DDEL-09. AS1411 APTAMER-CONJUGATED NANOSPHERES FOR TARGETING GLIOBLASTOMA THERAPY

Abstract Postoperative chemotherapy remains essential for treating glioblastoma (GBM), with nanocarrier-based drug delivery emerging as the most efficient method. However, non-specific delivery across the blood-brain barrier (BBB) can limit drug accumulation in tumors and cause damage to nearby tissues. As cancer progresses, angiogenic processes lead to the formation of an irregular blood-tumor barrier (BTB), necessitating nanodrug platforms for precise targeting and efficient drug delivery to cancer cells. In this study, we aimed to demonstrate targeted cancer therapy by selectively identifying tumor cells overexpressing nucleolin (NCL) protein using Dox-loaded AS1411 aptamer-conjugated nanospheres. Drug nanocarriers were synthesized from small molecules with sizes ranging from 100 to 300 nm to facilitate drug delivery. Selective drug delivery and cellular uptake were demonstrated for NCL-positive GBM cells (U87 and U251) compared to NCL-negative normal human astrocyte (NHA) cells. Flow cytometric analysis using FAM dye-labeled AS1411 aptamer-conjugated nanospheres confirmed that drug delivery to GBM U87 and U251 cells was actively targeted by specific AS1411-NCL interactions. Confocal laser scanning microscopy and cytotoxicity analysis confirmed that inoculation of Dox-loaded AS1411 aptamer-conjugated nanospheres induced selective internalization in GBM U87 and U251 cells. Moreover, to evaluate cytotoxicity and anti-tumor effects after treatment with PBS, Apt-Nanospheres, Free Dox, and Dox-Apt-Nanospheres, the results were analyzed through cell counting kit (CCK-8) analysis, evaluation of differences in 3D tumor sphere radii, and an in vivo GBM xenograft tumor model. The AS1411 aptamer-conjugated nanosphere drug delivery system was developed for dual-target treatment of GBM. AS1411-mediated specific recognition and drug accumulation significantly enhanced binding to NCL-positive U87 and U251 cells and improved cytotoxicity efficiency compared to Free Dox. Additionally, this study demonstrated that the active targeting model using aptamer-mediated drug delivery was more effective in improving drug penetration and retention in tumor cells than non-specific enhanced permeability and retention (EPR)-mediated delivery and passive drug delivery.