Lee Jin Woo, Park Jin-Woo, Khang Dongwoo
Department of Molecular Medicine, School of Medicine, Gachon University, Incheon, South Korea.
Department of Periodontology, School of Dentistry, Kyungpook National University, Daegu, South Korea.
PLoS One. 2015 Jun 15;10(6):e0129856. doi: 10.1371/journal.pone.0129856. eCollection 2015.
Osteoblast differentiation can be modulated by variations in order of nanoscale topography. Biopolymers embedded with carbon nanotubes can cause various orders of roughness at the nanoscale and can be used to investigate the dynamics of extracellular matrix interaction with cells. In this study, clear relationship between the response of osteoblasts to integrin receptor activation, their phenotype, and transcription of certain genes on polymer composites embedded with carbon nanotubes was demonstrated. We generated an ultrathin nanocomposite film embedded with carbon nanotubes and observed improved adhesion of pre-osteoblasts, with a subsequent increase in their proliferation. The expression of genes encoding integrin subunits α5, αv, β1, and β3 was significantly upregulated at the early of time-point when cells initially attached to the carbon nanotube/polymer composite. The advantage of ultrathin nanocomposite film for pre-osteoblasts was demonstrated by staining for the cytoskeletal protein vinculin and cell nuclei. The expression of essential transcription factors for osteoblastogenesis, such as Runx2 and Sp7 transcription factor 7 (known as osterix), was upregulated after 7 days. Consequently, the expression of genes that determine osteoblast phenotype, such as alkaline phosphatase, type I collagen, and osteocalcin, was accelerated on carbon nanotube embedded polymer matrix after 14 days. In conclusion, the ultrathin nanocomposite film generated various orders of nanoscale topography that triggered processes related to osteoblast bone formation.
成骨细胞分化可通过纳米级形貌顺序的变化来调节。嵌入碳纳米管的生物聚合物可在纳米级引起各种粗糙度，并可用于研究细胞外基质与细胞相互作用的动力学。在本研究中，证明了成骨细胞对整合素受体激活的反应、其表型以及嵌入碳纳米管的聚合物复合材料上某些基因的转录之间存在明确的关系。我们制备了一种嵌入碳纳米管的超薄纳米复合膜，并观察到前成骨细胞的粘附得到改善，随后其增殖增加。当细胞最初附着于碳纳米管/聚合物复合材料时，编码整合素亚基α5、αv、β1和β3的基因表达在时间点早期显著上调。通过对细胞骨架蛋白纽蛋白和细胞核进行染色，证明了超薄纳米复合膜对前成骨细胞的优势。成骨细胞分化所必需的转录因子，如Runx2和Sp7转录因子7（即osterix）的表达在7天后上调。因此，在14天后，决定成骨细胞表型的基因，如碱性磷酸酶、I型胶原蛋白和骨钙素的表达在嵌入碳纳米管的聚合物基质上加速。总之，超薄纳米复合膜产生了各种纳米级形貌顺序，触发了与成骨细胞骨形成相关的过程。
