Assessing the ability of bovine mesenchymal stem cells to grow on okara-based scaffolds derived from soy milk waste.

Primary mesenchymal stem cells used in cultured meat production are anchorage-dependent, and therefore require a solid substrate for attachment and proliferation. However, widely used commercial microcarriers are typically composed of synthetic polymers, creating a significant bottleneck as they require complex and costly cell-detachment processes prior to consumption. This study investigated the repurposing of okara, a by-product of soy milk and tofu production, into microcarriers for the cultivation of adipose-derived bovine mesenchymal stem cells (AD-bMSCs). We developed and characterized multiple soy-based scaffold variants by subjecting the raw material to treatments ranging from high homogenization and plasma exposure to simple freeze-drying and wet application. Comparative analysis revealed that complex processing did not improve cell performance. Instead, the minimally processed wet okara variant emerged as the most promising candidate, streamlining production by eliminating the need for drying and pre-soaking steps. In preliminary larger-volume experiments, OP-M showed promising support for AD-bMSC growth under static conditions, with performance comparable to that of commercial microcarrier controls, from day 17 onward. Cells expanded on these soy microcarriers retained their ability to proliferate, and maintained high expression of the mesenchymal surface markers CD44 and CD29. Furthermore, cell functionality was demonstrated by successful lipid accumulation following detachment from scaffolds, at levels comparable to those observed under 2D control conditions. These findings suggest that agricultural waste can be valorized into a high-value, edible bio-scaffold that supports stem cell expansion without compromising cellular characteristics. Okara-derived microcarriers hold the potential to provide a scalable and sustainable alternative to existing microcarrier systems in cultured meat production, although further research is needed to establish and optimize this platform.