基于D-最优设计的SD大鼠皮肤化学脱毛参数优化

Optimization of chemical hair removal in SD rats by D-optimal design

目的对SD大鼠皮肤进行脱毛参数研究,为建立皮肤光老化动物模型提供基本实验条件。方法以毛发残存量和皮损面积为评价指标,分别考察Na_2S作用浓度及时间对脱毛效果的影响,在此基础上进一步通过D-最优设计优化Na_2S脱毛参数。结果 Na_2S浓度是影响脱毛能力的关键因素,5%以下几乎无脱毛效果,7%以上则开始出现皮损并逐步加重,6%为脱毛基础浓度;在6%Na_2S浓度下作用5 min开始脱毛,10 min时皮肤表面较光滑,15 min时非常光滑,15 min之后皮损显现,20 min时皮损加重,25 min时肉眼可见皮肤灼烧样外观,D-最优设计表明7%Na_2S作用10 min效果最好,未见皮损且无残余毛发。结论基于D-最优设计的SD大鼠皮肤化学脱毛可实现高效脱毛。

Objective To screen the optimal parameters for depilation in SD rats, and to provide an experimental prerequisite for the establishment of animal models of skin photoaging. Methods The effects of concentrations and time of the chemical depilatory Na2 S treatment on the hair removal efficiency were evaluated by the number of residual hair per milimeter square and the damaged area of the skin in rats, and the parameters for hair removal were further optimized by D-optimal design. Results Working concentration of Na2 S was the critical factor affecting its capability of hair removal. No depilation was observed when the concentration of Na2 S was lower than 5%, while skin damage began to appear and be-came severe gradually when the concentration of Na2 S was above 7%. Therefore, 6% Na2 S was taken as the basic concen-tration for depilation. Hair removal was observed with 6% Na2 S treatment for 5 min. After 10 min of treatment, the surface of the skin turned to be smooth, and this tendency continued until 15 min. After 15 min, skin damage occurred and turned more severe after 20 min. When treated for over 25 min, skin damage similar to skin burns was observed with naked eyes. Overall, our study with the D-optimal design showed that the effect of hair removal in the SD rats was optimal when treated with 7% Na2 S for 10 min, causing no skin damage and residual hair left. Conclusions Highly efficient hair removal in SD rats can be achieved with chemical depilatory optimized by D-optimal design.