ZnO nanoparticles attenuate polymer-wear-particle induced inflammatory osteolysis by regulating the MEK-ERK-COX-2 axis

Xiangchao Meng; Wei Zhang; Zhuocheng Lyu; Teng Long; You Wang

doi:10.1016/j.jot.2022.04.001

ZnO nanoparticles attenuate polymer-wear-particle induced inflammatory osteolysis by regulating the MEK-ERK-COX-2 axis

J Orthop Translat. 2022 Apr 22:34:1-10. doi: 10.1016/j.jot.2022.04.001. eCollection 2022 May.

Authors

Xiangchao Meng¹, Wei Zhang¹, Zhuocheng Lyu¹, Teng Long¹, You Wang¹

Affiliation

¹ Department of Bone and Joint Surgery, Renji Hospital, School of Medicine, Shanghai Jiaotong University, 145 Middle Shandong Road, 200001, Shanghai, China.

Abstract

Background/objectives: Advanced thermoplastic materials, such as polyether-ether-ketone (PEEK) and highly cross-linked polyethylene (HXLPE), have been increasingly used as orthopaedic implant materials. Similar to other implants, PEEK-on-HXLPE prostheses produce debris from polymer wear that may activate the immune response, which can cause osteolysis, and ultimately implant failure. In this study, we examined whether the anti-inflammatory properties of zinc oxide nanoparticles (ZnO NPs) could attenuate polymer wear particle-induced inflammation.

Methods: RAW264.7 cells were cultured with PEEK or PE particles and gradient concentrations of ZnO NPs. Intracellular mRNA expression and protein levels of pro-inflammatory factors TNF-α, IL-1β, and IL-6 were detected. An air pouch mouse model was constructed to examine the inflammatory response and expression of pro-inflammatory factors in vivo. Furthermore, an osteolysis rat model was used to evaluate the activation of osteoclasts and destruction of bone tissue induced by polymer particles with or without ZnO NPs. Protein expression of the MEK-ERK-COX-2 pathway was also examined by western blotting to elucidate the mechanism underlying particle-induced anti-inflammatory effects.

Results: ZnO NPs (≤50 nm, 5 μg/mL) showed no obvious cytotoxicity and attenuated PEEK or PE particle-induced inflammation and inflammatory osteolysis by reducing MEK and ERK phosphorylation and decreasing COX-2 expression.

Conclusion: ZnO NPs (≤50 nm, 5 μg/mL) attenuated polymer wear particle-induced inflammation via regulation of the MEK-ERK-COX-2 axis. Further, ZnO NPs reduced bone tissue damage caused by particle-induced inflammatory osteolysis.

The translational potential of this article: Polymer wear particles can induce inflammation and osteolysis in the body after arthroplasty. ZnO NPs attenuated polymer particle-induced inflammation and inflammatory osteolysis. Topical use of ZnO NPs and blended ZnO NP/polymer composites may provide promising approaches for inhibiting polymer wear particle-induced inflammatory osteolysis, thus expanding the range of polymers used in joint prostheses.

Keywords: Inflammatory osteolysis; Mitogen-activated protein kinase pathway; Wear particle; Zinc oxide nanoparticles.