title: Biphasic mode of antibacterial action of aminoglycoside antibiotics-loaded elastic hydroxyapatite-glucan composite.
abstract: Following the quest for new composite materials for bone tissue engineering, a novel elastic hydroxyapatite-glucan composite loaded with two aminoglycoside antibiotics was prepared. The porosity of the composite and the drug release profiles in closed-loop and semi-open systems were tested. The antibacterial activity of the drug was estimated against two Gram-positive and two Gram-negative bacterial strains causing orthopedic infections. It was found that the loaded antibiotic acted in a biphasic mode. The majority of the drug was released within 48-119 h in a pore-dependent manner and inhibited the bacterial growth in the culture medium. However, a small residual amount of the drug was bound to the composite microstructure via ionic interactions and acted as a short-lived barrier against bacterial adhesion to the composite, although the surrounding medium was no longer protected against bacterial infection. Sub-inhibitory concentrations of the released drug were observed in the medium only during the last two days of the experiment (minimized risk of occurrence of drug-resistant strains). Thus the novel drug-loaded elastic hydroxyapatite-glucan composite, demonstrating a biphasic mode of antibacterial action, may be recommended for antibiotic prophylaxis in bone substitute implantation, with less emphasis on the treatment of bone infections.
authors.affiliation: Department of Biochemistry and Biotechnology, Medical University of Lublin, 20-093 Lublin, Poland. anna.belcarz@umlub.pl
authors.forename: Anna
authors.initials: A
authors.lastname: Belcarz
authors.forename: Aneta
authors.initials: A
authors.lastname: Zima
authors.forename: Grażyna
authors.initials: G
authors.lastname: Ginalska
mesh_terms: D000583:Amikacin / Q000737:chemistry / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D018786:Bone Substitutes; D002626:Chemistry, Pharmaceutical; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D017886:Durapatite / Q000737:chemistry*; D004548:Elasticity; D005839:Gentamicins / Q000737:chemistry / Q000494:pharmacology*; D005936:Glucans / Q000737:chemistry*; D006090:Gram-Negative Bacteria / Q000187:drug effects / Q000254:growth & development; D006094:Gram-Positive Bacteria / Q000187:drug effects / Q000254:growth & development; D007700:Kinetics; D016062:Porosity; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D013678:Technology, Pharmaceutical / Q000379:methods
chemical_list: D000900:Anti-Bacterial Agents; D018786:Bone Substitutes; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D005839:Gentamicins; D005936:Glucans; D000583:Amikacin; D017886:Durapatite
keywords: Amikacin; Bacterial strains; Ceramics; Elastic bone-replacing material; Gentamicin; Multiphasic release