Efficient tumor-targeting delivery of siRNA via folate-receptor mediated biomimetic albumin nanoparticles enhanced by all-trans retinoic acid

Acute myeloid leukemia (AML) is the most universal type and fatal disease of hematological malignancy, with poor outcomes despite chemotherapy and bone marrow transplantations. Benefited from the narrow tissue specificity of folate receptor beta (FR beta) aberrantly expressed on hematological linage cell lines, NPs modified with folate acid (FA) has been widely applied for crossing cell membrane barriers in FR-targeted therapies for AML. Thus, the biomimetic nanoparticles (NPs) mediated by FR beta were conducted by an albumin modifier as previously synthesized and cationic liposomes. However, how to further enhance the tumor-targeting and cellular uptake of NPs have been great challenges in cancer therapy. It was reported that FR beta could be selectively augmented by all-trans retinoic acid (ATRA). Herein, we demonstrated the enhanced active tumor-targeting of FA-modified siRNA-loaded biomimetic albumin NPs (Lip-S@FBH) could be achieved by upregulating FR beta expression via ATRA NPs. And the systematic administration of ATRA NPs significantly promoted endocytosis and thereby increased the intracellular concentration of Lip-S@FBH. This strategy combined the FR beta amplification effect with the effective delivery of siRNA, is mostly desirable for the AML-targeting therapy.