Data underlying the publication: Microfluidic system for efficient molecular delivery to artificial cell membranes

The cell membrane represents a crucial interface to consider in biomedical research, as a significant proportion of drugs interacts with this barrier. While understanding membrane-drug interactions is important, existing in vitro platforms for drug screening predominantly focus on interactions with whole cells or tissues. This preference is partly due to the instability of membrane-based systems and the technical challenges associated with buffer replacement around lipid membranes formed on microfluidic chips. Here, we introduce a novel microfluidic design capable of forming stable freestanding lipid bilayers with efficient replacement of the media in their local environment for molecular delivery to the membrane. With the use of bubble traps and resistance channels, we achieved sufficient hydrodynamic control to maintain membrane stability during the membrane formation and the molecular delivery phases. As a proof of concept, we successfully formed 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine (POPC) bilayers on the chip and delivered the antibiotic azithromycin at low (5 μM) and high (250 μM) doses. Using optical tweezers, we characterized how azithromycin influenced the membrane elastic properties, including tension and bending rigidity. This microfluidic device is a versatile tool that can deliver various buffers, molecules or nano-/microparticles to freestanding membranes, and study the resulting impact on the membranes’ properties.<br><br>

细胞膜是生物医学研究中不可或缺的关键界面，因为有相当比例的药物会与这一屏障发生相互作用。尽管解析膜-药物相互作用至关重要，但当前用于药物筛选的体外（in vitro）平台，大多仅关注完整细胞或组织层面的相互作用。这种研究偏向性部分源于基于膜的体系稳定性不足，以及微流控芯片上形成的脂质膜周围缓冲液更换所面临的技术难题。本研究提出一种新型微流控设计，可构建稳定的独立支撑脂质双层膜，并能高效更换其局部环境中的培养基，以实现向膜递送分子的目的。通过引入气泡陷阱与阻力通道，我们实现了充分的流体力学调控，可在膜形成及分子递送阶段维持膜结构的稳定性。

作为概念验证，我们成功在芯片上构建了1-棕榈酰-2-油酰-sn-甘油-3-磷酸胆碱（1-palmitoyl-2-oleoyl-glycero-3-phosphocholine，POPC）双层膜，并以低浓度（5 μM）与高浓度（250 μM）两种剂量递送了抗生素阿奇霉素（azithromycin）。借助光镊（optical tweezers）技术，我们表征了阿奇霉素对膜弹性性质（包括膜张力与弯曲刚度）的影响。这款微流控装置是一款多功能研究工具，可向独立支撑脂质膜递送各类缓冲液、分子或纳米/微米颗粒，并可由此研究其对膜性质产生的影响。