Alginate based hydrogel for tissue regeneration: optimization, antibacterial activity and mechanical properties

Purpose: In this work our aim was to reveal the relationship between sodium alginate concentration and crosslinking level, also the ratio of release of the antibacterial additives: silver nanoparticles and metronidazole. Moreover, we examine obtained hydrogel as a potential dressing material for regenerative medicine. Design/methodology/approach: In the research specimens of hydrogels were tested to define their mechanical and physicochemical properties like antibacterial activity against gramnegative Escherichia coli and gram-positive Staphylococcus aureus, viscosity and conductivity. Findings: The concentration of alginate and presence of antibacterial additives influence on the crosslinking level. Mechanical properties of hydrogels are similar to human skin. Only hydrogels with addition of metronidazole and AgNP inhibits bacteria growth after 18 h. In case of gram-negative Escherichia coli both of the aseptic additives inhibits bacteria growth, but sodium alginate hydrogel with silver nanoparticles gives better results in tests with grampositive Staphylococcus aureus. Research limitations/implications: The presence of metronidazole in hydrogel, especially its incorporation and binding with mannuronic and guluronic acid residues must be clarified in more advanced research. Practical implications: Obtained results shows that sodium alginate hydrogels with 0.1mg/ml of alginate, due to its properties are proper as a dressing material. Based on the results, and more advanced tests with metronidazole, we can consider dressing design. Originality/value: Unique value of this work is that we completed the gap in knowledge about the relation of crosslinking level and mechanical properties with are crucial to proper tissue healing and addition of popular aseptic agents.