A General Strategy for Extrusion Bioprinting of Bio‐Macromolecular Bioinks through Alginate‐Templated Dual‐Stage Crosslinking

Abstract

The recently developed 3D bioprinting technology has greatly improved the ability to generate biomimetic tissues that are structurally and functionally relevant to their human counterparts. The selection of proper biomaterials as the bioinks is a key step toward successful bioprinting. For example, viscosity of a bioink is an important rheological parameter to determine the flexibility in deposition of free-standing structures and the maintenance of architectural integrity following bioprinting. This requirement, however, has greatly limited the selection of bioinks, especially for those naturally derived due to their commonly low mechanical properties. Here the generalization of a mechanism for extrusion bioprinting of bio-macromolecular components, mainly focusing on collagen and its derivatives including gelatin and gelatin methacryloyl, is reported. Specifically, a templating strategy is adopted using a composite bioink containing both the desired bio-macromolecular component and a polysaccharide alginate. The physically crosslinkable alginate component serves as the temporal structural support to stabilize the shape of the construct during bioprinting; upon subsequent chemical or physical crosslinking of the bio-macromolecular component, alginate can be selectively removed to leave only the desired bio-macromolecule. It is anticipated that this strategy is general, and can be readily expanded for use of a wide variety of other bio-macromolecular bioinks.

Anisotropic structural color particles from colloidal phase separation

“…As a kind of derivation of modified extracellular matrix components, GelMA has superb biocompatibility, and thus, the GelMA anisotropic hydrogel SCPs were suitable for cell culture ( fig. S12) (40)(41)(42)(43). Similar to the pNIPAM anisotropic hydrogel SCPs, the resultant GelMA anisotropic hydrogel SCPs could also exhibit vivid colors ( fig.…”

Expanding and optimizing 3D bioprinting capabilities using complementary network bioinks

“…The different complementary network bioinks were printed using a tight range of process parameters, thus providing a generalized 3D printing methodology with broadened scope. Unlike the use of viscosity modifiers [e.g., alginate ( 20 ) and cellulose ( 21 , 22 )] that are retained in the bioprinted structure, the complementary network bioinks naturally release the majority of gelatin at 37°C. Critically, the inclusion of gelatin did not notably affect the mechanical properties of the hydrogels after thermal release, nor the ability of encapsulated chondrocytes and osteosarcoma cells to produce cartilaginous or mineralized tissue, respectively.…”

Plant-Derived Biomaterials: A Review of 3D Bioprinting and Biomedical Applications

“…As discussed, the viscosity of alginate is an important component to control when 3D bioprinting, it has been shown that a viscosity of 300-30,000 millipascal second (mPa•S) is optimal for printing, an alginate concentration of 2-4% provides this viscosity (He et al, 2016). Alginate can be printed effectively at a range of temperatures in order to achieve the required viscosity (He et al, 2016;Zhu et al, 2018). However, alginatebased hydrogels have been shown to be most effective at 37 • C due to: accurate extrusion flow rate, decreased occurrence of obstruction and compatibility with cell viability (Ding et al, 2018).…”

“…Fabrication of tissue engineered aortic valve conduits using an alginate/gelatin polymer bioink has been successfully achieved using 3D bioprinting techniques. It was found that by direct encapsulation Duan et al, 2013;Malda et al, 2013;Dolati et al, 2014;Kundu et al, 2015;Li et al, 2015a;Markstedt et al, 2015;Zhang et al, 2015;Ansari et al, 2016;Daly et al, 2016;He et al, 2016;Nishimura et al, 2018;Park et al, 2018;Solovieva et al, 2018;Zhu et al, 2018 Nanocellulose Bhattacharya et al, 2012;Lou et al, 2014;Malinen et al, 2014;Li et al, 2015b;Markstedt et al, 2015;Rees et al, 2015;Torres-Rendon et al, 2015;Toivonen et al, 2016;…”

“…Alginate has been produced as sponges, foams, fibers, and hydrogels for wound healing purposes (Sun and Tan, 2013). Its gel-forming ability enables a moist environment surrounding the wound, promoting healing, and leading to a superior cosmetic repair (Zhu et al, 2018). High water absorptivity and optimal water vapor transmission rate make alginate excellent at treating wounds with large volume exudate; in addition, cell-adhesion is limited thereby reducing the occurrence of secondary injury when removing the dressing, making alginate excellent for use in burns patients (Mirzaei et al, 2018).…”