title: Marine structure derived calcium phosphate-polymer biocomposites for local antibiotic delivery.
abstract: Hydrothermally converted coralline hydroxyapatite (HAp) particles loaded with medically active substances were used to develop polylactic acid (PLA) thin film composites for slow drug delivery systems. The effects of HAp particles within PLA matrix on the gentamicin (GM) release and release kinetics were studied. The gentamicin release kinetics seemed to follow Power law Korsmeyer Peppas model with mainly diffusional process with a number of different drug transport mechanisms. Statistical analysis shows very significant difference on the release of gentamicin between GM containing PLA (PLAGM) and GM containing HAp microspheres within PLA matrix (PLAHApGM) devices, which PLAHApGM displays lower release rates. The use of HAp particles improved drug stabilization and higher drug encapsulation efficiency of the carrier. HAp is also the source of Ca2+ for the regeneration and repair of diseased bone tissue. The release profiles, exhibited a steady state release rate with significant antimicrobial activity against Staphylococcus aureus (S. aureus) (SH1000) even at high concentration of bacteria. The devices also indicated significant ability to control the growth of bacterial even after four weeks of drug release. Clinical release profiles can be easily tuned from drug-HAp physicochemical interactions and degradation kinetics of polymer matrix. The developed systems could be applied to prevent microbial adhesion to medical implant surfaces and to treat infections mainly caused by S. aureus in surgery.
authors.affiliation: School of Chemistry and Forensic Science, University of Technology Sydney, Ultimo NSW 2007, Australia. innocent.macha@uts.edu.au.
authors.forename: Innocent J
authors.initials: IJ
authors.lastname: Macha
authors.affiliation: CIRIMAT Carnot Institute, CNRS-INPT-UPS, University of Toulouse, 31030 Toulouse, France. sophie.cazalbou@univ-tlse3.fr.
authors.forename: Sophie
authors.initials: S
authors.lastname: Cazalbou
authors.affiliation: School of Chemistry and Forensic Science, University of Technology Sydney, Ultimo NSW 2007, Australia. Besim.Ben-Nissan@uts.edu.au.
authors.forename: Besim
authors.initials: B
authors.lastname: Ben-Nissan
authors.affiliation: The ithree Institute, Faculty of Science, University of Technology Sydney, Broadway NSW 2007, Australia. Kate.l.harvey@student.uts.edu.au.
authors.forename: Kate L
authors.initials: KL
authors.lastname: Harvey
authors.affiliation: Faculty of Science, University of Technology Sydney, Broadway NSW 2007, Australia. Bruce.Milthorpe@uts.edu.au.
authors.forename: Bruce
authors.initials: B
authors.lastname: Milthorpe
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D002130:Calcium Phosphates / Q000008:administration & dosage / Q000737:chemistry*; D002516:Ceramics / Q000737:chemistry; D016503:Drug Delivery Systems / Q000379:methods*; D005839:Gentamicins / Q000008:administration & dosage; D006882:Hydroxyapatites / Q000737:chemistry; D008826:Microbial Sensitivity Tests; D008855:Microscopy, Electron, Scanning; D011108:Polymers / Q000008:administration & dosage / Q000737:chemistry*; D013211:Staphylococcus aureus / Q000187:drug effects; D013718:Tensile Strength
chemical_list: D000900:Anti-Bacterial Agents; D002130:Calcium Phosphates; D005839:Gentamicins; D006882:Hydroxyapatites; D011108:Polymers; C119955:coralline hydroxyapatite; C020243:calcium phosphate