Key Laboratory of Optoelectronic Technology and Systems, Ministry of Education, Defence Key Disciplines Lab of Novel Micro-Nano Devices and System Technology, Chongqing University, Chongqing 400044, China.
Chongqing Key Laboratory of Translational Research for Cancer Metastasis and Individualized Treatment, Chongqing University Cancer Hospital, Chongqing, 400030, China.
Acta Biomater. 2021 Nov;135:234-242. doi: 10.1016/j.actbio.2021.08.006. Epub 2021 Aug 10.
Hanging drop (HD) is one of the most popular methods used for forming three-dimensional (3D) cell spheroids. However, conventional hanging drop systems are only applicable for short-term spheroid culture due to their inconvenience in exchanging cell culture media. Here we present a medium-reservoir-integrated superhydrophobic (MRI-SH) chip for long-term HD spheroid cultures. The device consists of two main components: i) a patterned superhydrophobic (SH) surface containing an array of wettable spots which anchor arrays of droplets of cell suspension, and ii) an array of chambers that serve as medium reservoirs, both interconnected via an array of thru-holes. This configuration provides two distinct advantages over conventional HD configurations: i) the high wettability contrast of the SH pattern on the chip leads to the formation and adhesion of nearly spherical hanging droplets on its surface, which minimizes interactions between the liquid and the substrate; ii) the integrated chambers provide large volumes of medium to maintain longer culture durations. Using this device, spheroids of MHCC97H cells were successfully formed, and the cultured spheroids could maintain high viability for up to 30 days and exhibited enhanced spheroid morphology compared to those cultured in the conventional HD systems. STATEMENT OF SIGNIFICANCE: This paper presents a medium-reservoir-integrated superhydrophobic hanging drop (HD) platform for the long-term culture of spheroids with enhanced morphology. By monolithically integrating medium reservoirs and a patterned SH surface into a single device, this HD platform can not only produce high-quality spheroids, but also permit them to sustain high viability for up to 30 days without the need for tedious medium replenishment. We believe that such a platform will be valuable in a wide range of biological or biomedical applications, including tissue engineering, regenerative medicine, and drug discovery.
悬滴法（HD）是用于形成三维（3D）细胞球体的最流行方法之一。然而，由于传统的悬滴系统在更换细胞培养基方面不太方便，因此仅适用于短期球体培养。在这里，我们提出了一种带有介质储库的集成超疏水（MRI-SH）芯片，用于长期 HD 悬滴培养。该设备由两个主要部分组成：i）包含阵列式可润湿点的图案化超疏水（SH）表面，这些点可固定细胞悬浮液的液滴阵列，ii）作为介质储库的阵列室，两者均通过阵列式通孔相互连接。与传统的 HD 配置相比，这种配置具有两个明显的优势：i）芯片上 SH 图案的高润湿性对比导致在其表面上形成并粘附近乎球形的悬滴，从而最大程度地减少了液体与基底之间的相互作用；ii）集成的腔室提供了大量的介质，以维持更长的培养时间。使用该设备成功地形成了 MHCC97H 细胞的球体，并且培养的球体在长达 30 天的时间内保持高活力，并且与在传统的 HD 系统中培养的球体相比，其形态得到了增强。意义声明：本文提出了一种带有介质储库的集成超疏水悬滴（HD）平台，用于长期培养具有增强形态的球体。通过将介质储库和图案化 SH 表面整体集成到单个设备中，这种 HD 平台不仅可以产生高质量的球体，而且可以在无需繁琐的介质补充的情况下，使它们维持长达 30 天的高活力。我们相信，这样的平台将在广泛的生物学或生物医学应用中具有价值，包括组织工程、再生医学和药物发现。
