Decoupled Thermo‐ and pH‐Responsive Hydrogel Microspheres Cross‐Linked by Rotaxane Networks. Issue 48 (26th October 2017)

• Record Type: Journal Article
• Authors: Kureha, Takuma; Aoki, Daichi; Hiroshige, Seina; Iijima, Keisuke; Aoki, Daisuke; Takata, Toshikazu; Suzuki, Daisuke
• Is Part Of: Angewandte Chemie international edition. Volume 56:Issue 48(2017)
• Page Start: 15393
• Page End: 15396
• Publication Date: 2017-10-26
• Subjects: hydrogel microspheres -- multi-responsiveness -- precipitation polymerization -- rotaxane cross-linkers -- supramolecular chemistry; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201709633
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Rotaxane cross‐linked (RC) microgels that exhibit a decoupled thermo‐ and pH‐responsive volume transition were developed. The pH‐induced changes of the aggregation/disaggregation states of cyclodextrin in the RC networks were used to control the swelling capacity of the entire microgels. Different from conventional thermo‐ and pH‐responsive microgels, which are usually obtained from copolymerizations involving charged monomers, the RC microgels respond to temperature as intended, even in the presence of charged functional molecules such as dyes in the microgel dispersion. The results of this study should lead to new applications, including drug delivery systems that require a retention of their smart functions even in environments that may contain foreign ions, for example, in in vivo experiments. Abstract : Dual‐responsive smart microgels in which thermoresponsive polymers are cross‐linked by rotaxane networks were developed. Although charged monomers, which usually afford pH‐responsiveness for such materials, were not used, the rotaxane cross‐linked microgels respond to pH changes and temperature. This dual‐responsiveness is due to the control over the aggregation/disaggregation states of cyclodextrin.