Lipid-bilayer-coated nanogels allow for sustained release and enhanced internalization.

Nanoparticle drug delivery system improves the therapeutic efficacy of a drug; however, achieving sustained release from nanoparticles is challenging, owing to the increase of surface area and pronounced burst release. In this study, by incorporating an organogel of 12-hydroxystearic acid (12-HSA) into lipid-bilayers, a gel-liposomal formulation was developed to sustain drug release over time. The lipid-bilayer-coated nanogels (LBCNs) with a particle size of approximately 200 nm and with a core-shell structure had an entrapment efficiency of up to 80% for paclitaxel. LBCNs could continually release both hydrophobic and water-soluble drugs over time. Interestingly, the incorporation of organogel enhanced the cellular uptake of liposomes significantly and, accordingly, enabled improved cytotoxicity of chemotherapy agent against the cancer cells. In conclusion, by formulating the organogel into the lipid bilayers, gel-liposomes were developed, allowing for sustained drug release, improved internalization and the resultant enhancement of cytotoxicity of chemotherapy agent to cancer cells.