对临床现有液体敷料赋予pH依赖性，通过动物实验验证其有效性。

检测正常皮肤、清洁创面、感染创面pH，作为pH依赖性成膜的理论依据。在现有商品化液体敷料基础上，通过添加不同浓度卡波姆制成pH依赖性成膜的新型液体敷料，体外不同pH条件下检测成模性。根据创面pH选择能在创面成膜但在正常皮肤不能成膜的卡波姆浓度，制成pH依赖的成膜性液体敷料。检测该液体敷料的生物相容性(细胞毒性、致敏性、皮内刺激)及物理屏障作用(保湿性、阻菌性)。SD大鼠全层皮肤缺损创面模型在体检测其有效性。

正常皮肤pH(5.90±0.25)显著小于清洁创面(6.54±0.36)和感染创面(7.54±0.35)，差异有统计学意义(t＝－3.32，P＝0.011；t＝8.61，P<0.001)，清洁创面pH显著小于感染创面(t＝－4.44，P＝0.002)。配置pH分别为6、7、8的琼脂板，涂抹液体敷料，观察到pH为7和8时能完整成膜，但当pH为6时无法形成片状薄膜。成膜性液体敷料细胞毒性为1级，不具有潜在细胞毒性，无致敏性，皮内埋植无刺激性。调节液体敷料pH为6、7、8，当pH为6时，不具有保湿性和阻菌性；当pH为7和8时，保湿率分别为(4.76±2.04)%和(7.58±1.62)%，阻菌率分别为(33.17±5.59)%和(45.36±7.57)%。动物实验显示，相较于不具有成膜性的液体敷料，造模后第10天创面愈合率增高[(69.02±3.39)% vs (75.34±3.64)%，t＝2.84，P＝0.022]，创面愈合时间缩短[(23.60±0.89)d vs (20.40±2.61)d，t＝2.60，P＝0.032]。

通过调节卡波姆浓度可形成pH依赖的成膜性液体敷料，在创面上成膜，但不影响正常皮肤，促进创面愈合，改善使用舒适性。

To modify the existing liquid dressing with pH dependence, verify its effectiveness through animal experiments.

Measured the pH of normal skin, clean wounds, and infected wounds as the theoretical basis for pH dependent film formation. On the basis of existing commercialized liquid dressings, a new type of pH dependent film-forming liquid dressing was prepared by adding different concentrations of carbopol. The moldability was tested in vitro under different pH conditions. Based on the pH of the wound, a carbopol concentration that could form a film on the wound but couldn′t form a film on normal skin was selected to prepare a pH dependent film-forming liquid dressing. Detectd the biocompatibility (cytotoxicity, sensitization, intradermal stimulation) and physical barrier effect (moisturizing properties, antibacterial properties) of the liquid dressing. The effectiveness of the liquid dressing in vivo was detected though the full thickness skin defect wound model in SD rats.

The pH of normal skin was 5.90±0.25, which was significantly lower than 6.54±0.36 of clean wounds and 7.54±0.35 of infected wounds (t=-3.32, P=0.011; t=8.61, P<0.001). The pH of clean wounds was also significantly lower than that of infected wounds (t=-4.44, P=0.002). Configured agar plates with pH values of 6, 7, and 8, applied liquid dressings. Complete film formation could be achieved at pH values of 7 and 8, but sheet-like film couldn′t be formed at pH values of 6. The cytotoxicity of the liquid dressings was level 1, with no potential cytotoxicity. No sensitization and irritation during intradermal implantation was found in the liquid dressings. Adjusted the pH of the liquid dressing to 6, 7, and 8. When the pH was 6, it didn′t have moisturizing and antibacterial properties. When the pH was 7 and 8, the moisture retaining rate was (4.76±2.04)% and (7.58±1.62)%, respectively, and the antibacterial rate was (33.17±5.59)% and (45.36±7.57)%, respectively. Animal experiments showed that compared to liquid dressings without film forming properties, the wound healing rate on the 10th day after modeling significantly increased[(69.02±3.39)% vs (75.34±3.64)%, t=2.84, P=0.022], and the wound healing time significantly reducted [(23.60±0.89)d vs (20.40±2.61)d, t=2.60, P=0.032] .

By adjusting the concentration of carbopol, pH dependent film-forming liquid dressings can be made, which form a film on the wound surface without affecting normal skin, promote wound healing, and improve comfort level.