Ionizable cationic lipid nanoparticles loaded with miRNA‐125b/BLZ945 for pancreatic cancer treatment

Abstract In prior research, both miRNA‐125b and BLZ945 have shown potential in effectively inhibiting M2 macrophage polarization and producing antitumor effects. Nevertheless, their physicochemical characteristics present significant challenges for efficient in vivo delivery. Ionizable cationic lipid nanoparticles (LNPs), recognized for their superior biocompatibility and drug‐loading capacity, serve as a novel carrier for nucleic acid‐based therapeutics. In our study, we successfully encapsulated both agents within LNPs and conducted a thorough characterization. Subsequently, we investigated their potential to repolarize M2 macrophages in vitro and evaluated their in vivo distribution, biosafety, and antitumor efficacy. The findings revealed that the LNPs maintained excellent drug‐loading efficiency, consistent particle size, and stable zeta potential. All formulations effectively inhibited M2 macrophage polarization in vitro. Upon administration in vivo, the LNPs not only demonstrated favorable biosafety profiles but also accumulated efficiently in tumor tissues, substantially reducing tumor burden, particularly notable in co‐loaded LNPs. Our results affirm that LNPs are an effective carrier for miRNA‐125b and BLZ945, highlighting this encapsulation approach as promising for the treatment of solid tumors and meriting further investigation. Practitioner points : (i) Ionizable cationic nanoparticles provide high and stable encapsulation rates to efficiently load nucleic acid polymers into the LNP, avoiding the rapid accumulation of circulating macrophages, which can lead to reduced penetration of the LNP into target tissues. Therefore, it can be used as a novel drug delivery method to benefit clinical patients. (ii) miRNA‐125b LNP/BLZ945 LNP attenuated the depleting effect of BLZ945 on macrophages and significantly inhibited macrophage M2 polarization. It could be effectively distributed in tumors and showed good biosafety while exerting antitumor effects, bringing hope to clinical pancreatic tumor patients.