title: Dual pH-Mediated Mechanized Hollow Zirconia Nanospheres.
abstract: We demonstrate for the first time how to assemble mechanized hollow zirconia nanospheres (MHzNs), consisting of hollow mesoporous zirconia nanospheres (HMZNs) as nanoscaffolds and supramolecular switches anchored on the exterior surface of HMZNs. The remarkable advantage of substitution of HMZNs for conventional mesoporous silica nanoscaffolds is that HMZNs can suffer the hot alkaline reaction environment, which provides a novel strategy for functionalization and thus achieve dual pH-mediated controlled release functions by simple and practicable assembly procedure. Under neutral solution, cucurbituril[7] (CB[7]) macrocycles complexed with propanone bis(2-aminoethyl)ketal (PBAEK) to form [2]pseudorotaxanes as supramolecular switches, blocking the pore orifices and preventing the undesirable leakage of cargoes. When solution pH was adjusted to alkaline range, CB[7] macrocycles, acting as caps, disassociated from PBAEK stalks and opened the switches due to the dramatic decrease of ion-dipole interactions. While under acidic conditions, PBAEK stalks were broken on account of the cleavage of ketal groups, resulting in the collapse of supramolecular switches and subsequent release of encapsulated cargoes. MHzNs owning dual pH-mediated controlled release characteristic are expected to apply in many fields. In this work, the feasibility of doxorubicin (DOX)-loaded MHzNs as targeted drug delivery systems was evaluated. In vitro cellular studies demonstrate that DOX-loaded MHzNs can be easily taken up by SMMC-7721 cells, can rapidly release DOX intracellularly, and can enhance cytotoxicity against tumor cells, proving their potential for chemotherapy.
authors: School of Chemical Engineering, ‡Computational Institute for Molecules and Materials, and §National Special Superfine Powder Engineering Research Centre, Nanjing University of Science and Technology , Nanjing 210094, China.
authors: MingDong
authors: M
authors: Wang
authors: School of Chemical Engineering, ‡Computational Institute for Molecules and Materials, and §National Special Superfine Powder Engineering Research Centre, Nanjing University of Science and Technology , Nanjing 210094, China.
authors: GuangCai
authors: G
authors: Gong
authors: School of Chemical Engineering, ‡Computational Institute for Molecules and Materials, and §National Special Superfine Powder Engineering Research Centre, Nanjing University of Science and Technology , Nanjing 210094, China.
authors: Jing
authors: J
authors: Feng
authors: School of Chemical Engineering, ‡Computational Institute for Molecules and Materials, and §National Special Superfine Powder Engineering Research Centre, Nanjing University of Science and Technology , Nanjing 210094, China.
authors: Ting
authors: T
authors: Wang
authors: School of Chemical Engineering, ‡Computational Institute for Molecules and Materials, and §National Special Superfine Powder Engineering Research Centre, Nanjing University of Science and Technology , Nanjing 210094, China.
authors: ChenDi
authors: C
authors: Ding
authors: School of Chemical Engineering, ‡Computational Institute for Molecules and Materials, and §National Special Superfine Powder Engineering Research Centre, Nanjing University of Science and Technology , Nanjing 210094, China.
authors: BaoJing
authors: B
authors: Zhou
authors: School of Chemical Engineering, ‡Computational Institute for Molecules and Materials, and §National Special Superfine Powder Engineering Research Centre, Nanjing University of Science and Technology , Nanjing 210094, China.
authors: Wei
authors: W
authors: Jiang
authors: School of Chemical Engineering, ‡Computational Institute for Molecules and Materials, and §National Special Superfine Powder Engineering Research Centre, Nanjing University of Science and Technology , Nanjing 210094, China.
authors: JiaJun
authors: J
authors: Fu
keywords: dual pH-stimuli-responsive controlled release; hollow mesoporous zirconia nanospheres; mechanized hollow zirconia nanospheres; supramolecular switches; targeted drug delivery