Recombinant production of growth factors for application in cell culture

Culturing eukaryotic cells has widespread applications in research and industry, including the emerging field of cell-cultured meat production colloquially referred to as "cellular agriculture". These applications are often restricted by the high cost of growth medium necessary for cell growth. Mitogenic protein growth factors ([GF]{.caps}s) are essential components of growth medium and account for upwards of 90% of the total costs. Here, we present a set of expression constructs and a simplified protocol for recombinant production of functionally active [GF]{.caps}s, including [FGF]{.caps}-2, [IGF]{.caps}-1, [PDGF]{.caps}-[BB]{.caps} and [TGF]{.caps}-β1 in Escherichia coli. Using this expression system, we produced soluble [GF]{.caps}s from species including bovine, chicken, and fish. Bioactivity analysis revealed orthologs with improved performance compared to commercially available alternatives. We estimated that the production cost of [GF]{.caps}s using our methodology will significantly reduce the cost of cell culture medium, facilitating low-cost protocols tailored for cultured meat production and tissue engineering.