To observe the effect of xenotransplantation of GGTA1/β4GalNT2 double-gene knockout inbred line Wuzhishan miniature pig skin preserved in liquid nitrogen.

Cryopreserved double-gene knockout pig split skin and commercially gene transfected pig skin were used. The double-gene knockout pig skin was preserved by vitrification method, and the skin was thawed when used for xenotransplantation. The receptor were rhesus monkey, which were divided into experimental group and control group, with 4 animals in each group, and four pieces of 4 cm×4 cm skin were removed on each monkey′s back, forming a full-thickness skin excision model. Cryopreserved double-gene knockout pig skin and gene transfected pigs kin were transplanted respectively. The survival of the skin was observed at different time points after the operation, and the vitality of the skin was evaluated by color, texture, etc. And samples were taken for pathological examination. Serum was taken before operation and on the 4th, 7th, 10th, 14th and 21st days after operation to detect IL-2, IL-4, IFN-γ, and IL-12 content.

The survival time of pig skin in the experimental group was [10-21(14.5±3.4)d], significantly longer than [7-14(10.6±2.7)d] in the control group (t=3.272, P=0.004). The skin grafts of both groups survived well on the 4th day after operation. On the 7th day after operation, there were small blisters on 2 skin grafts in the experimental group, and big blisters on 6 skin grafts in the control group. On the 10th day after operation, 5 skin grafts in the experimental group were completely torn off, 6 and 4 skin grafts were still warm and soft in the experimental and control group respectively. On the 12th day after operation, 3 and 1 skin grafts in the experimental group and the control group were still warm and soft. On the 14th day after operation, one skin graft in the experimental group remained warm and soft, while all skin grafts lost viablity in the control group. Pathological observation showed that the histological morphology of the skin grafts in both groups were normal on the 4th day after operation. On the 7th day after operation, the structure of skin epidermal cells in the experimental group was complete, while the number of epidermal cells in the control group was reduced. In a part of the skin grafts in both groups, engraft could be seen between the skin and wound bed. On the 10th day after operation, the number of epidermal cells in the experimental group decreased, and the interface between epidermis and dermis was partially separated, while the number of epidermal cells in the control group was further reduced compared with before, and the phenomenon of engraft still existed. On the 14th day after operation, the number of epidermal cells was significantly reduced and the phenomenon of engraft still existed in the experimental group. While infiltration of inflammatory cells in the wound bed could be seen in the control group. Serum IL-2 and IL-4 levels on the 10th day after operation, serum IFN-γ before operation and on the 4th day after operation, and the IFN-γ/IL-4 on the 14th day after operation in the experimental group were higher than those in the control group.

Cryopreserved GGTA1/β4GalNT2 double-gene knockout inbred line Wuzhishan miniature pig skin survives well after transplantation, and can obtain a relatively long survival time.

To investigate the effects of hot and humid environments (HHE) exposure with different time on the recovery of mice suffered from radiation injury combined with skin-wound trauma (R-W-CI) by evaluating survival rate, hematopoietic injury recovery and cutaneous wound healing.

The parameters of the HHE simulation experiment module were set as 36 ℃±0.5 ℃ in temperature and 70%±5% in relative humidity, which were confirmed by detecting rectal temperature after mice were put in the module. The animal model of severe hematopoietic acute radiation sickness was established by mice with 6.0 Gy ⁶⁰Co γ-rays whole body irradiation. The animal model of severe R-W-CI was established with mice exposed to ⁶⁰Co γ-rays (6.0 Gy) followed by a 2.0% total-body-surface-area wounds within 1 h after irradiation. Mice from both models were set into HHE for 1 h before irradiation and transferred to one portable HHE simulation chamber during transportation and irradiation. The injured mice were continued to be put into HHE module for another 1.0 h or 7.0 h followed by maintaining conventional ambient temperature and humidity conditions. For hematopoietic acute radiation sickness model, the mice were divided into four groups: normal control (NC group), radiation injury (R group), radiation injury exposed to HHE for 1.0 h(R+ HHE1.0 h group), radiation injury exposed to HHE for 7.0 h(R+ HHE7.0 h group). Indexes including rectal temperature, survival rate, body weight and complete blood count were measured to estimate the effects of different HHE exposure time on the recovery of radiation injury. For R-W-CI model, routine fluid supplement and wound bandaging or levofloxacin (LEV) were implemented as routine supportive treatments. The mice were divided into seven groups: normal control(NC group), combined radiation-trauma injury (R-W-CI group), combined radiation-trauma injury treated with levofloxacin (R-W-CI+ LEV group), combined radiation-trauma injury exposed to HHE for 1.0 h(R-W-CI+ HHE 1.0 h group), combined radiation-trauma injury exposed to HHE for 7.0 h(R-W-CI+ HHE 7.0 h group), combined radiation-trauma injury exposed to HHE for 1.0 h and treated with levofloxacin (R-W-CI+ HHE 1.0 h+ LEV group), combined radiation-trauma injury exposed to HHE for 7.0 h and treated with levofloxacin (R-W-CI+ HHE 7.0 h+ LEV group). The HHE exposure effects on mice suffered from R-W-CI were evaluated by detecting survival rate, body weight, complete blood count and wound healing. In addition, the effects of antibacterial therapy with LEV in R-W-CI models were also evaluated.

The simulation experiment module conducted the HHE with well effects, confirmed by significant increased rectal temperature of mice after put into the module. In model of severe hematopoietic acute radiation sickness, HHE exposure for 1.0 h and 7.0 h impacted body weight recovery but had no effect on survival rate. For R-W-CI model, in the absence of LEV treatment, survival rate in R-W-CI+ HHE 1.0 h group was significantly higher than that in R-W-CI group (χ²=5.496, P=0.019). LEV treatment could significantly increase the survival rate in both R-W-CI+ LEV group and R-W-CI+ HHE 1.0 h+ LEV group, but not in R-W-CI+ HHE 7.0 h+ LEV group. 28 days after injury, the recovery of white blood cells in R-W-CI+ HHE 1.0 h+ LEV group was significantly better than that in R-W-CI+ LEV group (F=6.549, P=0.021) and R-W-CI+ HHE 7.0 h+ LEV group (F=11.901, P=0.05). The wound healing in R-W-CI+ HHE 7.0 h+ LEV group was significantly delayed, while the wound healing in R-W-CI+ HHE 1.0 h+ LEV group was significantly accelerated.

Long-term (7.0 h) exposure to HHE after R-W-CI was detrimental, while short-term (1.0 h) exposure to HHE was beneficial to recovery of severe R-W-CI. The antibiotic therapy is important supportive treatment for R-W-CI exposed to HHE.

To modify the existing liquid dressing with pH dependence, verify its effectiveness through animal experiments.

Measured the pH of normal skin, clean wounds, and infected wounds as the theoretical basis for pH dependent film formation. On the basis of existing commercialized liquid dressings, a new type of pH dependent film-forming liquid dressing was prepared by adding different concentrations of carbopol. The moldability was tested in vitro under different pH conditions. Based on the pH of the wound, a carbopol concentration that could form a film on the wound but couldn′t form a film on normal skin was selected to prepare a pH dependent film-forming liquid dressing. Detectd the biocompatibility (cytotoxicity, sensitization, intradermal stimulation) and physical barrier effect (moisturizing properties, antibacterial properties) of the liquid dressing. The effectiveness of the liquid dressing in vivo was detected though the full thickness skin defect wound model in SD rats.

The pH of normal skin was 5.90±0.25, which was significantly lower than 6.54±0.36 of clean wounds and 7.54±0.35 of infected wounds (t=-3.32, P=0.011; t=8.61, P<0.001). The pH of clean wounds was also significantly lower than that of infected wounds (t=-4.44, P=0.002). Configured agar plates with pH values of 6, 7, and 8, applied liquid dressings. Complete film formation could be achieved at pH values of 7 and 8, but sheet-like film couldn′t be formed at pH values of 6. The cytotoxicity of the liquid dressings was level 1, with no potential cytotoxicity. No sensitization and irritation during intradermal implantation was found in the liquid dressings. Adjusted the pH of the liquid dressing to 6, 7, and 8. When the pH was 6, it didn′t have moisturizing and antibacterial properties. When the pH was 7 and 8, the moisture retaining rate was (4.76±2.04)% and (7.58±1.62)%, respectively, and the antibacterial rate was (33.17±5.59)% and (45.36±7.57)%, respectively. Animal experiments showed that compared to liquid dressings without film forming properties, the wound healing rate on the 10th day after modeling significantly increased[(69.02±3.39)% vs (75.34±3.64)%, t=2.84, P=0.022], and the wound healing time significantly reducted [(23.60±0.89)d vs (20.40±2.61)d, t=2.60, P=0.032] .

By adjusting the concentration of carbopol, pH dependent film-forming liquid dressings can be made, which form a film on the wound surface without affecting normal skin, promote wound healing, and improve comfort level.

To discuss the clinical efficacy of sodium carboxyl-methyl-cellulose dressings (CMC-Na) combined with vacuum sealing drainage (VSD) in the treatment of diabetic foot ulcer.

A total of 120 patients with diabetic foot admitted to Department of Endocrinology and Metabolism, Affiliated Hospital of Weifang Medical University from October 1, 2020 to December 31, 2021 were selected. The patients were divided into control group, CMC-Na group, and CMC-Na combined with VSD group according to different treatment plans, with 40 cases in each group. On the basis of conventional hypoglycemia and anti-infection, the control group was treated with Huangbai liquid rinsing and saline gauze dressing, the CMC-Na group was treated with CMC-Na on the basis of the control group, and the CMC-Na combined with VSD group was treated with CMC-Na combined with VSD on the basis of the control group. At 1 week, 2 weeks and 4 weeks of treatment, the reduction rate of diabetes foot ulcer wound, changes in sinus depth, curative effect and patient satisfaction were compared among the three groups.

(1)Ulcer wound reduction rate: all three groups showed an increasing trend of ulcer wound reduction rate with the extension of the treatment time (F=203.588, 582.072, 606.211; P<0.05). At 1 week and 2 weeks of treatment, the CMC-Na combined with VSD group was superior to the control group, and the difference was statistically significant (t=6.920, 23.086; P<0.05), but there was no difference between the CMC-Na combined with VSD group and the CMC-Na group (t=3.064, 14.305; P>0.05). At 4 weeks of treatment, the CMC-Na combined with VSD group was significantly better than the control group and the CMC-Na group, and the difference was statistically significant (t=-7.038, -4.999; P<0.05). (2)Changes in sinus depth: all three groups showed a decreasing trend in sinus depth with the extension of treatment time (F=7.888, 4.197, 12.388; P<0.05). The CMC-Na combined with VSD group was significantly better than the control group, and the difference was statistically significant (t=-2.293, -2.958, -3.289; P<0.05). Compared with the CMC-Na group, the sinus depth was smaller in the CMC-Na combined with VSD group, but the difference was not statistically significant (t=-0.241, -1.166, -1.162, P>0.05). (3)Total effective rate: total effective rate of the three groups were 75.0%, 92.5% and 97.5% respectively, the difference was statistically significant (χ²=10.836, P<0.05). (4)Satisfaction: The satisfaction in the three groups was 45.0%, 82.5%, 95.0% respectively, the difference was statistically significant (χ²=8.683, P<0.05).

Treatment of diabetes foot ulcer with combination of CMC-Na and VSD can significantly promote wound healing, improve patient satisfaction.

To investigate the effects of kunzea ericoides leaf extract on human dermal fibroblasts (HDFs) concerning the migration, proliferation, and collagen synthesis ability and to observe the impact of kunzea ericoides leaf extract on wound healing in rats.

After stimulation of kunzea ericoides leaf extract in different concentrations, assays of CCK-8 and Calcein/PI staining were applied to screen the optimal concentration of kunzea ericoides leaf extract on HDFs. The expression of Ki67 was detected to observe the proliferation ability of HDFs. Wound-healing assay was applied to detect the migration ability of HDFs after incubation with kunzea ericoides leaf extract. The expressions of typeⅠcollagen, type Ⅲ collagen, and α-smooth muscle actin were detected using the immunofluorescence and western blot assay, representing the collagen synthesis ability change of HDFs. The models of rat skin defect were established and treated with or without kunzea ericoides leaf extract, and the healing time was compared. Furthermore, the wound area tissue's morphology and collagen composition were observed using HE and Masson staining assays after complete healing.

The optimal concentration of kunzea ericoides leaf extract for HDFs was determined as 1% based on CCK-8 assay and Calcein/PI staining. In addition, the Ki67 expression was increased significantly [(0.71±0.16) vs (0.18±0.06), t=7.156, P<0.001], kunzea ericoides leaf extract enhanced the cell proliferation. The wound-healing assay confirmed that kunzea ericoides leaf extract improved the migration ability of HDFs. The results of the immunofluorescence and western blot assay showed that kunzea ericoides leaf extract increased the expressions of typeⅠcollagen, type Ⅲ collagen, and α-smooth muscle actin in HDFs [(43.22±7.58) vs (16.71±1.68), t=7.635, P<0.001; (46.62±5.90) vs (27.44±1.60), t=7.016, P<0.01; (1.32±0.14) vs (0.46±0.06), t=9.947, P<0.01], which meant kunzea ericoides leaf extract improved the collagen synthesis ability of HDFs. The healing time in the kunzea ericoides leaf extract group was (13.6±1.5)d, significantly shorter than (16.7±1.6)d of the control group (t=6.270, P<0.001). The results of HE and Masson staining suggested that after applying kunzea ericoides leaf extract, the skin tissue from the wound area resembled normal skin morphology and demonstrated more collagen deposition [(84.36±7.82) vs (67.72±5.24), t=5.595, P<0.001].

Kunzea ericoides leaf extract can promote the proliferation, migration, and collagen synthesis ability of HDFs, and might promote wound healing in rats by enhancing the function of dermal fibroblasts.

To investigate the clinical effect of flap combined with vacuum sealing drainage, lavage and drainage in the treatment of plate exposure after internal fixation of tibial fracture.

From January 2012 to June 2022, 12 patients with tibial fracture and postoperative plate exposure were treated with surgical debridement combined with vacuum sealing drainage, continuous lavage and drainage in Department of Cosmetic Burn and Plastic Surgery, the People′s Hospital of Leshan and in Department of Burn Plastic Surgery, Sichuan Provincial Corps Hospital of Armed Police, and appropriate type of flap repairment (muscle, myocutaneous or axial pattern skin flap) in accordance with wound condition. Regular postoperative follow-up were conducted, along with regular X-ray review. Removed the internal fixation after clinical fracture healing.

All 12 patients had viable flaps (muscle, myocutaneous and axial pattern skin flap), closed wounds and controlled infection condition. All patients were followed up for 4-18 months. The plates were retained during the whole treatment duration until the fracture healed with full functional recovery.

In patients with exposed plates after internal fixation of tibial fractures, the combination treatment method of flap with vacuum sealing drainage, continuous lavage and drainage has advantages in retaining the internal fixation during the fracture healing, leading to wound repairment and full functional recovery at the same time.

To analyze the clinical effect of low dose insulin local injection for survival of adipose derived stem cells (ADSCs) and transplanted flap and diabetic chronic refractory wound healing.

A total of 110 diabetic patients with chronic ulcer difficult healing wounds from June 2017 to January 2019 were enrolled and divided randomly into blank group, control group, low dose group (0.5 U insulin), medium dose group (1.0 U insulin) and high dose group (2.0 U insulin), each group of 22 cases. The patients all got free skin flap transplantation and local injection of ADSCs for four weeks. Compared wound healing degree, survival rate of skin flaps and blood flow of wound, expressions of HSP-90, VEGF, TGF-β and IL-1 in healing-unhealed interface tissue detected by ELISA, microvessel number detected by CD31 immunohistochemistry and blood sugar level measured by glucose oxidase method among the groups after two and four weeks.

The wound healing degree, survival rate of skin flaps and blood flow of wound after two and four weeks in low dose group were all significantly higher than the other groups, expressions of HSP-90, VEGF, TGF-β and IL-1 were higher, and microvessel number were more than the other groups(P<0.05). While there was no significant difference in blood sugar level among the groups (P>0.05).

It can greatly promote survival of ADSCs and transplanted flap, improve quality of wound healing in diabetic chronic refractory wound with low dose insulin local injection, which may be related to higher expressions of HSP-90, VEGF, TGF-β, IL-1 and microvessel number, without influence of blood sugar, and has better safety and efficacy.

To explore the effect of comprehensive nursing intervention in the perioperative period of pediatric free flap transplantation.

In the Department of Burns and Skin Surgery, the First Affiliated Hospital of Air Force Military Medical University, from January 2019 to January 2020, 48 children who underwent free flap repair surgery for lower limb skin defects were selected as the routine nursing group. From February 2020 to February 2021, 48 children who underwent free flap repair surgery for lower limb skin defects were assigned to the comprehensive nursing intervention group. The routine nursing group received routine nursing measures during the perioperative period, while the comprehensive nursing intervention group clarified nursing goals based on preoperative and postoperative emotions, intraoperative insulation measures, postoperative limb placement, and blood flow observation of the patients, and implemented comprehensive nursing interventions.

The incidence of complications in the comprehensive nursing intervention group was significantly lower than that in the routine nursing group (4.2% vs 16.7%, P<0.05). The survival rate of the flap in the comprehensive nursing intervention group was better than that in the routine nursing group (97.9% vs 89.5%, P<0.05). The compliance scores of children and caregivers in the comprehensive nursing intervention group were higher than those in the routine nursing group [(34.02±2.75) vs (28.22±1.64), t=5.761, P<0.05; (34.65±4.20) vs (29.37±3.28), t=5.524, P<0.05]. The facial expression grading scores of the comprehensive nursing intervention group at 24 hours and 3 days after surgery were lower than those of the routine nursing group [(2.41±0.23) vs (3.26±0.19), t=19.580, P<0.05; (1.78±0.11) vs (2.74±0.18), t=30.482, P<0.05]. The comprehensive nursing intervention group had lower scores on the anxiety self-assessment scale at 24 hours and 3 days after surgery than the routine nursing group [(55.87±1.73) vs (61.98±2.01), t=15.841, P<0.05; (45.89±2.50) vs (56.78±1.68), t=24.911, P<0.05].

Comprehensive nursing intervention can reduce the incidence of perioperative complications in pediatric free flap transplantation, increase flap survival rate, improve clinical prognosis, and promote postoperative recovery.

To compare the efficacy of meshed skin grafting and ReCell epidermal cell transplantation in the treatment of deep partial-thickness burns.

A tatal of 40 patients with deep partial-thickness burns who were admitted to the Department of Burns at Beijing Jishuitan Hospital, Capital Medical University from January 2019 to January 2022 and met the inclusion criteria were randomly divided into a study group and a control group. The study group received treatment with ReCell epidermal cell transplantation, while the control group received treatment with meshed skin grafting (1∶2). Postoperative wound observation and evaluation were performed at regular intervals and photographs were taken. The healing time, donor site area, operation time, postoperative pain, and postoperative scar formation were compared between the two groups. Data were analyzed using t test and χ² or Fisher test.

This study included 20 patients in the ReCell epidermal cell transplantation group and 20 patients in the meshed skin graft group. There was no statistically significant difference between the two groups in baseline characteristics such as age, gender, and burn area.The healing time was (15.3±2.3)d in the study group and (18.5±3.5)d in the control group, and there was a significant difference between the two groups (P<0.05). For the same repaired 100 cm² wound, the donor site area was (1.8±0.2)cm² in the study group and (48.3±2.9) cm² in the control group. The average operation time was (45.3±6.3)min in the study group and (50.4±9.9)min in the control group, and there was no significant difference between the two groups. Postoperative pain: on postoperative day 1, 3, and 7, the pain index of the study group was significantly lower than that of the control group (P<0.05). Postoperative scar formation: in the follow-up at 3, 6, 9, and 12 months after surgery, the scar score of the study group was significantly lower than that of the control group (P<0.05), especially at 9 and 12 months after surgery.

ReCell epidermal cell transplantation has a shorter healing time, smaller donor site area, less postoperative pain and scar formation compared to meshed skin grafting in the treatment of deep partial-thickness burns, and there is no significant difference in operation time. ReCell epidermal cell transplantation is an effective treatment for deep partial-thickness burns, which can improve the therapeutic effect.