Peng Han, Ning Ma, Huifeng Ren, Huaping Xu, Zhibo Li, Zhiqiang Wang, and Xi Zhang Langmuir, 2010, 26, 14414-14418. We have fabricated a polymeric superamphiphile based on the electrostatic interaction between the double hydrophilic block copolymer of poly(ethylene glycol)-b-acrylic acid (PEG-b-PAA) and a selenium-containing surfactant (SeQTA). The polymeric superamphiphiles are able to self-assemble to form micelles in solution. The micelles can be disassembled with the addition of 0.1% H2O2 because SeQTA is very sensitive to oxidation. The selenide group in SeQTA is oxidized into seleno...

Ning Ma, Huaping Xu, Liping An, Juan Li, Zhiwei Sun, and Xi Zhang Langmuir, 2011, 27, 5874–5878. We have developed a potential radiation-sensitive drug-delivery system using active diselenide-containing block co-polymer aggregates in aqueous solution that can load and release anticancer drugs. These aggregates were sensitive to even a low dose of γ-radiation, such as 5 Gy, which is close to the radiation dose received by patients during a single radiotherapy treatment. This line of research may open an avenue for the combination of radiotherapy and chemotherapy.

Huifeng Ren, Yaoting Wu, Ning Ma, Huaping Xu, and Xi Zhang Soft Matter, 2012, 8, 1460-1466. In this paper we report the synthesis and study of a series of side-chain selenium-containing amphiphilic poly(ethylene oxide-b-acrylic acid) block copolymers PEO-b-PAA-Se. These block copolymers can selfassemble in aqueous solution and form spherical micellar aggregates. The selenide group of PEO-bPAA-Se can change into hydrophilic selenoxide under mild oxidation of 0.1% hydrogen peroxide, leading to the disassembly of the spherical micellar aggregates. Small compounds like Nile Red can be encaps...

Huaping Xu, Monika Schönhoff, and Xi Zhang Small, 2012, 8, 517-523. Layer-by-layer assembly (LbL) is a rich, versatile, and powerful technique for fabricating multilayer thin films with controlled architecture and functions. Singly charged, uncharged, or water-repellent molecules cannot be used directly in conventional LbL assembly. This problem can be solved with unconventional LbL methods, by employing the preassembly of building blocks in solution and the use of these assemblies for LbL formation at the interface. This Concept summarizes different methods of unconventional LbL assembl...

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.