College of Marine Life Science, Ocean University of China, 5# Yushan Road, Qingdao 266003, Shandong Province, China.
College of Marine Life Science, Ocean University of China, 5# Yushan Road, Qingdao 266003, Shandong Province, China; Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266000, PR China.
Int J Biol Macromol. 2020 Jul 1;154:758-764. doi: 10.1016/j.ijbiomac.2020.03.075. Epub 2020 Mar 24.
Alkali/urea, a green dissolution system for chitosan, have been widely used in preparation of chitosan-derived materials. However, there are no related reports detail the structure stability and biocompatibility of chitosan in alkali/urea, which are important for its large-scale application. In this work, chitosan was dissolved in KOH/urea solution and stored at different temperature for different time. The structure, viscosity, molecule weight (Mw), degree of deacetylation (DD), and biocompatibility of chitosan were determined. The Mw of chitosan decreased from 1011 KDa to 827-834 KDa, and DD increased from 76.9% to 85.7-93.5% after been stored at 25 °C and 4 °C for 5 weeks. Incomplete dissolution of chitosan and increase of DD enhanced its thermal stability by forming new crystallization zone. In contrast, chitosan stored in -20 °C for 5 weeks was stable without obvious change of Mw and DD. Moreover, the processed chitosans were no-toxic and safety for the biomedicine applications.
碱/尿素是一种广泛用于壳聚糖衍生材料制备的绿色溶解体系。然而，关于壳聚糖在碱/尿素中的结构稳定性和生物相容性的相关报道还很少，而这些性质对于壳聚糖的大规模应用非常重要。在这项工作中，壳聚糖溶解在 KOH/尿素溶液中，并在不同温度下储存不同的时间。对壳聚糖的结构、黏度、分子量（Mw）、脱乙酰度（DD）和生物相容性进行了测定。壳聚糖的 Mw 从 1011 kDa 降低到 827-834 kDa，DD 从 76.9%增加到 85.7-93.5%，在 25°C 和 4°C 下储存 5 周后。壳聚糖不完全溶解和 DD 的增加通过形成新的结晶区来提高其热稳定性。相比之下，在-20°C 下储存 5 周的壳聚糖则保持稳定，Mw 和 DD 没有明显变化。此外，处理后的壳聚糖无毒性，可安全应用于生物医学领域。
