Polyethyleneimine-coated Iron Oxide Nanoparticles as a Vehicle for the Delivery of Small Interfering RNA to Macrophages In Vitro and In Vivo

• Published in: Journal of visualized experiments no. 144
• Main Authors: Jia, Na, Wu, Haoan, Duan, Juanli, Wei, Chunxue, Wang, Kaixuan, Zhang , Yu, Mao, Xiaohua
• Format: Journal Article
• Language: English
• Published: United States 05.02.2019
• Subjects: atherosclerosis; autoimmune diseases; cell lines; cell viability; Ferric Compounds - chemistry; gene silencing; Humans; immune response; macrophages; Macrophages - metabolism; magnetic properties; nanoparticles; Nanoparticles - chemistry; neoplasms; Polyethyleneimine - chemistry; RNA, Small Interfering - genetics; small interfering RNA; therapeutics; Transfection
• ISSN: 1940-087X; 1940-087X
• DOI: 10.3791/58660

Because of their critical role in regulating immune responses, macrophages have continuously been the subject of intensive research and represent a promising therapeutic target in many disorders, such as autoimmune diseases, atherosclerosis, and cancer. RNAi-mediated gene silencing is a valuable approach of choice to probe and manipulate macrophage function; however, the transfection of macrophages with siRNA is often considered to be technically challenging, and, at present, few methodologies dedicated to the siRNA transfer to macrophages are available. Here, we present a protocol of using polyethyleneimine-coated superparamagnetic iron oxide nanoparticles (PEI-SPIONs) as a vehicle for the targeted delivery of siRNA to macrophages. PEI-SPIONs are capable of binding and completely condensing siRNA when the Fe:siRNA weight ratio reaches 4 and above. In vitro, these nanoparticles can efficiently deliver siRNA into primary macrophages, as well as into the macrophage-like RAW 264.7 cell line, without compromising cell viability at the optimal dose for transfection, and, ultimately, they induce siRNA-mediated target gene silencing. Apart from being used for in vitro siRNA transfection, PEI-SPIONs are also a promising tool for delivering siRNA to macrophages in vivo. In view of its combined features of magnetic property and gene-silencing ability, systemically administered PEI-SPION/siRNA particles are expected not only to modulate macrophage function but also to enable macrophages to be imaged and tracked. In essence, PEI-SPIONs represent a simple, safe, and effective nonviral platform for siRNA delivery to macrophages both in vitro and in vivo.