A thermogelling organic-inorganic hybrid hydrogel with excellent printability, shape fidelity and cytocompatibility for 3D bioprinting

Abstract

Alginates are the most commonly used bioink in biofabrication, but their rheological profiles makes it very challenging to perform real 3D printing. In this study, an advanced hybrid hydrogel ink was developed, a mixture of thermogelling diblock copolymer, alginate and clay i.e. Laponite XLG. The reversible thermogelling and shear thinning properties of the diblock copolymer in the ink system improves handling and 3D printability significantly. Various three-dimensional constructs, including suspended filaments, were printed successfully with high shape fidelity and excellent stackability. Subsequent ionic crosslinking of alginate fixates the printed scaffolds, while the diblock copolymer is washed out of the structure, acting as a fugitive material on the (macro)molecular level. Finally, cell-laden printing and culture over 21 days demonstrated good cytocompatibility and feasibility of the novel hybrid hydrogels for 3D bioprinting. We believe that the developed material could be interesting for a wide range of bioprinting applications including tissue engineering and drug screening, potentially enabling also other biological bioinks such as collagen, hyaluronic acid, decellularized extracellular matrix or cellulose based bioinks.

Immuno-activated mesenchymal stem cell living electrospun nanofibers for promoting diabetic wound repair

“…Biomaterials have been widely used in tissue regeneration. An ideal biomaterial possesses essential properties such as hierarchical architectures and ECM composition similar to native tissues [ 41 ]. Nanofibers have been widely used in regenerative engineering due to their feasibility in modification, more interactions with tissue environment as well as delivery of regenerative signals to the tissues [ 42 ].…”

Perfusable Tissue Bioprinted into a 3D-Printed Tailored Bioreactor System

“…For this study, we used a commercially available bioink and a blend composed of alginate and POx, both showing the required features for printing [22,23]. The POx-Alginate bioink was included in this study to allow a head-to-head comparison with the commercial bioink.…”

“…The POx-Alginate bioink was included in this study to allow a head-to-head comparison with the commercial bioink. Previously, we have shown that the combination of alginate and the POx-based diblock copolymer hydrogels significantly improves the 3D printability of alginate and allows for long-term cell culture [23]. Now, we wanted to compare it directly with a commercial bioink to gauge the potential of our experimental bioink.…”

“…The thermogelling AB diblock copolymer (Me-PMeOx100-b-PnPrOzi100-EIP), further referred to as 'POx', comprising the hydrophilic poly(2-methyl-2-oxazoline) (PMeOx) block and thermoresponsive poly(2-n-propyl-2-oxazine) (PnPrOzi) block was synthesized as described by Lorson et al [22]. Derived from Hu et al [23], Alginate-POx bioink was generated by mixing 25 weight % POx-polymer and 1 weight % alginate in PBS -(diluted with Millipore water by a ratio of 1:3) overnight at 4 • C.…”

Combining 3D Printing and Cryostructuring to Tackle Infection and Spine Fusion

“…A process scheme showing the combination of 3D printing and cryostructuring is depicted in Figure 4. Regarding biological behavior, the CaMgP paste hardened by 3.5 M DAHP and the alginate used in this study have been separately evaluated in previous studies, [17,57] with positive results on cell viability. Thus, it is reasonable to assert that the dual component system here proposed is cytocompatible and promising for spine fusion and bone applications.…”