Title : Boron Doped Nano Hydroxyapatite: Antibacterial and Synergistic Effect with beta-lactame Antibiotics
Abstract:
Nowadays, synthetic biomaterials are extensively employed in the manufacture of medical devices and implants. Here, we studied on the development of a novel antimicrobial nanocomposite against a wide spectrum of bacteria including multi-drug resistance (MDR). This is why, we considered to produce boron-doped nano-hydroxyapatite (B-nHAp). In our groups’ previous studies bone-like nano hydroxyapatite (n-HAp) and B-nHAp were synthesized. In this study, we considered that, B-nHAp with antibacterial and β-lactamase inhibitory characteristics provides an interesting approach to inhibit adherence and growth of bacteria. Moreower, synergistic effect of B-nHAp/β-lactam antibiotic combinations extends its spectrum against MDR pathogenic bacteria with safe biocompatibility and appropriate tissue interactions as well as their nontoxicity in-vitro toward odonteoblasts and mesenchymal stem cells.
In-vitro antimicrobial activities of nHAp and B-nHAp was investigated by Disk Potentiation Tests, Double Disc Synergy Test, Agar Dilution Method and Etest® methods according to the recommendation of the Clinical and Laboratory Standards Institute. In this study, Escherichia coli, American Type Culture Collection (ATCC) 25922, Staphylococcus aureus ATCC 25923, Enterobacter cloacae ATCC 1143 (control strain for the Ampc disk test: strong positive), Klebsiella pneumoniae ATCC1144 (control strain for the Ampc disk test: weak positive), Klebsiella pneumoniae ATCC 700603 (control strain for extended-spectrum β-lactamase) were used. As β-lactam antibiotics, ampicillin, ceftriaxone, ceftazidime, ceftazidime/clavulanic acid, amoxicillin, amoxicillin/clavulanic acid, cefotetan, cefotaxime and cefoxitin were selected.
The results denoted that B-nHAp showed antibacterial activity against gram positive and gram-negative bacteria. As due to the β-lactamase inhibitory properties of B, B-nHAp showed synergistic effect when used in combination with β-lactame antibiotics and increased the effectiveness of antibiotics in all tests. However, nHAp showed no antimicrobial activity against tested microorganisms. In the light of these results, we concluded that B-nHAp nanocomposite developed by our group can be used in various dental and orthopeadic implant materials during manufacturing.
