Green biosynthesis of hydroxyapatite-silver nanoparticle nanocomposite using aqueous Indian curry leaf (Murraya koengii) extract and its biological properties

Implant-associated disease triggered by bacterial colonization would hinder the osseointegration of bone implant at the implantation site and further jeopardize the outcome of bone regeneration. Thus, the use of implant material with intrinsic antibacterial property can be promising to address the shortcoming associated with bacterial infection. In the present study, we aimed to develop an antibacterial implant material based on a combination of hydroxyapatite (HAp) and silver nanoparticle (AgNPs) via a green biosynthetic route. In this work, aqueous extract of Indian curry leaf (Murraya koengii) was employed as a bio-reducing and stabilizing agent for the in-situ fabrication of HAp-AgNPs nanocomposite. According to XRD, EDX, TEM, XPS and FTIR results, AgNPs had been successfully synthesized and deposited to the surface of HAp, where the amount and size of decorated AgNPs were found to rely on the concentration of AgNO₃ precursor used. Antibacterial examinations in vitro showed that HAp-AgNPs nanocomposites displayed an effective antibacterial activity against Escherichia coli and Staphylococcus aureus bacteria when AgNO₃ precursor concentration used >1 mM. Furthermore, HAp-AgNPs-5 and HAp-AgNPs-7 nanocomposites also exhibit improved bioactivity in comparison with pristine HAp, being able of developing more bone-like apatite after 4 weeks of soaking in Hank's balanced salt solution. These findings significantly demonstrate the feasibility of HAp-AgNPs nanocomposite to be applied as antibacterial implant material for orthopedic application.