Non-viral nanoparticle delivers small interfering RNA to macrophages in vitro and in vivo.

Mei Zhang,Yunxiang Gao,Bocheng Zhao,Julian A Kim,Kevin Caja,Subhra Mohapatra

doi:10.1371/journal.pone.0118472

Abstract

Macrophages are increasingly being viewed as therapeutic target for various cancers and many inflammatory diseases. Sequence specific gene reduction by siRNA represents an attractive approach to modulate macrophage function. However, delivery of the therapeutic siRNA into macrophages by non-viral nanoparticles has been a major technical challenge. In this study, we developed a glucan-based siRNA carrier system (BG34-10-Re-I) and demonstrated that the BG34-10-Re-I can effectively assemble siRNA into uniformly distributed nanoparticles of the novel core-shell structure. The BG34-10-Re-I/siRNA nanoparticles effectively reduced gene expression of macrophage migration inhibitory factor (MIF) in primary macrophages at both protein and mRNA level. The nanoparticles also mediated a sustained reduction of MIF within primary macrophages. Moreover, systemic injection of the nanoparticles into the Balb/c mice bearing 4T1 mammary tumors resulted in the MIF reduction in tumor-associated macrophages. Mechanistic studies demonstrated that the glucan-shell and the siRNA-core structure contribute to the effective delivery of MIF siRNA to macrophages both in vitro and in vivo. This study represents the first development of the primary macrophage MIF gene targeted non-viral nanoparticle system for both in vitro and in vivo applications.

Highlights

Macrophages play a significant role in various inflammatory diseases and cancers and are increasingly being viewed as therapeutic target of great potential [1,2,3,4,5,6,7,8,9]
Molecular weight (Mw) and molecular weights (Mw) distribution of the BG34 of kDa (BG34-10) and the BG34-10-Re-I were characterized by high performance size exclusion chromatographic (SEC), demonstrating that they are homogeneous glucan materials with uniformly distributed Mw (Fig. A—(B) in S1 Dataset)
In order to determine whether the BG34-10-Re-I/(AF488-migration inhibitory factor (MIF)-small interfering RNA (siRNA)) nanoparticles can deliver the siRNA into cytoplasm where the RNAi machinery works, we examined the co-location of the AF488-MIF-siRNA with sub-cellular compartments within macrophage cells (Fig. 3)

Summary

Introduction

Macrophages play a significant role in various inflammatory diseases and cancers and are increasingly being viewed as therapeutic target of great potential [1,2,3,4,5,6,7,8,9]. In Vitro and In Vivo SiRNA Delivery to Primary Macrophage integration into dividing cells do not work for macrophages [11]. Macrophage-targeted drug delivery system needs to facilitate an active uptake of siRNA drugs [12,13,14]. Macrophages are professional phagocytes endowed with many potent degradative enzymes. These enzymes can disrupt nucleic acid integrity, making gene transfer inefficient and short-lived [11]. Macrophage-targeted drug delivery system needs to protect the integrity and stability of siRNA during delivery [12,13,14]. Macrophage-targeted delivery system needs to enable a prolonged delivery of siRNA to mediate functional property [12,13,14]

Methods

Results

Discussion

Conclusion