Abstract

Glioblastoma (GBM) is the most aggressive and treatment-resistant primary brain tumour, with a dismal 5-year survival rate of only 3–6%. Despite advances in surgical resection, chemotherapy, and radiotherapy. The poor prognosis of GBM is largely attributed to its highly infiltrative nature and the ongoing challenge of delivering therapeutic agents across the blood-brain barrier (BBB) while minimizing systemic toxicity and off-target effects. Telomerase reverse transcriptase (TERT) is frequently upregulated in GBM and plays a critical role in tumour cell immortality and resistance to apoptosis, making it a compelling target for gene-silencing strategies. Small interfering RNA (siRNA) has emerged as a promising therapeutic modality for specific gene knockdown; however, its clinical application is limited by rapid degradation in biological fluids, poor cellular uptake, and inefficient endosomal escape.

Recent advances in lipid nanoparticle (LNP) technology have provided a robust platform for the delivery of nucleic acids, including siRNA, offering enhanced stability, biocompatibility, and efficient transfection. LNPs, typically less than 100 nm in diameter, can encapsulate siRNA, protect it from enzymatic degradation, and facilitate its transport across the BBB via endocytosis, thereby improving delivery to tumour cells.

In this study, we investigated the therapeutic potential of LNP-encapsulated siRNA targeting TERT in GBM cell line. LNP-siRNA TERT complexes were synthesized and characterized for size, encapsulation efficiency, and release kinetics. GBM cell lines were treated with LNP-siRNA TERT, and gene silencing efficacy was assessed using quantitative RT-PCR and Western blot analysis. Cell viability and apoptosis were evaluated using MTT assay and immunofluorescence staining.

Our results demonstrate that LNP-mediated delivery of siRNA TERT leads to robust and specific knockdown of TERT mRNA and protein levels in GBM cells. This gene silencing was associated with significant reductions in cell viability, indicating effective disruption of TERT-driven oncogenic processes. Encapsulation and release studies revealed that LNPs provided sustained siRNA delivery, with maximal gene silencing and cytotoxic effects observed at 48 hours post-treatment, suggesting a potential window of saturation and optimal therapeutic impact.

In summary, the findings highlight the potential of LNP-based siRNA delivery systems to overcome the major barriers associated with RNAi therapeutics in GBM, including instability, poor cellular uptake, and limited BBB penetration. Targeted silencing of TERT via LNP-encapsulated siRNA offers a promising approach for the development of more effective and specific therapies for GBM, with the potential to improve patient outcomes.