Development of siRNA and Budesonide Dual-Loaded Hybrid Lipid–Polymer Nanoparticles by Microfluidics Technology as a Platform for Dual Drug Delivery to Macrophages : An In Vitro Mechanistic Study

Macrophages play a key role in the development of many diseases, like tissue injury, cancer, and autoimmune diseases. So far, single-drug loaded nanoparticles are developed to target macrophages. Nevertheless, macrophage dysregulation can induce multiple conditions, i.e., inflammation and fibrosis. Therefore, the simultaneous codelivery of a small molecule drug and a small interfering RNA (siRNA) for gene silencing may be beneficial to modulate macrophage dysfunction. Herein, hybrid lipid–polymer nanoparticles (LPNs) coloaded with both budesonide and enhanced green fluorescence protein siRNA (eGFP-siRNA) as model anti-inflammatory small molecule drug and siRNA, respectively, are developed by an optimized microfluidics method. Specifically, a poly(lactic-co-glycolic acid) core is coated by a lipid shell, and LPNs with size homogeneity and colloidal stability are obtained. Both payloads are loaded efficiently, and a controlled release is achieved. Additionally, LPNs are nontoxic in murine RAW 264.7 cells and human THP-1 cells and are efficiently taken up by these cells. Finally, the transfection efficiency of dual-loaded LPNs is high at low LPNs doses, thus proving the suitability of this nanosystem for gene silencing. Overall, the optimized LPNs are a suitable nanoplatform for the dual drug delivery to macrophages for the treatment of complex conditions requiring dual therapeutic approaches.