中文摘要：

利用超临界溶液浸渍法（SSI）将磺胺嘧啶银（AgSD）负载到不对称壳聚糖膜（ACF）制备伤口敷料，研究了SSI过程操作压力及温度对载药量的影响，并对AgSD—ACF的吸水量、水蒸气渗透速率、体外释放、抑菌性能和动物皮肤伤口愈合行为进行了考察．结果表明，AgSD—ACF的载药量随着CO2压力的升高先增加后减少，而温度对载药量的影响较复杂，在20MPa和50℃时载药量达到最大为5．0mg／g．AgSD—ACF的水蒸气渗透速率和吸水量可通过改变ACF中致密层的厚度进行调节．AgSD—ACF具有缓释作用，可持续释放10h以上，并且对金黄色葡萄球菌和绿脓杆菌均有较强的抑制作用．动物试验显示AgSD—ACF伤口敷料具有促进大鼠皮肤伤口愈合的作用．

英文摘要：

Supercritical solution impregnation （SSI） process was applied to prepare asymmetric chitosan films （ACFs） loaded with silver sulfadiazine （AgSD） suitable for wound dressing. ACFs with different dense layers （65 μm and 125 μm） and porous layers were first prepared using solvent casting and lyophilization method respectively,and then AgSD was loaded into ACFs using SSI process. The effects of impregnation pressure （from 8 MPa to 30 MPa） and temperature （40,50 and 60 ℃） on drug loading capacity （DLC） were investigated in detail, and the properties of AgSD-ACF were characterized such as morphology, water uptake （WU） , water vapor transmission rate （WVTR） , in vitro release, antibacterial and animal tests. The results showed that DLC of the AgSD-ACF increased with the elevation of the pressure and decreased when the pressure increased further; while the temperature affected the DLC in a complex manner, and the maximum DLC was achieved to be 5.0 mg/g at 20 MPa and 50 ℃. The in vitro release study indicated that the AgSD- ACF could prolong the release of AgSD to beyond 10 h under a sustained manner. The water uptake and water vapor transmission rate of AgSD-ACFs could be well adjusted by changing the thickness of the dense layer. AgSD-ACFs had a remarkable antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa. The result of animal test showed that AgSD-ACFs could promote the healing of the wounds in SD rats. The supereritical solution impregnation method makes it possible to fabricate drug loaded polymer matrix without using organic solvents and high temperature, which provide a promising way to prepare drug loaded films for potential applications in wound dressing.