A research group including Research Student Yuki Kamiya (at the time of research) of the School of Engineering, Specially Appointed Assistant Professor Yingzhe Wang and Professor Keisuke Morishima at the Graduate School of Engineering at the University of Osaka, developed a new method for stereolithography of arteriole-scale tubular hydrogels that flexibly accommodates the fabrication of complex shapes and multi-material structures by utilizing the meniscus phenomenon (a phenomenon where liquid surfaces curve due to surface tension) within microfluidic channels. The results were published in Advanced Materials.
(b) (i) Formation of the meniscus interface within a hydrophilic microchannel. (ii) UV irradiation projected across the curved meniscus interface. (iii) Photopolymerization of the hydrogel to form a ring-like structure at the channel wall. (iv) Tube formation through sequential ring fabrication along the microchannel. Scale bar, 500 µm.
Credit: 2026, Yuki Kamiya et al., Meniscus-Guided Interfacial Ring-by-Ring Assembly for In Situ Fabrication of Tubular Hydrogel Structures, Advanced Materials
Until now, methods have been developed to mold microscopic hydrogel structures inside microfluidic channels and construct biological tissues using those structures as scaffolds. However, fabricating tubular structures with curves and branches like blood vessels, or structures composed of multiple materials, has proven difficult.
The research group developed a new method to construct tubular structures by continuously forming hydrogel rings at the meniscus interface formed inside microfluidic channels.
When photocurable hydrogel and mineral oil are introduced into a hydrophilic flow channel, a meniscus interface is formed where the hydrogel becomes concave and the oil becomes convex. By irradiating ultraviolet (UV) light onto this interface, the hydrogel near the inner wall of the flow channel can be selectively cured into a ring shape. Furthermore, by continuously forming these hydrogel rings along the axial direction of the flow channel, they succeeded in fabricating tubular hydrogels.
In addition, applying the same method inside flow channels with curved or branched sections, they succeeded in fabricating hydrogel tubes with curved and branched structures. By fabricating red hydrogel tubes inside or adjacent to blue hydrogel tubes, they achieved the fabrication of tube structures possessing different material distributions in radial and axial directions.
This has made it possible to fabricate hollow hydrogel tubes composed of multiple materials that balance structural stability with complex shapes using hydrogels. In the future, seeding and culturing vascular constituent cells using these hydrogel tubes as scaffolds is expected to replicate vascular tissue closer to living organisms.
Morishima stated: "This research began from the grand dream of Mr. Kamiya, who was a fourth-year undergraduate student at the time, wanting to create soft and thin blood vessels through which blood flows outside the body using biomaterials. Without overlooking the very familiar phenomenon of the meniscus, Mr. Kamiya's flexible challenge spirit and curiosity, which linked to an innovative and original idea, resulted in a very interesting research outcome connected to cutting-edge research. He is currently studying in the doctoral program at Carnegie Mellon University Graduate School in the United States, aiming to become a researcher."
Journal Information
Publication: Advanced Materials
Title: Meniscus-Guided Interfacial Ring-by-Ring Assembly for In Situ Fabrication of Tubular Hydrogels
DOI: 10.1002/adma.74064
This article has been translated by JST with permission from The Science News Ltd. (https://sci-news.co.jp/). Unauthorized reproduction of the article and photographs is prohibited.