Exploring anti-integrin α6 antibody and transferrin-decorated dual drug-loaded liposomes as a promising nanoplatform for glioblastoma therapy: a preclinical approach

Purpose: Glioblastoma multiforme (GBM) is an aggressive malignancy with poor prognosis and high morbidity, primarily due to the blood-brain barrier (BBB) limiting the effectiveness of standard chemotherapy. We developed a dual-ligand liposome-based drug delivery system to overcome this challenge by enhancing tumor targeting. Our approach utilizes liposomes loaded with temozolomide (TMZ) and O6-benzylguanine (O6-BG) and conjugated with transferrin and anti-integrin antibodies, enabling them to cross the BBB and deliver drugs directly to the tumor site. Methods: The thin-layer hydration method was employed to prepare ligand-functionalized liposomes. Compared to the free drug combination, the cytotoxic potential of liposomes was estimated using MTT and apoptosis assays. A radioisotope was tagged to assess plasma, brain, and organ distribution in nude mice. Non-invasive bioluminescence imaging was utilized to visualize tumor response. Results: The optimized nanovesicles (187.4 ± 6.5 nm) exhibited prolonged drug release in tumors, contributing to cell death, as demonstrated through in vitro studies. The drug synergistic effect (combination index: 0.3) resulted in a 1.75- and 3.45-fold increase in cytotoxicity against GBM cells compared to the free drug combinations. Gamma scintigraphy indicated prolonged retention at the tumor site with minimal distribution to other vital organs post-12 h treatment. Despite a reduced dose of TMZ, this unique nanoliposome achieved a two-fold reduction in tumor size, as evidenced by a corresponding decrease in the cell proliferation index. Conclusion: This study opens new avenues for enhancing the therapeutic efficacy of drug combinations by optimizing cellular targeting while significantly decreasing systemic toxicity.