Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), 77, Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Republic of Korea.
Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), 77, Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Republic of Korea.
Biofabrication. 2021 Jun 29;13(3). doi: 10.1088/1758-5090/ac044c.
Despite the potential of a nanofibrous (NF) microwell array as a permeable microwell array to improve the viability and functions of spheroids, thanks to the superior permeability to both gases and solutes, there have still been difficulties regarding the stable formation of spheroids in the NF microwell array due to the low aspect ratio (AR) and the large interspacing between microwells. This study proposes a nanofibrous oval-shaped microwell array, named the NOVA microwell array, with both a high AR and a high well density, enabling us to not only collect cells in the microwell with a high cell seeding efficiency, but also to generate multiple viable and functional spheroids in a uniform and stable manner. To realize a deep NOVA microwell array with a high aspect ratio (AR = 0.9) and a high well density (494 wells cm), we developed a matched-mold thermoforming process for the fabrication of both size- and AR-controllable NOVA microwell arrays with various interspacing between microwells while maintaining the porous nature of the NF membrane. The human hepatocellular carcinoma (HepG2) cell spheroids cultured on the deep NOVA microwell array not only had uniform size and shape, with a spheroid circularity of 0.80 ± 0.03 at a cell seeding efficiency of 94.29 ± 9.55%, but also exhibited enhanced viability with a small fraction of dead cells and promoted functionality with increased albumin secretion, compared with the conventional impermeable microwell array. The superior characteristics of the deep NOVA microwell array, i.e. a high AR, a high well density, and a high permeability, pave the way to the production of various viable and functional spheroids and even organoids in a scalable manner.
尽管纳米纤维（NF）微井阵列作为一种可渗透的微井阵列具有提高球体活力和功能的潜力，这要归功于其对气体和溶质的优异渗透性，但由于低纵横比（AR）和微井之间的大间隔，仍然存在稳定形成 NF 微井阵列中球体的困难。本研究提出了一种纳米纤维椭圆形微井阵列，称为 NOVA 微井阵列，具有高 AR 和高井密度，不仅可以以高细胞接种效率收集微井中的细胞，还可以以均匀和稳定的方式生成多个有活力和功能的球体。为了实现具有高纵横比（AR = 0.9）和高井密度（494 个井/cm）的深 NOVA 微井阵列，我们开发了一种匹配模具热成型工艺，用于制造具有各种微井间隔的尺寸和 AR 可控的 NOVA 微井阵列，同时保持 NF 膜的多孔性。在深 NOVA 微井阵列上培养的人肝癌（HepG2）细胞球体不仅具有均匀的大小和形状，球体的圆度为 0.80 ± 0.03，细胞接种效率为 94.29 ± 9.55%，而且具有较高的活力，死细胞比例较小，白蛋白分泌增加，功能增强，与传统的不可渗透微井阵列相比。深 NOVA 微井阵列的优越特性，即高 AR、高井密度和高渗透性，为可扩展地生产各种有活力和功能的球体甚至类器官铺平了道路。
