Homemade-device-induced negative pressure promotes wound healing more efficiently than VSD-induced positive pressure by regulating inflammation, proliferation and remodeling

Abstract

Vacuum sealing drainage (VSD) is an effective technique used to promote wound healing. However, recent studies have shown that it exerts positive pressure (PP) rather than negative pressure (NP) on skin. In this study, we created a homemade device that could maintain NP on the wound, and compared the therapeutic effects of VSD-induced PP to those of our homemade device which induced NP on wound healing. The NP induced by our device required less time for wound healing and decreased the wound area more efficiently than the PP induced by VSD. NP and PP both promoted the inflammatory response by upregulating neutrophil infiltration and interleukin (IL)‑1β expression, and downregulating IL‑10 expression. Higher levels of epidermal growth factor (EGF), transforming growth factor (TGF)‑β and platelet-derived growth factor (PDGF), and lower levels of basic fibroblast growth factor (bFGF) were observed in the wound tissue treated with NP compared to the wound tissue exposed to PP. Proliferation in the wound tissue exposed to NP on day 10 was significantly higher than that in wound tissue exposed to PP. NP generated more fibroblasts, keratinized stratified epithelium, and less epithelia with stemness than PP. The levels of ccollagen Ⅰ and Ⅲ were both decreased in both the NP and PP groups. NP induced a statistically significant increase in the expression of fibronectin (FN) on days 3 and 10 compared to PP. Furthermore, the level of matrix metalloproteinase (MMP)‑13 increased in the NP group, but decreased in the PP group on day 3. NP also induced a decrease in the levels of tissue inhibitor of metalloproteinase (TIMP)‑1 and TIMP‑2 during the early stages of wound healing, which was significantly different from the increasing effect of PP on TIMP‑1 and TIMP‑2 levels at the corresponding time points. On the whole, our data indicate that our homemade device which induced NP, was more efficient than VSD‑induced PP on wound healing by regulating inflammation, secretion, proliferation and the distribution of different cells in wound tissue.

Figures

Figure 1

Construction of homemade NP device. (A) Representative images of plaster-made mold of homemade NP device, including the bottom and upper part. (B) Representative images of medical silicon homemade device. (C) Representative images of the VSD device. (D) Treatment of animals with wounds with our homemade device. The wound was covered with our homemade device, and an infusion needle was punctured into the device cavity and connected to a portable suction pump. NP, negative pressure; VSD, vacuum sealing drainage.

Figure 2

NP promotes wound healing and reduces the wound proportion area more efficiently than PP. (A) Detection of pressure on skin that was induced by the homemade device on wound healing. (B) Detection of pressure on skin that was induced by the VSD. (C) Statistical analysis of the required time for wound healing in the different treatment groups. Data are presented as the means ± SEM, n=3. *P<0.05, compared with the control; ▲P<0.05, compared with NP. (D) Representative images of wound healing on days 0, 3, 7, and 10 in the different treatment groups. (E) Statistical analysis of the wound proportion area in the different treatment groups. Data are presented as the means ± SEM, n=3. **P<0.01, ***P<0.001, compared with the control; ▲▲▲P<0.001, compared with NP. NP, negative pressure; PP, positive pressure; VSD, vacuum sealing drainage.

Figure 3

Analysis of inflammatory and growth factor secretion in wound tissue in the NP and PP groups. (A) Representative images of H&E staining of inflammatory cells in wound tissues following pressure treatment on days 3, 7, 10, and 14. The upper lane indicates the control group, the middle lane indicates the NP group, and the lower lane indicates the PP group. (B) Statistical quantification of macrophage infiltration in wound tissue at different time points. (C) Statistical quantification of neutrophil infiltration in wound tissue at different time points. Statistical analysis of the mRNA expression of (D) IL-1β, (E) IL-10, (F) EGF, (G) TGF-β1, (H) IGF-1, (I) bFGF, (J) PDGF, (K) VEGF in wound tissue examined by qPCR. Data are presented as the means ± SEM, n=3 experiments. ***P<0.001, **P<0.01, *P<0.05, compared with the control. ▲▲▲P<0.001, ▲▲P<0.01, compared with NP. NP, negative pressure; PP, positive pressure.

Figure 4

Histological analysis of different cell markers in wound tissue in the different pressure treatment groups. Representative images of H&E staining and immunofluorescence staining in wound tissues following pressure treatment on days 3, 7, 10, and 14. Ki67, CD31, CD90, CD29, CK10, CK14, CK19, S-100A4, and Masson's staining were all used for histological analysis.

Figure 5

Statistical analysis of the histological results of different cell markers in wound tissue in the different pressure treatment groups. Statistical quantification of the IOD value of (A) Ki67, (B) CD31, (C) CD90, (D) CD29, (E) CK10, (F) CK14, (G) CK19, (H) S-100A4, (I) Masson's staining. Data are presented as the means ± SEM, n=3 experiments. ***P<0.001, **P<0.01, *P<0.05, compared with the control. ▲▲▲P<0.001, ▲▲P<0.01, compared with NP. IOD, integrated option density; NP, negative pressure.

Figure 6

NP and PP affect the generation of extracellular matrix components. (A) Representative images of dermal papilla structure in the different pressure treatment groups. (B) Protein expression of different matrix components in wound tissues treated with different pressure types. Different time points (day 3, 7, 10 and 14) were recorded. Statistical quantification of IOD value of (C) collagen I, (D) collagen III, (E) UgI-Y3 (FN), (F) MMP-13, (G) TIMP-1, (H) TIMP-2. Data are presented as the means ± SEM, n=3 experiments. ***P<0.001, **P<0.01, *P<0.05, compared with the control. ▲▲▲P<0.001, ▲▲P<0.01, compared with NP. NP, negative pressure; PP, positive pressure; IOD, integrated option density.