Multi-functionalized liposome for brain drug delivery to treat glioblastoma

Abstract

To date, delivery of therapeutic agents into the brain to target malignant brain tumors such as glioblastoma multiforme (GBM) remains a significant challenge due to the existence of the blood-brain barrier (BBB). A multitude of delivery systems, such as hydrogels, micelles, liposomes, or polymeric nanoparticles have been proposed as carriers for brain drug delivery and for GBM targeting. However, many of them exhibited limited tumor-specific inhibition effects. Herein, a drug-encapsulated dual-functionalized thermosensitive liposomal system was developed for targeted delivery across the BBB. Specifically, a GBM-specific cell-penetrating peptide and an anti-GBM antibody were conjugated onto the liposome surface. In addition, superparamagnetic iron oxide nanoparticles (SPIONs) and Doxorubicin (DOX) were co-loaded inside the synthesized dual-functionalized liposomes (DOX@P1NS/TNC-FeLP) in order to achieve thermo-triggered drug release by converting electromagnetic energy to heat using an alternating magnetic field (AMF). In parallel, an optimized in vitro blood-brain barrier (BBB) model was established by co-culturing mouse brain endothelial cells and astrocytes. The successful establishment of the model was confirmed by the expression of tight junction proteins and a stable trans-endothelial electrical resistance (TEER) value. This in vitro model was then used to investigate the BBB penetration capabilities and mechanisms of DOX@P1NS/TNC-FeLPs. Results revealed that, with functionalization of the antibody and CPP, this newly developed drug delivery system (DDS) was able to transport higher concentrations of DOX across the BBB model, confirming its potential as nanocarriers for future brain drug delivery. Additionally, results from immunofluorescent (IF) staining and RT-qPCR further demonstrated that DOX@P1NS/TNC-FeLPs specifically entered U-87 human GBM cells and suppressed tumor cells proliferation without causing significant impact on healthy brain cell function. As a conclusion, the DOX@P1NS/TNC-FeLPs present potent and precise anti-GBM capability and therefore is suggested as a promising DDS to target GBM and deliver therapeutic agents across the BBB.