Inhibitor encapsulated, self-healable and cytocompatible chitosan multilayer coating on biodegradable Mg alloy: a pH-responsive design
Inhibitor encapsulated, self-healable and cytocompatible chitosan multilayer coating on biodegradable Mg alloy: a pH-responsive design
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可生物降解镁合金上的抑制剂封装、自修复和细胞相容性壳聚糖多层涂层：pH响应型设计
DOI：
10.1039/c6tb00117c
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发表时间：
2016-01-01
影响因子：
7
通讯作者：
Wei, Shicheng
中科院分区：
文献类型：
--
作者：
Jia, Zhaojun;Xiong, Pan;Wei, Shicheng
设计对外界刺激有智能响应的功能生物材料已成为一个迅速发展的领域，受到广泛关注。本工作有助于开发一种具有有趣的自我修复能力的反馈活性防腐蚀系统，以保护镁（Mg）免受生物腐蚀。该系统是由内部的微/纳米多孔，陶瓷状的预涂层开发容易从基板，和最外层的抑制剂（纳米级的铈（Ce）氧化物）含有壳聚糖（CS）的多层膜。在这里，预涂层充当“锚定”和“阻挡”层，以分别获得结构完整性和改善的阻抗。绿色CS用作Ce被捕获的货物，利用Ce-NH 2络合化学。通过电化学阻抗谱评价了涂层的阻隔性能。通过浸泡降解试验对活性缓蚀剂的Mg 2+释放、pH值变化、裂纹发展和扫描开尔文电位进行了评估。令我们高兴的是，与裸合金相比，涂层有效地保护了基底免受体外生物腐蚀。因此，pH触发Ce氧化物沉淀的形成，沿着CS大分子的pH缓冲活性和可移动溶胀能力，有助于抑制阳极活性和动态修复裂纹/缺陷。此外，涂层基质具有生物相容性，以引起更好的附着和生长的成骨细胞。
The design of functional biomaterials that respond intelligently to external stimuli has become a rapidly growing area with widespread interest. This work contributes to the development of a feedback-active anticorrosion system with intriguing self-healing ability to protect magnesium (Mg) from biocorrosion. The system was constituted by an inner micro/nano-porous, ceramic-like pre-coating developed readily from the substrate, and an outermost inhibitor (nanosized cerium (Ce) oxides) containing chitosan (CS) multilayers. Here, the pre-coating acted as both an "anchoring'' and a "barrier'' layer to acquire structural integrity and improved impedance, respectively. Green CS served as cargo for Ce to be entrapped, harnessing Ce-NH2 complexation chemistry. The coating barrier properties were evaluated by electrochemical impedance spectroscopy. The active corrosion inhibition was assessed by immersion degradation tests with respect to Mg2+ release, pH alteration, crack development, and scanning Kelvin potential. To our delight, the coatings effectively protected the substrate from biocorrosion in vitro compared with bare alloys. Putatively, the pH-triggered formation of Ce oxide precipitation, along with the pH-buffering activity and movable swelling capacity of CS macromolecules, should have contributed to restraining the anodic activity and healing the cracks/defects dynamically. Furthermore, the coated substrate had the biocompatibility to elicit better attachment and growth of osteoblasts.