3D printing of sacrificial thioester elastomers using digital light processing for templating 3D organoid structures in soft biomatrices

• Published in: Biofabrication 2021-10, Vol.13 (4), p.44104
• Main Authors: Carberry, Benjamin J, Hergert, John E, Yavitt, F Max, Hernandez, Juan J, Speckl, Kelly F, Bowman, Christopher N, McLeod, Robert R, Anseth, Kristi S
• Format: Article
• Language: English
• Subjects: 3D printing; biofabrication; covalent adaptable networks; Elastomers; Hydrogels; intestinal organoids; Organoids; Polyethylene Glycols; Printing, Three-Dimensional; stimuli-induced degradation; thioester exchange
• ISSN: 1758-5082; 1758-5090; 1758-5090
• DOI: 10.1088/1758-5090/ac1c98

Biofabrication allows for the templating of structural features in materials on cellularly-relevant size scales, enabling the generation of tissue-like structures with controlled form and function. This is particularly relevant for growing organoids, where the application of biochemical and biomechanical stimuli can be used to guide the assembly and differentiation of stem cells and form architectures similar to the parent tissue or organ. Recently, ablative laser-scanning techniques was used to create 3D overhang features in collagen hydrogels at size scales of 10-100 m and supported the crypt-villus architecture in intestinal organoids. As a complementary method, providing advantages for high-throughput patterning, we printed thioester functionalized poly(ethylene glycol) (PEG) elastomers using digital light processing (DLP) and created sacrificial, 3D shapes that could be molded into soft ( ' < 1000 Pa) hydrogel substrates. Specifically, three-arm 1.3 kDa PEG thiol and three-arm 1.6 kDa PEG norbornene, containing internal thioester groups, were photopolymerized to yield degradable elastomers. When incubated in a solution of 300 mM 2-mercaptoethanol (pH 9.0), 1 mm thick 10 mm diameter elastomer discs degraded in