New Layered Double Hydroxides/Phospholipid Bilayer Hybrid Material with Strong Potential for Sustained Drug Delivery System

A new supra-organized hybrid material obtained in aqueous medium via anionic exchange of self-assembled unilamellar anionic liposomes with the nitrate ions present in the interlayers of layered double hydroxides (LDH) is fully characterized. This material presents original properties linked to the simultaneous presence of a phospholipid bilayer derived from liposomes, still used as vectors for lipophilic drugs, and LDH, which protects the bilayer and brings about a pH sensitivity. The exchange rate is controlled via the added amount of liposomes. TGA, XRD, and TEM confirm the organization of the entrapped phospholipids as a bilayer. The presence of the latter allows the material to load lipophilic and neutral drugs, which represent the largest fraction of those newly synthesized. Furthermore, in physiological conditions, preliminary tests show a sustained release of phospholipids (1.5% for 7 days and 6% for 14 days), whereas a fluorescent lipophilic drug-mimic reveals the reorganization of the phospholipids into liposomes in the release medium. In the field of biocompatible materials, these new hybrid particles have a strong potential for the storage and sustained release of neutral or lipophilic drugs.