PTD-DBM
Summary
PTD-DBM is a cell-penetrating fusion peptide that competitively displaces CXXC5, a negative regulator of Wnt signaling, from the Dishevelled protein. Developed at Yonsei University, it restored hair regrowth in depilated mice and promoted wound-induced hair follicle neogenesis in mouse models, while human balding scalp shows the CXXC5 upregulation the peptide targets. No human clinical trial has been published; all efficacy data comes from mouse models and human cell or tissue analysis.
Also known as: Protein Transduction Domain-Dishevelled Binding Motif, CXXC5 Competing Peptide
Key Findings at a Glance
- • CXXC5, a negative regulator of Wnt signaling, is upregulated in balding human scalp dermal papilla cells; PTD-DBM competitively blocks the CXXC5-Dishevelled interaction to restore beta-catenin signaling.
- • Topical PTD-DBM restored hair regrowth in depilated mice and promoted wound-induced hair follicle neogenesis, with CXXC5 knockout mice phenocopying the effect.
- • The 2023 Cells study placed CXXC5 downstream of the DHT-prostaglandin D2 axis in androgenetic alopecia, positioning the peptide as a downstream intervention.
- • All primary data comes from a single laboratory whose principal investigator holds commercial rights; no human trial or independent replication has been published.
PTD-DBM Overview & Molecular Profile
PTD-DBM (protein transduction domain-Dishevelled binding motif) is a 25-amino acid synthetic peptide developed by Kang-Yell Choi's group at Yonsei University, Seoul. It fuses an octaarginine cell-penetrating domain, through a four-glycine linker, to a motif derived from CXXC5, a zinc-finger protein that acts as a brake on Wnt/beta-catenin signaling by binding the PDZ domain of Dishevelled. The group first identified CXXC5 as a negative regulator of cutaneous wound healing (2015), then showed it is upregulated in miniaturized follicles of human balding scalp and that blocking it stimulates hair regrowth (2017). A 2023 study placed CXXC5 downstream of the dihydrotestosterone-prostaglandin D2 axis in androgenetic alopecia, and a separate 2023 study embedded PTD-DBM in a hydrogel patch that promoted regenerative, scar-attenuated wound healing in mice. The peptide is mechanistically distinct from cosmetic copper peptides such as GHK-Cu, which act through unrelated pathways. All primary efficacy data comes from the Yonsei laboratory, whose principal investigator holds commercial interests in the technology, and no human trial has been published.
Mechanism of Action: Gene Activation & Angiogenesis
Canonical Wnt signaling requires Dishevelled (Dvl) to relay the Frizzled receptor signal that stabilizes beta-catenin. CXXC5 binds the PDZ domain of Dvl and suppresses this relay, acting as a negative feedback regulator; CXXC5 knockout mice show accelerated hair cycling, confirming the physiological role. The DBM segment of PTD-DBM (RKTGHQICKFRKC, taken from the Dvl-binding region of CXXC5) competitively occupies the same interaction surface, freeing endogenous Dvl to restore beta-catenin signaling. In human dermal papilla cells, PTD-DBM reversed CXXC5-mediated suppression of alkaline phosphatase activity (a dermal papilla vitality marker) and cell proliferation. The N-terminal octaarginine protein transduction domain carries the peptide across cell membranes and, at high applied concentrations, through skin.
Research-Observed Effects
Hair Regrowth in Animal Models
Moderate ResearchTopical PTD-DBM restored hair regrowth in depilated mice in the 2017 Journal of Investigative Dermatology study, with beta-catenin activation in follicles, and reversed prostaglandin D2-suppressed regrowth in the 2023 Cells study. CXXC5 knockout mice show accelerated hair cycling, phenocopying peptide treatment and supporting target specificity. Human relevance is supported indirectly: CXXC5 is upregulated in dermal papilla cells of balding human scalp. No human treatment study has been published.
Wound-Induced Hair Follicle Neogenesis
Preliminary ResearchIn mouse full-thickness wound models, PTD-DBM promoted wound-induced hair follicle neogenesis, and the 2017 study reported that combining it with the GSK-3beta inhibitor valproic acid, which activates Wnt signaling at a second node, further drove de novo follicle formation. A 2023 Advanced Healthcare Materials study delivered PTD-DBM with valproic acid from a pyrogallol-hyaluronic acid hydrogel patch, achieving regenerative wound healing with reduced scar formation, induction of stem cell markers (CD105, Nestin), and increased collagen III. All evidence is from mouse models.
CXXC5-Dishevelled Interaction Blockade
Moderate ResearchTarget engagement is supported by converging evidence: the competing peptide activated Wnt reporter signaling and beta-catenin accumulation in human dermal fibroblasts and dermal papilla cells, reversed CXXC5-driven suppression of alkaline phosphatase and proliferation, and CXXC5 knockout phenocopied peptide effects across hair regrowth and wound models. This mechanism-reversal consistency across readouts is the strongest aspect of the PTD-DBM evidence base.
DHT-PGD2 Axis Counteraction
Preliminary ResearchThe 2023 Cells study established that dihydrotestosterone drives prostaglandin D2 production in balding scalp dermal papilla cells, which upregulates CXXC5 and suppresses Wnt signaling. PTD-DBM treatment or CXXC5 knockout overcame both PGD2-induced and DHT-induced hair suppression in mice, positioning the peptide downstream of the androgenetic alopecia signaling chain rather than at the androgen receptor itself.
Scar Attenuation in Wound Repair
Preliminary ResearchBeyond hair, the 2015 Journal of Experimental Medicine study identified CXXC5 as a negative regulator of cutaneous wound healing and showed that topical PTD-DBM co-treated with valproic acid synergistically accelerated wound closure in mice; the peptide alone was reported to activate beta-catenin and collagen production in vitro. The 2023 hydrogel patch study reported reduced scarring with suppressed alpha-smooth muscle actin and induced collagen III, suggesting a shift from fibrotic toward regenerative healing. These findings come from the same laboratory and remain mouse-only.
Safety & Tolerability
PTD-DBM has never been administered to humans in a published study. Mouse topical studies did not report local or systemic toxicity, but formal dermal safety, irritation, and sensitization testing has not been published, and sustained Wnt/beta-catenin pathway activation carries a theoretical oncogenic concern that long-term studies have not addressed.
Human data: No human interventional data exists. Human evidence is limited to observational analysis of scalp tissue (CXXC5 upregulation in balding scalp) and in vitro experiments on cultured human dermal papilla cells and fibroblasts.
Regulatory status: Research compound only; not approved for any indication in any jurisdiction.
- PubMed 28595998
Topical mouse studies reported hair regrowth (PMID: 28595998) and, in combination with valproic acid, accelerated wound healing (PMID: 26056233) without described local or systemic toxicity, but no formal dermal safety, irritation, or sensitization data has been published in any species.
Animal - PubMed 28595998
Human data is observational tissue analysis only: CXXC5 upregulation in balding scalp supports the target hypothesis but provides no information on treatment safety in humans.
Human observational - PubMed 36831222
Sustained Wnt/beta-catenin activation is oncogenic in principle - the pathway is mutationally activated in colon and skin cancers - so chronic pharmacological reactivation of this pathway on skin carries a theoretical risk that has not been evaluated in long-term studies.
Theoretical
Research Protocol Doses Reported in Published Literature
Research Disclaimer: Doses reported below are from published preclinical research protocols. PTD-DBM is not approved by the US FDA for human use; regulatory status can differ in other countries, so see the regulatory status note in the safety section of this page. This information is provided for research reference only and does not constitute a dosing recommendation.
No human dosing exists. Published mouse protocols applied PTD-DBM topically: 100 micromolar daily for 11 days to full-thickness dorsal wounds (2015), and 10 millimolar solutions (300 microliters per application) every other day to depilated dorsal skin (2023). The 100-fold higher concentration in the later work reflects the barrier that intact stratum corneum presents even to a polyarginine transduction peptide. In vitro studies on human cells used 2 to 10 micromolar.
All doses above are reported from published research protocols using laboratory subjects. Refer to the cited studies in the Research Studies section above for original source data.
Research Studies & References
The Dishevelled-binding protein CXXC5 negatively regulates cutaneous wound healing
Lee SH, Kim MY, Kim HY, et al.
Journal of Experimental Medicine (2015)
This study identified CXXC5 as a negative regulator of cutaneous wound healing through its interaction with Dishevelled. CXXC5 was upregulated in healing skin, including in human wound biopsy tissue, and CXXC5 knockout mice showed enhanced Wnt signaling and accelerated wound closure. The competing PTD-DBM peptide, applied topically at 100 micromolar daily for 11 days, accelerated wound healing in mice when co-treated with the GSK3-beta inhibitor valproic acid, an effect the authors describe as synergistic rather than attributable to the peptide alone. PTD-DBM also activated Wnt reporter activity in wounded tissue and enhanced fibroblast migration and collagen-related readouts in human dermal fibroblasts at 2 to 10 micromolar. This paper introduced PTD-DBM as a research tool and established the CXXC5-Dishevelled interaction as a druggable node in skin repair.
Targeting of CXXC5 by a Competing Peptide Stimulates Hair Regrowth and Wound-Induced Hair Neogenesis
Lee SH, Seo SH, Lee DH, et al.
Journal of Investigative Dermatology (2017)
The central PTD-DBM hair paper connected CXXC5 to hair loss and tested the competing peptide as a regrowth strategy. CXXC5 was upregulated in miniaturized hair follicles of human balding scalps and suppressed alkaline phosphatase activity and proliferation in cultured human dermal papilla cells. CXXC5 knockout mice displayed accelerated hair regrowth. Topical PTD-DBM restored hair regrowth in depilated mice, and combined treatment with valproic acid, a GSK-3beta inhibitor, further promoted wound-induced hair follicle neogenesis. The authors proposed the CXXC5-Dishevelled interaction as a target for hair loss treatment.
CXXC5 Mediates DHT-Induced Androgenetic Alopecia via PGD(2)
Ryu YC, Park J, Kim YR, et al.
Cells (2023)
This study mechanistically linked androgenetic alopecia to the CXXC5 pathway. Prostaglandin D2, a known alopecia inducer, was shown to act through CXXC5: hair loss caused by PGD2 was reversed by CXXC5 knockout or by topical PTD-DBM (10 millimolar, applied every other day), and PGD2 suppression of wound-induced hair neogenesis was likewise overcome. Dihydrotestosterone was shown to induce hair loss via PGD2-driven CXXC5 upregulation, and combined inhibition of GSK-3beta and CXXC5 alleviated DHT-induced loss. The paper positions CXXC5 as a downstream mediator of the DHT-PGD2 axis. The senior author declares a commercial interest through CK Regeon Inc., licensee of the technology.
Adhesive Hydrogel Patch-Mediated Combination Drug Therapy Induces Regenerative Wound Healing through Reconstruction of Regenerative Microenvironment
Lee SH, An S, Ryu YC, et al.
Advanced Healthcare Materials (2023)
This formulation study delivered PTD-DBM and valproic acid from pyrogallol-functionalized hyaluronic acid adhesive hydrogel patches in mouse wound models. The combination patches significantly inhibited scar formation during healing, suppressed differentiated cell markers such as alpha-smooth muscle actin, induced stem cell markers including CD105 and Nestin, and increased collagen III, a factor associated with regenerative rather than fibrotic repair. The work extends PTD-DBM from a topical solution research tool into a materials-based delivery format and supports a pro-regenerative, anti-scarring role for CXXC5-Dishevelled blockade in wound healing.
KY19382, a novel activator of Wnt/beta-catenin signalling, promotes hair regrowth and hair follicle neogenesis
Ryu YC, Lee DH, Shim J, et al.
British Journal of Pharmacology (2021)
This paper describes KY19382, the small-molecule successor from the same research program, which activates Wnt/beta-catenin signaling through the CXXC5-Dishevelled axis identified with PTD-DBM. KY19382 raised alkaline phosphatase and PCNA levels in human dermal papilla cells, increased hair length in ex vivo mouse vibrissa and human hair follicle cultures, induced hair regrowth in mice, and promoted de novo follicle generation in wound-induced hair neogenesis and hair patch assays. The compound demonstrates that the target class validated by PTD-DBM is being pursued pharmaceutically, a signal of both translational intent and the commercial interests surrounding the program.
Frequently Asked Questions
How does PTD-DBM promote hair growth?
PTD-DBM blocks CXXC5, a protein that suppresses Wnt/beta-catenin signaling by binding Dishevelled. Releasing this brake reactivates Wnt signaling in dermal papilla cells, the cells that orchestrate follicle cycling, promoting re-entry into the growth (anagen) phase. In depilated mice the peptide restored hair regrowth, and CXXC5 knockout mice show the same accelerated cycling, confirming the target. Human follicles have not been treated in any published trial.
What connects PTD-DBM to DHT and androgenetic alopecia?
The 2023 Cells study showed that dihydrotestosterone drives prostaglandin D2 production in balding scalp dermal papilla cells, and PGD2 upregulates CXXC5, which suppresses Wnt signaling and hair growth. PTD-DBM acts downstream of this chain: it overcame both PGD2-induced and DHT-induced hair suppression in mice without touching the androgen receptor. It is therefore mechanistically complementary to, not competitive with, anti-androgen approaches.
Has PTD-DBM been tested in humans?
No human clinical trial or treatment study has been published as of 2026. Human evidence is limited to tissue and cell analysis: CXXC5 is upregulated in balding human scalp dermal papilla cells, and PTD-DBM reverses CXXC5-driven suppression in cultured human cells. Efficacy and safety in people are unknown.
Who developed PTD-DBM, and has the research been replicated?
PTD-DBM was developed by Kang-Yell Choi's group at Yonsei University, Seoul, and essentially all primary data comes from that laboratory. The principal investigator is CEO of CK Regeon Inc., which holds the license to the technology - a conflict of interest declared in the 2023 paper. No independent laboratory has published a replication. The same program has produced KY19382, a small molecule targeting the same pathway, reported in the British Journal of Pharmacology in 2021.
Can PTD-DBM penetrate skin when applied topically?
Partially. The octaarginine protein transduction domain improves cellular uptake, but intact stratum corneum remains a major barrier: mouse studies that applied the peptide to depilated (disrupted) skin used 10 millimolar solutions, roughly 100 times the concentration used on open wounds. This concentration gap is direct evidence that penetration through unbroken skin is limited, and it constrains how in vitro potency translates to topical use.
Related Peptides
View allAHK-Cu
AHK-Cu (copper tripeptide-3) is the copper complex of the tripeptide Ala-His-Lys, a synthetic analog of GHK-Cu studied for hair follicle and skin applications.
GHK-Cu
GHK-Cu is a naturally occurring copper complex of the tripeptide glycyl-L-histidyl-L-lysine. It has been extensively studied for wound healing, skin rejuvenation, and tissue remodeling.
BPC-157
BPC-157 is a synthetic pentadecapeptide derived from a protective protein found in gastric juice. It has been extensively studied for its potential regenerative and protective properties in various tissue types.
Follow Peptpedia on Google
Add Peptpedia as a Preferred Source and Google can highlight our links with a "preferred" badge in your Top Stories and AI Overviews.