Graduate School of Pharmaceutical Sciences, Tohoku University, Aramaki, Aoba-ku, Sendai, Japan.
Colloids Surf B Biointerfaces. 2012 Mar 1;91:274-9. doi: 10.1016/j.colsurfb.2011.11.017. Epub 2011 Nov 18.
Layer-by-layer (LbL) thin films containing insulin were prepared by alternately depositing insulin and poly(allylamine hydrochloride) (PAH) onto a solid surface at pH 7.4. The deposition behavior of the LbL films was studied using a quartz crystal microbalance, UV-vis absorption spectrometer, ζ-potential analyzer, and an atomic force microscope. The insulin-containing LbL films were stable in neutral pH media, but the films decomposed in solutions at pH 5.0 or lower. The decomposition of the LbL films can be rationalized on the basis of the loss of electrostatic interactions between insulin and PAH due to a shift in the net electric charge of insulin from negative to positive in acidic media. The films also decomposed to some extent in media at pH 9.0 and 10. A circular dichroism analysis showed that insulin retained its original conformation when released from LbL film into acidic solutions.
采用层层（LbL）自组装技术，在 pH 值为 7.4 时将胰岛素和聚烯丙基盐酸盐（PAH）交替沉积在固体表面上，制备了含有胰岛素的 LbL 薄膜。采用石英晶体微天平、紫外-可见吸收光谱仪、Zeta 电位分析仪和原子力显微镜研究了 LbL 薄膜的沉积行为。含有胰岛素的 LbL 薄膜在中性 pH 介质中稳定，但在 pH 值为 5.0 或更低的溶液中会分解。根据胰岛素在酸性介质中净电荷从负到正的变化导致胰岛素与 PAH 之间的静电相互作用丧失，可以合理地解释 LbL 薄膜的分解。该薄膜在 pH 值为 9.0 和 10.0 的介质中也会发生一定程度的分解。圆二色性分析表明，胰岛素从 LbL 薄膜释放到酸性溶液中时，仍保持其原始构象。
