Spray-dried microparticles composed of carboxylated cellulose nanofiber and cysteamine and their oxidation-responsive release property

초록

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 mu m 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 H2O2. According to DSC analysis, CA contained in the MPs exhibited the melting point at a lower temperature (ca. 50-53 degrees C) than free CA (ca. 69 degrees C). The volume mean diameter of the MPs was 12.1 to 13.8 mu m. The release of FITC-dextran loaded in MPs was promoted when H2O2 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.

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