载银与载庆大霉素硅灰石涂层体外抗菌性能的对比研究

In vitro comparison of antibacterial properties of plasma sprayed wollastonite coatings loading silver and gentamicin

目的制备具有长效药物缓释效果的骨科抗菌植入材料表面涂层。方法采用等离子体喷涂技术在钛合金表面沉积硅灰石涂层。一组试样在浓度为重量百分率5％的硝酸银溶液中浸泡24h获得载银硅灰石涂层，另一组试样通过与装载庆大霉素的胶原溶液发生接枝反应制得载庆大霉素硅灰石涂层。两种涂层的性能通过抗菌剂体外溶液释放实验、抗金黄色葡萄球菌的抑菌环实验和成骨细胞接触培养毒性实验进行表征。结果成功制备载银与载庆大霉素硅灰石涂层。载银硅灰石涂层均匀释放银离子达50d；涂层抗金黄色葡萄球菌能力可维持40d以上。载庆大霉素硅灰石涂层呈爆发性释放庆大霉素，涂层抗金黄色葡萄球菌能力可以维持18d。两种涂层均不影响成骨细胞在其表面的黏附、增殖以及碱性磷酸酶活性的表达。结论载银硅灰石涂层与载庆大霉素硅灰石涂层相比，抗菌剂释放较均匀、抗菌时效较长，更具临床应用前景。

Objective To develop antibacterial coatings for orthopedic implants with a sustained release of drugs. Methods Wollastonite coatings were deposited on the titanium substrates by an atmospheric plasma spray system. After soaking in weight percent of 5% AgNO3 solution for 24 h, the wollastonite coatings loading silver were obtained. Gentamicin were loaded on the wollastonite coatings by collagen grafting process. The release rates of drugs from wollastonite coatings were investigated by the in vitro solution soaking test. One strain of S. aureus was used in zone of inhibition test to evaluate the antibacterial properties of drug loaded wollastonite coatings, and the cell culture test was used to evaluate their cytotoxieity. Results Silver and gentamicin loaded wollastonite coatings were successfully prepared. The release of silver ions from the silver loaded wollastonite coatings lasted 50 d in deionized water, effectively inhibiting the growth of S. aureus for 40 d. While an initial burst release of gentamiein was found during the in vitro solution soaking test. The gentamicin released from gentamicin loaded wollastonite coatings can inhibit the growth of S. aureus for 18 d. Both the two kinds of antibacterial woUastonite coatings showed no adverse effect on cellular adhesion, proliferation and alkaline phosphatase expression. Conclusions Compared with gentamiein loaded wollastonite coatings, silver loaded wollastonite coatings may have more promising clinical applications due to the even and long-time antibacterial agent release.