[Effect of decellularized adipose tissue combined with vacuum sealing drainage on wound inflammation in pigs]

To preliminary explore the effect of decellularized adipose tissue (DAT) combined with vacuum sealing drainage (VSD) on wound inflammation in pigs.

The DAT was prepared through the process of freeze-thaw, enzymatic digestion, organic solvent extraction, and vacuum freeze-drying. The appearance of DAT was observed before and after freeze-drying. HE staining was used to observe its structure and acellular effect. Eighteen male Bama minipigs were recruited, and four dorsal skin soft tissue wounds in diameter of 4 cm were made on each pig and randomly divided into 4 groups for different treatments. The wounds were treated with DAT combined with VSD in DAT/VSD group, DAT in DAT group, VSD in VSD group, and sterile gauze dressing in control group. HE staining was performed at 3, 7, 10, and 14 days after treatment. Moreover, the expressions of inflammatory factors [interleukin 1β (IL-1β), IL-6, and tumor necrosis factor α (TNF-α)], as well as the phenotypes of M1 and M2 macrophage phenotypic markers [inducible nitric oxide synthase (iNOS) and arginase 1 (ARG-1)] were detected by real-time fluorescence quantitative PCR (qRT-PCR). ELISA was used to determine the content of iNOS and ARG-1.

General observation and HE staining showed that DAT obtained in this study had a loose porous structure without cells. The neutrophils of wounds were significantly less in DAT/VSD group than in control group and DAT group ( P<0.05) at 3 days after treatment, and the difference was not significant ( P>0.05) between DAT/VSD group and VSD group. And the neutrophils were significantly less in DAT/VSD group than in other three groups ( P<0.05) at 7, 10, and 14 days. The mRNA expressions of IL-1β, IL-6, TNF-α, and iNOS were significantly lower in DAT/VSD group than in other three groups at 3, 7, 10, and 14 days ( P<0.05), while the mRNA expression of ARG-1 was significantly higher in DAT/VSD group than in other three groups ( P<0.05). ELISA showed that the content of iNOS was significantly lower in DAT/VSD group than in other three groups at 3, 7, 10, and 14 days ( P<0.05), while the content of ARG-1 was significantly higher in DAT/VSD group than in other three groups ( P<0.05).

DAT combined with VSD can significantly reduce inflammatory cell infiltration during wound healing, regulate the expressions of inflammatory factors and macrophage phenotype, and the effect is better than single use of each and conventional dressing change.