Construction of PEI‐EGFR‐PD‐L1‐siRNA dual functional nano‐vaccine and therapeutic efficacy evaluation for lung cancer

BACKGROUND: PD‐1/PD‐L1 tumor immunotherapy shows effective anticancer in treatment of solid tumors, so PEI lipid nanoparticles (PEI‐LNP)/siRNA complex (EPV‐PEI‐LNP‐SiRNA) with the therapeutic function of PD‐L1‐siRNA and EGFR short peptide/PD‐L1 double immune‐enhancing function were constructed for the prevention and treatment of EGFR‐positive lung cancer in this study. METHOD: In this study, PEI lipid nanoparticles (PEI‐LNP)/siRNA complex (EPV‐PEI‐LNP‐siRNA) with the therapeutic function of PD‐L1‐siRNA and EGFR short peptide/PD‐L1 double immune‐enhancing function were constructed for the prevention and treatment of EGFR‐positive lung cancer and functional evaluation was conducted. RESULTS: On the basis of the construction of the composite nano‐drug delivery system, the binding capacity, cytotoxicity, apoptosis and uptake capacity of siRNA and EPV‐PEI‐LNP were tested in vitro, and the downregulation effect of PD‐L1 on A549 cancer cells and the cytokine levels of cocultured T cells were tested. Lipid nanoparticles delivered siRNA and EGFR short peptide vaccine to non‐small cell lung cancer (NSCLC), increasing tumor invasion and activation of CD8 + T cells. Combination therapy is superior to single target therapy. CONCLUSION: Our constructed lipid nanoparticles of tumor targeted therapy gene siRNA combination had the ability to target cells in vitro and downregulate the expression of PD‐L1, realizing the tumor‐specific expression of immune‐stimulating cytokines, which is a highly efficient and safe targeted therapy nano‐vaccine.