pH-Induced Shape-Memory Polymers

• Published in: Macromolecular rapid communications. Vol. 33; no. 12; pp. 1055 - 1060
• Main Authors: Han, Xiao-Juan, Dong, Zhen-Qiang, Fan, Min-Min, Liu, Yan, li, Jian-Hu, Wang, Yi-Fu, Yuan, Qi-Juan, Li, Bang-Jing, Zhang, Sheng
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 27.06.2012; WILEY‐VCH Verlag; Wiley
• Subjects: Alginates - chemistry; Applied sciences; beta-Cyclodextrins - chemistry; biocompatibility; Biocompatible Materials - chemistry; Cross-Linking Reagents - chemistry; cyclodextrin; Exact sciences and technology; host-guest systems; Hydrogen-Ion Concentration; Natural polymers; pH sensitive; Physicochemistry of polymers; Polymers - chemistry; shape memory; Starch and polysaccharides; Temperature; Biological properties; Graft copolymer; Biodegradability; Cytotoxicity; Amidation; Mechanism; Inclusion polymer; Shape memory effect; pH; host-guest systems; biocompatibility; Mechanical properties; Tensile property; Alginates; Experimental study; In vitro; Chemical coupling; Polyelectrolyte; Cyclodextrin; Chemical modification; Amine polymer; Preparation; pH sensitive; Oside polymer; Hydrogel; shape memory
• ISSN: 1022-1336; 1521-3927; 1521-3927
• DOI: 10.1002/marc.201200153

A novel pH sensitive shape‐memory polymer (SMP) is prepared by cross‐linking the β‐cyclodextrin modified alginate (β‐CD‐Alg) and diethylenetriamine modified alginate (DETA‐Alg): The pH reversible β‐CD‐DETA inclusion complexes serve as a reversible phase, and the cross‐linked alginate chains serve as a fixing phase. It is shown that this material can be processed into temporary shape as we needs at pH 11.5 and recover to its initial shape at pH 7. The recovery ratio and the fixity ratio were 95.7 ± 0.9% and 94.8 ± 1.1%, respectively. Furthermore, this material showed good degradability and biocompatibility. Because the shape transition pH value is quite close to that of our body fluid and this pH triggered shape‐memory effect is convenient and safe to use, this material has a high potential for medical application. This paper describes a biocompatible and biodegradable SMP, which can be processed into different temporary shapes at pH 11.5 and recover to its permanent shape at pH 7. The shape memory effect was obtained using the pH sensitive inclusion behavior between CD molecules and guest molecules. The recovery ratio and the fixity ratio were 95.7 ± 0.9% and 94.8 ± 1.1%, respectively.