title: Tetrathiafulvalene terminal-decorated PAMAM Dendrimers for triggered release synergistically stimulated by redox and CB[7].
abstract: A series of polyamidoamine (PAMAM) dendrimers with tetrathiafulvalene (TTF) at the periphery (Gn-PAMAM-TTF), generation 0-2, were synthesized. These functionalized dendrimers exist as nanospheres with diameters around 80-100 nm in aqueous phase, which can encapsulate hydrophobic molecules. The terminal TTF groups can go through a reversible redox process upon addition of the oxidizing and reducing agents. Each terminal TTF(+•) group of the oxidized Gn-PAMAM-TTF assembled with cucurbit[7]uril (CB[7]) forming a 1:1 inclusion complex with association constants of (3.14 ± 0.36) × 10(5), (1.29 ± 0.12) × 10(6), and (1.79 ± 0.24) × 10(6) M(-1) for generation 0-2, respectively, even at the aggregate state. The formation of the inclusion complex loosened the structure of the nanospheres and initiated the release of cargo, and the release mechanism was validated by dynamic light scattering (DLS), cryo-transmission electron microscopy (TEM), and electron paramagnetic resonance (EPR) experiments. This study provides a potential strategy for the development of drug delivery systems synergistically triggered by redox and supramolecular assembly.
authors.affiliation: Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Beijing 100190, People's Republic of China.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Zhang
authors.forename: Yi
authors.initials: Y
authors.lastname: Zeng
authors.forename: Tianjun
authors.initials: T
authors.lastname: Yu
authors.forename: Jinping
authors.initials: J
authors.lastname: Chen
authors.forename: Guoqiang
authors.initials: G
authors.lastname: Yang
authors.forename: Yi
authors.initials: Y
authors.lastname: Li