Bacterial infections and lack of osseointegration may negatively affect the success of titanium (Ti) implants. In the present study, a functional coating composed of chitosan (CS) microspheres and nano hydroxyapatite (nHA) was prepared to obtain antimicrobial Ti implants with enhanced bioactivity. First, the chitosan microspheres were fixed to Ti surfaces activated by alkali and heat treatment, then nHA coatings were precipitated onto these surfaces. Ciprofloxacin was loaded into the microspheres using two different procedures; encapsulation and diffusion. Scanning electron microscopy micrographs of the modified Ti surfaces showed that the coating was successfully deposited onto the Ti surfaces and stable for 30 days in PBS. The drug was completely released from free microspheres loaded by encapsulation in 21 days whereas only 89% release was observed after immobilization. The burst release also decreased from ca. 55% to ca. 35%. The release was further reduced following the nHA precipitation. The modified Ti surfaces showed antimicrobial activity based on the bacterial time-kill assay using S. aureus, but the efficiency was affected by both nHA precipitation and drug loading strategy. Highest antimicrobial activity was seen in the samples without nHA layer, and when the drug was loaded by diffusion. Fourier transform infrared spectroscopy and X-ray diffraction analyses revealed that nHA on the surface enhanced HA growth in simulated body fluid for 3 weeks, showing increased osseointegration potential. Therefore, the proposed coating may be used to prevent Ti implant failure originated from bacterial infection and/or low bioactivity.

细菌感染和缺乏骨整合可能会对钛 (Ti) 植入物的成功产生负面影响。在本研究中，制备了由壳聚糖 (CS) 微球和纳米羟基磷灰石 (nHA) 组成的功能涂层，以获得具有增强生物活性的抗菌钛植入物。首先，将壳聚糖微球固定在通过碱和热处理活化的 Ti 表面，然后在这些表面上沉淀 nHA 涂层。使用两种不同的程序将环丙沙星加载到微球中；封装和扩散。改性钛表面的扫描电子显微镜显微照片表明，涂层成功沉积在钛表面上，并在 PBS 中稳定了 30 天。药物在 21 天内从通过封装加载的游离微球中完全释放，而固定后仅观察到 89% 的释放。爆发式释放也从大约减少。55% 到大约 35%。在 nHA 沉淀后，释放量进一步减少。基于细菌时间杀灭试验，改性钛表面显示出抗菌活性金黄色葡萄球菌，但效率受 nHA 沉淀和载药策略的影响。在没有 nHA 层的样品中以及通过扩散加载药物时，可以看到最高的抗菌活性。傅里叶变换红外光谱和 X 射线衍射分析表明，表面上的 nHA 增强了模拟体液中 HA 的生长 3 周，显示出增加的骨整合潜力。因此，所提出的涂层可用于防止由细菌感染和/或低生物活性引起的钛植入物失败。