Pore Size Manipulation in 3D Printed Cryogels Enables Selective Cell Seeding

• Published in: Advanced materials technologies 2018-04, Vol.3 (4), p.n/a
• Main Authors: Serex, Ludovic, Braschler, Thomas, Filippova, Aleksandra, Rochat, Ariane, Béduer, Amélie, Bertsch, Arnaud, Renaud, Philippe
• Format: Article
• Language: English
• Subjects: 3D printing; bioprinting; collagen coating; cryogels; selective seeding
• ISSN: 2365-709X; 2365-709X
• DOI: 10.1002/admt.201700340

Cryogels are macroporous materials that display remarkable properties, such as high pore interconnection, large surface to volume ratio, and high mechanical stability, making them good candidates for 3D cell culture. However, shaping cryogels remains challenging because of the harsh conditions of synthesis at temperatures as low as −80 °C. In this paper, a solution for the 3D printing of functionalized cryogels is proposed. A microfabricated dispensing probe allowing the last second mixing of cryogel precursors as well as control of the temperature of the extruded material during printing is presented. This dispensing tool allows multilayer 3D printing of cryogels with on demand local pore size change through the control in temperature of the dispensed solution. Moreover, thanks to advanced functionalization of the scaffold, cells can be cultured in 3D within the printed scaffold and exhibited spreading. The ability to tune the pore size of the printed cryogels allows to select during printing where cells will get seeded. Microfabricated nozzle for 3D bioprinting allows on‐the‐fly tuning of printed biomaterials properties. The nozzle features a microfluidic mixer for last second mixing of multiple components as well as a heater allowing quick changes in the printed solution temperature, resulting in changes of the pore's size in the printed structure. This ultimately allows to selectively seed cells in the cryogel.