Development of an Efficient Murine Tissue Expansion Model for Skin Regeneration Research

Skin regeneration is essential for the healing of various superficial wounds and can be promoted by mechanical stimulation. Tissue expansion is a widely used strategy to accelerate skin regeneration by controlled mechanical stretch; however, its clinical efficacy is often restricted by a mismatch between mechanical loading and the skin's regenerative capacity. To address this limitation, the development of a standardized animal model of tissue expansion is urgently required. In this study, we established a tissue expansion model in Sprague-Dawley rats. Following the dorsal implantation of a 10 mL tissue expander, 5 mL of saline was injected immediately after the surgery. After a two-week recovery period, animals underwent a regimen of twice-weekly saline injections (10 mL per session). The expansion kinetics exhibited a characteristic trend of rapid skin growth followed by a gradual deceleration. In the later stages, severe complications such as skin necrosis, tissue breakdown, and expander exposure were observed. This work establishes a reproducible preclinical framework that closely mimics the physiological and pathological processes of human tissue expansion, providing a foundational model to investigate regenerative mechanisms and optimize clinical protocols.