Liu Daohong, Zhang Lihai, Li Tongtong, Wang Guoqi, Du Hailong, Hou Hongping, Han Li, Tang Peifu
Department of Orthopaedics, The Genearl Hospital of People's Liberation Army, 28 Fuxing Road, Haidian District, Beijing, 100853, China.
Cell Biochem Biophys. 2014 Sep;70(1):539-47. doi: 10.1007/s12013-014-9953-0.
Clinical studies found that negative-pressure wound therapy (NPWT) displayed significant clinical benefits in the healing of infected wounds. However, the effect of NPWT on local inflammatory responses in acute infected soft-tissue wound has not been investigated thoroughly. The purpose of this study was to test the impact of NPWT on local expression of proinflammatory cytokines, amount of neutrophils, and bacterial bioburden in wound from acute infected soft-tissue wounds. Full-thickness wounds were created on the back of rabbits, and were inoculated with Staphylococcus aureus strain ATCC29213. The wounds were treated with sterile saline-moistened gauze dressings and NPWT with continuous negative pressure (-125 mmHg). Wound samples were harvested on days 0 (6 h after bacterial inoculation), 2, 4, 6, and 8 at the center of wound beds before irrigation for real-time PCR analysis of gene expression of IL-1β, IL-8, and TNF-α. Wound biopsies were examined histologically for neutrophil quantification in different layers of tissue. Quantitative bacterial cultures at the same time point were analyzed for bacterial clearance. Application of NPWT to acute infected wounds in rabbits was compared with treatment with sterile saline-moistened gauze, over an 8-day period. NPWT-treated wounds exhibited earlier and greater peaking of IL-1β and IL-8 expression and decrease in TNF-α expression over the early 4 days (P < 0.05). Furthermore, histologic examination revealed that significantly increased neutrophil count was observed in the shallow layer in wound biopsies of NPWT treatment at day 2 (P < 0.001). In addition, there was a statistically significant decrease of bacteria load from baseline (day 0) at days 2 and 8 in NPWT group (P < 0.05). In conclusion, this study demonstrates that NPWT of acute infected soft-tissue wounds leads to increased local IL-1β and IL-8 expression in early phase of inflammation, which may trigger accumulation of neutrophils and thus accelerate bacterial clearance. Meanwhile, the success of NPWT in the treatment of acute wounds can attenuate the expression of TNF-α, and the result may partly explain how NPWT can avoid significantly impairing wound healing.
临床研究发现，负压伤口治疗（NPWT）在感染伤口愈合方面显示出显著的临床益处。然而，NPWT对急性感染性软组织伤口局部炎症反应的影响尚未得到充分研究。本研究的目的是测试NPWT对急性感染性软组织伤口局部促炎细胞因子表达、中性粒细胞数量和伤口细菌生物负荷的影响。在兔背部制造全层伤口，并接种金黄色葡萄球菌ATCC29213菌株。伤口分别用无菌盐水湿润的纱布敷料和持续负压（-125 mmHg）的NPWT进行处理。在第0天（细菌接种后6小时）、第2、4、6和8天，在冲洗伤口床中心之前采集伤口样本，用于实时PCR分析IL-1β、IL-8和TNF-α的基因表达。对伤口活检组织进行组织学检查，以量化不同组织层中的中性粒细胞。同时分析相同时间点的定量细菌培养物以确定细菌清除情况。在8天的时间里，将NPWT应用于兔急性感染伤口，并与用无菌盐水湿润的纱布治疗进行比较。NPWT治疗的伤口在早期4天内IL-1β和IL-8表达出现更早、更高的峰值，而TNF-α表达下降（P < 0.05）。此外，组织学检查显示，在第2天NPWT治疗的伤口活检浅层中观察到中性粒细胞计数显著增加（P < 0.001）。此外，NPWT组在第2天和第8天的细菌负荷较基线（第0天）有统计学意义的下降（P < 0.05）。总之，本研究表明，急性感染性软组织伤口的NPWT导致炎症早期局部IL-1β和IL-8表达增加，这可能引发中性粒细胞的积聚，从而加速细菌清除。同时，NPWT在急性伤口治疗中的成功可减弱TNF-α的表达，这一结果可能部分解释了NPWT如何避免对伤口愈合造成显著损害。
