25AA Preclinical Only
PTD-DBM
A cell-penetrating competitor peptide that blocks the CXXC5–Dishevelled interaction to re-activate Wnt/β-catenin signaling; preclinical evidence spans hair follicle neogenesis, wound repair, and longitudinal bone growth.
In Plain English:
Your body contains a braking protein called CXXC5 that clamps down on Wnt signaling—a pathway essential for growing new hair follicles, healing wounds, and forming bone. PTD-DBM is a synthetic fusion peptide with two parts: a protein transduction domain (PTD) borrowed from the HIV TAT protein that lets it slip through cell membranes, and a Dishevelled Binding Motif (DBM) that mimics the CXXC5 docking sequence and competitively blocks CXXC5 from parking on the Dishevelled (Dvl) protein. When that brake is lifted, Wnt/β-catenin signaling flows freely, driving dermal papilla cell proliferation, follicle neogenesis, collagen synthesis, and—in bone—osteoblast differentiation. Mouse studies show new hair follicle formation within 3–4 weeks, accelerated wound closure, and extended tibial growth. No completed human clinical trial exists as of May 2026.
Research Maturity
Preclinical Only (~15 PTD-DBM / parent-mechanism papers since 2015; preclinical only, single research group+ Studies)
Focus
Hair & Skin
Soft Tissue Repair
Origin
Synthetically designed fusion peptide. Protein transduction domain is derived from the HIV-1 TAT (47–57) sequence (RRRRRRRR). Dishevelled Binding Motif was designed by Prof. Kang-Yell Choi's laboratory at Yonsei University (Seoul, South Korea) and first described in a wound healing context in Lee et al., J Exp Med, 2015. CK Regeon (formerly CK Biotechnology) holds translational rights.
Mechanism
PTD-DBM is a bipartite competitor peptide. The polyarginine PTD (8×Arg) drives electrostatic membrane insertion and endosomal release, delivering the DBM cargo intracellularly without requiring a receptor. The DBM sequence (RKTGHQICKFRKC) mimics the CXXC5 binding surface that contacts the PDZ domain of Dishevelled (Dvl1/2/3). Competitive occupancy of the Dvl PDZ domain by DBM prevents CXXC5 from exerting negative feedback on the Wnt/β-catenin cascade. Freed β-catenin accumulates in the nucleus and activates TCF/LEF-target genes including Axin2, Cyclin D1, and cMyc. Downstream consequences: (1) Hair—dermal papilla stem cells re-enter anagen, follicle neogenesis is stimulated, and prostaglandin D2 (PGD2)/BMP-induced CXXC5 overexpression (present in androgenetic alopecia) is overridden. (2) Wound repair—enhanced keratin-14 expression, collagen I synthesis, and keratinocyte migration; synergistic with valproic acid (GSK-3β inhibitor). (3) Bone—osteoblast differentiation markers (ALP, osteocalcin) increase; growth plate chondrocyte proliferation is extended, producing measurable tibial elongation in adolescent mice.
Outcome
Hair follicle neogenesis and anagen re-entry (mouse AGA, wound-induced models); accelerated cutaneous wound closure and collagen synthesis; longitudinal bone elongation via growth plate preservation; reversal of PGD2/DHT-mediated Wnt suppression.
