3D lab-grown muscle detects protein synthesis more sensitively

A University of Toronto team combined miniature 3D lab-grown muscle tissues with stable-isotope tracing, a method used in human studies, to measure muscle protein synthesis. The researchers compared isotopes with common puromycin labeling and tested amino acids, ketones and electrically induced contractions. Stable isotopes consistently detected increased protein synthesis after amino-acid stimulation, while the conventional method often missed significant changes. The 3D tissues also behaved more like real human muscle than standard 2D cell cultures. The model could screen nutrition, exercise and candidate treatments faster and more cheaply before selecting interventions for invasive, expensive and hard-to-scale human muscle biopsies. It remains a laboratory model without full blood flow, nerves, immunity or whole-body metabolism, so any intervention still requires animal or human confirmation.