摘要目的：通过观察海藻酸钙敷料对糖尿病大鼠创面组织基质金属蛋白酶9(MMP-9)的影响，探讨其对糖尿病大鼠创面愈合促进作用的机制。方法雄性糖尿病SD大鼠36只，麻醉成功后用无菌手术剪于背部剪一直径为20 mm的圆形伤口，随机数字表法分为两组：实验组(n=18)伤口采用海藻酸钙敷料换药，对照组(n=18)则采用经典棉纱布敷料。观察两组大鼠创面愈合情况，行苏木素伊红(HE)和马松三色法(Masson)染色，观察肉芽组织厚度、炎症反应以及胶原蛋白水平，以Western blotting法和逆转录聚合酶链反应(RT-PCR)法检测创面愈合过程中MMP-9 mRNA和蛋白表达的变化。采用t检验和卡方检验比较两组间数据差异。结果术后第8、10、12和14天时实验组伤口愈合率明显快于对照组(χ2=8.333、5.124、14.047、16.547，均P<0.05)。术后各期实验组伤口炎症反应较对照组平缓。术后第3天时，对照组与实验组肉芽组织厚度分别为(1476±118)和（812±136）μm（t=6.384，P=0.003），第7天时分别为(1369±86)和（480±105）μm,t=11.307，P=0.000。术后第7和14天时，对照组胶原蛋白较实验组明显较少(15%±5%比51%±5%、28%±5%比61%±5%，t=9.308、8.196,均P<0.05)。RT-PCR结果显示，术后第3天时，实验组MMP-9 mRNA水平明显低于对照组(0.028±0.003比0.037±0.004, t=3.118,P=0.036)；术后第7天和14天时实验组MMP-9 mRNA水平仍明显低于对照组(0.026±0.003比0.033±0.003、0.021±0.003比0.030±0.002，t=2.858、7.003，均P<0.05)。同时Western Blotting的结果显示，实验组MMP-9蛋白表达在术后3、7、14天均明显低于对照组(t=10.595、10.400、12.359,均P<0.05)。结论海藻酸钙敷料可能通过抑制伤口MMP-9 mRNA及蛋白表达，减少胶原蛋白的降解，从而促进创面的愈合。

abstractsObjective To clarify the mechanism of calcium alginate dressings for improving the express of wound healing by its effects on the expression of matrix metallopeptidase 9(MMP-9) in the wound tissue in diabetes rats. Methods The thirty-six male diabetic SD rats, wounded on the back(with a diameter of 20 mm) with sterile scissors, were randomized divided into two groups according to random number table: the experimental group (n=18, treated with calcium alginate dressing for 14 days) and the control group (n=18, treated with conventional gauze dressing). The wound healing rates in the two groups were obtained, HE and Masson staining methods were used to evaluate the thickness and inflammatory response of granulation tissue and level of collagen in it, meanwhile Western blotting and realtime&nbsp;polymerase chain reaction(RT-PCR) methods were applied to evaluate the expression of mRNA and protein of MMP-9 during the process of wound closure. The t-test and chi-square were used to test the differences between the data of the two groups. Results The wound healing rate in the experimental group was faster than that in the control group at day 8, 10,12 and 14 (χ2=8.333, 5.124, 14.047, 16.547, all P<0.05). The inflammatory response in experimental group was milder than that in control group at different periods post-operation. Significant statistical difference in thickness of granulation were found in the two groups at day 3 ((1476 ± 118) vs (812 ± 136)μm, t=6.384, P=0.003) and day 7((1369 ± 86) vs (480 ± 105)μm, t=11.307, P=0.000). The level of collagen in control group were much lower than those in in experimental group at day 7 and 14 (15%± 5% vs 51%± 5%, 28%± 5% vs 61%± 5%, t=9.308, 8.196,both P<0.05). And the mRNA expression of MMP-9 in the experimental group decreased significantly when compared with those in the control group at day 3, 7 and 14 (0.028±0.003 vs 0.037±0.004, 0.026±0.003 vs 0.033±0.003, 0.021±0.003 vs 0.030 ± 0.002, t=3.118, 2.858, 7.003, all P<0.05). Meanwhile the protein levels of MMP-9 in the experimental group were significantly lower than those in the control group at day 3, 7, 14(t=10.595, 10.400, 12.359, all P<0.05). Conclusions Calcium alginate dressing promotes skin ulcer healing by inhibiting the expression of MMP-9 so as to reduce the degradation of collagen in diabetic SD rats.