Organotypic micrometre-size 3D aggregates of skin cells (multicellular spheroids) have emerged as a promising in vitro model that can be utilized as an alternative of animal models to test active ingredients (AIs) of skincare products; however, a reliable dermal spheroid-based microfluidic (MF) model with a goal of in vitro AI screening is yet to be developed. Here, we report a MF platform for the growth of massive arrays of dermal fibroblast spheroids (DFSs) in a biomimetic hydrogel under close-to-physiological flow conditions and with the capability of screening AIs for skincare products. The DFSs formed after two days of on-chip culture and, in a case study, were used in a time-efficient manner for screening the effect of vitamin C on the synthesis of collagen type I and fibronectin. The computational simulation showed that the uptake of vitamin C was dominated by the advection flux. The results of screening the benchmark AI, vitamin C, proved that DFSs can serve as a reliable in vitro dermal model. The proposed DFS-based MF platform offers a high screening capacity for AIs of skincare products, as well as drug discovery and development in dermatology.

中文翻译：

---

真皮球体微流控阵列：护肤品活性成分筛选平台

皮肤细胞（多细胞球体）的器官型微米级 3D 聚集体已成为一种很有前景的体外模型，可用作动物模型的替代品，以测试护肤产品的活性成分 (AI)；然而，一个可靠的基于真皮球体的微流体 (MF) 模型，其目标是体外AI筛选尚待开发。在这里，我们报告了一个 MF 平台，用于在接近生理流动条件下在仿生水凝胶中生长大量真皮成纤维细胞球体 (DFS)，并具有筛选护肤产品 AI 的能力。DFSs 在芯片上培养两天后形成，在一个案例研究中，以一种省时的方式用于筛选维生素 C 对 I 型胶原蛋白和纤连蛋白合成的影响。计算模拟表明，维生素 C 的吸收受平流通量的支配。筛选基准 AI 维生素 C 的结果证明 DFS 可以作为可靠的体外真皮模型。拟议的基于 DFS 的 MF 平台为护肤产品的 AI 以及皮肤病学的药物发现和开发提供了高筛选能力。