TB-500

TB-500 corresponds to thymosin β4 (Tβ4), an N-acetylated peptide of roughly 43 amino acids that is the major G-actin-sequestering molecule in mammalian cells. Tβ4 is released by platelets and other cell types after injury, and reviews describe it as a multifunctional regenerative peptide acting on cell migration, inflammation, and apoptosis. [1][2] In commercial research material the name “TB-500” is used for the synthetic peptide carrying this actin-binding activity. [1]

The defining biochemical property of the β-thymosins is high-affinity binding to monomeric (G-)actin, which removes actin from the dynamic assembly–disassembly cycle of the cytoskeleton. [2] In activated and migrating cells this sequestering activity is linked in the literature to cytoskeletal remodeling, directional cell migration, and the cellular machinery underlying wound repair and angiogenesis. [2]

A dedicated body of work examines Tβ4 in vascular biology. Reviews report that exogenous Tβ4 can enhance endothelial-cell migration, capillary formation, and pericyte recruitment, and that it participates in vasculogenesis, angiogenesis, arteriogenesis, and extracellular-matrix remodeling in development and in injury models. [3] These vascular effects are frequently tied back to its cytoskeletal and paracrine signalling roles. [3]

In rodent models, Tβ4 has been associated with accelerated wound closure. One study using recombinant human Tβ4 reported promotion of full-thickness cutaneous wound healing in mice alongside lymphocyte proliferation. [4] Broader reviews summarise dermal, corneal, and pressure-/venous-ulcer models in which Tβ4 was associated with reduced inflammation and apoptosis and supported repair — observations that provided the rationale for subsequent human trials. [5]

Cardiovascular research is a major theme of the Tβ4 literature. In a model of the injured adult heart, Tβ4 was reported to facilitate epicardial neovascularization by mobilising epicardium-derived progenitor cells and stabilising the vascular plexus through collateral-vessel growth. [6] Review work places these findings within wider efforts to apply Tβ4 — via injection or implant coatings — to post-myocardial-infarction repair and cardiac tissue engineering. [7]

Preclinical neuroscience studies have examined Tβ4 as a neuroprotective and neurorestorative candidate. In experimental traumatic-brain-injury and stroke paradigms, treatment was associated with angiogenesis, neurogenesis, and axonal remodeling, processes the authors connect to functional recovery in animal models. [8]

Unlike many research peptides, Tβ4 has progressed into human ophthalmic trials, where it has been investigated in the context of dry-eye disease and neurotrophic keratopathy. [9] This bench-to-bedside trajectory is specific to those clinical programmes and does not extend to the research-grade material supplied here, which remains for in-vitro and laboratory use only. [1]