mRNA Nanoparticle Engineering of Macrophages for Lung Disease Immunotherapy

This study aims to optimize mRNA lipid-nanoparticles (LNPs) for enhanced protein expression in macrophages, targeting potential treatments for cancer and lung diseases. We also examine their efficacy in other tumor microenvironment (TME) cells. LNPs containing reporter mRNA (Luciferase/eGFP) were generated using the ethanol injection method and evaluated for physical properties. Transfection efficiency and kinetics was tested in murine macrophages (RAW 264.7), osteosarcoma cells (K7M2), and fibroblasts (NIH-3T3). In vivo, tolerability and protein expression were assessed by administering mRNA LNPs via pulmonary administration (P.A.) to BALB/c mice, monitoring health and bioluminescence intensity (BLI) in the lungs and thoracic area. The LNPs optimized transfection in macrophages while maintaining the ability to transfect K7M2 and 3T3 cells up to 48 hours. With highest expression observed in macrophages. In vivo studies showed the LNPs were well tolerated up to 0.25 mg mRNA/kg, with protein expression detected in the thoracic region up to 12 hours.