The Anti-Glioblastoma Effects of Novel Liposomal Formulations Loaded with Cannabidiol, Celecoxib, and 2,5-Dimethylcelecoxib.

: Glioblastoma multiforme (GBM) therapy efficacy remains limited due to the poor blood-brain barrier-penetrating power of drugs as well as dysregulated cellular signaling pathways of tumor cells leading to drug resistance. Novel drug delivery systems such as liposome-based nanoformulations improve the bioavailability and stability of water-insoluble drugs, while co-delivery of two anti-cancer compounds can further increase their anti-tumor effectiveness due to synergistic effects. Thus, the aim of this study was to obtain liposomal nanoformulations encapsulating cannabidiol (CBD), celecoxib (CELE), and 2,5-dimethylcelecoxib (DMC) and their combinations and to verify their anti-GBM properties. : Five liposomal nanoformulations were obtained using a modified thin-film hydration technique. Two GBM cell lines and non-cancerous astrocytes were used for the biological evaluation of the tested nanoformulations. The cytotoxicity experiments were performed using the MTT assay, whereas flow cytometry-based analysis assessed the effect of the liposomes on apoptosis, cell cycle distribution, and oxidative stress. To determine the impact of the tested nanoformulations on Nrf2, Wnt/β-catenin, and NF-κB signaling pathways, qPCR, Western blot and ELISA techniques were used. : The findings of this study demonstrate that liposomal nanoformulations containing CBD, CELE, and DMC exhibit significant anti-GBM activity, particularly through the induction of apoptosis and oxidative stress and modulation of the key signaling pathways. Although no clear synergistic/additive effects were observed between CBD and CELE or DMC when co-loaded in nanoformulations, the combination of CBD and CELE effectively suppressed Wnt/β-catenin and NF-κB signaling and activated the Nrf2 pathway. These results support the therapeutic potential of liposome-based co-delivery of CBD and CELE in GBM therapy. However, further in vivo studies are warranted to determine these nanoformulations' translational relevance and clinical applicability.