A Magnetic T7 Peptide&AS1411 Aptamer-Modified Microemulsion for Triple Glioma-Targeted Delivery of Shikonin and Docetaxel

Abstract

Glioma-targeted drug delivery is a hugely challenging task because of the multibarrier in the brain. In this study, we report a magnetic T7 peptide&AS1411 aptamer-modified microemulsion for triple glioma-targeted delivery of shikonin and docetaxel (Fe₃O₄@T7/AS1411/DTX&SKN-M). Such a system comprises two tumor-targeted ligands (T7 peptide and AS1411 aptamer), ultra-small superparamagnetic iron oxide nanoparticle (Fe₃O₄), and shikonin&docetaxel-coloaded microemulsion (SKN&DTX-M). Fe₃O₄@T7/AS1411/DTX&SKN-M is capable of stably circulating in the blood, accumulating around the brain under an external magnetic field, distributing inside the glioma via the affinity to nucleolin/transferrin receptor, and retarding the growth of orthotopic glioma. Fe₃O₄@T7/AS1411/DTX&SKN-M encapsulated Fe₃O₄ nanoparticles in the core to obtain the superparamagnetism, which did not influence the main surface properties. Introducing 6% (wt%) of DSPE-PEG₂₀₀₀-T7 and 180 nM of AS1411 collaboratively enhanced the murine glioma (G422) cellular uptake of Fe₃O₄@T7/AS1411/DTX&SKN-M and thereby achieved the strongest antiproliferation among all the groups. Notably, the drug distribution at the brain sites of orthotopic Luc-G422 glioma tumor-bearing nude mice treated with Fe₃O₄@T7/AS1411/DTX&SKN-M was overwhelming among all the treatments. Most importantly, Fe₃O₄@T7/AS1411/DTX&SKN-M not only significantly reduced the luminescence signal at the brain areas of orthotopic Luc-G422 glioma mice but also prolonged the overall survival period. The enhancement of anti-glioma efficacy was associated with down-regulating the population of CD133- and CD44-positive cells within the tumors. In summary, such a triple glioma-targeted delivery of shikonin and docetaxel using combinational magnetism and T7/AS1411 modification strategies provides a promising method for synergistic and precise glioma therapy.