IL-10 Gene Transfection in Primary Endothelial Cells via Linear and Branched Poly(β-amino ester) Nanoparticles Attenuates Inflammation in Stimulated Macrophages

Poly­(β-amino esters) or PBAEs are highly efficient synthetic polymers optimized for gene delivery, a complicated process dependent on polymer properties such as hydrophobicity, charge, and degradability. The modular design of PBAEs has allowed for the identification of which polymer and nanoparticle properties significantly affect gene delivery efficiency in various cell types. However, these investigations need to be extended to more difficult-to-transfect cells such as primary endothelial cells, which hold enormous potential for atherosclerosis. Here a small library of 6 different PBAEs were screened for efficacy and safety in two types of primary endothelial cells (ECs). Nearly all polymers were more efficient than commercial transfection reagents (p < 0.05), reaching 60% and 15% transfection efficiency in human and mouse primary ECs, respectively. The top performing PBAE was used to deliver a plasmid encoding the anti-inflammatory cytokine interleukin-10 (IL-10), which has the potential to reduce inflammation in atherosclerosis. Significant increases in IL-10 mRNA and protein were detectable in ECs 72 h after transfection with PBAE:IL-10 nanoparticles. Macrophages cultured in conditioned medium from IL10-transfected ECs showed activation of anti-inflammatory signaling pathways. In addition, these macrophages secreted significantly less (25%) tumor necrosis factor α (TNFα) when challenged with lipopolysaccharide (LPS). These results underline the capabilities of PBAEs to be expanded as a fine-tunable platform for anti-inflammatory gene delivery within the context of atherosclerosis