Zhang Bowen, Leng Junqing, Ouyang Zhicong, Yang Zijian, Zhang Qing, Li Qingchu, Li Dichen, Zhao Huiyu
State Key Laboratory for Manufacturing System Engineering, School of Mechanical Engineering, Xi'an Jiaotong University, 710054 Xi'an, Shaanxi, China; National Medical Products Administration (NMPA), Key Laboratory for Research and Evaluation of Additive Manufacturing Medical Devices, Xi'an Jiaotong University, 710054 Xi'an, Shaanxi, China.
Academy of Orthopedics·Guangdong Province, Orthopedic Hospital of Guangdong Province, Department of Spine Surgery, Center for Orthopaedic Surgery, The Third Affiliated Hospital of Southern Medical University, 510665 Guangzhou, China.
Biomater Adv. 2023 Mar;146:213310. doi: 10.1016/j.bioadv.2023.213310. Epub 2023 Jan 24.
Polyetheretherketone (PEEK) has been widely used in the preparation of orthopedic implants due to its biological inertness and similar mechanical modulus to natural bone. However, the affinity between biological tissue (bone and soft tissue) and PEEK surface is weak, leading to low osseointegration and an increased risk of inflammation. The situation could be improved by modifying PEEK surface. Surfaces with good hydrophilicity and proper microtopography would promote cellular adhesion and proliferation. This work presented a two-step surface modification method to achieve the effect. Polyacrylic acid (PAA) chains were grafted on PEEK surface by UV irradiation. Then, ethylenediamine (EDA) was added to introduce amino groups and promote the cross-linking of PAA chains. Furthermore, a mathematical model was built to describe and regulate the surface topography growth process semi-quantitatively. The model fits experimental data quite well (adjusted R = 0.779). Results showed that the modified PEEK surface obtained superhydrophilicity. It significantly improved the adhesion and proliferation of BMSCs and MFBs by activating the FAK pathway and Rho family GTPase. The cellular affinity performed better when the surface topography was in network structure with holes in about 25 μm depth and 20-50 μm diameter. Good hydrophilicity seems necessary for the FAK pathway activation, but simply improving surface hydrophilicity might not be enough for cellular affinity improvement. Surface topography at micron scale should be a more important cue. This simple surface modification method could be contributed to further study of cell-microtopography interaction and have potential applications in clinical PEEK orthopedic implants.
聚醚醚酮（PEEK）因其生物惰性以及与天然骨相似的机械模量，已被广泛应用于骨科植入物的制备。然而，生物组织（骨组织和软组织）与PEEK表面之间的亲和力较弱，导致骨整合性低且炎症风险增加。通过对PEEK表面进行改性可以改善这种情况。具有良好亲水性和适当微观形貌的表面会促进细胞黏附和增殖。这项工作提出了一种两步表面改性方法来实现这一效果。通过紫外线照射将聚丙烯酸（PAA）链接枝到PEEK表面。然后，加入乙二胺（EDA）以引入氨基并促进PAA链的交联。此外，建立了一个数学模型来半定量地描述和调节表面形貌生长过程。该模型与实验数据拟合得很好（调整后的R = 0.779）。结果表明，改性后的PEEK表面具有超亲水性。它通过激活黏着斑激酶（FAK）途径和Rho家族GTP酶，显著改善了骨髓间充质干细胞（BMSCs）和成纤维细胞（MFBs）的黏附和增殖。当表面形貌为具有约25μm深度和20 - 50μm直径孔洞的网络结构时，细胞亲和力表现更好。良好的亲水性似乎是激活FAK途径所必需的，但仅仅提高表面亲水性可能不足以改善细胞亲和力。微米级的表面形貌应该是一个更重要的线索。这种简单的表面改性方法有助于进一步研究细胞与微观形貌的相互作用，并在临床PEEK骨科植入物中具有潜在应用。
