黄原胶纳米微凝胶的制备及其pH/还原响应性能

以胱胺四酰肼为交联剂,将其与黄原胶在水溶液中进行酰胺化反应,通过"一步法"制备得到pH和还原刺激响应性纳米微凝胶;采用傅里叶红外光谱仪、核磁共振氢谱仪、动态激光光散射仪、扫描电镜和透射电镜对其结构和形貌进行了表征,研究了纳米微凝胶的性能及其药物控释效果。结果表明：该纳米微凝胶具有明显的pH和还原响应性。纳米微凝胶中含有游离的酰肼基团,可与阿霉素分子中的酮羰基反应形成pH敏感的酰腙键。胱胺四酰肼中的双硫键可在较高浓度的谷胱甘肽作用下还原,导致微凝胶交联结构被破坏,促使药物释放。该纳米微凝胶生物相容性良好,有望用作靶向释放抗癌药物载体。

Preparation of Xanthan Nano Microgel and Its pH/Redox Responsiveness

Xanthan nano microgels with pH/redox responsiveness were prepared through an amidation reaction of xanthan in aqueous solution by "one pot" method using cystine hydrazide as the crosslinker. The structures and morphologies of the xanthan nano microgels were characterized by Fourier Transform Infrared Spectroscopy (FT-IR), Nuclear Magnetic Resonance (¹H-NMR), Dynamic Light Scattering (DLS), Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM). The properties and the drug controlled release of the nano microgels were investigated. Xanthan nano microgels had obvious pH and redox responsiveness. The free acyl groups of the microgels could react with ketone carbonyl groups of the doxorubicin, yielding pH sensitive acylhydrazone bonds. The disulfide bonds in cystamine tert-acylhydrazine could be reduced by glutathione solutions,leading to breakdown of the crosslinking structure and drug release. The nano microgels were biocompatible and they had promising prospects as anti-cancer drug carriers for targeted release.