基于壳聚糖/银离子的可逆温敏水凝胶的制备与性能

Preparation and properties of thermotropic reversible gel based on chitosan and silver cation

摘要:

通过壳聚糖与银离子的超分子络合作用制备了一系列可逆温敏水凝胶CS-Ag。该系列水凝胶在常温状态下处于半透明稳定的可流动溶胶状态，当温度高于50°C时2min内即可转变为凝胶固体状态，温度低于50°C时恢复为可流动溶胶状态，该相变过程可重复5次以上，稳定性好。采用红外光谱（FT-IR）、X射线衍射（XRD）、X射线光电子能谱（XPS），扫描电镜（SEM）和X-射线能谱（EDS）测试对水凝胶CS-Ag的结构和化学状态进行表征。通过同时调节AgNO3的用量和体系的pH值可制备具有相同凝胶温度的水凝胶体系。该水凝胶体系的溶胶-凝胶转换是由壳聚糖的氨基在不同温度下的各种超分子相互作用控制。CS-Ag-19水凝胶对大肠杆菌表现出良好的抗菌活性，并具有可注射和温敏凝胶性能，具有作为水凝胶抗菌敷料的应用潜力。

Abstract:

A series thermoreversible hydrogel CS-Ag were prepared by the supermolecule complexation of chitosan with silver ion. The CS-Ag systems are in the semi-transparent and stable flowable sol state at room temperature, and become the gel state at temperature above 50 °C in 2 min and recover to flowable sol state when temperature was below 50 °C. This phase transition process could be repeated at least 5 times and shows a good stability. The structure and chemical state of the hydrogel were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and X-ray energy spectrometer (EDS). The thermoreversible hydrogel CS-Ag with same gelation temperature could be prepared by adjusting the AgNO3 amount and the pH value simultaneously. The different supramolecular interactions of the -NH2 group of chitosan in the hydrogel system at different temperatures were proposed to dominate the reversible thermo-responsive process of CS-Ag hydrogel. CS-Ag-19 hydrogel showed good antibacterial, and injectable and thermos-gelation performance, and it had potential application as hydrogel antibacterial dressing.