Keyes Christine, Duhamel Jean, Fung Shan-Yu, Bezaire Jeremy, Chen P
Department of Chemistry , University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada.
J Am Chem Soc. 2004 Jun 23;126(24):7522-32. doi: 10.1021/ja0381297.
Microcrystals of a hydrophobic cargo were stabilized by EAK16 II, a self-assembling oligopeptide, and suspended in aqueous solution. Pyrene was used as a model hydrophobic compound. Egg phosphatidylcholine (EPC) vesicles were prepared to mimic a cell membrane. Pyrene was released from its EAK16 II coating into EPC vesicles. The excimer decay profiles were acquired. They showed that pyrene is present in the crystalline form when stabilized by EAK16 II, it is molecularly dispersed in EPC vesicles, and it is completely released from its EAK16 II coating into the membrane bilayers. The release of pyrene from the microcrystals coated with EAK16 II into the EPC membrane was followed by fluorescence as a function of time. The amount of pyrene released into the EPC vesicles at a given time was quantified using a calibration curve. The concentration of pyrene released was determined as a function of time, and the concentration-versus-time profile was fitted with one exponential. The rate of pyrene release was found to depend on the peptide-to-pyrene molecular ratio. Higher peptide-to-pyrene ratios lead to slower transfer of pyrene to the lipophilic environment. Scanning electron micrographs demonstrated that a thicker coating on the pyrene crystals results in a slower release. The data presented in this work demonstrate that the self-assembling EAK16 II can stabilize a hydrophobic cargo in aqueous solution and deliver it into a lipophilic environment, and that the rate of transfer can be adjusted by tuning the peptide-to-pyrene ratio.
一种疏水性货物的微晶由一种自组装寡肽EAK16 II稳定，并悬浮于水溶液中。芘被用作模型疏水性化合物。制备了鸡蛋磷脂酰胆碱（EPC）囊泡以模拟细胞膜。芘从其EAK16 II涂层释放到EPC囊泡中。获取了准分子衰变曲线。结果表明，芘在由EAK16 II稳定时以晶体形式存在，在EPC囊泡中呈分子分散状态，并且它从其EAK16 II涂层完全释放到膜双层中。芘从涂有EAK16 II的微晶释放到EPC膜中的过程通过荧光随时间的变化进行跟踪。使用校准曲线对给定时间释放到EPC囊泡中的芘量进行定量。确定释放的芘浓度随时间的变化关系，并将浓度与时间曲线拟合为一个指数函数。发现芘的释放速率取决于肽与芘的分子比。更高的肽与芘比例导致芘向亲脂性环境的转移更慢。扫描电子显微镜照片表明，芘晶体上更厚的涂层导致释放更慢。这项工作中呈现的数据表明，自组装的EAK16 II可以在水溶液中稳定疏水性货物并将其递送至亲脂性环境，并且转移速率可以通过调整肽与芘的比例来调节。
