Abstract

Two chitosan, CS, microfibers loaded with the herbal persimmon leaves, PL, and the non-herbal metformin hydrochloride, MH, were wet spun, respectively. SEM images shown that these two CS microfibers have different surface morphologies at the as-spun state due to the PL-loaded fiber presented the squamae-like structure and the MH-loaded fiber presented some bright dots. This suggested that the PL and MH were loaded in the CS chains by different mechanisms and some loaded MH molecules out of the CS chains might be free and separated by spinning-induced extrusion forces. FTIR spectra analysis indicated that the PL was loaded in the CS chains mainly by the O-H groups and formed the interpenetration network and the MH was loaded in the CS chains mainly by the N-H groups and formed the sheathing structure. The loading of these herbal and non-herbal drugs in CS chains both shown good miscibility while the mechanical properties were reduced as compared with the pure CS fiber. The release of the PL and MH from CS fibers both followed the same Langmuir kinetics model, while the comparisons found that the released amount was greater for the PL and the release rate was faster for the MH.

摘要

分别湿纺了两个壳聚糖CS超细纤维，其中装有柿子叶PL和非草药盐酸二甲双胍MH。SEM图像表明，这两种CS超细纤维在初纺状态下具有不同的表面形态，这是由于PL负载的纤维呈现出鳞状结构，而MH负载的纤维呈现出亮点。这表明PL和MH通过不同的机理被装载到CS链中，并且CS链之外的一些被装载的MH分子可能是自由的，并通过纺丝诱导的挤压力而分离。FTIR光谱分析表明，PL主要由OH基团负载在CS链上，形成互穿网络，MH主要由NH基团负载在CS链上，形成鞘结构。与纯CS纤维相比，这些草药和非草药药物在CS链中的负载均显示出良好的混溶性，而机械性能却降低了。CS纤维中PL和MH的释放均遵循相同的Langmuir动力学模型，而比较发现PL的释放量更大，MH的释放速率更快。