School of Materials Science and Engineering, State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027, China.
School of Materials Science and Engineering, State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027, China; The Affiliated Stomatologic Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, China.
Acta Biomater. 2018 Apr 15;71:49-60. doi: 10.1016/j.actbio.2018.03.009. Epub 2018 Mar 15.
Mechanical stimuli at the bone-implant interface are considered to activate the mechanotransduction pathway of the cell to improve the initial osseointegration establishment and to guarantee clinical success of the implant. However, control of the mechanical stimuli at the bone-implant interface still remains a challenge. In this study, we have designed a strategy of a magnetically responsive coating on which the mechanical stimuli is controlled because of coating deformation under static magnetic field (SMF). The iron oxide nanoparticle/mineralized collagen (IOP-MC) coatings were electrochemically codeposited on titanium substrates in different quantities of IOPs and distributions; the resulting coatings were verified to possess swelling behavior with flexibility same as that of hydrogel. The relative quantity of IOP to collagen and the IOP distribution in the coatings were demonstrated to play a critical role in mediating cell behavior. The cells present on the outer layer of the distributed IOP-MC (O-IOP-MC) coating with a mass ratio of 0.67 revealed the most distinct osteogenic differentiation activity being promoted, which could be attributed to the maximized mechanical stimuli with exposure to SMF. Furthermore, the enhanced osteogenic differentiation of the stimulated MC3T3-E1 cells originated from magnetically actuated mechanotransduction signaling pathway, embodying the upregulated expression of osteogenic-related and mechanotransduction-related genes. This work therefore provides a promising strategy for implementing mechanical stimuli to activate mechanotransduction on the bone-implant interface and thus to promote osseointegration.
The magnetically actuated coating is designed to produce mechanical stimuli to cells for promoting osteogenic differentiation based on the coating deformation. Iron oxide nanoparticles (IOPs) were incorporated into the mineralized collagen coatings (MC) forming the composite coatings (IOP-MC) with spatially distributed IOPs, and the IOP-MC coatings with outer distributed IOPs (O-IOPs-MC) shows the maximized mechanical stimuli to cells with enhanced osteogenic differentiation under static magnetic field. The upregulated expression of the associated genes reveals that the enabled mechanotransduction signaling pathway is responsible for the promoted cellular osteogenic differentiation. This work therefore provides a promising strategy for implementing mechanical stimuli to activate mechanotransduction on the bone-implant interface to promote osseointegration.
被认为在骨-植入物界面处的机械刺激会激活细胞的机械转导途径，以改善初始骨整合的建立并保证植入物的临床成功。然而，对骨-植入物界面处的机械刺激的控制仍然是一个挑战。在这项研究中，我们设计了一种磁响应涂层策略，该策略可通过静态磁场（SMF）下的涂层变形来控制机械刺激。在不同数量的 IOP 和分布的情况下，将氧化铁纳米颗粒/矿化胶原（IOP-MC）涂层通过电化学共沉积在钛基底上；结果表明，所得涂层具有与水凝胶相同的柔韧性的溶胀行为。涂层中 IOP 与胶原的相对数量和 IOP 分布在调节细胞行为方面起着关键作用。具有 0.67 质量比的分布 IOP-MC（O-IOP-MC）涂层外层上的细胞表现出最明显的成骨分化活性，这归因于最大程度的机械刺激以及暴露于 SMF。此外，刺激的 MC3T3-E1 细胞的成骨分化增强源于磁驱动的机械转导信号通路，体现了成骨相关和机械转导相关基因的上调表达。因此，这项工作为在骨-植入物界面上实施机械刺激以激活机械转导并促进骨整合提供了一种有前途的策略。
