RESUMO
Objective:To investigate the reparative efficacy and mechanism of pressure-adjustable macroporous antibacterial hydrogel in the treatment of infected wounds.Methods:Staphylococcus aureus was used to establish wound infection models in healthy C57BL/6 mice. The models were divided into 3 groups subjected to 3 different treatments: a negative control group with no hydrogel treatment (group A), a control group treated by common medical hydrogel (group B) and an experiment group treated by pressure-adjustable macroporous antibacterial hydrogel (group C). On days 1, 3, 6, 9 and 12, the effects of 3 treatments were compared on the wound area and the number of bacterial colonies under scab, on the apoptosis of fibroblasts based on the changes of type Ⅰ procollagen, and on the inhibition of inflammation during wound repair by detecting the expression of interleukin-6 (IL-6) and tumor necrosis factor (TNF-α).Results:On days 1 and 3, there was no significant difference between the 3 groups in the wound area ( P>0.05), but on days 6, 9 and 12, there were significant differences between the 3 groups in the wound area ( P<0.05). On day 6, the wound areas in group B (1.23 cm 2 ± 0.16 cm 2) and in group C (1.14 cm 2 ± 0.12 cm 2) were significantly smaller than that in group A (1.56 cm 2 ± 0.16 cm 2) ( P<0.05), but there was no significant difference between groups B and C ( P>0.05). On days 9 and 12, the wound areas in group B (0.97 cm 2 ± 0.13 cm 2 and 0.76 cm 2 ± 0.10 cm 2) and in group C (0.66 cm 2 ± 0.06 cm 2 and 0.48 cm 2 ± 0.07 cm 2) were significantly smaller than those in group A (1.49 cm 2 ± 0.11 cm 2 and 1.39 cm 2 ± 0.13 cm 2), and those in group C were significantly smaller than those in group B (all P<0.05). On day 1, there was no significant difference between the 3 groups in the number of bacterial colonies under scab ( P>0.05). On days 3, 6, 9 and 12, the numbers of bacterial colonies under scab in groups B and C were significantly smaller than that in group A ( P<0.05), and that in group C was significantly smaller than that in group B ( P< 0.05). The nucleic acid electrophoresis showed that the grayscale bands in group C were significantly darker than those in groups A and B. The early apoptosis rate of the fibroblasts in group C[low-right positive fluorescence (LR%): 9.72%] was significantly lower than that in group A (43.99%) and that in group B (38.43%), and that in group B was significantly lower than that in group A ( P<0.05). On day 12, the ratio of the gray values of IL-6 and β-actin (0.64 ± 0.10) and the ratio of the gray values of TNF-α and β-actin (0.34 ± 0.05) in the fibroblasts in group C were significantly higher than those in group A (1.22 ± 0.21 and 0.60 ± 0.14) and in group B (0.88 ± 0.02 and 0.41 ± 0.06) ( P<0.01). Conclusion:The pressure-adjustable macroporous antibacterial hydrogel is an effective treatment of infected wounds and its mechanism may be related to the reduced apoptosis of fibroblasts.