Zhonghua Shao Shang Za Zhi. 2021 Nov 25;37:1-9. doi: 10.3760/cma.j.cn501120-20200927-00424. Online ahead of print.
ABSTRACT
Objective: To investigate the effects of temperature-sensitive hydroxybutyl chitosan hydrogel on wound healing of full-thickness skin defect in rats. Methods: The experimental research method was used. Fifty-one male and female Sprague-Dawley rats aged 7-10 weeks were selected, and two round full-thickness skin defect wounds with a diameter of 2 cm were made on the back of the rats at a distance of about 1.0 cm to the spine. The wounds were divided into temperature-sensitive hydrogel group, gel group, and blank control group, with 34 wounds in each group. Wounds in the first two groups were smeared with 0.3 mL temperature-sensitive hydroxybutyl chitosan hydrogel and carboxymethyl chitosan hydrogel, respectively immediately after injury, and the wounds in the blank control group were dealt with no treatment. The wounds in the three groups were all covered with vaseline gauze. The state of temperature-sensitive hydroxybutyl chitosan hydrogel and carboxymethyl chitosan hydrogel was observed every day when the dressing was changed, and the difficulty of removing vaseline oil gauze was recorded. On the 3rd, 7th, 10th, 14th, and 21st day after injury, the wound healing of the three groups was observed and the wound healing rate was calculated. On the 3rd, 7th, 10th, 14th, and 21st day after injury, 4 wounds of 2 rats in each group were collected for the following observation and detection. The inflammatory cell infiltration, angiogenesis, and re-epithelialization were observed by hematoxylin eosin staining. The regeneration and remodeling of collagen were observed by Masson staining, and the the collagen volume fraction was calculated.The expressions of interleukin-6 (IL-6), transforming growth factor β1 (TGF-β1), and matrix metalloproteinase-1 (MMP-1) were detected by enzyme-linked immunosorbent assay method. Data were statistically analyzed with analysis of variance for factorial design, one-way analysis of variance, and Bonferroni test. Results: Chitosan gel was liquid gel and could flow with the body position, while the temperature-sensitive hydroxybutyl chitosan hydrogel was solid gel and could not flow with the body position, and the distribution of the latter was more uniform. The vaseline gauze was easy to remove in wounds of temperature-sensitive hydrogel group, which was not easy to remove in the other two groups. On the 3rd, 7th, 10th, 14th, and 21st day after injury, the wound granulation tissue grew well in temperature-sensitive hydrogel group and gel group, with no obvious infection, and two rats in blank control group died of wound infection on the 3rd and 5th day after injury. On the 7th, 10th, 14th, and 21st day after injury, the wound healing rates in temperature-sensitive hydrogel group and gel group were significantly higher than that in blank control group (P<0.01). On the 10th day after injury, the wound healing rate in temperature-sensitive hydrogel group was significantly higher than that in gel group (P<0.05). A large number of neutrophils and lymphocytes infiltrated into the wounds in the three groups on the 3rd day after injury. The inflammatory cell infiltration was gradually reduced and the wound healed gradually in temperature-sensitive hydrogel group and gel group from the 7th to 21st day after injury, and the epidermis and dermis could be seen, without hair follicles and other skin appendages. The wounds in blank control group did not heal completely on 21st day after injury. From the 3rd to 10th day after injury, the number of newly formed collagen fibers increased gradually in the wounds of the three groups. On the 14th and 21st day after injury, the collagen fibers in the wounds of temperature-sensitive hydrogel group and gel group were denser and more orderly than those in blank control group. On the 10th, 14th, and 21st day after injury, the collagen volume fraction of wounds in temperature-sensitive hydrogel group and gel group was significantly higher than that in blank control group (P<0.01). On the 14th day after injury, the collagen volume fraction of wounds in temperature-sensitive hydrogel group was significantly higher than that in gel group (P<0.01). On the 3rd, 7th, and 10th day after injury, the expressions of IL-6 of wound in temperature-sensitive hydrogel group were significantly higher than those in gel group and blank control group (P<0.01), and the expressions of IL-6 of wound in gel group were significantly lower than those in blank control group (P<0.01). On the 3rd, 7th, and 10th day after injury, the expressions of TGF-β1 of wound in temperature-sensitive hydrogel group were significantly higher than those in gel group and blank control group (P<0.01). The expressions of TGF-β1 of wound in gel group were significantly lower than those in blank control group on the 3rd, 7th day after injury (P<0.01), and the expression of TGF-β1 of wound in gel group was significantly higher than that in blank control group on the 10th day after injury (P<0.01). On the 14th day after injury, the expression of TGF-β1 of wound in gel group was significantly higher than that in temperature-sensitive hydrogel group and control group (P<0.01). On the 21st day after injury, the expression of TGF-β1 of wound in temperature-sensitive hydrogel group was significantly lower than that in gel group and blank control group (P<0.01), and the expression of TGF-β1 of wound in gel group was significantly lower than that in blank control group (P<0.01). On the 7th day after injury, the expression of MMP-1 of wound in gel group was significantly higher than that in temperature-sensitive hydrogel group and blank control group (P<0.01). On the 10th, 14th, and 21st day after injury, the expressions of MMP-1 of wound in temperature-sensitive hydrogel group were significantly higher than those in hydrogel group and blank control group (P<0.01). On the 10th day after injury, the expression of MMP-1 of wound in hydrogel group was significantly lower than that in blank control group (P<0.01). On the 14th and 21st day after injury, the expressions of MMP-1 of wound in hydrogel group were significantly higher than those in blank control group (P<0.01). Conclusions: Temperature-sensitive hydroxybutyl chitosan hydrogel can promote the healing of full-thickness skin defect wounds in rats by increasing the expression of IL-6, TGF-β1, and MMP-1, regulating the wound healing environment, inhibiting inflammatory reaction, improving the strength of tissue repair, and promoting collagen synthesis and decomposition.
PMID:34839597 | DOI:10.3760/cma.j.cn501120-20200927-00424
