Preparation, characterization and antibacterial properties of silver nanoparticles–hydroxyapatite composites by a simple and eco-friendly method

Hydroxyapatite (HA) has been widely used as an implant material due to its high chemical similarity with the mineral component of bone extracellular matrix. Silver nanoparticles (AgNPs), when used in adequate amounts, are known to provide beneficial effects on biomaterials due to their powerful antimicrobial activity. In this work, HA powder was obtained by chemical precipitation and AgNPs were synthesized in colloidal suspension in the presence of chitosan. The HA powder was immersed in as-prepared AgNPs colloids to produce silver nanoparticle–hydroxyapatite composites (HA-AgNPs) with theoretical silver proportion ranging from 0.016 to 0.40 wt%. The AgNPs synthesis and adsorption onto HA were studied by a UV–vis technique, while the presence of silver in HA-AgNPs was confirmed by ICP-AES and EDS analysis. XRD and TEM characterization showed no significant changes in the structure and morphology of HA after AgNPs incorporated. High-resolution SEM showed spherical AgNPs (5–10 nm diameter) and TEM analysis revealed nanosized rod-shaped HA particles (100–150 nm long and 40–50 nm wide). A good antibacterial ability was observed in all materials against two bacterial strains (Escherichia coli and Staphylococcus aureus) using the disk diffusion method. Considering the simple methodology involved in the production of these materials, it is suggested that the HA-AgNPs can be used for development of antibacterial biomaterial applications.