Synergistic Cancer Metabolic Therapy via Co-Delivery of 3-Bromopyruvate and Temozolomide with a Supramolecular Shuttle

Combination therapy has shown promise in treating aggressive cancers by using several drugs simultaneously to target different biological pathways, with the added benefit of potentially reducing toxicity. Given the critical role of mitochondrial dysfunction in tumor progression, targeting mitochondrial metabolism represents a promising therapeutic avenue. In this study, we developed a mitochondria-targeted nanofiber based on self-assembling peptides, engineered to co-deliver two complementary therapeutic agents for glioblastoma treatment. The nanofiber carries 1,3-bromopyruvate (BrP), a glycolysis inhibitor, and temozolomide, an alkylating chemotherapeutic, conjugated via a matrix metalloproteinase-9 (MMP-9)-responsive linker for controlled, on-demand release. To enhance selectivity for glioblastoma cells, the nanofiber surface was functionalized with the targeting peptide falGea binding specifically to EGFRvIII, commonly overexpressed in tumor cells, and gH625, a cell-penetrating peptide known to facilitate the blood-brain barrier (BBB) transport. The nanofibers were comprehensively characterized for their aggregation behavior, structural stability, and morphology. Mitochondrial targeting and functional effects were evaluated by using isolated rat brain mitochondria. Therapeutic efficacy was assessed in U-87 MG glioblastoma cells cultured in both 2D and 3D systems. Additionally, BBB permeability was examined by using a dynamic 3D in vitro BBB model, demonstrating the transport-enhancing role of gH625. These findings support the potential of multifunctional, mitochondria-targeted nanofibers as an effective platform for glioblastoma therapy, offering both precision targeting and enhanced drug delivery across the BBB.