Xu Shao
,
Zhou Zhiyu
,
Gao Manman
,
Zou Changye
,
Che Yinglin
,
Cody Bünger
,
Zou Xuenong
,
Zhou Lei
材料科学技术（英）
doi:10.1016/j.jmst.2016.08.009
Titanium (Ti) nanorods fabricated using selective corrosion of Ti substrate by anodic technology show better biocompatibility with pre-osteoblast cells. The current study investigated the response of the murine pre-osteoblast cell MC3T3-E1 on Ti nanorod topography and untreated Ti surfaces by means of examination of the morphology and osteogenic differentiation responsible for the pre-osteoblast reaction. The morphology of MC3T3-E1 cells was observed using scanning electron microscopy, and alkaline phosphatase (ALP) activity was measured using a colorimetric assay after incubation for 7, 14, and 21 days. The expression of three osteogenic differentiation markers including ALP, osteocalcin (OCN), and collagen type 1A1 (COL1A1) and two transcription factors including runt related transcription factor 2 (Runx2) and osterix (Osx) at different time points was detected using real-time polymerase chain reaction analysis in both groups. Osx was used to confirm the protein level. The results showed that Ti nanorod surfaces provided prolonged higher levels of ALP activity compared with unmodified Ti surface on the 14th and 21st days. Gene expression analysis of ALP, OCN, and COL1A1 showed significant upregulation with modified nanorod topography after incubation for 14 and 21 days. Osteogenic transcription factors of Runx2 and Osx exhibited changes consistent with the osteogenic differentiation markers, and this may contribute to the persistently active differentiation of MC3T3-E1 cells in the Ti nanorod group. These results demonstrated that the current nanostructured surface may be considered bioadaptive topography to control cellular behaviors and osteoblast differentiation. The in vivo performance and applicability are further required to investigate osseointegration between implant and host bone in the early stages for prevention of aseptic implant loosening.
关键词:
Titanium
,
Nanorods
,
Osteointegration
,
Osteoblast differentiation
陈高飞
,
公茂琼
,
邹鑫
,
吴剑峰
,
汪胜
工程热物理学报
对乙烷、丙烷纯质及三种不同浓度比例的乙烷／丙烷二元混合物在内径为8mm的水平管内进行了饱和流动沸腾传热特性的实验研究，重点分析了热流密度、质量流量的变化对二元混合工质传热系数的影响。选用了4种专用于计算混合物流动换热的关联式，并与实验数据进行了比较，其中Gungor—Winterton and Thome关联式和Zou关联式的预测偏差相对较小，且计算过程较为简单，较适合用于该工况范围的混合工质传热预测。
关键词:
流动沸腾
,
乙烷
,
丙烷
,
传热关联式
,
水平管
