Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, People's Republic of China.
Acta Biomater. 2012 Jan;8(1):439-48. doi: 10.1016/j.actbio.2011.10.021. Epub 2011 Oct 20.
The extracellular microenvironment plays a key role in the regulation of cellular behavior. To mimic the natural extracellular microenvironment, TiO(2) nanotube (TNT) arrays as drug nanoreservoirs for loading of bone morphogenetic protein 2 (BMP2) were constructed on titanium substrates and then covered with multilayered coatings of gelatin/chitosan (Gel/Chi) for controlled drug release. The multilayered coatings were constructed via a spin-assisted layer-by-layer assembly technique. The successful fabrication of this system was monitored by field emission scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy and contact angle measurements. Multilayered coating with Gel/Chi retained the drug bioactivity and release properties, which were revealed by superoxide dismutase activity measurement. In addition, cytoskeleton observation and wound healing assay confirmed that BMP2-loaded and multilayer-coated TNT arrays were able to stimulate motogenic responses of mesenchymal stem cells (MSCs). More importantly, the system demonstrated that it was capable of promoting the osteoblastic differentiation of MSCs. This study may have potential impact on the development of bone implants for enhanced bone osseointegration.
细胞外微环境在调节细胞行为方面起着关键作用。为了模拟天然细胞外微环境，将负载骨形态发生蛋白 2（BMP2）的 TiO2 纳米管（TNT）阵列作为药物纳米储库构建在钛基板上，然后用明胶/壳聚糖（Gel/Chi）的多层涂层覆盖，以控制药物释放。多层涂层通过旋转辅助层层组装技术构建。通过场发射扫描电子显微镜、原子力显微镜、X 射线光电子能谱和接触角测量来监测该系统的成功制备。通过超氧化物歧化酶活性测量揭示了具有 Gel/Chi 的多层涂层保留了药物的生物活性和释放特性。此外，细胞骨架观察和伤口愈合试验证实，负载 BMP2 和多层涂层的 TNT 阵列能够刺激间充质干细胞（MSCs）的运动反应。更重要的是，该系统证明它能够促进 MSCs 的成骨分化。这项研究可能对开发用于增强骨整合的骨植入物具有潜在影响。
