Rapid bioinspired mineralization using cell membrane nanofragments and alkaline milieu
Rapid bioinspired mineralization using cell membrane nanofragments and alkaline milieu
复制标题
DOI：
10.1039/c8tb01544a
复制
发表时间：
2018-10-14
影响因子：
7
通讯作者：
Matsumoto, Takuya
中科院分区：
文献类型：
--
作者：
Hara, Emilio Satoshi;Okada, Masahiro;Matsumoto, Takuya
骨是一种复杂的有机-无机杂化材料，其形成涉及由细胞调控的复杂时空序列事件。更深入地了解不同尺寸尺度下骨矿化背后的机制，并使用多学科方法，可能会发现体外功能性骨组织设计和制造的新途径。本研究的目的是首先调查的环境因素，总理初始矿化使用次级骨化中心作为体内模型，然后应用所获得的知识，在体外快速合成骨样组织。首先，直接和强大的测量pH值表明，股骨骨骺是碱性的（pH值8.5），在初始矿物质阶段，在出生后第6天。我们发现，碱性环境是决定性的，不仅碱性磷酸酶的活性，这先于矿物形成在P6，但也确定初始矿物沉淀和球形形态。接下来，工程方法被用于合成基于碱性环境和人工软骨细胞膜纳米片段的骨样组织，之前被证明是矿物质形成的成核位点。有趣的是，使用人工细胞膜纳米片段的矿化仅在1天内实现。最后，在碱性pH下离体培养股骨骨骺强烈诱导软骨细胞破裂，这是先前显示的软骨细胞膜纳米片段的来源，也增强了矿物质形成。总之，这些发现不仅揭示了体内初始骨形成的微环境条件，而且还表明碱性环境可用作增强骨组织体外合成方法的重要因素。
Bone is a sophisticated organic-inorganic hybrid material, whose formation involves a complex spatio-temporal sequence of events regulated by the cells. A deeper understanding of the mechanisms behind bone mineralization at different size scales, and using a multidisciplinary approach, may uncover novel pathways for the design and fabrication of functional bone tissue in vitro. The objectives of this study were first to investigate the environmental factors that prime initial mineralization using the secondary ossification center as an in vivo model, and then to apply the obtained knowledge for rapid in vitro synthesis of bone-like tissue. First, the direct and robust measurement of pH showed that femur epiphysis is alkaline (pH 8.5) at the initial mineral stage at post-natal day 6. We showed that the alkaline milieu is decisive not only for alkaline phosphatase activity, which precedes mineral formation at P6, but also for determining initial mineral precipitation and spherical morphology. Next, engineering approaches were used to synthesize bone-like tissue based on alkaline milieu and artificial chondrocyte membrane nanofragments, previously shown to be the nucleation site for mineral formation. Interestingly, mineralization using artificial cell membrane nanofragments was achieved in just 1 day. Finally, ex vivo culture of femur epiphysis in alkaline pH strongly induced chondrocyte burst, which was previously shown to be the origin of chondrocyte membrane nanofragments, and also enhanced mineral formation. Taken together, these findings not only shed more light on the microenvironmental conditions that prime initial bone formation in vivo, but they also show that alkaline milieu can be used as an important factor for enhancing methods for in vitro synthesis of bone tissue.