(T1030-12-71) Enhancing Nucleic Acid Delivery to the Alcoholic Liver Using Polarized Macrophage-Derived Biomimetic Nanoparticles

Purpose: Alcohol overuse causes damage to the liver and multiple other organs. Up to a third of people who misuse alcohol develop liver damage. Long-term alcohol consumption causes chronic liver disease, including liver fibrosis, cirrhosis, and hepatocellular carcinoma. There are no approved treatments for liver fibrosis, resulting in liver transplantation as the only curative option. RNA interference (RNAi) is a promising method for treating various diseases. Polycations combined with nucleic acids are common methods for RNAi delivery such as imidazole-polyethylenimine (PEI-IAA) that reduces the cytotoxicity of PEI alone. The inflammatory state during alcohol-associated liver disease (AALD) provides a great opportunity for nanoparticle-targeted delivery to affected hepatic cells. During AALD, the resident macrophage, Kupffer cells (KCs), increase in number and polarize between M1 or M2 phenotypes depending on the stage of disease. Here, we take advantage of KC plasticity and designed polarized (LPS-induced M1 and IL-4-induced M2) macrophage membrane-coated PEI-IAA biomimetic nanoparticles to deliver siRNA in AALD models.

Methods: Macrophages (Raw 264.7) were polarized in vitro either into M1 or M2 phenotype. M1 was polarized using LPS (lipopolysarrides) and M2 was polarized using IL4. Then the macrophage membrane was extracted and coated onto the PEI-IAA/Cy5.5-siRNA nanoparticles to formulate biomimetic nanoparticles. Then the biodistribution of different groups of nanoparticles were tested on the Lieber-DeCarli fed AALD mouse models using IVIS.

Results: We tested both M1 (CD80, CD86) and M2 (CD163, CD206) biomarkers on the macrophage derived membranes. The polarized properties of biomimetic nanoparticles were successfully proved in vitro using flow cytometry or RT-PCR that proteins of polarized macrophages were kept on the macrophage derived membranes. Biodistribution results indicate that the macrophage membrane-camouflaged nanoparticles significantly increase siRNA accumulation in Lieber-DeCarli fed mice compared to pair-fed controls. Moreover, the macrophage membrane-camouflaged nanoparticles have longer retention in the setting of AALD compared with nanoparticles without coating.

Conclusion: Overall, our study provides the novel use of polarized macrophage membrane-coated nanoparticles that facilitates nucleic acid delivery to the liver as a potential beneficial treatment for AALD.

Acknowledgements: The University of Nebraska Medical Center is gratefully acknowledged.