Impact of Biomechanical Forces on Antibiotics Release Kinetics from Hydroxyapatite Coated Surgical Fixation Pins

作     者：Mirjam Lilja Jan H.Sorensen Torben C.Sorensen Maria Astrand Philip Procter Hartwig Steckel Maria Stromme 

作者机构：Division for Nanotechnology and Functional MaterialsDepartment of Engineering SciencesThe Angstrom LaboratoryUppsala UniversityUppsalaSweden Sandvik Coromant ABStockholmSweden Department of Pharmaceutics and BiopharmaceuticsChristian Albrecht University KielKielGermany Stryker Trauma GmbHSchonkirchenGermany Stryker Trauma AGSelzachSwitzerland School of Engineering and DesignBrunel UniversityUxbridgeUK 

出 版 物：《Journal of Biomaterials and Nanobiotechnology》 (生物材料与纳米技术（英文）)

年 卷 期：2013年第4卷第4期

页      面：343-350页

学科分类：1002[医学-临床医学] 100214[医学-肿瘤学] 10[医学] 

主　　题：Hydroxyapatite Fixation Pin Tobramycin Coating Wear Drug Release Gamma Sterilization 

摘      要：This work investigates the impact of biomechanical wear and abrasion on the antibiotic release profiles of hydroxyapatite (HA) coated fixation pins during their insertion into synthetic bone. Stainless steel fixation pins are coated with crystalline TiO2 by cathodic arc evaporation forming the bioactive layer for biomimetic deposition of Tobramycin containing HA. Tobramycin is either introduced by co-precipitation during HA formation or by adsorption-loading after HA deposition. The samples containing antibiotics are inserted into bone mimicking polyethylene foam after which the drug release is monitored using high performance liquid chromatography. This analysis shows that HA coating wear and delamination significantly decrease the amount of drug released during initial burst, but only marginally influence the sustained release period. Spalled coating fragments are found to remain within the synthetic bone material structure. The presence of HA within this structure supports the assumption that the local release of Tobramycin is not only expected to eliminate bacteria growth directly at the pin interface but as well at some distance from the implant. Furthermore, no negative effect of gamma sterilization could be observed on the drug release profile. Overall, the observed results demonstrate the feasibility of a multifunctional implant coating that is simultaneously able to locally deliver clinically relevant doses of antibiotics and an HA coating capable of promoting osteoconduction. This is a potentially promising step toward orthopaedic devices that combine good fixation with the ability to treat and prevent post-surgical infections.