Jammed Microgel Inks for 3D Printing Applications

TLDR

3D printing requires inks with suitable rheological properties that can be stabilized after deposition, a challenge addressed in bioprinting with hydrogels. The study proposes using jammed microgel inks that allow property tuning via microgel design and mixing. Jammed microgel inks are shear‑thinning, recover quickly, can be cross‑linked, and support diverse materials and cell viability during printing. This particle‑based approach enables a broader range of biomedical inks for 3D printing.

Abstract

Abstract 3D printing involves the development of inks that exhibit the requisite properties for both printing and the intended application. In bioprinting, these inks are often hydrogels with controlled rheological properties that can be stabilized after deposition. Here, an alternate approach is developed where the ink is composed exclusively of jammed microgels, which are designed to incorporate a range of properties through microgel design (e.g., composition, size) and through the mixing of microgels. The jammed microgel inks are shear‐thinning to permit flow and rapidly recover upon deposition, including on surfaces or when deposited in 3D within hydrogel supports, and can be further stabilized with secondary cross‐linking. This platform allows the use of microgels engineered from various materials (e.g., thiol‐ene cross‐linked hyaluronic acid (HA), photo‐cross‐linked poly(ethylene glycol), thermo‐sensitive agarose) and that incorporate cells, where the jamming process and printing do not decrease cell viability. The versatility of this particle‐based approach opens up numerous potential biomedical applications through the printing of a more diverse set of inks.