A serial investigation is initiated aiming to explore the biological activity of some newly synthetized chemical compounds for the development of novel antimicrobial collagen based biomaterials.
Anna Staneva, Madalina Albu-Kaya, Boris Martinov, Iliana Ivanova, Todorka Vladkova
Abstract: A serial investigation is initiated aiming to explore the biological activity of some newly synthetized chemical compounds for the development of novel antimicrobial collagen based biomaterials. Collagen/ZnTiO3, Collagen/RGO, Collagen/(Ag/RGO), Collagen/(Ag/RGO/SiO2) and Collagen/(ZnTiO3/SiO2) composites have been so far studied and all of them demonstrate a specific antimicrobial activity against Gram-negative and Gram-positive bacteria and in some cases against fungi. The aim of this investigation is to develop new antimicrobial collagen biomaterials using RGO, ZnO, and TiO2 embedded in TEOS as another antimicrobial agent, combining the biological activity of RGO, ZnO and TiO2 with the dispersing effect of SiO2. The new Collagen/(RGO/ZnO/TiO2/SiO2) composites demonstrate an antimicrobial activity dependent on the agent loading level. It is specific in respect to Gram-negative, Grampositive bacteria and fungi. An optimal balance between the antimicrobial activity and the cytotoxicity is achieved by varying the concentration of the antimicrobial agent, RGO/ZnO/TiO2/SiO2, in Collagen/(RGO/ZnO/TiO2/SiO2) composites. It is suggested that the mechanism of the antimicrobial action includes the simultaneous proceeding of (i) metal ions chelation; (ii) free oxygen radicals formation due to the interactions between the microbial cells and the antimicrobial agent; (iii) mechanical demolition of the cell walls and membranes by RGO crystal nanoparticles. The broad spectrum antibacterial and anti-fungal activity combined with the low cytotoxicity at an optimal Collagen/Antimicrobial agent ratio makes the studied Collagen/(RGO/ZnO/TiO2/SiO2) composites a promising antimicrobial material increasing the medical biomaterials assortment.
Keywords: antimicrobial agent; RGO/ZnO/TiO2/SiO2; Collagen/(RGO/ZnO/TiO2/SiO2) composites; antimicrobial activity; cytotoxicity.