Gellan gum-based granular gels as suspension media for biofabrication

• Published in: PloS one 2024-11, Vol.19 (11), p.e0312726
• Main Authors: McCormack, Andrew, Porcza, Laura M, Leslie, Nicholas R, Melchels, Ferry P W
• Format: Article
• Language: English
• Subjects: 3-D printers; Analysis; Animals; Biological products; Biology and life sciences; Biomedical engineering; Biomimetics; Biopolymers; Bioprinting - methods; Cell culture; Crosslinking; Droplets; Engineering and technology; Fabrication; Filaments; Gelation; Gellan gum; Gels; Gels - chemistry; Humans; Hydrogels; Hydrogels - chemistry; Medical research; NMR; Nuclear magnetic resonance; Physical Sciences; Physiological aspects; Polymers; Polysaccharides; Polysaccharides, Bacterial - chemistry; Printing; Printing, Three-Dimensional; Properties; Regenerative medicine; Rheology; Stress analysis; Suspensions; Temperature; Temperature tolerance; Tissue engineering; Tissue Engineering - methods; Tissue Scaffolds - chemistry; Viscoplasticity; Viscosity; Yield stress
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0312726

Engineering 3D tissue-like constructs for applications such as regenerative medicine remains a major challenge in biomedical research. Recently, self-healing, viscoplastic fluids have been introduced as suspension media to allow lower viscosity, water-rich bioinks to be printed within them for the fabrication of more biomimetic structures. Here, we present gellan gum granular gels produced through the application of shear during gelation, as a candidate suspension medium. We demonstrate that these granular gels exhibit viscoplasticity over a wide range of temperatures, permitting their use for 3D bioprinting of filaments and droplets at low (4°C) as well as physiological temperatures. These granular gels exhibit very low yield stresses (down to 0.4 Pa) which facilitated printing at print speeds up to 60 mm.s-1. Furthermore, we demonstrate the printing of cell-laden droplets maintained over 7 days to show the potential for multiple days of cell culture, as well as the fabrication of hydrogel features within a crosslinkable version of the suspension medium containing granular gellan gum and gelatine-methacryloyl. The combination of ease of preparation, high printing speed, wide temperature tolerance, and crosslinkability makes this gellan gum sheared through cooling-induced gelation an attractive candidate for suspended biofabrication.