Outcome of cutaneous wound healing is the scar. Although considerable efforts have been invested in this field, scar-less healing has not been achieved satisfactorily. The lack of a good research model has been one of the reasons to this undesirable situation. However, the deer antler regeneration may provide such a model. Antlers regenerates from the scar-less wound healing over the top of the pedicles (permanent bony protuberances). Interestingly, removal of the pedicle periosteum (PP) results in not only failure of antler regeneration, but scar formation. Astonishingly, subcutaneous transplantation of the PP on forehead of the same deer induced an ectopic pedicle and antler growth. When the ectopic antler became hard and dropped off, the wound left over the ectopic pedicle stump achieved scar-less healing. Therefore, scar-less wound healing over the pedicle stump is not because that pedicle skin is capable of doing so, but achieved through induction of the closely-attached PP. PP cells (PPCs) were then found to have stem cell attributes, thus called antler stem cells. Further, we found that direct injection of the PPCs or topical application of the PPC conditioned medium on wounds to a rat model stimulated regenerative healing of full-thickness cutaneous wounds. Therefore, substances of PPCs for scar-less wound healing are not species-specific. Overall, our findings show that PPCs may have therapeutic potential in enhancing the quality of wound healing and preventing scar formation in clinical settings.

Dr Li received his PhD from Medical School of University of Otago New Zealand on stem cells and antler regeneration in 1997, and subsequently was employed as a senior scientist by AgResearch New Zealand to further his research on antler biology. In 2019, he jointed Changchun Sci-Tech University and established Institute of Antler Science and Technology as the founding director. Through years of antler research, he came to realize that antlers are a fascinating biomedical research model. Annual renewal of antlers offers unique opportunities to explore how nature has solved the problem of mammalian organ regeneration. Unprecedented growth rate (up to 2 cm/day!) of antlers provides a rare system where fast cell proliferation is elegantly regulated without becoming cancerous. The autonomous self-differentiation ability of antler stem cells (from which an organ can form in a postnatal animal) can serve as an invaluable model for generic stem cell research. During the course of investigation, Dr Li has published over 130 papers in peer-reviewed SCI journals (mainly as the first or corresponding author), attended over 30 relevant conferences, and co-authored 4 books.