title: Low temperature direct 3D printed bioceramics and biocomposites as drug release matrices.
abstract: The aim of this study was to investigate the adsorption and desorption kinetics of antibiotics to microporous bioceramics fabricated by a novel low temperature 3D powder direct printing process. The adsorption of vancomycin, ofloxacin and tetracycline onto hydroxyapatite, brushite and monetite showed a linear correlation with the drug concentration in the immersion solution, whereas a non-linear relationship was found between the immersion time and the amount of adsorbed drug. Differences in the total amount of adsorbed drugs were correlated to the specific surface areas of the matrices, which varied between 2.4-13.1 m(2)/g. Normalised drug loadings were found to be in the range of 1.5-1.8 mg/m(2) for vancomycin and ofloxacin, whereas higher loads of up to 5-7 mg/m(2) were obtained for tetracycline. Vancomycin and ofloxacin were rapidly released into PBS buffer within 1-2 days, while tetracycline showed a much slower release rate of approximately 25% after 5 days of immersion. Additional polymer impregnation of the drug loaded matrix with PLA/PGA polymer solutions enabled the release kinetics to be delayed such that sustained release was achieved in polymer ceramic biocomposites.
authors.affiliation: Department for Functional Materials in Medicine and Dentistry, University of Würzburg, Pleicherwall 2, Würzburg, Germany. uwe.gbureck@fmz.uni-wuerzburg.de <uwe.gbureck@fmz.uni-wuerzburg.de>
authors.forename: Uwe
authors.initials: U
authors.lastname: Gbureck
authors.forename: Elke
authors.initials: E
authors.lastname: Vorndran
authors.forename: Frank A
authors.initials: FA
authors.lastname: Müller
authors.forename: Jake E
authors.initials: JE
authors.lastname: Barralet
mesh_terms: D000327:Adsorption; D000900:Anti-Bacterial Agents / Q000737:chemistry*; D001672:Biocompatible Materials; D002130:Calcium Phosphates / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical; D004337:Drug Carriers; D004339:Drug Compounding; D004343:Drug Implants; D017886:Durapatite / Q000737:chemistry*; D007700:Kinetics; D008956:Models, Chemical; D015242:Ofloxacin / Q000737:chemistry; D011091:Polyesters / Q000737:chemistry; D011100:Polyglycolic Acid / Q000737:chemistry; D016062:Porosity; D011208:Powders; D012995:Solubility; D013499:Surface Properties; D013678:Technology, Pharmaceutical / Q000379:methods; D013696:Temperature; D013752:Tetracycline / Q000737:chemistry; D014640:Vancomycin / Q000737:chemistry
chemical_list: D000900:Anti-Bacterial Agents; D001672:Biocompatible Materials; D002130:Calcium Phosphates; D004337:Drug Carriers; D004343:Drug Implants; D011091:Polyesters; D011208:Powders; D011100:Polyglycolic Acid; C033616:poly(lactide); D014640:Vancomycin; C485838:calcium phosphate, monobasic, anhydrous; D017886:Durapatite; D015242:Ofloxacin; D013752:Tetracycline; C494366:calcium phosphate, dibasic, dihydrate