Synthesis of CaO-Fe and CaO-Ag nanocomposites using raw and hydrolyzed waste chicken eggshell and investigation of their antimicrobial, biofilm inhibition activity, DNA cleavage ability, and antioxidant activity properties

Abstract

In this study, CaO-Fe and CaO-Ag nanocomposites were synthesized and various biological properties were characterized. E. coli cell viability, antimicrobial, antioxidant, antibiofilm, and DNA cleavage properties were examined. All nanocomposites, namely raw CaO-Ag (R-CaO-Ag), hydrolyzed CaO-Ag (H-CaO-Ag), raw CaO-Fe (R-CaO-Fe), and hydrolyzed CaO-Fe (H-CaO-Fe), were found to have good antioxidant, antimicrobial, and antibiofilm properties. They showed antioxidant activity of 83.33%, 70.60%, 74.73%, and 72.78%, respectively, at 200 mg/L nanocomposites. When DNA cleavage properties of R-CaO-Ag, H-CaO-Ag, R-CaO-Fe, and H-CaO-Fe were evaluated at different concentrations, single-strand break was observed for all samples. It was shown that R-CaO-Ag was more effective against S. aureus and C. tropicalis, and H-CaO-Ag was more effective against E. hirae. It was found that the antimicrobial activities of R-CaO-Ag and H-CaO-Ag were higher compared to R-CaO-Fe and H-CaO-Fe. The microbial cell viability of nanocomposites was examined at three different concentrations. Even at the lowest concentration (125 mg/L), high values of E. coli inhibition were found as 98.65%, 100%, 90.24%, and 88.63%, respectively. Also, it was observed that all nanocomposites exhibited excellent biofilm inhibition activities. The antibiofilm abilities of one Gr (+) and one Gr (−) microorganism at three different concentrations were investigated. Biofilm inhibition percentages of R-CaO-Ag, H-CaO-Ag, R-CaO-Fe, and H-CaO-Fe were found as 65.83%, 86.5%, 89.67%, and 93.62% for S. aureus at 500 mg/L, respectively, while it was 50.06%, 90.68%, 71.69%, and 92.36% for P. aeruginosa, respectively, at 500 mg/L.