Application of silver nanoparticles for improving motor recovery after spinal cord injury via reduction of pro-inflammatory M1 macrophages

Jie Lin; Peikai Chen; Zhijia Tan; Yi Sun; Wai Kit Tam; Di Ao; Wei Shen; Victor Yu-Leong Leung; Kenneth Man Chee Cheung; Michael Kai Tsun To

doi:10.1016/j.heliyon.2023.e15689

Application of silver nanoparticles for improving motor recovery after spinal cord injury via reduction of pro-inflammatory M1 macrophages

Heliyon. 2023 May 9;9(5):e15689. doi: 10.1016/j.heliyon.2023.e15689. eCollection 2023 May.

Authors

Jie Lin^{1

2}, Peikai Chen¹, Zhijia Tan¹, Yi Sun³, Wai Kit Tam², Di Ao², Wei Shen², Victor Yu-Leong Leung², Kenneth Man Chee Cheung^{1

2}, Michael Kai Tsun To^{1

2}

Affiliations

¹ Department of Orthopaedics & Traumatology, The University of Hong Kong Shenzhen Hospital, School of Clinical Medicine, The University of Hong Kong, Shenzhen, Guangdong, 518053, China.
² Department of Orthopaedics & Traumatology, School of Clinical Medicine, The University of Hong Kong, 21 Sassoon Road, Pokfulam, Hong Kong SAR, China.
³ Department of Sports Medicine, Peking University-Shenzhen Hospital, Shenzhen, Guangdong, 518034, China.

Abstract

Silver nanoparticles (AgNPs) possess anti-inflammatory activities and have been widely deployed for promoting tissue repair. Here we explored the efficacy of AgNPs on functional recovery after spinal cord injury (SCI). Our data indicated that, in a SCI rat model, local AgNPs delivery could significantly recover locomotor function and exert neuroprotection through reducing of pro-inflammatory M1 survival. Furthermore, in comparison with Raw 264.7-derived M0 and M2, a higher level of AgNPs uptake and more pronounced cytotoxicity were detected in M1. RNA-seq analysis revealed the apoptotic genes in M1 were upregulated by AgNPs, whereas in M0 and M2, pro-apoptotic genes were downregulated and PI3k-Akt pathway signaling pathway was upregulated. Moreover, AgNPs treatment preferentially reduced cell viability of human monocyte-derived M1 comparing to M2, supporting its effect on M1 in human. Overall, our findings reveal AgNPs could suppress M1 activity and imply its therapeutic potential in promoting post-SCI motor recovery.