Synthesis of novel core@shell of MgAl layered double hydroxide @ porous magnetic shell (MgAl-LDH@PMN) as carrier for ciprofloxacin drug

Abstract

MgAl-layered double hydroxide (MgAl-LDH) derived from a metal-organic framework (MOF), was synthesized by hydrothermal method. A biocompatible MgAl-LDH core-porous magnetic nanoparticles (PMN) shell (MgAl-LDH@PMN) was synthesized using solvothermal method and modified with amino groups as a potential pH-controlled drug delivery carrier. MgAl-LDH with a sheet-like morphology was coated with porous Fe3O4 or porous magnetite via the functionalization of (3-aminopropyl) triethoxysilane using a post-synthesis route (MgAl-LDH@PMN-NH2). The core@shell was characterized using a range of techniques such as x-ray diffraction patterns (XRD), scanning electron microscopy (SEM), diffuse reflectance spectroscopy (DRS), Brunauer-Emmett-Teller (BET), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic light scattering (DLS) and transmission electron microscopy (TEM). The MgAl-LDH@PMN-NH2 core@shell indicated a spherical morphology and good porosity. Ciprofloxacin (CIPRO) drug was incorporated in the pore channels and surface of the MgAl-LDH@PMN-NH2 and the drug release properties were examined at pH 4.0 and 7.4. The TG results demonstrated that drug loading contents on the modified carrier was 40%. The delayed release property exhibited by MgAl-LDH@PMN-NH2 was attributed to the strong interactions of the drug molecules with the surface amino-functionality and the charged LDH surface. The characterization and drug release was also investigated for the un-modified carrier (MgAl-LDH@PMN) with drug loading 15% under identical conditions. The porosity and functionalization of the PMN shell and the surface charge density of the layered structure of MgAl-LDH are the major reasons for the controlled release of the CIPRO drug. Moreover, the favorable delay in drug release from both core@shells at pH 4 was attributed to the high level of ionization and dissolution. Biocompatibility was evaluated by examination of the cell line MCF-7 response to the un-modified and modified carriers.