Cascade liposomal delivery for glioblastoma through multi-stage biological checkpoints

Although receptor-targeted liposomes provide promising opportunities for glioblastoma therapy, their clinical translation remains limited by sequential biological barriers encountered after systemic administration. Here, we establish a multi-stage checkpoint framework linking carrier properties with stage-specific transport constraints, including systemic clearance, BBB/BTB heterogeneity, extracellular matrix resistance, and myeloid sequestration. We analyze receptor-mediated transcytosis through a mechanistic triad of ligand engagement, intracellular sorting, and abluminal release, highlighting the binding-site barrier and affinity paradox that restrict effective parenchymal delivery. Successful transcytosis represents only the initial step and we further develop a cascade targeting framework integrating tissue penetration, tumor cell recognition, and intracellular payload availability. Key translational challenges, including tumor microenvironment modulation, Quality by Design (QbD) manufacturing, safety, and companion diagnostics, are critically examined. Future progress will depend on evaluating liposomal platforms according to productive cellular exposure, with bulk accumulation serving only as a supporting measure, and on using quantitative transport profiling and imaging-guided stratification to identify patients whose biological barriers are compatible with specific liposomal designs.