PEG-MGF

PEG-MGF (PEGylated Mechano Growth Factor) is a pegylated variant of Mechano Growth Factor (MGF) — a splice variant of insulin-like growth factor 1 (IGF-1) that is produced in skeletal muscle in response to mechanical stress (exercise, overload, injury). MGF is generated by alternative splicing of the IGF-1 gene, producing a C-terminal E-domain peptide sequence distinct from systemic IGF-1. The MGF E-domain has unique biological activity: it activates muscle satellite cells (muscle stem cells) from their quiescent state, driving them into the cell cycle to proliferate and subsequently fuse with existing muscle fibres — a process essential for muscle repair and adaptation. Unlike systemic IGF-1, which primarily activates the IGF-1 receptor for hypertrophy signalling, MGF's satellite cell activation mechanism targets the regenerative dimension of muscle repair. The PEGylation (attachment of polyethylene glycol) extends the peptide's half-life from minutes to hours by increasing hydrodynamic radius and reducing renal clearance, making PEG-MGF suitable for sustained-release research. The PEGylated peptide retains the MGF E-domain's satellite cell activation activity while providing the prolonged exposure necessary for studying the full satellite cell activation-proliferation-fusion cascade in muscle repair models.