Duan Bo, Shou Kangquan, Su Xiaojuan, Niu Yahui, Zheng Guan, Huang Yao, Yu Aixi, Zhang Yu, Xia Hong, Zhang Lina
College of Chemistry and Molecular Sciences, Wuhan University , Wuhan 430072, China.
Zhongnan Hospital, Wuhan University , Wuhan 430072, China.
Biomacromolecules. 2017 Jul 10;18(7):2080-2089. doi: 10.1021/acs.biomac.7b00408. Epub 2017 Jun 28.
Chitin exists abundantly in crab and shrimp shells as the template of the minerals, which inspired us to mineralize it for fabricating bone grafting materials. In the present work, chitin nanofibrous microspheres were used as the matrix for in situ synthesis of hydroxyapatite (HA) crystals including microflakes, submicron-needles, and submicron-spheres, which were penetrated by long chitin nanofibers, leading to the hierarchical structure. The shape and size of the HA crystals could be controlled by changing the HA synthesis process. The tight interface adhesion between chitin and HA through the noncovanlent bonds occurred in the composite microspheres, and HAs were homogeneously dispersed and bounded to the chitin nanofibers. In our findings, the inherent biocompatibilities of the both chitin and HA contributed the bone cell adhesion and osteoconduction. Moreover, the chitin microsphere with submicron-needle and submicron-sphere HA crystals remarkably promoted in vitro cell adhesion and in vivo bone healing. It was demonstrated that rabbits with 1.5 cm radius defect were almost cured completely within three months in a growth factor- and cell-free state, as a result of the unique surface microstructure and biocompatibilities of the composite microspheres. The microsphere scaffold displayed excellent biofunctions and an appropriate biodegradability. This work opened up a new avenue to construct natural polymer-based organic-inorganic hybrid microspheres for bone regeneration.
几丁质作为矿物质的模板大量存在于蟹壳和虾壳中，这启发我们使其矿化以制备骨移植材料。在本研究中，几丁质纳米纤维微球被用作原位合成羟基磷灰石（HA）晶体的基质，这些晶体包括微薄片、亚微米针状和亚微米球状，被长几丁质纳米纤维贯穿，形成了分级结构。HA晶体的形状和尺寸可以通过改变HA合成过程来控制。几丁质与HA之间通过非共价键形成紧密的界面粘附，在复合微球中HA均匀分散并与几丁质纳米纤维结合。在我们的研究结果中，几丁质和HA固有的生物相容性有助于骨细胞粘附和骨传导。此外，带有亚微米针状和亚微米球状HA晶体的几丁质微球显著促进了体外细胞粘附和体内骨愈合。结果表明，半径为1.5 cm缺损的兔子在无生长因子和无细胞状态下，三个月内几乎完全治愈，这得益于复合微球独特的表面微观结构和生物相容性。微球支架表现出优异的生物功能和适当的生物降解性。这项工作为构建用于骨再生的天然聚合物基有机-无机杂化微球开辟了一条新途径。
