Biomimetic Mineralization of Hierarchical Nanofiber Shish-Kebabs in a Concentrated Apatite-Forming Solution
Biomimetic Mineralization of Hierarchical Nanofiber Shish-Kebabs in a Concentrated Apatite-Forming Solution
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DOI：
10.1021/acsabm.0c01133
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发表时间：
2021-01-18
影响因子：
4.7
通讯作者：
Li, Christopher Y.
中科院分区：
文献类型：
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作者：
Gleeson, Sarah E.;Kim, Seyong;Li, Christopher Y.
近年来，被称为“烤肉串”（NFSKs）的分级聚合物纳米结构在指导矿物分布以实现生物矿化方面显示出巨大的潜力。在这项工作中，我们报告控制仿生矿化嵌段共聚物含NFSK。通过在PCL纤维骨架上结晶聚己内酯-嵌段-聚（丙烯酸）（PCL-b-PAA）串来形成NFSK。嵌段共聚物串以类似于100-300 nm的间距周期性地分布在PCL纳米纤维上。自由离子可以渗透到阴离子PAA纳米结构域中，并启动NFSK模板仿生矿化过程。在本研究中使用的浓缩磷酸钙溶液，这导致显着加速矿化动力学与以前研究的模拟体液系统相比。电子显微镜，傅里叶变换红外光谱，广角X射线衍射被用来表征矿化NFSK的结构和形态。确定了一个三阶段的矿化过程，并在第二阶段后观察到碳酸化的非化学计量羟基磷灰石，矿物位置在烤肉串中模板化。这种加速的矿化过程产生了仿生磷酸钙相沿着纤维的周期性矿物分布，并且矿物形成时间的减少允许更有效的生物矿化研究和复合材料形成。
Recently, hierarchical polymer nanostructures called nanofiber shish-kebabs (NFSKs) have shown great potential in directing the distribution of minerals for biomineralization. In this work, we report controlled biomimetic mineralization in block copolymer-containing NFSKs. NFSKs were formed by crystallizing polycaprolactone-block-poly(acrylic acid) (PCL-b-PAA) kebabs on PCL fiber backbones. The block copolymer kebabs were periodically distributed on PCL nanofibers with a spacing of similar to 100-300 nm. Free ions could infiltrate into anionic PAA nanodomains and initiate the NFSK-templated biomimetic mineralization process. A concentrated calcium phosphate solution was used in the present study, which led to significantly accelerated mineralization kinetics compared with the previously studied simulated body fluid systems. Electron microscopy, Fourier-transform infrared spectroscopy, and wide-angle X-ray diffraction were used to characterize the structure and morphology of the mineralized NFSKs. A three-stage mineralization process was identified, and carbonated nonstoichiometric hydroxyapatite was observed after stage 2 with the mineral location templated within kebabs. This accelerated mineralization process yielded a periodic mineral distribution of a biomimetic calcium phosphate phase along the fibers, and the decrease in mineral formation time allows for more efficient biomineralization study and composite formation.