In vitro evaluation of antimicrobial activity of nano composite biomaterials based on hydroxyapatite

Abstract

Antimicrobial materials based on hydroxyapatite are potentially attractive in a wide variety of medical and stomatological applications. The objective of this paper is to examine antimicrobic activity of cobalt-substituted calcium hydroxyapatite nanopowders and biphased calciumphosphate/ poli-lactide-co-glicolide. The antimicrobial effects of these substances (powders) against two pathogen bacterial strains- Escherichia coli (ATCC 25922) and Staphylococcus aureus (ATCC 25923) were tested by disc diffusion method and quantitative antimicrobial test in liquid medium. It was noted that the inhibition zone of the bacterial cells S. aureus around the sample of the Ca/Co- HAp, was a lot bigger compared to the inhibition zone of bacterial cells E. coli around the sample of the mentioned biomaterial, which means that this material has bigger antimicrobic activity on S. aureus, in relation to E. coli. Quantitative antimicrobial test in liquid medium demonstrate that cobalt-substituted calcium hydroxyapatite samples show viable cells reduction of both tested microorganisms. It may be concluded that nanoparticles of cobalt-substituted calcium hydoxyapatite nano-powders has a satisfactory antimicrobic activity according to the tested bacteria strain.