Suspended Tissue Open Microfluidic Patterning (STOMP) recreates natural cell habitats.
While it’s easy to get caught up in the allure of 3D printed end-use parts, such as advanced aerospace engine parts or bioresorbable implants, some of the most exacting and impactful developments in the additive manufacturing (AM) industry have come from tooling applications.
The latest example comes from an interdisciplinary team of researchers at the University of Washington. Led by chemistry professor Asleigh Theberge and mechanical engineering professor Nate Sniadecki, the team has developed a new tool to aid future research in human tissue modeling.
One of the major challenges in this field is the difficulty of taking the natural environments in which cells develop and replicating them in laboratory conditions. To that end, human tissue researchers have been suspending cells in a gel between two freestanding posts to grow heart, lung, skin and musculoskeletal tissues. This works well for studying these tissues independently, but less so for studying multiple tissue types together, which requires more precise control over their composition and spatial arrangement.
Enter STOMP: Suspended Tissue Open Microfluidic Patterning, a device that enables scientists to examine how cells respond to mechanical and physical cues while creating distinct regions in a suspended tissue. This device, which is small enough to fit on a fingertip, was designed in SolidWorks 3D printed with Formlabs clear resin V4 using a Form 3B+ 3D printer.
According to its developers, the STOMP device can recreate biological interfaces, such as those between bones and ligaments or between fibrotic and healthy heart tissue. The device docks on to a two-post system and contains an open microfluidic channel with geometric features to manipulate the spacing and composition of different cell types, and for creating multiple regions within single suspended tissue without the need for additional equipment of capabilities.
STOMP is designed to enhance a tissue-engineering method called casting, where a gel mixture of living and synthetic materials are pipetted into a mold or frame. STOMP uses capillary action to permit scientists to space out different cell types in whatever pattern their experiment requires. The device also incorporates degradable hydrogel walls that can be broken down while leaving tissues intact.
“Normally when you put cells in a 3D gel,” Sniadecki said in a press release, “they will use their own contractile forces to pull everything together — which causes the tissue to shrink away from the walls of the mold. But not every cell is super strong, and not every biomaterial can get remodeled like that. So that kind of nonstick quality gave us more versatility.”
The researchers put STOMP to the test in two experiments: one that compared the contractile dynamics of diseased and healthy engineered heart tissue, and another that models the ligament that connects a tooth to its bone socket.
“This method opens new possibilities for tissue engineering and cell signaling research,” Theberge said in the same release. “It was a true team effort of multiple groups working across disciplines.”
The research is published in the journal Advanced Science.
