Pharmaceutical Analysis, Groningen Research Institute of Pharmacy, University of Groningen, Groningen, The Netherlands.
W.J. Kolff Institute for Biomedical Engineering and Materials Science, University Medical Center Groningen, Groningen, The Netherlands.
Sci Rep. 2024 Feb 3;14(1):2831. doi: 10.1038/s41598-024-53266-y.
The application of microfluidic devices as next-generation cell and tissue culture systems has increased impressively in the last decades. With that, a plethora of materials as well as fabrication methods for these devices have emerged. Here, we describe the rapid prototyping of microfluidic devices, using micromilling and vapour-assisted thermal bonding of polymethyl methacrylate (PMMA), to create a spheroid-on-a-chip culture system. Surface roughness of the micromilled structures was assessed using scanning electron microscopy (SEM) and atomic force microscopy (AFM), showing that the fabrication procedure can impact the surface quality of micromilled substrates with milling tracks that can be readily observed in micromilled channels. A roughness of approximately 153 nm was created. Chloroform vapour-assisted bonding was used for simultaneous surface smoothing and bonding. A 30-s treatment with chloroform-vapour was able to reduce the surface roughness and smooth it to approximately 39 nm roughness. Subsequent bonding of multilayer PMMA-based microfluidic chips created a durable assembly, as shown by tensile testing. MDA-MB-231 breast cancer cells were cultured as multicellular tumour spheroids in the device and their characteristics evaluated using immunofluorescence staining. Spheroids could be successfully maintained for at least three weeks. They consisted of a characteristic hypoxic core, along with expression of the quiescence marker, p27. This core was surrounded by a ring of Ki67-positive, proliferative cells. Overall, the method described represents a versatile approach to generate microfluidic devices compatible with biological applications.
在过去的几十年中，作为下一代细胞和组织培养系统的微流控设备的应用显著增加。随着这一趋势，出现了大量用于这些设备的材料和制造方法。在这里，我们描述了使用微铣削和聚甲基丙烯酸甲酯（PMMA）的蒸汽辅助热键合来快速原型制作微流控设备，以创建微球芯片培养系统。使用扫描电子显微镜（SEM）和原子力显微镜（AFM）评估微铣削结构的表面粗糙度，结果表明制造过程会影响微铣削基板的表面质量，微铣削通道中可以观察到铣削轨道。创建了大约 153nm 的粗糙度。使用氯仿蒸汽辅助键合进行同时的表面平滑和键合。用氯仿蒸气处理 30 秒即可降低表面粗糙度并将其平滑至大约 39nm 的粗糙度。随后对多层 PMMA 基微流控芯片进行键合，形成了耐用的组件，如拉伸测试所示。MDA-MB-231 乳腺癌细胞在该装置中培养为多细胞肿瘤球体，并通过免疫荧光染色评估其特征。球体至少可以成功维持三周。它们具有特征性的缺氧核心，并表达静止标志物 p27。该核心被 Ki67 阳性增殖细胞的环所包围。总体而言，所描述的方法代表了一种通用的方法，可以生成与生物学应用兼容的微流控设备。
