New Granular Hydrogel for Tissue Bioprinting

September 18, 2022

By: Cici Zhu

A shortage of available organs for patients in need of transplants is an ever-growing problem. To mitigate this issue, researchers have been working on a potential solution involving “3D printing” organs using engineered biomaterial that is able to host cells and form tissues. Most bioinks used for bioprinting organs are based on bulk hydrogels: polymer networks capable of maintaining their structure even when holding large amounts of water; however, bulk hydrogel bioinks are unable to properly integrate into the body and support cells in thick tissue constructs. A new granular hydrogel bioink developed by Penn State researchers makes use of self-assembling nanoparticles to bind hydrogel microparticles (also known as microgels), and is able to achieve improved shape fidelity, porosity, and cell integration.

Bulk Hydrogel Bioink vs. Granular Hydrogel Bioink

In order for bioprinted organs to function properly, they must be able to maintain their shape as well as integrate into the body. The bulk hydrogel bioinks have been unsuccessful because they are unable to accomplish both of these things simultaneously; increasing the bulk hydrogel bioink’s stiffness increases its shape fidelity, but decreases porosity (which consequently delays, and sometimes inhibits, integration). In contrast, the granular hydrogel separates stiffness from porosity by using nanoparticles to reversibly adhere microgels to each other. This makes it such that dense packing of microgels is no longer required for the printed tissue to maintain its shape, and porosity is not affected. The novel granular hydrogel bioink shows potential for further application in tissue engineering and regeneration.

Works Cited

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“New Granular Hydrogel Bioink Could Expand Possibilities for Tissue Bioprinting.” ScienceDaily, www.sciencedaily.com/releases/2022/09/220901135837.htm. Accessed 18 Sept. 2022.

Schwab, Andrea, et al. “Printability and Shape Fidelity of Bioinks in 3D Bioprinting.” NCBI, Oct. 2020, www.ncbi.nlm.nih.gov/pmc/articles/PMC7564085.

Bowlby, Beatrice. “Novel Hydrogel Bioink Improves 3D-printed Biomaterials.” BioTechniques, 7 Sept. 2022, www.biotechniques.com/bioengineering-biophysics/novel-hydrogel-bioink-improves-3d-printed-biomaterials.