A facile and effective approach to prepare К-carrageenan / polyvinyl alcohol hydrogel as a potential wound dressing

Since К-carrageenan (КC) can be crosslinked by potassium cations while polyvinyl alcohol (PVA) can be crosslinked by borated anions, the present work was undertaken to crosslink the КC/PVA blends in one step using potassium tetraborate tetrahydrate (PTB) as a crosslinker for forming КC/PVA/PTB hydrogels. Factors affecting crosslinking of that blends such as PTB concentration, steeping time in PTB aqueous solution, КC/PVA weight ratio, and crosslinker type were studied. The results indicated that the optimal conditions for preparing the КC/PVA/PTB gels are: КC/PVA weight ratio, 1; PTB concentration, 4%; and steeping time, 8 h. Among boric acid, potassium chloride, borax, and PTB as potential crosslinkers for the КC/PVA (50/50) matrix, the later, i.e. PTB, achieves the highest crosslinking magnitude and produces KC/PVA/PTB gel having a superior liquid-holding capacity (1020%) as well as high gel fraction (98.6%) properties. The chemical structure of the formed КC/PVA/PTB gel was confirmed using FTIR analysis. The potential application of the КC/PVA/PTB gel as wound dressings was investigated by treating non-woven cotton fabric samples with КC/PVA (50/50) matrices in absence and presence of curcumin or silver nano-particles (Ag-NPs) as bio-additives followed by crosslinking with PTB. The prepared dressings exhibits superior antibacterial activities as well as significant mechanical properties expressed in the good tensile strength, elongation at break, elastic modulus, stiffness, air permeability, and porosity properties. Besides, the treated fabric exhibits moderate cytotoxicity. The prepared Ag-NPs were evaluated via UV-Vis, TEM, and XRD analysis whereas the prepared dressings were characterized using SEM and EDX analysis.