Yiming Qi, Yuli Fu, Xueer Wu, Ziyan Chen, Yuepeng Tang, Hushan Ao, Haichao Zhu, Chenming Zou, Bixi Sun, Chaozhu Zheng, Zhaozhong Wang, Jingwen Hou, Yuxin Shi, Jin Zhu, Feihu Wang, Shengrong Guo
Lipid nanoparticles (LNPs) are effective carriers for intratumoral delivery of cytokine-encoding mRNA, but their clinical use is limited by apolipoprotein E (ApoE)-mediated hepatic tropism, which causes off-target cytokine expression and hepatotoxicity. Here, we reprogrammed LNP morphology by partially substituting native cholesterol with a TLR7/8 agonist-conjugated analog (R-Chol), generating flower-shaped LNPs (RLNPs) with reduced ApoE adsorption. Upon intratumoral injection, RLNPs maintained efficient tumor transfection while markedly decreasing liver accumulation and IL-12 mRNA-induced hepatotoxicity. Hydrodynamic modeling indicated that the distinct surface curvature of RLNPs constrained ApoE binding. RLNPs were further functionalized with CD47-SIRPα blocking peptide (IL-12 mRNA@CRLNPs), eliciting potent M1 macrophage-driven immune activation in orthotopic 4T1 tumors. When embedded in a photo-cross-linkable hydrogel (mCRLNP@HAMA gel) and combined with αPD-L1, this platform achieved sustained postoperative delivery, thereby preventing tumor recurrence and ensuring prolonged systemic safety. These findings highlight cholesterol structural tuning as a strategy to control LNP morphology and biodistribution, advancing safe and translational cytokine-based cancer immunotherapy.