Abstract

Dolphins have a unique ability to heal large soft tissue injuries without medical intervention.¹ By further characterizing stem and regenerative cell physiology in dolphins, we hope to elucidate some of the mechanisms of enhanced wound healing which could be applied to multiple species. Adipose-derived stem cells (ASCs) are multipotent mesenchymal stem cells with the potential for tissue repair and regeneration. To determine if treating cutaneous wounds with autologous ASCs enhances wound healing in dolphins, we utilized an incisional model² to study the wound healing process. Small incisions simulating rake lesions (9 cm long x 3 mm deep) were created on the right and left side of three dolphins, craniolateral to the dorsal fin. One wound was treated with an injection of an autologous ASC preparation into the wound bed. The other wound was treated with the carrier solution alone. Closure of the wounds was monitored daily by visual inspection. Biopsies were obtained from the stem cell treated wound and the control carrier treated wound at post-treatment day 1, 5, and 15. The incisional wound and excised tissue were assessed by standard histological examination and analyzed for wound healing parameters (extent of closure, stratum germinativum mitoses and inflammatory cell numbers). The ASC treated wounds exhibited higher mitotic rates and accelerated wound closure than in the control wounds. This study demonstrates that stem cells enhance wound epidermal healing in dolphins and may be a clinically useful cellular therapeutic product to augment treatment of a variety of pathologic conditions.

Acknowledgements

We thank our colleagues, staff, trainers, and research department at the U.S. Navy Marine Mammal Program and the U.S. Army Animal Care Specialists for their crucial assistance in the implementation and execution of these procedures. Special thanks to Forrest Gomez, Jenny Meegan, CPT Laura Cotte, CPT Kamala Rapp, CPT Erika Stapp, and Sacha Stevenson. This work was funded by Office of Naval Research contract N00014-09-C-0378 and oversight provided by the Navy Bureau of Medicine and Institutional Animal Use and Care Committee.

References

1.  Zasloff M. Observations on the remarkable (and mysterious) wound-healing process of the bottlenose dolphin. J Invest Dermatol. 2011;131:2503–2505.

2.  Bruce-Allen LJ, Geraci JR. Wound healing in the bottlenose dolphin (Tursiops truncatus). Can J Fish Aquat Sci. 1985;42:216–228.