TEMPO-modified cellulose nanofiber (TM CNF) microparticles (MPs) incorporating cysteamine (CA) were prepared by a spray-drying method. MPs on SEM micrographs were flat wrinkled balls-like and less than 10 μm in diameter. The energy-dispersive X-ray spectroscopy, the elemental mapping, and the X-ray photon spectroscopy were performed to understand the content and the distribution of CA in the TM CNF MPs. FT-IR spectroscopy showed that the thiol groups of CA molecules contained in MPs were oxidized by the treatment of H 2 O 2 . According to DSC analysis, CA contained in the MPs exhibited the melting point at a lower temperature (ca. 50–53 °C) than free CA (ca. 69 °C). The volume mean diameter of the MPs was 12.1 to 13.8 μm. The release of FITC-dextran loaded in MPs was promoted when H 2 O 2 solution was used as a release medium. The promoted release could be ascribed to the oxidization-induced reorientation of CA molecules and the subsequently occurring dislocation of TM CNF.

中文翻译：

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羧化纤维素纳米纤维和半胱胺组成的喷雾干燥微粒及其氧化响应释放特性

通过喷雾干燥法制备了掺入半胱胺 (CA) 的 TEMPO 改性纤维素纳米纤维 (TM CNF) 微粒 (MPs)。SEM 显微照片上的 MP 是扁平的皱纹球状，直径小于 10 微米。进行能量色散 X 射线光谱、元素映射和 X 射线光子光谱以了解 TM CNF MP 中 CA 的含量和分布。FT-IR光谱表明MPs中CA分子的巯基被H 2 O 2 氧化。根据 DSC 分析，MP 中所含的 CA 在比游离 CA（约 69 °C）更低的温度（约 50-53 °C）下表现出熔点。MP 的体积平均直径为 12.1 至 13.8 μm。当使用 H 2 O 2 溶液作为释放介质时，促进了负载在 MP 中的 FITC-葡聚糖的释放。