Highly Elastic Biodegradable Single-Network Hydrogel for Cell Printing

Abstract

Cell printing is becoming a common technique to fabricate cellularized printed scaffold for biomedical application. There are still significant challenges in soft tissue bioprinting using hydrogels, which requires live cells inside the hydrogels. Moreover, the resilient mechanical properties from hydrogels are also required to mechanically mimic the native soft tissues. Herein, we developed a visible-light cross-linked, single-network, biodegradable hydrogel with high elasticity and flexibility for cell printing, which is different from previous highly elastic hydrogel with double-network and two components. The single-network hydrogel using only one stimulus (visible light) to trigger gelation can greatly simplify the cell printing process. The obtained hydrogels possessed high elasticity, and their mechanical properties can be tuned to match various native soft tissues. The hydrogels had good cell compatibility to support fibroblast growth in vitro. Various human cells were bioprinted with the hydrogels to form cell–gel constructs, in which the cells exhibited high viability after 7 days of culture. Complex patterns were printed by the hydrogels, suggesting the hydrogel feasibility for cell printing. We believe that this highly elastic, single-network hydrogel can be simply printed with different cell types, and it may provide a new material platform and a new way of thinking for hydrogel-based bioprinting research.

Extrusion 3D Printing of Polymeric Materials with Advanced Properties

“…To overcome the difficulty and complexity of the dual‐network hydrogels systems, Hong and co‐workers designed and synthesized a novel type of single‐network hydrogel for 3D printing. [ 112 ] Such a system requires only one light stimulus to initiate gelation. After the acrylated polycaprolactone−poly(ethylene glycol)−polycaprolactone precursors with controlled viscosity were extruded, visible light was utilized to irradiate the polymers to efficiently trigger gelation.…”

Chemical insights into bioinks for 3D printing

“…As for Gel-MA based bioinks, other acrylated compounds can be covalently incorporated in the network to afford additional properties. Xu et al 170 used a triblock copolymer of diacrylated PCL-PEG-PCL as a major component of their extruded bioink (Fig. 24) that reacts as other diacrylated compounds ( Fig 18A).…”

“…57,58 Fig. 24 A) PEG-PCL-DA bioink, 170 and (B) acrylated-RGD. 57,58 Combination of PEG and gelatin, two of the most popular acrylated precursors, has been investigated for stereolithography 171 or extrusion.…”

“…25B) absorbs at 375 nm and is less toxic than Irgacure. 106,159,170 Eosin Y (2′,4′,5′,7′tetrabromofluorescein disodium salt, Fig. 25C) absorbs at 514nm (blue visible light), which induces less oxidative stress for cells.…”

3D Bioprinted Vascularized Tumour for Drug Testing

“…It remained above 80% even on day seven. The viability is comparable or superior to that of HUVECs and fibroblasts cultured on other hydrogels, such as the poly(ethylene glycol)-polycaprolactone hydrogel or alginate dialdehyde-gelatine [30,31]. The results suggest that the GAF hydrogel is suitable for bioprinting as well as for growing HUVECs and LFs.…”