Reversing inflammatory microenvironment by a single intra-articular injection of multi-stimulus responsive lipogel to relieve rheumatoid arthritis and promote joint repair

Jun Tao; Peng Yang; Mingying Gao; Fan Zhang; Yongzhong Wu; Yan Jiang; Yunxuan Ning; Zhenglin Li; Fanrong Ai

doi:10.1016/j.mtbio.2023.100622

Reversing inflammatory microenvironment by a single intra-articular injection of multi-stimulus responsive lipogel to relieve rheumatoid arthritis and promote joint repair

Mater Today Bio. 2023 Mar 31:20:100622. doi: 10.1016/j.mtbio.2023.100622. eCollection 2023 Jun.

Authors

Jun Tao¹, Peng Yang¹, Mingying Gao², Fan Zhang^{3

4}, Yongzhong Wu⁵, Yan Jiang¹, Yunxuan Ning¹, Zhenglin Li^{3

4}, Fanrong Ai⁶

Affiliations

¹ The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330000, PR China.
² Pingyang Hospital Affiliated to Wenzhou Medical University, Wenzhou, Zhejiang 325400, PR China.
³ School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, PR China.
⁴ Oujiang Laboratory (Zhejiang Lab for Regenerative Medicine, Vision and Brain Health), Wenzhou, Zhejiang 325000, PR China.
⁵ Department of Orthopaedics, The Second People's Hospital of Jingdezhen, Jingdezhen, Jiangxi 333099, PR China.
⁶ School of Advanced Manufacturing, Nanchang University, Nanchang, Jiangxi 330031, PR China.

Abstract

Rheumatoid arthritis (RA) is a common chronic disease dominated by inflammatory synovitis, which is characterized with hyperplastic synovium, up-regulated matrix metalloproteinase (MMP) expression, hypoxic joint cavity and excessive reactive oxygen species (ROS) accumulation. Such local adverse microenvironment in RA joints further exacerbates the infiltration of synovial inflammatory cells, especially M1-type macrophages. Regulating intra-articular pathological conditions, eliminating excess M1 macrophages or converting them to an anti-inflammatory M2 phenotype may break the vicious progression circle. Herein, we develop a multi-stimulus responsive lipogel as effective platform to relieve RA symptoms and promote articular cartilage recovery via reversing its inflammatory microenvironment. The injectable lipogel is fabricated by loading polydopamine nanoparticles and methotrexate into a thermosensitive gel, and intra-articularly injected to form the therapeutic depot (PDA/MTX@TSG) in situ. The gel degrades slowly under esterase hydrolysis, and maintains sustained drug release in physiological conditions. Meanwhile, it can 1) induce a reversible gel-sol phase transition upon mild photothermal treatment (external NIR light control), and 2) specifically respond to MMP-rich RA microenvironment (internal enzymatic hydrolysis effect). Such stimulus-responsive system can deliver therapeutic components in a controllable manner, and significantly reverse adverse inflammatory microenvironment of RA joints through ROS eliminating, hypoxia alleviating, and M1-M2 macrophage polarization effects. Animal experiments indicate that observable RA relief and joint repair are realized after a single lipogel injection combined with NIR irradiation. Our study highlights the importance of altering local RA microenvironment via anti-inflammatory macrophage polarization, and therefore presents a potent therapeutic strategy for RA treatment in clinical intervention.

Keywords: Drug delivery; Lipogel; Macrophage polarization; Methotrexate; Reactive oxygen species; Rheumatoid arthritis.