Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, Shepherd's Bush, London, W12 0BZ, UK.
Institute of Chemical Biology, Molecular Sciences Research Hub, Imperial College London, Shepherd's Bush, London, W12 0BZ, UK.
Lab Chip. 2022 Mar 1;22(5):972-985. doi: 10.1039/d1lc01155c.
Simple diffusion of molecular entities through a phospholipid bilayer, is a phenomenon of great importance to the pharmaceutical and agricultural industries. Current model lipid systems to probe this typically only employ fluorescence as a readout, thus limiting the range of assessable chemical matter that can be studied. We report a new technology platform, the UV-DIB, which facilitates label free measurement of small molecule translocation rates. This is based upon the coupling of droplet interface bilayer technology with implemented fiber optics to facilitate analysis ultraviolet spectroscopy, in custom designed PMMA wells. To improve on current DIB technology, the platform was designed to be reusable, with a high sampling rate and a limit of UV detection in the low μM regime. We demonstrate the use of our system to quantify passive diffusion in a reproducible and rapid manner where the system was validated by investigating multiple permeants of varying physicochemical properties across a range of lipid interfaces, each demonstrating differing kinetics. Our system permits the interrogation of structural dependence on the permeation rate of a given compound. We present this ability from two structural perspectives, that of the membrane, and the permeant. We observed a reduction in permeability between pure DOPC and DPhPC interfaces, concurring with literature and demonstrating our ability to study the effects of lipid composition on permeability. In relation to the effects of permeant structure, our device facilitated the rank ordering of various compounds from the xanthine class of compounds, where the structure of each permeant differed by a single group alteration. We found that DIBs were stable up to 5% DMSO, a molecule often used to aid solubilisation of pharmaceutical and agrochemical compounds. The ability of our device to rank-order compounds with such minor structural differences provides a level of precision that is rarely seen in current, industrially applied technologies.
分子实体通过磷脂双层的简单扩散对制药和农业行业具有重要意义。目前用于探测这种扩散的典型模型脂质系统通常仅使用荧光作为读出信号，从而限制了可研究的可评估化学物质的范围。我们报告了一种新的技术平台，即 UV-DIB，它可以促进小分子转运速率的无标记测量。这是基于液滴界面双层技术与光纤实施的结合，以促进在定制设计的 PMMA 井中进行紫外光谱分析。为了改进当前的 DIB 技术，该平台设计为可重复使用，具有高采样率和在低 μM 范围内的紫外检测限制。我们展示了以可重复且快速的方式量化被动扩散的系统的用途，该系统通过研究多种具有不同物理化学性质的透皮剂在一系列脂质界面上的扩散，每种透皮剂都表现出不同的动力学来验证。我们的系统允许从给定化合物的渗透速率的结构依赖性方面进行询问。我们从两个结构角度展示了这种能力，即膜和透皮剂。我们观察到在纯 DOPC 和 DPhPC 界面之间的通透性降低，这与文献一致，并证明了我们研究脂质组成对通透性影响的能力。关于透皮剂结构的影响，我们的设备促进了各种黄嘌呤类化合物的排序，其中每个透皮剂的结构仅通过一个基团改变。我们发现 DIB 在高达 5%的 DMSO 中稳定，DMSO 是一种常用于助溶制药和农用化学品的分子。我们的设备能够对具有如此微小结构差异的化合物进行排序，这提供了当前工业应用技术中很少见的精度水平。
