Takasaki: Soft Gel Breakthrough Enables Lab-Grown Slow-Twitch Muscle Fibers
Researchers in Japan have developed a protein-based gel that mimics the softness and microgrooves of natural skeletal muscle, allowing precursor cells to mature into true slow-twitch fibers in the lab for the first time. These endurance-oriented muscle cells are critical for posture, glucose metabolism, and combating age-related decline. The advance, published 8 August 2025 in Scientific Reports (DOI: 10.1038/s41598-025-12744-7), paves the way for regenerative therapies, drug screening, and transplantable muscle tissue. Slow-twitch (type I) fibers rely on oxidative metabolism, express high levels of MYH7, GLUT4, and myoglobin, and are regulated by PGC-1?. Replicating them outside the body has eluded scientists due to mismatched mechanical cues. “Conventional plastic or glass substrates are orders of magnitude too stiff,” said lead researcher Dr. Mitsumasa Taguchi of the Takasaki Institute for Advanced Quantum Science at Japan’s National Institutes for Quantum Science and Technology (QST).…
