School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002, China.
Biomacromolecules. 2011 Aug 8;12(8):2982-7. doi: 10.1021/bm200571k. Epub 2011 Jul 1.
1-Octyl amine was covalently coupled to sodium alginate(NaAlg) in an aqueous-phase reaction via acidamide functions using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC-HCl) as a coupling reagent to provide octyl-grafted amphiphilic alginate-amide derivative(OAAD) for subsequent use in λ-cyhalothrin (LCH) microcapsule application. The structure of OAAD was confirmed by FT-IR and (1)H NMR spectroscopies. The new alginate-amide derivative was used for fabricating microcapsule that can effectively encapsulate LCH by emulsification-gelation technique. The microcapsules were characterized by optical microscopy (OM), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and laser particle size analysis. The encapsulation efficiency and drug release behavior of LCH from the microcapsules were investigated. Results showed that the microcapsules were in spherical form with diameter mostly in the range of 0.5-10 μm and possessed a structure with LCH as core and OAAD as shell. The encapsulation efficiency and the release performance of the microcapsules were influenced by DS of OAAD and amount of CaCl(2). The mechanism of LCH release was found to vary from anomalous to Fickian to quasi-Fickian transport with the DS of OAAD varied from 10.8 to 30.3 and the CaCl(2)/emulsion ratios varied from 0.09 to 0.03%.
1-辛胺通过酸酰胺基团在水相反应中与海藻酸钠（NaAlg）共价结合，使用 1-乙基-3-（3-二甲基氨基丙基）碳化二亚胺盐酸盐（EDC-HCl）作为偶联试剂，提供辛基接枝两亲性海藻酸钠酰胺衍生物（OAAD），用于随后的 λ-氯氰菊酯（LCH）微胶囊应用。OAAD 的结构通过 FT-IR 和（1）H NMR 光谱得到确认。新的海藻酸钠酰胺衍生物用于通过乳化-凝胶技术制备可以有效包封 LCH 的微胶囊。通过光学显微镜（OM）、透射电子显微镜（TEM）、扫描电子显微镜（SEM）和激光粒度分析对微胶囊进行了表征。研究了 LCH 从微胶囊中的包封效率和释放行为。结果表明，微胶囊呈球形，直径大多在 0.5-10 μm 范围内，具有以 LCH 为核、OAAD 为壳的结构。微胶囊的包封效率和释放性能受 OAAD 的取代度（DS）和 CaCl（2）用量的影响。发现 LCH 的释放机制随 OAAD 的 DS 从 10.8 变化到 30.3 以及 CaCl（2）/乳液的比例从 0.09 变化到 0.03%而从异常扩散到菲克扩散再到拟菲克扩散变化。
