幹細胞の機能性を制御するためのマイクロ・ナノ複合パターン材料の創出

在这一年，我继续我的研究，以调查细胞生物材料的相互作用，使用微米和纳米图案。通过控制单细胞的大小，使用微图案，细胞纳米力学以及细胞摄取行为进行了研究。结果表明，细胞骨架力和细胞膜张力随细胞体积的增大而增大。高的膜张力需要高的包裹能量来吞没纳米颗粒。为了进一步区分细胞铺展面积和粘附面积对细胞功能的独立影响，设计了一系列微图案。微图案包括由许多小微粒组成的大圆圈。将人骨髓间充质干细胞在微模板上培养，诱导其向成骨细胞和脂肪细胞分化。结果表明，细胞粘附区比铺展区在干细胞命运决定中起更重要的作用。这些工作均发表在国际著名科学期刊上。制备了一系列不同深度和深宽比的纳米凹槽。结合我们的微图案化技术，成功地制备了混合微/纳米图案，并用于人骨髓间充质干细胞的肌样分化。混合微/纳米图案显示出良好的控制细胞排列的能力。干细胞的成肌分化仍在评估中。

In this year, I continued my research to investigate the cell-biomaterial interactions using micro- and nano-patterns. By controlling the size of single cells using micropatterns, the cell nanomechanics as well as the cellular uptake behavior were studied. The results showed that the cytoskeleton force and cell membrane tension increased with increase of cell size. And high membrane tension required high wrapping energy to engulf the nanoparticles. To further discriminate the independent influence of cell spreading area and adhesion area on cell functions, a serious of micropatterns were designed. The micropatterns included large circles that composed of numerous small microdots. Human mesenchymal stem cells were cultured on the micropatterns and were induced to differentiate into osteoblasts and adipocytes. The results showed that the cell adhesion area rather than the spreading area played more important roles in stem cell fate determination. All these works have been published in international famous scientific journals.The nanopatterns were fabricated using contact printing method. A serious of nanogrooves with different depth and aspect ratio were prepared. Combined with our micropatterning technique, the hybrid micro-/nano-patterns were successfully prepared and used for myogenic differentiation of human mesenchymal stem cells. The hybrid micro-/nano-patterns showed good capacity to control cell alignment. The myogenic differentiation of stem cells are still under evaluation.