Yu Fu, Junyi Chen, Huaping Xu, Chantal Van Oosterwijck, Xi Zhang, Wim Dehaen, and Mario Smet Macromol. Rapid Commun., 2012, 33, 798-804. A novel glutathione peroxidase (GPx) mimic has been prepared by incorporation of a selenium-based catalytic unit into the focal point of a fully-branched hyperbranched polymer. First, an AB2 monomer consisting of isatin and an electron rich aromatic moiety was polycondensed in the presence of 5-nitroisatin as a core reagent, resulting in a polymer with 100% degree of branching. The latter was coupled to the catalytically active moiety, Br(CH2)5SeSe(CH2)...

Yu Yi, Shixin Fa, Wei Cao, Lingwu Zen, Meixiang Wang, Huaping Xu, and Xi Zhang Chem. Commun., 2012, 48, 7495-7497. We have employed a selenium containing amphiphile to assist the formation of well-defined azacalixarene nanosheets, in which the SeN non-covalent interaction plays an important role.

Wei Cao, Yang Li, Yu Yi, Shaobo Ji, Lingwu Zeng, Zhiwei Sun, and Huaping Xu Chem. Sci., 2012, 3, 3403-3408. A novel coordination-responsive system for the controlled release of doxorubicin was fabricated by complexing platinum cations with selenium-containing polymers. Doxorubicin loaded in the platinum-coordinating micelles can be released in a controlled manner through the competitive coordination of the platinum cations with glutathione. The coordination micelles are quite biocompatible as vehicles of drug delivery, thus opening a new avenue in multidrug systems for cooperative chemot...

Peng Han, Sichao Li, Wei Cao, Yang Li, Zhiwei Sun, Zhiqiang Wang, and Huaping Xu J. Mater. Chem. B, 2013, 1, 740-743. We showed here that red light can be used to tune the self-assembly of amphiphilic diselenide-containing block copolymers, via the production of singlet oxygen in the presence ofchromophores such as porphyrin derivatives. Furthermore, red light can be used to trigger the release of encapsulated cargo in polymeric micelles.

Huaping Xu, Wei Cao, and Xi Zhang Acc. Chem. Res., 2013, 46, 1647-1658. Although researchers have made great progress in the development of responsive polymeric materials for controlled drug release or diagnostics over the last 10 years, therapeutic results still lag behind expectations. The development of special materials that respond to physiological relevant concentrations, typically within the micromolar or nanomolar concentration regime, remains challenging. Therefore, researchers continue to pursue new biomaterials with unique properties and that respond to mild biochemical signals ...

Wei Cao, Xiaoli Zhang, Xiaoming Miao, Zhimou Yang, and Huaping Xu Angew. Chem. Int. Ed., 2013, 52, 6233-6237. An overwhelming response: The exposure of a supramolecular hydrogel based on a diselenide-containing polymer and a peptide amphiphile containing a drug moiety to γ radiation led to a gel–sol transition owing to the oxidative cleavage of diselenide bonds in the polymer main chain (see picture). The hydrogel can also act as a UV-mediated drug self-delivery system and suggests a new avenue for combined radio- and chemotherapy.

Yu Yi, Huaping Xu, Lu Wang, Wei Cao, and Xi Zhang Chem. Eur. J., 2013, 19, 9506-9510. A new kind of SeN dynamic covalent bond has been found that can form between the Se atom of a phenylselenyl halogen species and the N atom of a pyridine derivative, such as polystyrene-b-poly(4-vinylpyridine). This SeN dynamic covalent bond can be reversibly and rapidly formed or cleaved under acidic or basic conditions, respectively. Furthermore, the bond can be dynamically cleaved by heating or treatment with stronger electron-donating pyridine derivatives. The multiple responses of SeN bond to extern...

Huifeng Ren, Yaoting Wu, Yang Li, Wei Cao, Zhiwei Sun, Huaping Xu, and Xi Zhang Small, 2013, 9, 3981-3986. A photoresponsive polyelectrolyte multilayer film containing a diselenide functional group is fabricated using an unconventional layer-by-layer method. The polycation backbone is constructed through copolymerization of di-(1-hydroxylundecyl) diselenide and 1,4-bis(2-hydroxyethyl)piperazine with 2,4-diisocyanatotoluene. A common polyanion poly(styrene sulfonate) is selected as the polyanion. The obtained film can be gradually disrupted under the irradiation of mild visible light, and...

Xiaoming Miao, Wei Cao, Wenting Zheng, Jingyu Wang, Xiaoli Zhang, Jie Gao, Chengbiao Yang, Deling Kong, Huaping Xu, Ling Wang, and Zhimou Yang Angew. Chem. Int. Ed., 2013, 52, 7781-7785. Mimicking nature: The reversible formation of self-assembled nanostructures of selenium-containing peptides can be controlled by redox triggers (see scheme, VC=vitamin C). As a consequence, the catalytic activity of these peptides is switchable. These results should lead to the development of nature-mimicking smart materials with promising properties.

Shaobo Ji, Wei Cao, and Huaping Xu Part. Part. Syst. Charact., 2013, 30, 1034-1038. The presence of too many reactive oxygen species (ROS) will damage cells. To eliminate ROS, a nanocomposite film containing diselenide bonds is fabricated via the layer-by-layer assembly method, using adamantane-terminated diselenide block copolymer micelles and β-cyclodextrin-modified nanoparticles as building blocks. This film possesses potential stability under the normal physiological condition and can eliminate different kinds of ROS.