Despotović Ines, Petrović Željka, Katić Jozefina, Mikić Dajana
Division of Physical Chemistry, Ruđer Bošković Institute, Bijenička Cesta 54, 10002 Zagreb, Croatia.
Division of Materials Chemistry, Ruđer Bošković Institute, Bijenička Cesta 54, 10002 Zagreb, Croatia.
Materials (Basel). 2024 Jun 3;17(11):2703. doi: 10.3390/ma17112703.
The surface modification of dental implants plays an important role in establishing a successful interaction of the implant with the surrounding tissue, as the bioactivity and osseointegration properties are strongly dependent on the physicochemical properties of the implant surface. A surface coating with bioactive molecules that stimulate the formation of a mineral calcium phosphate (CaP) layer has a positive effect on the bone bonding process, as biomineralization is crucial for improving the osseointegration process and rapid bone ingrowth. In this work, the spontaneous deposition of calcium phosphate on the titanium surface covered with chemically stable and covalently bound alendronate molecules was investigated using an integrated experimental and theoretical approach. The initial nucleation of CaP was investigated using quantum chemical calculations at the density functional theory (DFT) level. Negative Gibbs free energies show a spontaneous nucleation of CaP on the biomolecule-covered titanium oxide surface. The deposition of calcium and phosphate ions on the alendronate-modified titanium oxide surface is governed by Ca-phosphonate (-POH) interactions and supported by hydrogen bonding between the phosphate group of CaP and the amino group of the alendronate molecule. The morphological and structural properties of CaP deposit were investigated using scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction and attenuated total reflectance Fourier transform infrared spectroscopy. This integrated experimental-theoretical study highlights the spontaneous formation of CaP on the alendronate-coated titanium surface, confirming the bioactivity ability of the alendronate coating. The results provide valuable guidance for the promising forthcoming advancements in the development of biomaterials and surface modification of dental implants.
牙种植体的表面改性在建立种植体与周围组织的成功相互作用中起着重要作用，因为生物活性和骨整合特性强烈依赖于种植体表面的物理化学性质。用能刺激矿物磷酸钙（CaP）层形成的生物活性分子进行表面涂层，对骨结合过程有积极影响，因为生物矿化对于改善骨整合过程和促进骨快速生长至关重要。在这项工作中，采用综合实验和理论方法研究了磷酸钙在覆盖有化学稳定且共价结合的阿仑膦酸盐分子的钛表面上的自发沉积。利用密度泛函理论（DFT）水平的量子化学计算研究了CaP的初始成核。负吉布斯自由能表明CaP在生物分子覆盖的二氧化钛表面上自发成核。钙和磷酸根离子在阿仑膦酸盐改性的二氧化钛表面上的沉积受钙膦酸盐（-POH）相互作用控制，并由CaP的磷酸基团与阿仑膦酸盐分子的氨基之间的氢键支持。使用扫描电子显微镜、能量色散X射线光谱、X射线衍射和衰减全反射傅里叶变换红外光谱研究了CaP沉积物的形态和结构性质。这项综合实验 - 理论研究突出了CaP在阿仑膦酸盐涂层钛表面上的自发形成，证实了阿仑膦酸盐涂层的生物活性能力。研究结果为生物材料开发和牙种植体表面改性的未来有前景的进展提供了有价值的指导。
