Laboratory of Chemistry and Electrochemistry of Surfaces, University of Namur (FUNDP), Rue de Bruxelles 61, B-5000 Namur, Belgium.
Mater Sci Eng C Mater Biol Appl. 2013 Jul 1;33(5):2686-97. doi: 10.1016/j.msec.2013.02.025. Epub 2013 Feb 24.
Carbon nanotubes used as fillers in composite materials are more and more appreciated for the outstanding range of accessible properties and functionalities they generate in numerous domains of nanotechnologies. In the framework of biological and medical sciences, and particularly for orthopedic applications and devices (prostheses, implants, surgical instruments, …), titanium substrates covered by tantalum oxide/carbon nanotube composite coatings have proved to constitute interesting and successful platforms for the conception of solid and biocompatible biomaterials inducing the osseous regeneration processes (hydroxyapatite growth, osteoblasts attachment). This paper describes an original strategy for the conception of resistant and homogeneous tantalum oxide/carbon nanotubes layers on titanium through the introduction of carbon nanotubes functionalized by phosphonic acid moieties (-P(=O)(OH)2). Strong covalent C-P bonds are specifically inserted on their external sidewalls with a ratio of two phosphonic groups per anchoring point. Experimental results highlight the stronger "tantalum capture agent" effect of phosphonic-modified nanotubes during the sol-gel formation process of the deposits compared to nanotubes bearing oxidized functions (-OH, -C=O, -C(=O)OH). Particular attention is also paid to the relative impact of the rate of functionalization and the dispersion degree of the carbon nanotubes in the coatings, as well as their wrapping level by the tantalum oxide matrix material. The resulting effect on the in vitro growth of hydroxyapatite is also evaluated to confirm the primary osseous bioactivity of those materials. Chemical, structural and morphological features of the different composite deposits described herein are assessed by X-ray photoelectron spectroscopy (XPS), scanning (SEM) and transmission (TEM) electronic microscopies, energy dispersive X-rays analysis (EDX) and peeling tests.
用于复合材料的碳纳米管由于其在众多纳米技术领域中产生的出色的可及性能和功能而越来越受到关注。在生物和医学科学领域，特别是在矫形应用和器械（假体、植入物、手术器械等）中，涂覆有氧化钽/碳纳米管复合涂层的钛基底已被证明是用于设计固体和生物相容的生物材料的有趣且成功的平台，这些材料可以诱导骨质再生过程（羟基磷灰石生长、成骨细胞附着）。本文介绍了一种通过引入由膦酸基团（-P(=O)(OH)2）官能化的碳纳米管来构思具有耐抗性和均匀性的氧化钽/碳纳米管层的原始策略。强共价 C-P 键特别插入到它们的外表面壁上，每个锚固点有两个膦酸基团。实验结果突出显示了在沉积的溶胶-凝胶形成过程中，与具有氧化功能（-OH、-C=O、-C(=O)OH）的纳米管相比，膦酸改性纳米管对氧化钽的更强的“捕获剂”效应。还特别关注了官能化的速率和碳纳米管在涂层中的分散程度，以及它们被氧化钽基质材料包裹的程度对涂层的相对影响。还评估了体外生长羟基磷灰石的效果，以确认这些材料的主要骨生物活性。通过 X 射线光电子能谱 (XPS)、扫描（SEM）和透射（TEM）电子显微镜、能量色散 X 射线分析 (EDX) 和剥离试验评估了所描述的不同复合沉积物的化学、结构和形态特征。
