Synthesis and characterization of camptothecin-rhamnolipid-layered double hydroxide nanohybrid and its controlled release property

Camptothecin (CPT) is a kind of hydrophobic anticancer drug. The clinical application of CPT is limited by its poor water solubility and serious side effects. In this work, layered double hydroxide (LDH) nanosheets were prepared in an aqueous synthetic route, and rhamnolipid (RL) anions were assembled with LDH nanosheets to form a RL-LDH nanohybrid. A CPT-intercalated RL-LDH (CPT-RL-LDH) nanohybrid was then prepared via hydrophobic interaction in a saturated ethanol solution of CPT. A possible morphology of CPT molecules in the hydrophobic interlayer region of RL-LDH was proposed according to the size of CPT molecule and the gallery height of the RL-LDH. The obtained CPT-RL-LDH nanohybrid showed high thermal stability and controlled release of CPT. The diffusion of CPT through CPT-RL-LDH particles was the rate-limiting step of CPT release. The drug-RL-LDH nanohybrids can be used as potential drug delivery materials.