The aim of the present study was to compare and observe the expression levels of vascular endothelial growth factor (VEGF) and miRNA-17-5p during the treatment of seawater-immersed blast-injury wounds (SIBIW) under different conditions of vacuum sealing drainage (VSD), and to identify the optimized range of VSD treatment and partially explain its mechanisms. The bilateral hips and scapulae of experimental pigs (weight, 25-30 kg) were subjected to blast-injury wounds, followed by the seawater immersion. The animals then underwent conventional dressing treatment under 120, 180 and 240 mmHg VSD. Visual observation, in addition to histological, immunohistochemical and molecular biological techniques were applied to compare and observe the extent of wound healing and expression levels of VEGF and miRNA-17-5p. The wound healing of the VSD treatment group was improved compared with the control group, with 120 mmHg negative pressure producing the most marked effect. miR-17-5p expression was detected in the SIBIW granulation tissues. There was significant difference between each VSD treatment group and control group at each time point (P<0.05). Thus, the present results show that miR-17-5p can be expressed in SIBIW granulation tissues, and this effect is most evident under 120 mmHg negative pressure, which may inform the optimized negative range for the treatment of SIBIW.

The aims of this study were to observe the effects of vacuum sealing drainage ( VSD ) with three different negative pressures on the wound healing rate, macrophage count and the expression of hyaluronic acid ( HA ) as well as its receptor CD44 in seawater‐immersed blast‐injury wounds ( SIBIW ) and to determine the optimal negative pressure value. In a minipig SIBIW model, different suction pressures and routine dressing were applied. Histological and immunohistochemical comparisons as well as molecular biology methods were performed to compare the wound healing conditions, macrophage count and the levels of HA and CD44 . The wound healing rate of the VSD group was significantly higher than that of the control group, with the −120 mmHg group exhibiting the best effects. The macrophage count of the VSD group was higher than that of the control group. The HA level fluctuation was higher in the VSD group, with the −120 mmHg and the −180 mmHg groups showing the most significant fluctuation ( P < 0·05). CD44 was expressed in the full‐thickness wound‐limbic tissues and was higher in the treatment group than that in the control group, with the −120 mmHg group having the most obvious expression. VSD significantly improved the healing ability and increased the macrophage count and the HA content. It also promoted CD44 expression. −120 mmHg is the optimal negative pressure value.