Structurally-defined non-cationic docosahexaenoic acid based siRNA-micelles for safe and effective combinatorial glioblastoma therapy.

RNA interference (RNAi) has emerged as a highly promising therapeutic strategy for glioblastoma (GBM), yet its clinical efficacy heavily relies on the success of delivery systems. Traditional vehicles, including cationic polymers, lipids, and inorganic nanoparticles, frequently encounter critical challenges such as cationic toxicity, poor blood-brain barrier (BBB) penetration, or poorly-defined structures that hinder their clinical translation. To overcome these challenges, we developed a novel, structurally-defined non-cationic siRNA-micelle system based on siRNA-docosahexaenoic acid (DHA) conjugates. These conjugates self-assemble into stable siRNA-micelles that exhibit prolonged blood circulation, enhanced cellular uptake, and efficient BBB penetration. Due to their non-cationic nature and the inherent safety profile of DHA, these siRNA-DHA22 micelles exhibit exceptional biocompatibility, potentially minimizing carrier-based toxicity. By simultaneously targeting epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGFA), the siRNA-micelles potently inhibited tumor progression and substantially extended survival in orthotopic GBM mouse models via dual-target modulation. This structurally-defined, non-cationic siRNA delivery platform represents a robust and clinically translatable strategy for GBM treatment, and holds considerable promise for the RNAi-based therapy of other neurological disorders.