For Research Use Only — Not for Human or Veterinary Use
TB-500 Refill 10mg is supplied exclusively for in vitro and pre-clinical in vivo research use with the AbsoluteBioLab Reusable Metal Peptide Pen v3. This product has not been evaluated by the MHRA, FDA, or any other regulatory authority for safety or efficacy in humans or animals. Purchase confirms the buyer is a qualified researcher operating within applicable institutional and legal frameworks.
TB-500 Refill 10mg — Research-Grade Thymosin Beta-4 Actin-Binding Fragment Refill Cartridge for the AbsoluteBioLab Peptide Pen v3
The TB-500 Refill 10mg is a pre-filled lyophilised refill cartridge containing research-grade TB-500, a synthetic analogue of the naturally occurring peptide Thymosin Beta-4 (Tβ4). TB-500 corresponds to the actin-binding domain of Tβ4 — the 17-amino-acid sequence Ac-Leu-Lys-Lys-Thr-Glu-Thr-Gln-Glu-Lys-Asn-Pro-Leu-Pro-Ser-Lys-Glu-Thr-OH — that is responsible for the majority of Tβ4’s biological activity in tissue repair and regeneration models. This refill format is designed for direct use with the AbsoluteBioLab Reusable Metal Peptide Pen v3, providing a convenient and reproducible format for pre-clinical research programmes requiring repeated administration of TB-500.
Each refill cartridge contains 10mg of lyophilised TB-500 acetate salt, verified by RP-HPLC to a minimum purity of ≥99.0%, with molecular identity confirmed by ESI-MS. Endotoxin content is certified at <1.0 EU/mg by kinetic turbidimetric LAL assay, and residual moisture is verified at <5.0% by Karl Fischer titration. A batch-specific Certificate of Analysis is included with every order.
Thymosin Beta-4 is the most abundant member of the beta-thymosin family of actin-sequestering peptides, present at concentrations of 0.5–1.0 mg/ml in most mammalian cells. Tβ4 binds G-actin (monomeric actin) with high affinity (Kd ~0.7 μM) through its LKKTET actin-binding motif, regulating the pool of unpolymerised actin available for cytoskeletal dynamics. Beyond its actin-sequestering function, Tβ4 and its synthetic analogue TB-500 have been shown to promote cell migration, angiogenesis, wound healing, and anti-inflammatory responses through mechanisms including activation of the ILK (integrin-linked kinase)/Akt pathway, upregulation of VEGF and HGF, and modulation of NF-κB signalling. TB-500 has been extensively studied in pre-clinical models of cardiac injury, tendon repair, corneal wound healing, and neurological recovery.
Compound Identity & Molecular Data
| Parameter | Value |
|---|---|
| Compound Name | TB-500 (Thymosin Beta-4 actin-binding fragment, LKKTET motif) |
| Sequence | Ac-Leu-Lys-Lys-Thr-Glu-Thr-Gln-Glu-Lys-Asn-Pro-Leu-Pro-Ser-Lys-Glu-Thr-OH |
| Residue Count | 17 amino acids; N-terminal acetylation |
| Molecular Weight | 2,025.33 Da (free base, monoisotopic) |
| CAS Number | 77591-33-4 (Thymosin Beta-4 fragment) |
| Salt Form | Acetate salt (lyophilised) |
| Primary Targets | G-actin (LKKTET motif), ILK/Akt, VEGF/HGF upregulation, NF-κB modulation |
| Research Classification | Actin-sequestering peptide; tissue repair; anti-inflammatory; angiogenic |
Analytical Release Testing — Refill Cartridge Specification
| Test | Method | Specification | Notes |
|---|---|---|---|
| Purity | RP-HPLC (C18, UV 220 nm) | ≥99.0% | Acetonitrile/water gradient; TFA modifier |
| Identity | ESI-MS | Confirmed ±0.1 Da | Expected [M+H]⁺: 2,026.34; [M+2H]²⁺: 1,013.68 |
| Endotoxin | Kinetic turbidimetric LAL | <1.0 EU/mg | USP <85> compliant method |
| Residual Moisture | Karl Fischer titration | <5.0% | Coulometric KF; lyophilisation quality indicator |
| Quantity per Cartridge | Gravimetric | 10 mg ± 5% | Lyophilised acetate salt; net peptide content |
| Compatible Device | — | AbsoluteBioLab Peptide Pen v3 | Use with 4mm 31G pen needles |
Mechanism of Action — Actin Sequestration, ILK/Akt Activation, and Angiogenesis
TB-500’s primary mechanism involves binding to G-actin through its LKKTET motif, sequestering monomeric actin and regulating the dynamics of actin polymerisation and cytoskeletal organisation. This actin-regulatory function promotes cell migration by modulating lamellipodia formation and focal adhesion dynamics in endothelial cells, fibroblasts, and keratinocytes — processes essential for wound healing and tissue repair. The LKKTET sequence is the minimal actin-binding unit of Tβ4, and TB-500’s activity in cell migration assays closely mirrors that of full-length Tβ4, confirming that this 17-residue fragment captures the essential pharmacophore of the parent protein.
Beyond actin sequestration, TB-500 activates the ILK (integrin-linked kinase)/Akt signalling pathway, which promotes cell survival, proliferation, and angiogenesis. ILK is a serine/threonine kinase that acts downstream of integrins and growth factor receptors to phosphorylate Akt at Ser473, activating pro-survival and pro-proliferative signalling. ILK/Akt activation by TB-500 leads to upregulation of VEGF and HGF expression in endothelial cells and fibroblasts, further promoting angiogenesis and tissue repair. This VEGF/HGF upregulation creates a positive feedback loop that amplifies the angiogenic response at sites of tissue injury, contributing to the accelerated vascularisation observed in pre-clinical wound healing models treated with TB-500.
TB-500 also modulates inflammatory signalling by reducing NF-κB activation and pro-inflammatory cytokine production (TNF-α, IL-1β, IL-6) in macrophage and endothelial cell models. This anti-inflammatory activity, combined with its pro-angiogenic and pro-migratory effects, makes TB-500 a valuable research tool for investigating the mechanisms of tissue repair in inflammatory and ischaemic injury models. The compound’s small size (17 amino acids) and resistance to proteolytic degradation — conferred by the N-terminal acetylation and the proline residues at positions 11 and 13 — ensure biological activity in the protease-rich environment of healing tissue.
Research Applications
TB-500 is used across a broad range of pre-clinical tissue repair research disciplines. In cardiac research, TB-500 has been studied in rodent models of myocardial infarction, where it promotes cardiomyocyte survival, angiogenesis, and cardiac function recovery through ILK/Akt and VEGF mechanisms. In musculoskeletal research, TB-500 is used in tendon transection, ligament rupture, and muscle injury models, where it promotes fibroblast migration, collagen synthesis, and extracellular matrix remodelling. In corneal wound healing research, TB-500 has been shown to accelerate corneal epithelial wound closure through its actin-regulatory and cell migration-promoting effects.
In neurological research, TB-500 has been studied in models of traumatic brain injury and spinal cord injury, where it reduces neuroinflammation and promotes axonal regrowth through ILK/Akt and NF-κB mechanisms. The refill cartridge format is particularly suited to research programmes requiring repeated subcutaneous administration over extended time courses, providing consistent, pre-measured doses with minimal handling variability. Researchers investigating the combined effects of BPC-157 and TB-500 should consider the BPC-157 / TB-500 Blend 10mg or the corresponding BPC-157 / TB-500 Blend Refill.
Reconstitution & Handling Guidance
TB-500 Refill cartridges are supplied in lyophilised form and must be reconstituted before use. For use with the AbsoluteBioLab Peptide Pen v3, reconstitute the cartridge with bacteriostatic water (0.9% benzyl alcohol in sterile water for injection) to the desired concentration. A typical reconstitution for research use is 2ml bacteriostatic water to yield a 5mg/ml solution. Allow the lyophilised cake to dissolve completely by gentle swirling — do not vortex. The reconstituted solution should be clear and colourless; discard if particulate matter or discolouration is observed.
TB-500 is soluble in aqueous buffers at concentrations up to 10mg/ml under standard conditions. For in vitro applications, reconstitute in sterile PBS (pH 7.4) or cell culture-grade water. Working solutions should be prepared fresh from frozen aliquots where possible to maintain peptide integrity.
Storage & Stability
| Condition | Temperature | Duration | Notes |
|---|---|---|---|
| Lyophilised cartridge (long-term) | −20°C | ≥24 months | Desiccated; protect from light and moisture |
| Lyophilised cartridge (short-term) | 2–8°C | Up to 4 weeks | Desiccated; suitable for active research use |
| Reconstituted in bacteriostatic water | 2–8°C | Up to 28 days | Benzyl alcohol preservative extends stability |
| Reconstituted aliquots (extended) | −80°C | Up to 12 months | Single-use aliquots; avoid repeated freeze-thaw cycles |
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