种植体表面MAO/HF-OPG复合纳米微球涂层的构建及其生物学性能研究

Bone resorption caused by peri-implant infection is one of the most important reasons of implant failure. There are two critical steps in this process. Firstly, the bacteria adhere to the implant surface and then form biofilm. And the inflammatory response of the body stimulates osteoclast differentiation and maturation to induce bone resorption. To this end, we propose to fabricate a coating on the surface of implant with dual effects on antibacterial and inhibiting the bone resorption. In this project, halogenated furanones (HF) with antibacterial effect and osteoprotegerin (OPG) with inhibiting effect on the bone resorption were respectively incorporated into polylactic acid nanoparticles to achieve the goal of controlled release. Then, the two kinds of drug-loaded nanoparticles were penetrated and cross-linked in the porous structure on the MAO coating on implant to fabricate the MAO/HF-OPG composite nanoparticles coating. By optimizing the preparative conditions of drug-loaded nanoparticles, and the fabrication design of the MAO/HF-OPG composite nanoparticles coating, the controlled release characteristic of drugs in the coating was revealed. The antibacterial properties and the mechanism of inhibiting the osteoclast differentiation, maturation and induceing the osteoclast death were respectively clarified by antibacterial tests and osteoclast culture in vitro. Finally, the actual effect of inhibiting the bone resorption by the MAO/HF-OPG composite nanoparticles coating under simulative environment of peri-implant infection was evaluated in vivo. The completion of this project will be expected to provide a new strategy to prevent bone resorption caused by peri-implant infection, and further improve the success rate and service life of dental implant.

种植体周围感染引起的骨吸收是导致种植失败的最重要原因之一。细菌在种植体表面黏附、增殖并形成菌斑以及机体炎症反应刺激破骨细胞分化、成熟引起骨吸收是该过程中的关键步骤。为此，我们构想在种植体表面构建出既具有抗菌作用又能抑制骨吸收的涂层。本项目拟将新型抗菌剂卤代呋喃酮（HF）和骨保护素（OPG）分别制备成聚乳酸缓控释载药纳米微球，然后采用渗涂交联法将这两种微球黏附至微弧氧化（MAO）处理的种植体表面构建MAO/HF-OPG复合纳米微球涂层。通过对载药纳米微球制备工艺及复合纳米微球涂层构建设计优化，揭示涂层中药物的控释特性。通过体外抗菌实验和破骨细胞培养阐明该涂层的抗菌规律以及抑制破骨细胞分化、成熟并诱导其凋亡的机制。最后通过体内实验评估该涂层在模拟种植体周围感染环境下抑制骨吸收的实际效果。本项目的完成有望成为预防种植体周围感染引起骨吸收的新方法，从而进一步提高种植体的成功率和使用寿命。

种植体周围感染引起的骨吸收是导致牙科种植体失败的最主要原因之一，会引起一系列不良后果，并且一旦出现骨吸收往往很难逆转。因此，寻找有效的方法预防种植体周围感染引起的骨吸收对牙科种植体的成功率和使用寿命非常重要。细菌在种植体表面黏附、增殖并形成菌斑以及机体炎症反应刺激破骨细胞分化、成熟是该过程中的关键步骤。为此，我们构想在牙科种植体表面构建出既具有抗菌作用又能抑制骨吸收的涂层，从而为形成稳定的骨结合提供良好的条件和健康的环境。本项目将新型抗菌剂卤代呋喃酮（HF）和破骨细胞抑制因子骨保护素（OPG）分别制备成缓控释纳米微球，然后采用渗涂交联法将这两种载药微球黏附至微弧氧化（MAO）处理的钛种植体表面从而构建出MAO/HF-OPG复合纳米微球涂层，通过体外释药实验揭示涂层的释药特性；通过体外抗菌实验和体外细胞培养阐明该涂层的抗菌规律以及抑制破骨细胞分化、成熟的机制；最后通过体内实验评估该涂层在模拟种植体周围感染环境下抑制骨吸收的实际效果。研究结果表明在钛种植体表面构建出来的MAO/HF-OPG复合纳米微球涂层具有良好的稳定性，扫描电镜观察涂层表面可见两种载药微球良好的分布在MAO涂层的微孔中，通过明胶彼此交联并交联至微孔壁，通过物理嵌合和化学交联两种方式使得载药微球黏附在MAO涂层的微孔中，从而防止载药微球在种植体植入过程以及行使功能时从微孔中脱落。体外释药研究结果表明该涂层可以长期稳定释放HF和OPG（释药时间均大于30天）。体外抗菌实验和体外细胞培养实验表明该涂层既具有良好的抗牙龈卟啉单胞菌和伴放线放线杆菌功能，又可以有效抑制破骨细胞的分化、成熟。比格犬体内实验研究表明该涂层在模拟种植体周围感染环境下具有良好的预防骨吸收的实际效果。本项目的完成有望为预防种植体周围感染引起骨吸收提供一种新方法，从而进一步提高牙科种植体的成功率和使用寿命。