Animal-free scaffold from brown algae provides a three-dimensional cell growth and differentiation environment for steak-like cultivated meat

Scaffolds for the production of cultivated meat, a promising sustainable meat alternative, should exhibit physical and chemical properties that enable three-dimensional animal cell culture, along with biological characteristics that support cell attachment, proliferation, and differentiation. Additionally, the scaffold should be crafted from edible materials and offer textural similarities to meat and have minimal influence on flavor and taste. Herein, an edible alginate-based alginate-cellulose hydrogel (ACe-gel) scaffold derived from the brown alga Undaria pinnatifida is developed. In terms of physical characteristics, the scaffold had porosity (119.5 ± 37.2 μm) and moisture-holding capacity (73.03 ± 3.82, 68.66 ± 9.54, and 84.17 ± 9.94 at 25 °C, 37 °C, and 60 °C, respectively) suitable for three-dimensional culture and differentiation of bovine muscle stem cells (bMuSCs). Accordingly, the scaffold was superior to a commercial alginate scaffold in terms of the attachment and proliferation of bMuSCs (5.5-fold over 72 h), and its performance was comparable with that of a lyophilized collagen scaffold (7.8-fold over 72 h, compared with the pure alginate). The bMuSCs cultured on the ACe-gel scaffold were capable of differentiating into muscle fibers, as verified by gene expression profile analysis. Furthermore, the scaffold exhibited minimal heavy metal contents and distinct seaweed odorants, while the stress-strain characteristics of the scaffold cultured with bMuSC (Young's modulus of raw ACe-gel: 285.19 ± 83.37 kPa, cooked ACe-gel meat: 880.60 ± 485.60 kPa) closely resembled that of meat (raw beef: 267.76 ± 156.42 kPa, cooked beef: 1331.94 ± 762.43 kPa). These findings highlight that the seaweed-derived and animal-free ACe-gel scaffold has strong potential for utilization as a food technology for cultured meat production in the future.