Self-assembled lipid liquid crystalline drug delivery systems of hexagonal (H2) and cubic (V2) structure were synthesized and characterized by means of small angle X-ray scattering, and electrochemical techniques. Biological analyses of the delivery potentials of the H2 phase were performed using cytotoxic assay and confocal microscopy and compared with the cubic phase. The study demonstrated a slow release rate from the H2 phase, which may serve as a novel matrix for sustained release. The data also indicate that empty H2 and V2 nanoparticles exhibit relatively low cytotoxicity, however when loaded with a chemotherapeutic drug (doxorubicin), cause a significant reduction in cell viability. It was confirmed that V2 nanoparticles likely present a more efficient and rapid drug release, while H2 nanoparticles exhibit a less prolonged drug discharge capability. We propose that H2 nanoparticles may be considered as valuable tools for sustained drug delivery systems in cancer therapy.