The preparation and property of photo- and thermo-responsive hydrogels with a blending system

• Published in: Journal of materials science Vol. 55; no. 2; pp. 786 - 795
• Main Authors: Shuai, Shirong, Zhou, Siyao, Liu, Yu, Huo, Weirong, Zhu, Hongyu, Li, Yang, Rao, Zikun, Zhao, Cong, Hao, Jianyuan
• Format: Journal Article
• Language: English
• Published: New York Springer US 2020; Springer; Springer Nature B.V
• Subjects: Aqueous solutions; Biological products; Biomedical materials; Blending; Block copolymers; Characterization and Evaluation of Materials; Chemistry and Materials Science; Classical Mechanics; Crystallography and Scattering Methods; Hydrogels; Industrial equipment; Irradiation; Materials Science; NMR; Nuclear magnetic resonance; Phase transitions; Polyethylene glycol; Polymer Sciences; Polymerization; Polymers & Biopolymers; Polyols; Ring opening polymerization; Self-assembly; Sensitivity; Solid Mechanics; Substitution reactions; Technology application; Transition temperature; Ultraviolet radiation
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-019-04010-9

Hydrogels are the attractive biomaterials for biomedical applications. The dual-stimuli-responsive system, which is sensitive to both temperature and UV irradiation, was achieved through the self-assembly of amphiphilic block copolymers in aqueous solution and the cleavage of ο-nitrobenzyl (NB) ester groups under UV irradiation. The copolymer of poly(ε-caprolactone)- b -ο-nitrobenzyl-poly(ethylene glycol)-ο-nitrobenzyl- b -poly(ε-caprolactone) (PCL-NB-PEG-NB-PCL) was prepared by ring-opening polymerization (ROP) and nucleophilic substitution reaction of ε-caprolactone (ε-CL) using photo-sensitized polyethylene glycol as an initiator. After blending with poly(ε-caprolactone)- b -poly(ethylene glycol)- b -poly(ε-caprolactone) (PCL-PEG-PCL), the system exhibited the promising dual sensitivity with wide gel-phase window and controllable sensitive properties. The structures and dual-responsive behaviors were characterized by 1 H-NMR, GPC, DMA, UV–Vis, DLS and SEM. The results demonstrated the temperature and photo-sensitivity of the synthesized hydrogel and indicated that the blending of these two copolymers can easily adjust the phase transition temperature and broaden the gel-phase window through the content of NB groups in PCL-NB-PEG-NB-PCL and the hydrophilic/hydrophobic balance of system.