Ye Jing, Li Bo, Zheng Yufeng, Wu Shuilin, Chen Dafu, Han Yong
State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China.
Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, China.
Bioact Mater. 2021 Dec 21;15:173-184. doi: 10.1016/j.bioactmat.2021.11.028. eCollection 2022 Sep.
Nanorods can induce mechano-puncture of () that often impairs osseointegration of orthopedic implants, while the critical nanorod top sharpness able to puncture and the predominant contributor between top sharpness and length to mechano-puncture activity remains elusive. Herein, we fabricated three kinds of AlO-wrapped nanorods patterned arrays with different lengths and top sharpness. The top-sharp nanorods have lengths of 469 and 884 nm and the shorter show a length identical to the top-flat nanorods. Driven by the equivalent adhesive force of , the top-flat nanorods deform cell envelops, showing a bacteriostatic rate of 29% owing to proliferation-inhibited manner. The top-sharp nanorods puncture , showing a bactericidal rate of 96% for the longer, and 98% for the shorter that simultaneously exhibits fair osseointegration in bacteria-infected rat tibias, identifying top sharpness as a predominate contributor to mechano-puncture activity. Based on finite-element simulation, such top-flat nanorod derives the maximum stress (S) of 5.65 MPa on cell wall, lower than its ultimate-tensile-strength (13 MPa); while such top-sharp and shorter nanorod derives S of 20.15 MPa to puncture cell envelop. Moreover, a critical top conical angle of 138° is identified for nanorods able to puncture .
纳米棒可引发（）的机械穿刺，这常常会损害骨科植入物的骨整合，然而能够穿刺的关键纳米棒顶端尖锐度以及顶端尖锐度和长度对机械穿刺活性的主要贡献因素仍不明确。在此，我们制备了三种具有不同长度和顶端尖锐度的AlO包裹的纳米棒图案化阵列。顶端尖锐的纳米棒长度分别为469和884纳米，较短的纳米棒长度与顶端扁平的纳米棒相同。在（）的等效粘附力作用下，顶端扁平的纳米棒使细胞膜变形，由于增殖抑制方式，抑菌率为29%。顶端尖锐的纳米棒进行穿刺，较长的纳米棒杀菌率为96%，较短的纳米棒杀菌率为98%，且在细菌感染的大鼠胫骨中同时表现出良好的骨整合，这表明顶端尖锐度是机械穿刺活性的主要贡献因素。基于有限元模拟，这种顶端扁平的纳米棒在细胞壁上产生的最大应力（S）为5.65兆帕，低于其极限抗拉强度（13兆帕）；而这种顶端尖锐且较短的纳米棒产生20.15兆帕的应力以穿刺细胞膜。此外，确定能够穿刺（）的纳米棒的临界顶端锥角为138°。
