In vitro degradation of biodegradable polymer-coated magnesium under cell culture condition
In vitro degradation of biodegradable polymer-coated magnesium under cell culture condition
复制标题
DOI：
10.1016/j.apsusc.2012.03.036
复制
发表时间：
2012-06
影响因子：
6.7
通讯作者：
Liping Xu;A. Yamamoto
中科院分区：
文献类型：
--
作者：
Liping Xu;A. Yamamoto
将高分子量聚乳酸（PLLA）、低分子量聚乳酸（LMW）、高分子量聚己内酯（PCL）和低分子量聚己内酯（PCL-LMW）4种聚合物包覆镁（Mg）和未包覆镁（Mg）置于细胞培养条件下，研究了聚合物包覆镁的降解/腐蚀行为。在浸泡期间测量Mg 2+的释放。通过扫描电镜和能谱仪对表面形貌和化学成分进行了观察和鉴定。通过X射线CT观察获得断层扫描，并通过图像分析计算浸泡10天后的降解率。与未涂覆的Mg相比，所有类型的聚合物涂覆的Mg在整个浸泡过程中都显示出显著低的Mg 2+释放（p<0.05）。SEM和EDX结果表明，浸泡后，聚合物涂层和未涂层的Mg上都可以观察到腐蚀层。结果表明，与未涂层镁相比，聚合物涂层镁腐蚀层的形貌和化学成分没有明显差异，表明聚合物涂层并未改变镁基体在本实验条件下的腐蚀/降解过程和腐蚀产物。关于10天浸泡的层析成像和降解速率，可以发现聚合物涂覆的Mg显示出与未涂覆的Mg相比显著低的腐蚀速率（p<0.05）。PLLA涂覆的Mg显示出比PCL涂覆的Mg和未涂覆的Mg相对均匀的腐蚀。PCL-LMW的最大点蚀深度约为PLLA-LMW的3倍，这可能归因于聚合物微观结构的差异。这表明PLLA涂层可能是一个合适的选择，以延缓镁基板的机械性能的损失。
Magnesium (Mg) coated with four kinds of polymers, poly (l-lactic acid) (PLLA)-high molecular weight (HMW), PLLA-low molecular weight (LMW), poly (ɛ-caprolactone) (PCL)-HMW and PCL-LMW, and uncoated Mg were immersed under cell culture condition to study the degradation/corrosion behavior of the polymer-coated Mg. The releases of Mg2+are measured during the immersion. Surface morphology and chemical composition are observed and identified by SEM and EDX. The tomography is obtained by X-ray CT observation and degradation rate is calculated by image analysis after 10-day immersion. All kinds of polymer-coated Mg showed significantly low release of Mg2+(p<0.05) in the whole immersion process comparing to that of uncoated Mg. In SEM and EDX results show, a corrosion layer can be observed on both polymer-coated and uncoated Mg after immersion. There is no obvious difference on the morphology and chemical composition of the corrosion layer between polymer-coated and uncoated Mg, indicating the corrosion/degradation process and corrosion product of Mg substrate are not changed by the polymer films under the present condition compared with uncoated Mg. Concerning the tomography and degradation rate of 10-day immersion, it can be found that the polymer-coated Mg shows a significantly low corrosion rate (p<0.05) compared with that of uncoated Mg. PLLA coated Mg shows relatively uniform corrosion than PCL coated Mg and uncoated Mg. The largest pitting corrosion depth of PCL-LMW is about 3 times as large as the PLLA-LMW, which might be attributed to the difference of polymer microstructure. It is suggested that PLLA coating might be a suitable option for retarding the loss of mechanical properties of Mg substrate.