Tsao Ching Ting, Hsiao Meng Hsuan, Zhang Mengying Y, Levengood Sheeny Lan, Zhang Miqin
Department of Materials Science & Engineering, University of Washington, Seattle, WA, 98195, USA.
Macromol Rapid Commun. 2015 Feb;36(3):332-8. doi: 10.1002/marc.201400586. Epub 2014 Dec 17.
Smart hydrogels play an increasingly important role in biomedical applications, since materials that are both biocompatible and multi-stimuli-responsive are highly desirable. A simple, organic solvent-free method is presented to synthesize a biocompatible hydrogel that undergoes a sol-gel transition in response to multiple stimuli. Methoxy-poly(ethylene glycol) (mPEG) is modified into carboxylic-acid-terminated-methoxy-poly(ethylene glycol) (mPEG-acid), which is then grafted onto chitosan via amide linkages yielding mPEG-g-chitosan. Grafting of mPEG onto hydrophobic chitosan imparts hydrophilic properties to the resultant polymer. The mPEG-g-chitosan gel exhibits a controllable multi-stimuli-responsive property. The balance between hydrophilicity and hydrophobicity is believed to confer mPEG-g-chitosan with stimuli-responsive behavior. The effect of salt concentration, solute concentration, temperature, and pH on the sol-gel transition of mPEG-g-chitosan is evaluated and the underlying mechanisms of mPEG-g-chitosan polymer packing and gelation property is discussed.
智能水凝胶在生物医学应用中发挥着越来越重要的作用，因为兼具生物相容性和多刺激响应性的材料是非常理想的。本文提出了一种简单的无有机溶剂方法来合成一种生物相容性水凝胶，该水凝胶能响应多种刺激发生溶胶-凝胶转变。将甲氧基聚乙二醇（mPEG）改性为羧酸封端的甲氧基聚乙二醇（mPEG-酸），然后通过酰胺键将其接枝到壳聚糖上，得到mPEG-g-壳聚糖。将mPEG接枝到疏水性壳聚糖上赋予了所得聚合物亲水性。mPEG-g-壳聚糖凝胶表现出可控的多刺激响应特性。据信亲水性和疏水性之间的平衡赋予了mPEG-g-壳聚糖刺激响应行为。评估了盐浓度、溶质浓度、温度和pH对mPEG-g-壳聚糖溶胶-凝胶转变的影响，并讨论了mPEG-g-壳聚糖聚合物堆积和凝胶化性质的潜在机制。
