Simple, Rapid, and Large-Scale Fabrication of Multi-Branched Hydrogels Based on Viscous Fingering for Cell Culture Applications.

Hydrogels are widely used in cell culture applications. For fabricating tissues and organs, it is essential to produce hydrogels with specific structures. For instance, multiple-branched hydrogels are desirable for the development of network architectures that resemble the biological vascular network. However, existing techniques are inefficient and time-consuming for this application. To address this issue, we proposed a simple, rapid, and large-scale fabrication method based on viscous fingering. This approach utilizes only two plates. To produce a thin solution, a high-viscosity solution was introduced into the space between the plates, and one of the plates was peeled off. During this procedure, the solution's high viscosity resulted in the formation of multi-branched structures. Using this strategy, 180 mm × 200 mm multi-branched Pluronic F-127 hydrogels were successfully fabricated within 1 min. These structures were used as sacrificial layers for the fabrication of polydimethylsiloxane channels for culturing human umbilical vein endothelial cells (HUVECs). Similarly, multi-branched Matrigel and calcium (Ca)-alginate hydrogel structures were fabricated, and HUVECs were successfully cultured inside the hydrogels. Also, the hydrogels were collected from the plate, while maintain their structures. The proposed fabrication technique will contribute to the development of network architectures such as vascular structures in tissue engineering. This article is protected by copyright. All rights reserved.