Abstract:
Objective To investigate the effects of trehalose gel on full-thickness skin defect wounds in rats and scar hyperplasia in rabbit ears. Methods The study was an experimental study. The trehalose gel and carbomer gel were prepared, their appearance after irradiation sterilization, and their physicochemical characterization such as viscosity, film forming rate, bacteria resistance rate, heavy metal content, moisture retention rate, water vapor permeability, sterility, and biocompatibility such as cytotoxicity, intradermal irritation, and sensitization were observed. Thirty male Sprague-Dawley rats aged 8-10 weeks were divided into experimental group, positive control group, and negative control group using a random number table method, with 10 rats in each group. The full-thickness skin defect wound models were prepared on the back of rats in negative control group, positive control group, and experimental group, and were treated with routine dressing change, carbomer gel dressing change, and trehalose gel dressing change, respectively. The wound healing rates on 6 and 12 days after injury and the wound healing time were recorded. On 6 days after injury, the number of autophagosomes and autophagolysosomes in rat wound tissue was detected using transmission electron microscopy. The content of microtubule associated protein light chain 3Ⅰ (LC3Ⅰ) and LC3Ⅱ in rat wound tissue was detected using enzyme-linked immunosorbent assay method and their ratio was calculated. The proportion of type Ⅰ and Ⅲ collagens and their ratio, as well as the total collagen proportion in rat wound tissue were detected using sirius red picric acid staining method. The number of samples in the aforementioned experiments was all 5. Three male New Zealand albino model rabbits aged 3-4 months were taken, and 3 wounds deep to the perichondrium were created on each of the rabbit ears, with six wounds in each group and being grouped and treated as mentioned above. On 30 days after wound healing, the scar tissue of the rabbit ear was observed and evaluated using the Vancouver scar scale. The thickness of the epidermis and dermis in the scar tissue of the rabbit ear was measured using hematoxylin eosin staining, and the proportion of type Ⅰ and Ⅲ collagens and their ratio, as well as the total collagen proportion and arrangement in the scar tissue of the rabbit ear were measured using sirius red picric acid staining method. The number of samples was 6. Results The irradiated trehalose gel and carbomer gel were light yellow and transparent, without odor and impurities. The viscosity, film forming rate, bacteria resistance rate, and moisture retention rate of trehalose gel were significantly better than that of carbomer gel (with t values of 4.13, 3.50, 4.03, and 5.80, respectively, P<0.05), but the water vapor permeability was significantly lower than that of carbomer gel (t=-4.14, P<0.05). No heavy metals or bacteria were detected in any gel. Both of the two gel had no cytotoxicity, and the intradermal irritation and sensitization were negative. On 6 and 12 days after injury, the wound healing rates of rats in positive control group were significantly higher than that in negative control group (with t values of -6.82 and -4.58, respectively, P<0.05); the wound healing rate of rats in experimental group was significantly higher than those in positive control group (with t values of -8.90 and -4.25, respectively, P<0.05) and negative control group (with t values of -8.78 and -4.25, respectively, P<0.05). The wound healing time ((20.4±2.5), (23.4±2.5) d) of rats in positive control group and experimental group was significantly shorter than (27.0±2.1) d in negative control group (with t values of 2.45 and -4.49, respectively, P<0.05). On 6 days after injury, the number of autophagosomes and autophagolysosomes in wound tissue in experimental group of rats were significantly higher than those in positive control group (with t values of 7.37 and 9.33, respectively, P<0.05) and negative control group (with t values of -7.06 and -8.54, respectively, P<0.05). On 6 days after injury, the content of LC3 Ⅱ and LC3 Ⅱ/LC3 Ⅰ in wound tissue in positive control group of rats were significantly higher than that in negative control group (with t values of -4.48 and -2.47, respectively, P<0.05); the content of LC3Ⅰ and LC3 Ⅱ/LC3 Ⅰ in wound tissue in experimental group of rats were significantly higher than those in negative control group (with t values of 11.98 and 6.04, respectively, P<0.05) and positive control group (with t values of -6.64 and -4.17, respectively, P<0.05), the content of LC3Ⅰ was significantly lower than that in negative control group (t=2.33, P<0.05). On 6 days after injury, the proportions of total collagen and type Ⅰ collagen in wound tissue of rats in the three groups were similar, P>0.05. On 6 days after injury, the proportion of type Ⅲ collagen in wound tissue of rats in positive control group was significantly higher than that in negative control group (t=-3.19, P<0.05), and the type Ⅰ collagen/type Ⅲ collagen was significantly lower than that in negative control group (t=2.18, P<0.05); the proportion of type Ⅲ collagen in the wound tissue of rats in experimental group was significantly higher than those in negative control group and positive control group (with t values of -2.38 and 5.91, respectively, P<0.05), and type Ⅰ collagen/type Ⅲ collagen was significantly lower than those in negative control group and positive control group (with t values of 3.08 and -4.35, respectively, P<0.05). On 30 days after wound healing, it was observed that the rabbit ear scar proliferation in positive control group was similar to that in negative control group, while the rabbit ear scar proliferation in experimental group was significantly reduced. On 30 days after wound healing, the color, blood vessels, thickness, hardness score, and total score of rabbit ear scars in experimental group were significantly lower than those in positive control group (with t values of 3.80, 3.80, 2.39, 2.71, and 4.84, respectively, P<0.05) and negative control group (with t values of -3.81, -4.78, 0.04, -2.71, and -5.14, respectively, P<0.05). On 30 days after wound healing, there was no significant difference in the epidermal thickness of rabbit ear scar tissue among experimental group, negative control group, and positive control group (P>0.05); the dermal thickness of rabbit ear scar tissue in positive control group was significantly smaller than that in negative control group (t=5.42, P<0.05), while the dermal thickness of rabbit ear scar tissue in experimental group was significantly smaller than those in negative control group and positive control group (with t values of 11.91 and 8.49, respectively, P<0.05). On 30 days after wound healing, the collagen protein arrangement of scar tissue of rabbits in the three groups was disordered, and the total collagen proportion was similar (P>0.05). The proportion of type Ⅰ collagen of scar tissue in experimental group was significantly lower than that in positive control group (t=3.00, P<0.05), the content of type Ⅲ collagen was significantly higher than those in negative control group and positive control group (with t values of -4.46 and 4.05, respectively, P<0.05), and the type Ⅰcollagen/type Ⅲ collagen was significantly lower than those in negative control group and positive control group (with t values of 8.50 and -5.25, respectively, P<0.05). Conclusions Compared with carbomer gel, trehalose gel has a more suitable physicochemical characterization for wound healing, and has good biocompatibility. It can promote the wound healing of full-thickness defects in rats and reduce scar hyperplasia in rabbit ears based on autophagy activation.
Jin J,Chu YG.Effects of trehalose gel on full-thickness skin defect wounds in rats and scar hyperplasia in rabbit ears[J].Chin J Burns Wounds,2024,40(7):679-688.DOI: 10.3760/cma.j.cn501225-20240118-00020.