LipoLoad:RB: a nanocarrier comprising bacterial lipoprotein LipoMetQ and Rose Bengal

While conventional nanocarriers like liposomes are effective for small-molecule delivery, their fabrication often involves complex, multi-step processes. This work provides a proof-of-concept demonstrating a bacterial lipoprotein as a viable, genetically encoded, and self-assembling nanocarrier. We show specifically that the detergent-solubilized lipoprotein LipoMetQ from Neisseria meningitidis spontaneously forms micelle-like nanoparticles (termed LipoLoad), which entrap the small molecule Rose Bengal (RB) using a simple procedure of mixing and centrifugal ultrafiltration. The resulting LipoLoad: RB formulation was analyzed by dynamic light scattering and negative-stain TEM. Entrapment was found to decrease RB aggregation and enable a sustained release profile in vitro relative to the free drug. Furthermore, MTT assays performed on a subset of cancer cell lines revealed that LipoLoad: RB increased the intrinsic cytotoxic activity of RB. These results establish LipoLoad as a novel, biologically encoded nanocarrier. The facile production method, which does not require specialized equipment, and the formulation’s stability underscore the broad potential of bacterial lipoproteins as a modular platform for nanotechnology.