Development of a wound epithelialization healing model: reducing the impact of contraction healing on the wound surface.

Animal experiments are important in trauma-related studies because they simulate in vivo effects. Rodents are a good choice for preparing trauma models; however, contractile healing in rodents results in a healing pattern that differs considerably from that in humans. Therefore, this study developed a new rodent model that avoids contractile healing of the skin around the wound using an anti-contraction ring, and the skin in the wound's center remains intact and acts as a source for epithelialized diffusion healing. Cell proliferation, migration, revascularization, and collagen secretion did not differ between the novel and conventional full-skin defect trauma models. However, the healing rate at various stages significantly differed between the two groups owing to differences in the healing patterns. And without effective treatment, the experimental group cannot heal. The stabilities of the novel and conventional methods were good regardless of operator or batch. In summary, this new animal trauma model provides a stable experimental environment similar to that in humans, which may promote trauma-related research.

Trehalose promotes functional recovery of keratinocytes under oxidative stress and wound healing via ATG5/ATG7.

Wounds are in a stressed state, which precludes healing. Trehalose is a stress metabolite that protects cells under stress. Here, we explored whether trehalose reduces stress-induced wound tissue damage. A stress model was prepared by exposing human keratinocytes to hydrogen peroxide (H2O2), followed by trehalose treatment. Trehalose effects on expression of the autophagy-related proteins ATG5 and ATG7 and cell proliferation and migration were evaluated. For in vivo verification, a wound model was established in Sprague-Dawley rats, to measure the effects of trehalose wound-healing rate and reactive oxygen species (ROS) content. Histological changes during wound healing and trehalose's effects on ATG5 and ATG7 expression, necrosis, and apoptosis were examined·H2O2 stress increased ATG5 and ATG7 expression in vitro, but this was insufficient to prevent stress-induced damage. Trehalose further increased ATG5/ATG7 levels, which restored proliferation and increased migration by depolymerizing the cytoskeleton. However, trehalose did not exert these effects after ATG5 and ATG7 knockout. In vivo, the ROS content was higher in the wound tissue than in normal skin. Trehalose increased ATG5/ATG7 expression in wound tissue keratinocytes, reduced necrosis, depolymerized the cytoskeleton, and promoted cell migration, thereby promoting wound healing.

Therapeutic effect of concentrated growth factor preparation on skin photoaging in a mouse model.

OBJECTIVE: To establish a nude mouse model of photoaging and study the therapeutic effect of a concentrated growth factor preparation (CGF) on skin photoaging. METHODS: CGF was prepared from blood from Sprague-Dawley rats. A skin photoaging nude mouse model was developed using UV irradiation combined with the photosensitizer, 8-methoxypsoralen. Mice were divided randomly into seven groups (n = 6 per group): normal control, photoaging, mock treatment, saline treatment, CGF treatment, Filoca 135HA treatment, and plasma skin regeneration system irradiation (the latter two were positive controls). Body weight and skin appearance were observed and pathological changes were determined by hematoxylin and eosin staining. Fiber elasticity was evaluated by Weigert staining. Expression levels of proliferating cell nuclear antigen (PCNA) and matrix metalloproteinase 1 (MMP1) were determined by immunohistochemistry. RESULTS: A mouse model with typical features of photoaging skin was successfully developed. CGF significantly improved the skin appearance, wrinkle scores, pathological changes, and fiber elasticity, and increased PCNA and decreased MMP1 expression levels in photoaging mice, comparable to the two positive controls. CONCLUSION: CGF can improve the symptoms of skin photoaging in mice, suggesting that it may have applications in the treatment of skin aging in humans.

Comparative effectiveness of different therapies for treating striae distensae: A systematic review and network meta-analysis.

BACKGROUND: Striae distensae (SD) are common and aesthetically undesirable dermal lesions. The aim of this study is to comprehensively evaluate the effectiveness of different therapies in treating striae distensae using network meta-analysis. METHODS: A systematic search of electronic databases up to December 1, 2019 was conducted. Randomized controlled trails (RCTs) examining the effectiveness of different methods in treating striae distensae were included. The primary outcomes are clinical effective rate and patient's satisfaction degree. Risk of bias was assessed by the Cochrane risk of bias tool. Network meta-analysis was based on Bayesian framework. RESULTS: Fourteen trails that met the criteria with 651 subjects were included. The results of the network meta-analysis show that topical tretinoin combined bipolar radiofrequency showed the highest probability of being the best method to improve the clinical effectiveness and patient satisfaction rate of treating SD (84.5% and 95.7% respectively), closely followed by bipolar radiofrequency (75.3% and 84.3% respectively). Among laser treatment, CO2 fractional laser is superior to other lasers in the clinical effectiveness and patient satisfaction (72.0% and 58.1% respectively). Statistics showed the topical tretinoin was the worst-performing option in improving the clinical effectiveness and patient satisfaction rate of SD treatment (5.4% and 5.1% respectively). CONCLUSION: Based on the results of network meta-analysis, we recommend treating striae distensae with bipolar radio frequency combined topical tretinoin. The commonly used CO2 fractional laser can be considered as alternative treatment candidate. Additional large-scale RCTs are necessary to obtain more precise estimates of their relative efficacy.

Modification and utility of a rat burn wound model.

This study aimed to improve the conventional rat burn wound model and to validate its utility. In total, 60 Sprague-Dawley rats were divided equally into the control and experimental groups. Altogether, 60 burn wound models with zones of stasis were created in each group. Gross visual assessments of the burn wounds were performed at 0, 24, and 48 hours after burn creation. The rates of necrosis in the zones of stasis were calculated, and the blood flow from the wounds was examined. Wound tissues were collected 48 hours after the burn and subjected to hematoxylin and eosin staining to determine whether the models were successfully established. The model success rates were calculated. The success rate of the burn wound models was significantly different between the control group and the experimental group (93.33% [56/60] vs 100%; P = .042). The Cronbach's alpha values and the respective correlation coefficients indicated that the stability of the zones of stasis in the models on the two sides of the spine was higher in the experimental group than in the control group. The standard deviations of the rate of necrosis, blood flow, and density of necrotic cells and apoptosis cell density, and inflammatory factor content in the zones of stasis were smaller in the experimental group than in the control group at 48 hours after model construction. This suggested that the stability of repeated procedures was higher in the experimental group than in the control group. The novel device for creating burns in animal models facilitated the effective creation of zones of stasis for rat burn wound models. Both the model success rate and stability were higher compared with the conventional model construction method. In addition, the use of the novel device can better align with the requirements of self-controlled studies.