Zhao Xiaoduo, Karthik Namachivayam, Xiong Dangsheng, Liu Yuntong
School of Materials Science and Engineering, Nanjing University of Science and Technology, 210094, Nanjing, China; Jiangsu Key Laboratory of Advanced Micro/Nano Materials and Technology, 210094, Nanjing, China.
School of Materials Science and Engineering, Nanjing University of Science and Technology, 210094, Nanjing, China; Jiangsu Key Laboratory of Advanced Micro/Nano Materials and Technology, 210094, Nanjing, China.
J Mech Behav Biomed Mater. 2020 Dec;112:104032. doi: 10.1016/j.jmbbm.2020.104032. Epub 2020 Aug 19.
The biocompatible high-performance material PEEK (polyetheretherketone) is an attractive implant material, however, its hydrophobicity and high friction coefficients severely hinder its biomedical applications. Thus, it is inferred from the recent advances in surface modification technology, achieving the biomimetic natural joint lubrication systems on PEEK still remains a challenge. In view of the above, herein we proposed a novel two-step strategy to fabricate a "soft (dual cross-linked hydrogel) layer-hard (PEEK) substrate" texture that mimics the structure and function of soft cartilage on the hard basal bone in joints. At first, a layer of acrylic acid-co-acryl amide (AA-AM) hydrogel is anchored to the PEEK substrate through UV-initiated polymerization. In the second step, hydrogel coated PEEK substrate is immersed in ferric nitrate solution to create the secondary cross-linkage between Fe and -COOH groups in the hydrogel. As a result, the consequential top-coat hydrogel layer not only transforms the surface wettability (hydrophobic to hydrophilic) but also provides scratch resistance to the underlying PEEK substrate. The modified specimens display low friction coefficients in water under different load conditions. In addition, the obtained surface exhibits a certain self-repairing ability due to its unique physically reversible network structure. Therefore, this work provides a promising strategy for broadening the use of PEEK in orthopedic implants.
生物相容性高性能材料聚醚醚酮（PEEK）是一种有吸引力的植入材料，然而，其疏水性和高摩擦系数严重阻碍了其生物医学应用。因此，从表面改性技术的最新进展推断，在PEEK上实现仿生天然关节润滑系统仍然是一个挑战。鉴于此，我们在此提出了一种新颖的两步策略，以制造一种“软（双交联水凝胶）层-硬（PEEK）基底”结构，该结构模仿关节中硬基骨上软软骨的结构和功能。首先，通过紫外线引发的聚合反应将一层丙烯酸-丙烯酰胺（AA-AM）水凝胶固定在PEEK基底上。第二步，将涂有水凝胶的PEEK基底浸入硝酸铁溶液中，以在水凝胶中的铁和-COOH基团之间形成二次交联。结果，形成的表面涂层水凝胶层不仅改变了表面润湿性（从疏水性变为亲水性），而且还为下面的PEEK基底提供了抗划伤性。改性后的样品在不同负载条件下在水中显示出低摩擦系数。此外，由于其独特的物理可逆网络结构，所得表面具有一定的自修复能力。因此，这项工作为扩大PEEK在骨科植入物中的应用提供了一种有前景的策略。
