Bodhak Subhadip, Bose Susmita, Bandyopadhyay Amit
Washington State University, Pullman, 99164, USA.
Acta Biomater. 2009 Jul;5(6):2178-88. doi: 10.1016/j.actbio.2009.02.023. Epub 2009 Feb 20.
Our objective was to determine the role of surface charge and wettability on early stage mineralization as well as bone cell adhesion and proliferation on polarized HAp surface. To estimate the surface wettability, contact angles were measured in water, simulated body fluid (SBF) and Dulbecco's modified Eagle's medium/nutrient mixture F-12 Ham (DMEM). Experimental results show that HAp surface wettability and surface energy can be tailored by inducing surface charge without introducing any volumetric effects in the material. Increasing the surface charge increased the wettability and also the energy of HAp surfaces in all tested media. A maximum surface energy of 49.47+/-3.76mJ/m(2) was estimated for positively charged HAp surfaces polarized at 400(o)C. The in vitro bioactivity of polarized HAp samples was evaluated by soaking in SBF and DMEM (cell media). Cell-materials interaction was studied by culturing with human fetal osteoblast cells (hFOB). In vitro results show that tailoring the combined effect of wettability and charge polarity on the HAp surface enable differential binding of inorganic ions (e.g., Ca(2+), Cl(-), Na(+), HCO(3)(-) etc) and organic cell adhesive proteins (e.g., fibronectin, vitronectin etc) with different surface properties, which results in accelerated or decelerated mineralization as well as cell adhesion and proliferation on polarized HAp surface.
我们的目标是确定表面电荷和润湿性在早期矿化过程中的作用，以及在极化羟基磷灰石（HAp）表面上骨细胞的粘附和增殖情况。为了评估表面润湿性，我们测量了在水、模拟体液（SBF）和杜氏改良伊格尔培养基/营养混合物F-12哈姆（DMEM）中的接触角。实验结果表明，通过诱导表面电荷可以调整HAp表面的润湿性和表面能，而不会在材料中引入任何体积效应。在所有测试介质中，增加表面电荷会提高HAp表面的润湿性和表面能。对于在400℃极化的带正电的HAp表面，估计最大表面能为49.47±3.76mJ/m²。通过浸泡在SBF和DMEM（细胞培养基）中来评估极化HAp样品的体外生物活性。通过与人胎儿成骨细胞（hFOB）共培养来研究细胞与材料的相互作用。体外实验结果表明，调整HAp表面润湿性和电荷极性的综合效应，能够使具有不同表面性质的无机离子（如Ca²⁺、Cl⁻、Na⁺、HCO₃⁻等）和有机细胞粘附蛋白（如纤连蛋白、玻连蛋白等）产生差异结合，这导致极化HAp表面上的矿化加速或减速，以及细胞的粘附和增殖。
