A programmed surface on polyetheretherketone for sequentially dictating osteoimmunomodulation and bone regeneration to achieve ameliorative osseointegration under osteoporotic conditions

Yanyan Zheng; Ang Gao; Jiaxiang Bai; Qing Liao; Yuzheng Wu; Wei Zhang; Min Guan; Liping Tong; Dechun Geng; Xin Zhao; Paul K Chu; Huaiyu Wang

doi:10.1016/j.bioactmat.2022.01.042

A programmed surface on polyetheretherketone for sequentially dictating osteoimmunomodulation and bone regeneration to achieve ameliorative osseointegration under osteoporotic conditions

Bioact Mater. 2022 Feb 1:14:364-376. doi: 10.1016/j.bioactmat.2022.01.042. eCollection 2022 Aug.

Authors

Yanyan Zheng^{1

2}, Ang Gao¹, Jiaxiang Bai³, Qing Liao¹, Yuzheng Wu⁴, Wei Zhang⁵, Min Guan¹, Liping Tong¹, Dechun Geng³, Xin Zhao⁶, Paul K Chu⁴, Huaiyu Wang¹

Affiliations

¹ Center for Human Tissues and Organs Degeneration, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China.
² School of Basic Medical Sciences and Forensic Medicine, North Sichuan Medical College, Nanchong, 637000, China.
³ Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou, 215006, China.
⁴ Department of Physics, Department of Materials Science and Engineering, Department of Biomedical Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China.
⁵ Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
⁶ Department of Biomedical Engineering, The Hong Kong Polytechnic University, Hong Kong, China.

Abstract

Polyetheretherketone (PEEK) is a desirable alternative to conventional biomedical metals for orthopedic implants due to the excellent mechanical properties. However, the inherent bioinertness of PEEK contributes to inferior osseointegration of PEEK implants, especially under pathological conditions of osteoporosis. Herein, a programmed surface is designed and fabricated on PEEK to dictate osteoimmunomodulation and bone regeneration sequentially. A degradable hybrid coating consisting of poly(lactide-co-glycolide) and alendronate (ALN) loaded nano-hydroxyapatite is deposited on PEEK and then interleukin-4 (IL-4) is grafted onto the outer surface of the hybrid coating with the aid of N₂ plasma immersion ion implantation and subsequent immersion in IL-4 solution. Dominant release of IL-4 together with ALN and Ca²⁺ during the first few days synergistically mitigates the early acute inflammatory reactions and creates an osteoimmunomodulatory microenvironment that facilitates bone regeneration. Afterwards, slow and sustained delivery of ALN and Ca²⁺ in the following weeks boosts osteogenesis and suppresses osteoclastogenesis simultaneously, consequently ameliorating bone-implant osseointegration even under osteoporotic conditions. By taking into account the different phases in bone repair, this strategy of constructing advanced bone implants with sequential functions provides customizable and clinically viable therapy to osteoporotic patients.

Keywords: Osseointegration; Osteoimmunomodulation; Osteoporosis; Polyetheretherketone; Sequential release; Surface modification.