via green synthesis

Natural fibers are being employed in the development of the next generation of biomaterials, due to their reduced environmental impact and the ease of their functionalization with natural polymers. In this study, Barba del Viejo fibers were treated with NaOH and bonded with alginate through ionic gelation by using CaCℓ₂, which facilitates ionic interactions between alginate and Ca²⁺ions. Additionally, antimicrobial Barba del Viejo/alginate/silver nanoparticles(BVA/Ag^o) scaffolds were developed from the NaOH-treated BV-microfibers, silver salt and sodium alginate, with mint leaves extract as a nucleating agent. The functional and crystalline structure of microfibers and the hydrogels developed were analyzed using the FTIR and XRD. SEM explained that the diameter of the NaOH-treated microfibers was ⁓1.32 μm. The morphological images of the hydrogels, confirm the functionalization of alginate with microfibers and the formation of Ag^o nanoparticles within the hydrogels network. The swelling ratio of the hydrogels increased with alginate functionalization on BV-microfibers, improving NaOH treatment, but decreased the degradation rate. UV-spectra showed absorption peaks in the wavelength range of between 432 and 442 nm, confirming the surface plasmon resonance effect of the Ag^o nanoparticles within the scaffolds. TEM analysis confirms that the Ag^o nanoparticles in hydrogels were spherical in shape, with sizes ranging from ⁓2 and 10 nm. The zeta potential analysis indicates that the Ag^o nanoparticles possess negative charges, providing a stable surface that helps to prevent aggregation and, therefore, demonstrating a homogeneous distribution throughout all the BVA/Ag^o scaffolds prepared. The antimicrobial studies reveal that the BVA/Ag^o scaffolds exhibit significant antibacterial activity against E.coli and S.aureus bacteria. Further investigations are affirmed to study the potential applications of these scaffolds in infection-control wound dressing.