Zhang Lijie, Chen Yupeng, Rodriguez Jose, Fenniri Hicham, Webster Thomas J
Division of Engineering, Brown University, Providence, RI 02912, USA.
Int J Nanomedicine. 2008;3(3):323-33. doi: 10.2147/ijn.s2709.
Natural bone consists of hard nanostructured hydroxyapatite (HA) in a nanostructured protein-based soft hydrogel template (ie, mostly collagen). For this reason, nanostructured HA has been an intriguing coating material on traditionally used titanium for improving orthopedic applications. In addition, helical rosette nanotubes (HRNs), newly developed materials which form through the self-assembly process of DNA base pair building blocks in body solutions, are soft nanotubes with a helical architecture that mimics natural collagen. Thus, the objective of this in vitro study was for the first time to combine the promising attributes of HRNs and nanocrystalline HA on titanium and assess osteoblast (bone-forming cell) functions. Different sizes of nanocrystalline HA were synthesized in this study through a wet chemical precipitation process following either hydrothermal treatment or sintering. Transmission electron microscopy images showed that HRNs aligned with nanocrystalline HA, which indicates a high affinity between both components. Some of the nanocrystalline HA formed dense coatings with HRNs on titanium. More importantly, results demonstrated enhanced osteoblast adhesion on the HRN/nanocrystalline HA-coated titanium compared with conventional uncoated titanium. Among all the HRN/nanocrystalline HA coatings tested, osteoblast adhesion was the greatest when HA nanometer particle size was the smallest. In this manner, this study demonstrated for the first time that biomimetic HRN/nanocrystalline HA coatings on titanium were cytocompatible for osteoblasts and, thus, should be further studied for improving orthopedic implants.
天然骨由基于蛋白质的纳米结构软水凝胶模板（即主要是胶原蛋白）中的硬纳米结构羟基磷灰石（HA）组成。因此，纳米结构的HA一直是传统使用的钛上一种引人关注的涂层材料，用于改善骨科应用。此外，螺旋玫瑰花结纳米管（HRNs）是通过体内溶液中DNA碱基对构建块的自组装过程形成的新开发材料，是具有模仿天然胶原蛋白螺旋结构的软纳米管。因此，本体外研究的目的是首次将HRNs和纳米晶HA在钛上的有前景特性结合起来，并评估成骨细胞（骨形成细胞）的功能。在本研究中，通过水热处理或烧结后的湿化学沉淀过程合成了不同尺寸的纳米晶HA。透射电子显微镜图像显示HRNs与纳米晶HA排列在一起，这表明两种成分之间具有高亲和力。一些纳米晶HA在钛上与HRNs形成了致密涂层。更重要的是，结果表明与传统未涂层钛相比，HRN/纳米晶HA涂层钛上的成骨细胞粘附增强。在所有测试的HRN/纳米晶HA涂层中，当HA纳米颗粒尺寸最小时，成骨细胞粘附力最大。通过这种方式，本研究首次证明钛上的仿生HRN/纳米晶HA涂层对成骨细胞具有细胞相容性，因此，应进一步研究以改善骨科植入物。
