Functional composite microbeads for cell-based meat culture: effect of animal gelatin coating on cell proliferation and differentiation

Hydrogel microbeads are promising matrices for cell-based meat culture because they can be conveniently fabricated from food-grade materials. In this study, food-grade sodium alginate was successfully applied to fabricate edible microbeads with the desired diameters (∼200 µm) using electrospray technology. Pure alginate microbeads have poor cytoaffinity. To enhance the cytoaffinity of alginate microbeads for meat culture, we applied different gelatin coatings, namely porcine gelatin, bovine gelatin, and fish gelatin, onto alginate beads. The modification is non-toxic and environmentally friendly with the use of plant-derived crosslinkers and under mild reaction conditions. As all ingredients are food grade, the modified microbeads are edible and biodegradable, with the mean diameters of 142.96 ± 35.49 μm (porcine gelatin-coated beads), 105.12 ± 80.46 μm (bovine gelatin-coated beads), and 94.81 ± 67.38 μm (bovine gelatin-coated beads). These modified microbeads have self-fluorescence and can be easily distinguished under a fluorescent microscope. The hydrogel core enables the microbeads to have a density of 1.04 g cm−3 for suspension culture. Bovine gelatin-coated microbeads have the best primary porcine myoblast and C2C12 cell adhesion, and can achieve between 16- to 18-fold proliferation of different muscle cells. With the successful differentiation of C2C12 and proliferation of 3T3-L1 adipocytes on bovine gelatin-coated microbeads, cells and microbeads can form clusters, illustrating that our edible microbeads are promising microcarriers for mammalian cell culture for cell-based meat production.