Circadian-Tuned Peptide Drug/Gene Co-Delivery Nanocomplexes to Enhance Glioblastoma Targeting and Transfection.

Glioblastoma is the most prevalent and aggressive form of brain malignancy. Actual treatments face several challenges due to its high aggressiveness and poor prognosis. The chemotherapeutic agent temozolomide (TMZ) has limited therapeutic efficacy, and mutations in the tumour protein p53 gene (TP53) have been associated with treatment resistance. Thus, this study aimed to explore an innovative therapeutic strategy to enhance treatment efficacy of GBM. Previously, our team had developed a WRAP5 cell-penetrating peptide (CPP) functionalized with a transferrin receptor ligand (Tf) for the targeted delivery of TMZ and a p53-encoding plasmid to glioma cells. Our research had elucidated the circadian oscillations of the clock genes in the U87 glioma cells by employing two different computational models and observed that T16 and T8 time points revealed the highest circadian activity for Bmal1 and Per2 genes, respectively. Similar analysis was conducted for the transferrin receptor, which revealed that T7 and T8 were the key time points for its expression. A confocal microscopy study indicated the highest intracellular uptake of complexes and p53 mRNA expression at T8, the time point with the highest Per2 and transferrin receptor expression. Following mRNA analysis, the evaluation of p53 levels confirmed transcriptional changes at the protein level, and that T16 appears to be a favourable time point for enhancing therapeutic efficacy in U87 glioblastoma cells. These findings suggested that synchronizing the complexes' administration with the biological clock of GBM cells may significantly improve glioblastoma therapeutics.