Synthesis and antimicrobial properties of Zn-mineralized alginate nanocomposites

•Zn-mineralized alginate nanocomposites were produced in one-step method.•Presence of Zn-mineral phase has increased total nanocomposite Zn(II) content.•Stability and Zn(II) release are modulated by the presence of mineral phase.•Nanocomposites release Zn(II) inducing strong antimicrobial effect. New bioactive and antimicrobial biomaterials were produced by alginate-mediated biomineralization with Zn-mineral phase. The synthesis procedure is simple, cost-effective and resulted in two different Zn-mineralized alginate nanocomposites, Zn-carbonate/Zn-alginate and Zn-phosphate/Zn-alginate. The presence of Zn-mineral phase and its type, have significantly affected nanocomposite morphology, stability, total metallic loading and potential to release Zn(II) in physiological environment. Antimicrobial experiments showed that both types of Zn-mineralized nanocomposites exhibit strong antimicrobial effect against Escherichia coli, Staphylococcus aureus and Candida albicans. These results suggest that alginate biomineralization, where minerals are salts of essential metallic ions like Zn(II), represents a good strategy for designing multifunctional biomaterials for potential biomedical applications.