The recently developed additively manufacturing techniques have enabled the fabrication of porous biomaterials that mimic the characteristics of the native bone, thereby avoiding stress shielding and facilitating bony ingrowth. However, aseptic loosening and bacterial infection, as the leading causes of implant failure, need to be further addressed through surface biofunctionalization. Here, we used a combination of (1) plasma electrolytic oxidation (PEO) using Ca-, P-, and silver nanoparticle-rich electrolytes and (2) post-PEO hydrothermal treatments (HT) to furnish additively manufactured Ti-6Al-4V porous implants with a multi-functional surface. The applied HT led to the formation of hydroxyapatite (HA) nanocrystals throughout the oxide layer. This process was controlled by the supersaturation of Ca²⁺ and PO₄³⁻ during the hydrothermal process. Initially, the high local supersaturation resulted in homogenous nucleation of spindle-like nanocrystals throughout the surface. As the process continued, the depletion of reactant ions in the outermost surface layer led to a remarkable decrease in the supersaturation degrees. High aspect-ratio nanorods and hexagonal nanopillars were, therefore, created. The unique hierarchical structure of the microporous PEO layer (pore size < 3 μm) and spindle-like HA nanocrystals (<150 nm) on the surface of macro-porous additively manufactured Ti-6Al-4V implants provided a favorable substrate for the anchorage of cytoplasmic extensions assisting cell attachment and migration on the surface. The results of our in vitro assays clearly showed the important benefits of the HT and the spindle-like HA nanocrystals including a significantly stronger and much more sustained antibacterial activity, significantly higher levels of pre-osteoblasts metabolic activity, and significantly higher levels of alkaline phosphatase activity as compared to similar PEO-treated implants lacking the HT.

最近开发的增材制造技术使得能够制造模仿天然骨骼特征的多孔生物材料，从而避免了应力屏蔽并促进了骨的向内生长。但是，作为植入失败的主要原因，无菌性松动和细菌感染需要通过表面生物功能化进一步解决。在这里，我们结合使用了（1）使用富含Ca，P和银纳米粒子的电解质进行等离子体电解氧化（PEO），以及（2）PEO后水热处理（HT）以提供增材制造的Ti-6Al-4V具有多功能表面的多孔植入物。所施加的HT导致在整个氧化物层中形成羟基磷灰石（HA）纳米晶体。此过程由Ca ²⁺的过饱和控制和PO ₄ ^3-在水热过程中。最初，高的局部过饱和度导致整个表面纺锤状纳米晶体的均匀成核。随着该过程的继续，最外表面层中反应离子的消耗导致过饱和度显着降低。因此，创建了高纵横比的纳米棒和六角形的纳米柱。微孔PEO层（孔径<3μm）和大孔加法制造的Ti-6Al-4V植入物表面上的纺锤状HA纳米晶体（<150 nm）的独特的分层结构为锚固纳米线提供了良好的基质胞质延伸有助于细胞在表面的附着和迁移。我们体外的结果 分析清楚地表明，与类似的PEO相比，HT和纺锤状HA纳米晶体具有重要的优势，包括明显更强和更持久的抗菌活性，成骨细胞前代谢活性水平明显更高以及碱性磷酸酶活性水平更高-治疗的植入物缺乏HT。