Development of copper-doped bioglass/alginate composite membranes: Preliminary results on their characterization and antimicrobial properties

Abstract

In this study, copper-doped bioglass particles (Cu-BGs) were synthesized by modified Stöber method and then alginate membranes containing various amounts of Cu-BGs (0, 0.5, 1, 2, 5, and 10% w/w.) were obtained using solvent casting method, followed by crosslinking with calcium chloride. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), together with the zeta potential analysis indicated that Cu-BGs particles had homogeneity in size and shape with good dispersibility in water. It was possible to observe individual Cu-BGs particle and agglomerates in the cross-section of the membranes with SEM. SEM with energy-dispersive X-ray analysis confirmed the incorporation of Cu+2 ions on the samples. The swelling degree of Cu-BGs-containing membranes was found to be significantly lower than that of the native alginate membrane. The weight loss data showed that the increase in the Cu-BGs level improved the in vitro degradation behavior of the membranes. Regarding mechanical properties, maximum stress and elastic modulus increased with increasing Cu-BGs level, reaching the highest point with 2% Cu-BGs in the membranes. Interaction between alginate and Cu-BGs was exhibited by Infrared Spectroscopy and X-ray diffraction proved the amorphous structure of both alginate polymer and Cu-BGs. Agar disc diffusion assay and turbidity measurements revealed that obtained membranes did not show any antimicrobial properties against Staphylococcus aureus and Escherichia coli.