Preparation And Application Of Zirconia-based Nanoparticles For Drug Delivery Systems

Hollow mesoporous zirconia intelligent nano-containers(HMZSs-1),which is composed of hollow mesoporous zirconia nanospheres(HMZSs)and supramolecular switches,is designed and fabricated in this paper.HMZSs function as scaffold materials and[2]pseudorotaxane as supramolecular switches.Compared to silica based materials,HMZSs could endure hot alkaline reaction environment,providing novel strategies for functionalization.In this way,through a simple and viable assembly procedure,dual pH responsive controlled release function was endowed with HMZSs.In this paper,bis(2-aminoethyl)ketal(PBAEK)was synthesized and anchored onto the surface of HMZSs by single protection.The surface modification processes of HMZSs were characterized by transmission electron microscopy(TEM),nitrogen adsorption-desorption isotherm(BET),Fourier transform infrared spectroscopy(FTIR),solid-state nuclear magnetic resonance(SS 13C NMR)and thermogravimetric analysis(TG)Modified and structurally characterized.The release behaviors of HMZSs-1 were studied by ultraviolet-visible spectroscopy(UV-vis).It was found that in a neutral solution,the macrocyclic compounds of cucurbit[7](CB[7])complexed with PBAEK to form[2]pseudorotaxane as a supramolecular switch,blocking the orifice and preventing drug leakage.When the pH of the solution was adjusted to the basic range,the CB[7]macrocycle was isolated as the cap and dethreaded from the PBAEK chain,and the switch was opened due to a significant decrease in the ion-dipole interaction,the release efficiency reached 81%.Under acidic conditions,the PBAEK chain is destroyed due to the hydrolysis of the ketal group,resulting in the disassembly of the supramolecular switch and subsequent release of the drug,the release efficiency reached 82%.HMZSs-1 with controlled release characteristics of acid,base dual-response is expected to be applied in many fields.In this paper,the feasibility of rhodamine B(RhB)loaded HMZSs-1 as a drug delivery system was investigated.In vitro cell studies showed that RhB-loaded HMZSs-1 could be readily taken up by SMMC-7721 cells and release RhB rapidly in the cells,demonstrating their potential in developing drug delivery system for chemotherapy.