Synthesis and Characterisation of a Macrophage-derived Hybrid Nanoparticles for Doxorubicin Delivery to Glioblastoma

Glioblastoma (GBM) presents significant therapeutic challenges due to its aggressive nature, complex microenvironment and the limitations of conventional drug delivery systems. In this study, hybrid nanoparticles were developed by combining synthetic liposomes with macrophage-derived extracellular vesicles (EVs) to harness the strengths of both platforms. Two distinct liposomal formulations, DPPC:Chol:DSPE-mPEG2000 (F1) and DPPC:DPPS:Chol:DSPE-mPEG2000 (F2), were used as the basis for the synthesis. EVs derived from J774 macrophages were integrated with F1 and F2 to create hybrid nanoparticles (H-F1 and H-F2). Doxorubicin (DOX) was encapsulated using a pH gradient and a remote loading procedure. The mean particle size of H-F1-DOX and H-F2-DOX was 158.2 ± 1 nm and 162.8 ± 9 nm, respectively. The polydispersity index (PDI) was 0.130 ± 0.012 and 0.084 ± 0.033, while the zeta potential values were −14.9 ± 0.7 mV and −26.7 ± 3.1 mV, respectively. H-F2-DOX exhibited the highest encapsulation efficiency (EE%), reaching 76.5±3.4%. The encapsulated hybrids remained stable up to one week, at +5°C. The release of DOX from H-F2-DOX in DMEM supplemented with 10% serum showed pH sensitivity, with total DOX release of 64.9 ± 5.3% at pH 7.4 and 90.7 ± 6.5% at pH 5.5. The cell viability assay demonstrated that all formulations exhibited strong cytotoxic effects against GBM cells under normoxic conditions, with H-F2-DOX showing the most potent effect under hypoxia-mimetic conditions.