The number of antibiotic-resistant bacteria is increasing worldwide, and the demand for novel antimicrobials is constantly growing. Antimicrobial peptides (AMPs) could be an important part of future treatment strategies of various bacterial infection diseases. However, AMPs have relatively low stability, because of proteolytic degradation. As a consequence, carrier systems protecting the AMPs are greatly needed, to achieve efficient treatments. Dispersions of lipid-based liquid crystalline nanoparticles (cubosomes) are biocompatible drug delivery vehicles, well suited for delivery and protection of AMPs, due to their ability to encapsulate amphipathic molecules. However, the bacterial membrane disruptive properties of the AMP-loaded cubosomes remains unclear, but can be studied using neutron reflectivity.