In vivo and in vitro biocompatible alginate film crosslinked with Ca2+ and Co2+ manifests antiviral, antibacterial and anticancer activity

Alginate crosslinked with calcium cations is a promising hydrogel for biomedical applications as it is non-toxic, has suitable mechanical properties and is insoluble in water. Cobalt has been shown to possess antibacterial capacity against Gram-positive and Gram-negative bacteria, and has an angiogenesis effect. In this study, alginate films were crosslinked with Ca2+ and Co2+ ions to explore their biological properties in terms of antiviral capacity, antibacterial properties, anticancer activity and their toxicity. The results show that the hydrogel with a very small amount of cobalt was biocompatible in vivo using the Caenorhabditis elegans model and in vitro on human keratinocyte cells and it also exhibited antibacterial activity against the life-threatening methicillin-resistant Staphylococcus aureus. Furthermore, this hydrogel showed antiviral activity against a surrogate of SARS-CoV-2 and anticancer properties against melanoma and colon cancer cells, which render it a promising material for biomedical applications such as wound healing and tissue engineering. Water sorption experiments, Fourier transform infrared spectroscopy, electron microscopy with Energy Dispersive X-ray Spectrometry and degradation analysis in acid aqueous medium were performed to complete the characterization of these new materials.