W. M. Keck Biomedical Materials Laboratory, School of Mechanical and Materials Engineering, Washington State University, Pullman, Washington 99164-2920, USA.
J Biomed Mater Res B Appl Biomater. 2011 May;97(2):306-14. doi: 10.1002/jbm.b.31816. Epub 2011 Mar 25.
In spite of having excellent biocompatibility and osteogenic property of hydroxyapatite (HAp) and β-tricalcium phosphate (β-TCP), concerns have been raised regarding their degradation kinetics. Complete in vivo degradation of HAp takes years because of its slow degradation rate, and fast degradation rate of β-TCP limits its application. Biphasic calcium phosphates (BCPs) composed of both HAp and β-TCP have controlled degradation to some extent. Here, we have prepared three different BCPs composed of β-TCP and HAp. These BCP composites are successfully electrically polarized to generate surfaces with positive (P-poled) and negative (N-poled) charges. Thermally stimulated depolarized current measurement (TSDC) exhibits increased stored charge density with the increase in HAp percentage in the composites. Our study focuses on understanding the effect of composition variation as well as electrical polarization of these composites on early stage osteoblast-cell adhesion, proliferation, and extracellular matrix (ECM) formation capability. No matter what the composition is, N-poled (Negatively poled) surfaces show early stage osteoblast-cell adhesion, proliferation, and ECM formation when compared with U-poled (unpoled) and P-poled (positively poled) surfaces. Irrespective of the surface charge, an improved cell-material interactions are observed as the percentage of HAp content in the composites is increased. These electrically polarized BCP composites can have potential use in the area of orthopedics and dentistry.
尽管羟基磷灰石（HAp）和 β-磷酸三钙（β-TCP）具有优异的生物相容性和成骨性能，但人们对它们的降解动力学仍存在担忧。由于 HAp 的降解速率较慢，其完全体内降解需要数年时间，而 β-TCP 的快速降解速率限制了其应用。由 HAp 和 β-TCP 组成的双相磷酸钙（BCPs）在一定程度上控制了降解。在这里，我们制备了三种不同的由 β-TCP 和 HAp 组成的 BCP。这些 BCP 复合材料成功地进行了电极化，以产生带有正电荷（P 极化）和负电荷（N 极化）的表面。热刺激去极化电流测量（TSDC）显示，随着复合材料中 HAp 百分比的增加，存储电荷密度增加。我们的研究重点是了解这些复合材料的组成变化以及电极化对早期成骨细胞黏附、增殖和细胞外基质（ECM）形成能力的影响。无论组成如何，与 U 极化（未极化）和 P 极化（正极化）表面相比，N 极化（负极化）表面在早期表现出成骨细胞黏附、增殖和 ECM 形成。无论表面电荷如何，随着复合材料中 HAp 含量的增加，观察到细胞与材料之间的相互作用得到改善。这些电极化的 BCP 复合材料在矫形和牙科领域可能具有潜在的用途。
