title: Dendrimer-like assemblies based on organoclays as multi-host system for sustained drug delivery.
abstract: Chemical modification of nanoclay will ensure further progress on these materials. In this work, we show that montmorillonite (MTM) nanosheets can be modified with β-cyclodextrin (CD) via a nucleophilic substitution reaction between mono-6-(p-toluenesulfonyl)-6-deoxy-β-CD and an amino group of 3-aminopropyltriethoxysilane (APTES)-functionalized MTM. The resulting MTM-APTES-CD can be further self-assembled into dendrimer-like assemblies, exhibit a well-dispersed property even in Dulbecco's phosphate-buffered saline and do not aggregate for a period of at least 20days. The structure, morphology and assembly mechanism are systematically studied by (29)Si MAS NMR, FT-IR, (1)H NMR, SEM, FE-TEM, DLS and AFM, and the change in assemblies during the drug release is monitored using FE-TEM images. MTT assays indicate that the assemblies only have low cytotoxicity, while CLSM and TEM observations reveal that the assemblies can easily penetrate cultured human endothelial cells. When clopidogrel is used as a guest molecule, the assemblies show not only much higher loading capacities compared to MTM and other containing β-CD assemblies or nanoparticles, but also a sustained release of clopidogrel up to 30days. This is attributed to the fact that the guest molecule is both supramolecularly complexed within the dendritic scaffold and intercalated into CD and MTM hosts. Host-guest systems between assemblies and various guests hold promising applications in drug delivery system and in the biomedical fields.
authors.affiliation: Department of Medicinal Chemistry, School of Pharmacy, Chongqing Medical University, Chongqing, PR China; Chongqing Key Laboratory of Biochemistry and Molecular Pharmacology, Chongqing Medical University, Chongqing, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.affiliation: Department of Medicinal Chemistry, School of Pharmacy, Chongqing Medical University, Chongqing, PR China.
authors.forename: Lili
authors.initials: L
authors.lastname: Sun
authors.affiliation: Pharmaceutical Teaching Laboratory, Chongqing Medical University, Chongqing, PR China.
authors.forename: Lijun
authors.initials: L
authors.lastname: Pan
authors.affiliation: Department of Medicinal Chemistry, School of Pharmacy, Chongqing Medical University, Chongqing, PR China.
authors.forename: Zuopin
authors.initials: Z
authors.lastname: Lan
authors.affiliation: Department of Medicinal Chemistry, School of Pharmacy, Chongqing Medical University, Chongqing, PR China.
authors.forename: Tao
authors.initials: T
authors.lastname: Jiang
authors.affiliation: College of Laboratory Medicine, Chongqing Medical University, Chongqing, PR China.
authors.forename: Xiaolan
authors.initials: X
authors.lastname: Yang
authors.affiliation: Department of Medicinal Chemistry, School of Pharmacy, Chongqing Medical University, Chongqing, PR China.
authors.forename: Jianchun
authors.initials: J
authors.lastname: Luo
authors.affiliation: Department of Medicinal Chemistry, School of Pharmacy, Chongqing Medical University, Chongqing, PR China.
authors.forename: Ronghua
authors.initials: R
authors.lastname: Li
authors.affiliation: Department of Medicinal Chemistry, School of Pharmacy, Chongqing Medical University, Chongqing, PR China.
authors.forename: Liqing
authors.initials: L
authors.lastname: Tan
authors.affiliation: Department of Medicinal Chemistry, School of Pharmacy, Chongqing Medical University, Chongqing, PR China.
authors.forename: Shurong
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Department of Medicinal Chemistry, School of Pharmacy, Chongqing Medical University, Chongqing, PR China. Electronic address: minganyu666@outlook.com.
authors.forename: Mingan
authors.initials: M
authors.lastname: Yu
mesh_terms: D001546:Bentonite / Q000737:chemistry* / Q000633:toxicity; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D000077144:Clopidogrel; D003505:Cyclodextrins / Q000737:chemistry* / Q000633:toxicity; D003692:Delayed-Action Preparations; D050091:Dendrimers / Q000737:chemistry* / Q000633:toxicity; D004337:Drug Carriers / Q000737:chemistry* / Q000633:toxicity; D042783:Endothelial Cells / Q000187:drug effects; D006801:Humans; D046529:Microscopy, Electron, Transmission; D015394:Molecular Structure; D011437:Propylamines; D012821:Silanes / Q000737:chemistry* / Q000633:toxicity; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D013988:Ticlopidine / Q000008:administration & dosage / Q000031:analogs & derivatives
chemical_list: D003505:Cyclodextrins; D003692:Delayed-Action Preparations; D050091:Dendrimers; D004337:Drug Carriers; D011437:Propylamines; D012821:Silanes; D001546:Bentonite; D000077144:Clopidogrel; C477625:amino-propyl-triethoxysilane; D013988:Ticlopidine
keywords: Cyclodextrin; Dendrimer-like assemblies; Host–guest system; Hydrogen bond; Montmorillonite; Self-assembly