Salentinig Stefan, Phan Stephanie, Darwish Tamim A, Kirby Nigel, Boyd Ben J, Gilbert Elliot P
Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville Campus) , 381 Royal Parade, Parkville, VIC 3052, Australia.
Langmuir. 2014 Jul 1;30(25):7296-303. doi: 10.1021/la500835e. Epub 2014 Jun 20.
Free fatty acids play a vital role as fuel for cells and in lipid metabolism. During lipid digestion in the gastrointestinal tract, triglycerides are hydrolyzed, resulting in free fatty acid and monoglyceride amphiphilic products. These components, together with bile salts, are responsible for the transport of lipids and poorly water-soluble nutrients and xenobiotics from the intestine into the circulatory system of the body. In this study, we show that the self-assembly of digestion products from medium-chain triglycerides (tricaprylin) in combination with bile salt and phospholipid is highly pH-responsive. Individual building blocks of caprylic acid within the mixed colloidal structures are mapped using a combination of small-angle X-ray and neutron scattering combined with both solvent contrast variation and selective deuteration. Modeling of the scattering data shows transitions in the size and shape of the micelles in combination with a transfer of the caprylic acid from the core of the micelles to the shell or into the bulk water upon increasing pH. The results help to understand the process of lipid digestion with a focus on colloidal structure formation and transformation for the delivery of triglyceride lipids and other hydrophobic functional molecules.
游离脂肪酸作为细胞燃料和参与脂质代谢发挥着至关重要的作用。在胃肠道脂质消化过程中，甘油三酯被水解，产生游离脂肪酸和单酸甘油酯等两亲性产物。这些成分与胆汁盐一起，负责将脂质以及水溶性差的营养物质和外源性物质从肠道转运到身体的循环系统中。在本研究中，我们表明中链甘油三酯（三辛酸甘油酯）的消化产物与胆汁盐和磷脂的自组装对pH高度敏感。使用小角X射线和中子散射相结合的方法，结合溶剂对比度变化和选择性氘化，绘制了混合胶体结构中辛酸的各个构建单元。散射数据建模显示，随着pH值升高，胶束的大小和形状发生转变，同时辛酸从胶束核心转移到壳层或进入大量水中。这些结果有助于理解脂质消化过程，重点关注用于甘油三酯脂质和其他疏水性功能分子递送的胶体结构形成和转变。
