Effects of botulinum toxin type A on accelerating skin expansion in rats / 中华医学美学美容杂志

ABSTRACT

Objective To observe the effect of botulinum toxin type A (BTX-A) on the rate of skin expansion and the immediate retract rate of skin flaps in rats,and to explore new methods for drug-assisted skin expansion.Methods 18 Sprague-Dawley rats were randomly divided into two groups.After BTX-A or normal saline was injected intradermally into the back marking area,an expander was implanted.The expanders were inflated periodically by injecting normal saline to reach the designated intraexpander pressure.The inflation volume was recorded and the area of marked region was measured regularly.After 4 weeks of expansion,the expanded tissues were harvested and the immediate retract rates were measured.The hematoxylin-eosin staining was performed to observe the thickness of epidermis,dermis and the fibrous capsule,while Masson staining for detection of fibrous capsule collagen.Immunohistochemical staining with α-smooth muscle actin for myofibroblasts was also performed.Results The mean inflation volume and area of marked region of BTX-A group were significantly greater than those of the control group.There were lower immediate retract rate,thinner fibrous capsule,less collagen content and fewer α-SMA positive myofibroblasts in the fibrous capsule of the BTX-A group with statistically significant differences (P ＜ 0.05).There was no signigicant difference in the thicknesses of epidermis and dermis between the two groups (P＞0.05).Conclusions BTX-A can inhibit the formation of fibrous capsule to promote skin expansion,while reducing the immediate retract rate.It possess a potential for assisting effectively skin expansion.