In vivo therapeutic efficacy of TNFα silencing by folate-PEG-chitosan-DEAE/siRNA nanoparticles in arthritic mice

Abstract

Background

Tumor necrosis factor-alpha (TNFα), a pro-inflammatory cytokine, has been shown to play a role in the pathophysiology of rheumatoid arthritis. Silencing TNFα expression with small interfering RNA (siRNA) is a promising approach to treatment of the condition.

Methods

Towards this end, our team has developed a modified chitosan (CH) nanocarrier, deploying folic acid, diethylethylamine (DEAE) and polyethylene glycol (PEG) (folate-PEG-CH-DEAE₁₅). The gene carrier protects siRNA against nuclease destruction, its ligands facilitate siRNA uptake via cell surface receptors, and it provides improved solubility at neutral pH with transport of its load into target cells. In the present study, nanoparticles were prepared with siRNA-TNFα, DEAE, and folic acid-CH derivative. Nanoparticle size and zeta potential were verified by dynamic light scattering. Their TNFα-knockdown effects were tested in a murine collagen antibody-induced arthritis model. TNFα expression was examined along with measurements of various cartilage and bone turnover markers by performing histology and microcomputed tomography analysis.

Results

We demonstrated that folate-PEG-CH-DEAE₁₅/siRNA nanoparticles did not alter cell viability, and significantly decreased inflammation, as demonstrated by improved clinical scores and lower TNFα protein concentrations in target tissues. This siRNA nanocarrier also decreased articular cartilage destruction and bone loss.

Conclusion

The results indicate that folate-PEG-CH-DEAE₁₅ nanoparticles are a safe and effective platform for nonviral gene delivery of siRNA, and their potential clinical applications warrant further investigation.

Keywords:

• arthritis
• inflammation
• siRNA
• TNFα
• nanoparticles
• chitosan

Acknowledgments

The authors thank Dr Daniel Lajeunesse (Université de Montréal) for his critical review of the manuscript, Ms Caroline Bouchard for animal handling-treatment and Mr Ovid Da Silva for manuscript editing. This work was supported, in part, by grants from the Science and Technology Commission of Shanghai Municipality (No 16430723500), Ministère de l’Économie, de la Science et de l’Innovation du Québec (Programme de soutien à la recherche [PSR], volet 4: Soutien à des initiatives internationales de recherche et d’innovation [SIIRI], 2017–2020), Canadian Institutes of Health Research (CCM 104888), and CNPq (grant 407499/2013-0). This study was conducted in Montréal, QC, Canada, and São Jose do Rio Preto, SP, Brazil.

Availability of data and materials

Supporting data are available as the authors have full access to all study data.

Disclosure

JCF, MJT, QS, MB and IPDP have filed for a patent on the nanoparticles described in this study. The authors report no other conflicts of interest in this work.