Liposome-based Multifunctional glioblastoma-Targeted drug delivery

Introduction: Glioblastoma multiforme (GBM) is an aggressive and lethal brain tumor in humans with a median survival time of about 15 months after treatment. Doxorubicin (DOX) is a potent chemotherapeutic agent, but with... [ view full abstract ]

Introduction: Glioblastoma multiforme (GBM) is an aggressive and lethal brain tumor in humans with a median survival time of about 15 months after treatment. Doxorubicin (DOX) is a potent chemotherapeutic agent, but with severe side effects and inefficient blood-brain barrier (BBB) permeability. In this context, we developed multi-functionalized liposomes (LIP) for GBM therapy.

METHODS: LIP composed of Sphingomyelin, cholesterol (1:1, M/M) and 2.5mol% maleimide-PEG-lipid were prepared by extrusion procedure. DOX was incorporated in the LIP core by a transmembrane pH gradient. Free DOX was removed by gel filtration chromatography. To enhance the BBB permeability of DOX-LIP, a modified fragment of human Apolipoprotein E (mApoE, CWGLRKLRKRLLR) was covalently attached on LIP surface by thiol-maleimide coupling. After characterization, the ability of mApoE-(DOX)-LIP to deliver DOX across the BBB was evaluated using an in vitro model made by hCMEC/D3 cells. Cytotoxicity of mApoE-(DOX)-LIP was evaluated by MTT test on hCMEC/D3 cells, GBM cell lines and GBM stem-like cells, alone or in co-culture with brain endothelial cells. In vivo biodistribution of mApoE-(DOX)-LIP and their co-localization with tumor cells were evaluated by radiochemical and fluorescent assays, respectively.

RESULTS: mApoE-(DOX)-LIP displayed a size of 128±15 nm, the DOX incorporation rate was 95±3%, the yield of mApoE coupling on LIP surface was 91.48±2%. The in vitro endothelial permeability of mApoE-(DOX)-LIP was 5-fold higher respect to DOXO-LIP. mApoE-(DOX)-LIP exerted their cytotoxicity on GBM cells, stem cells included, without affecting the endothelial cells viability. In vivo results showed that the DOX incorporation in mApoE-LIP reduces (-30%) liver and heart DOX accumulation, increases (4-fold) the amount of DOX in brain. Moreover, the in vivo co-localization between DOX and GBM cells was detected.

DISCUSSION:Our finding suggests that mApoE-(DOX)-LIP could be promising candidates GBM treatment.