[Application of advanced biomaterials in wound repair].

Cutaneous wound healing is an extremely complex pathophysiological process. With the rapid development of material science and tissue engineering, the advanced biomaterials developed through multi-disciplinary integration are of multi-functions and effects, providing novel ideas, strategies, and methods for accelerating wound repair and improving the quality of wound repair, and even tissue regeneration. This paper summarized the application of various multi-functional advanced biomaterials in promoting wound repair.

[Pay attention to burn rehabilitation assessment].

With the vigorous development of burn rehabilitation, many burn units in China are paying more and more attention to the application of burn rehabilitation treatment methods in burn patients. However, the development of burn rehabilitation assessment cannot be ignored in the process of burn rehabilitation treatment. Burn rehabilitation assessment is characterized with a long assessment time span and a large and complex assessment contents, resulting in the inability to develop a standardized assessment form that is suitable for all burn patients. In addition, factors including the shortage of professionals in burn rehabilitation assessment in some domestic burn units, relatively small number of objective assessment instruments and various institutional limitations, have also led to insufficient motivation and low quality of burn rehabilitation assessment. Based on those, this article analyzes the characteristics and main contents of burn rehabilitation assessment in China, and puts forward some suggestions in view of the shortcomings of burn rehabilitation assessment, in order to provide a reference for burn rehabilitation practitioners.

[Strengthening the development and application of precision burn medicine].

In recent years, precision medicine in various clinical disciplines has made great progress. However, the progress and practice of precision medicine in burn surgery at present have lagged far behind other disciplines due to various reasons including the solidification of concepts and the lack of effective methods and equipment. This article briefly expound the necessities and possible strategies of strengthening the construction and promotion of precision burn medicine system from the aspects of accurate diagnosis of burn wound area and depth, precise treatment of burn wounds, precise monitoring diagnosis and treatment of burn complications and scars, and precise rehabilitation treatment. In order to rapidly promote the development of precision burn medicine in our country, it is hoped that burn medical staffs will pay much more attention to this field, especially to conceptual transformation, development of innovative strategies, tools, and equipment for precise diagnosis and treatment of burn wounds and complications.

[Research advances on venous thromboembolism in burn patients].

Venous thromboembolism (VTE) has become a serious medical problem faced by medical personnel all over the world, due to its high incidence, high fatality, and easily missed and misdiagnosed. Patients with severe burns are at high risk for VTE due to the presence of blood hypercoagulability, central venous catheterization, repeatedly received surgical procedures, and prolonged bed rest. Identifying the risk factors of VTE in burn patients and taking targeted preventive measures are the key to reduce the incidence of VTE. However, there are no risk assessment tools or prevention guidelines for VTE in burn patients at home and abroad, and scholars from various countries are actively exploring the occurrence, influencing factors, and prevention of VTE in burn patients. This paper reviews the research progress of the occurrence situation, related risk factors, risk assessment, and prevention of VTE in burn patients in recent years, and discusses the existing problems and future research directions in this field.

[Discussion on classification and diagnostic nomenclature of burn infection].

Infection is the most common complication after burn injury and one of the leading causes of death in burn patients. Thus, how to effectively prevent the occurrence and development of infection is an important task in treating burns. Till now, there are still many controversies in the clinical definition, diagnosis, and treatment of infection, especially burn infection. The authors of this article put forward their opinions and views on this subject, hoping to deepen the readers' understanding of burn infection.

[Paying more attention to burn induced coagulopathy].

Burn induced coagulopathy (BIC) is one of the common complications after burn injury. The types and clinical manifestations of BIC vary dramatically, which frequently leads serious consequences. However, at present BIC does not attract enough attention in clinic. In order to prevent and treat BIC more effectively, the authors suggest that it is necessary to strengthen coagulation surveillance, operation management, infection control, rational application of drugs, prevention and treatment of deep vein thrombosis, relative clinical and basic research, and others.

[Summary of the 14th Asia Pacific Burn Congress, the 18th Chinese Symposium on Burn Medicine, and the 2023 Huaxia Burn Forum].

The 14th Asia Pacific Burn Congress, the 18th Chinese Symposium on Burn Medicine, and the 2023 Huaxia Burn Forum was held successfully in Chongqing from September 13th to 16th, 2023. More than 1 000 participants from more than 10 countries and regions attended the congress, including over 100 overseas experts. The theme of the congress was homage, heritage, and innovation, and three-day academic exchange was held in the form of academician forum, keynote forum, and seven thematic sub-forums focused on the hot spots and difficulties in the fields of burns, trauma, wound repair, and related fields. The congress was compact, comprehensive, in-depth, and fruitful, with warm atmosphere at the meeting site.

[Role of functional hydrogel in promoting wound healing].

Cutaneous wounds are one of the commonest clinical diseases. At present, there are still many challenges in how to repair wounds quickly with high quality. With the rapid development and cross-integration of materials science and biomedicine, hydrogels that can integrate various excellent properties through flexible structural modification and combination of different functional components are widely applied in wound management and research. This paper attempted to summarize the role of hydrogel in promoting wound repair from the respects of matrix materials, special structures, and diverse functions of hydrogel.

[Effects of interleukin-4-modified gold nanozymes on the full-thickness skin defects in diabetic mice].

Objective: To investigate the effects and mechanism of interleukin-4-modified gold nanoparticle (IL-4-AuNP) on the wound healing of full-thickness skin defects in diabetic mice. Methods: Experimental research methods were adopted. Gold nanoparticle (AuNP) and IL-4-AuNP were synthesized by improving the methods described in published literature. The morphology of those two particles were photographed by transmission electron microscopy, and their particle sizes were calculated. The surface potential and hydration particle size of the two particles were detected by nanoparticle potentiometer and particle size analyzer, respectively. The clearance rate of IL-4-AuNP to hydrogen peroxide and superoxide anion was measured by hydrogen peroxide and superoxide anion kits, respectively. Mouse fibroblast line 3T3 cells were used and divided into the following groups by the random number table (the same below): blank control group, hydrogen peroxide alone group treated with hydrogen peroxide only, hydrogen peroxide+IL-4-AuNP group treated with IL-4-AuNP for 0.5 h and then treated with hydrogen peroxide. After 24 h of culture, the reactive oxygen species (ROS) levels of cells were detected by immunofluorescence method; cell count kit 8 was used to detect relative cell survival rate. The macrophage Raw264.7 mouse cells were then used and divided into blank control group and IL-4-AuNP group that treated with IL-4-AuNP. After 24 h of culture, the expression of arginase 1 (Arg-1) in cells was observed by immunofluorescence method. Twelve male BALB/c mice (mouse age, sex, and strain, the same below) aged 8 to 10 weeks were divided into IL-4-AuNP group and blank control group, treated accordingly. On the 16th day of treatment, whole blood samples were collected from mice for analysis of white blood cell count (WBC), red blood cell count (RBC), hemoglobin level, or platelet count and the level of aspartate aminotransferase (AST), alanine transaminase (ALT), urea, or creatinine. The inflammation, bleeding, or necrosis in the heart, liver, spleen, lung, and kidney tissue of mice were detected by hematoxylin-eosin (HE). Another 36 mice were selected to make diabetic model, and the full-thickness skin defect wounds were made on the back of these mice. The wounds were divided into blank control group, AuNP alone group, and IL-4-AuNP group, with 12 mice in each group, and treated accordingly. On the 0 (immediately), 4th, 9th, and 15th day of treatment, the wound condition was observed and the wound area was calculated. On the 9th day of treatment, HE staining was used to detect the length of neonatal epithelium and the thickness of granulation tissue in the wound. On the 15th day of treatment, immunofluorescence method was used to detect ROS level and the number of Arg-1 positive cells in the wound tissue. The number of samples was 6 in all cases. Data were statistically analyzed with independent sample t test, corrected t test, Tukey test, or Dunnett T3 test. Results: The size of prepared AuNP and IL-4-AuNP were uniform. The particle size, surface potential, and hydration particle size of AuNP and IL-4-AuNP were (13.0±2.1) and (13.9±2.5) nm, (-45.8±3.2) and (-20.3±2.2) mV, (14±3) and (16±4) nm, respectively. For IL-4-AuNP, the clearance rate to hydrogen peroxide and superoxide anion were (69±4)% and (52±5)%, respectively. After 24 h of culture, the ROS level of 3T3 in hydrogen peroxide alone group was significantly higher than that in blank control group (q=26.12, P<0.05); the ROS level of hydrogen peroxide+IL-4-AuNP group was significantly lower than that in hydrogen peroxide alone group (q=25.12, P<0.05) and close to that in blank control group (P>0.05). After 24 h of culture, the relative survival rate of 3T3 cells in hydrogen peroxide+IL-4-AuNP group was significantly higher than that in hydrogen peroxide alone group (t=51.44, P<0.05). After 24 h of culture, Arg-1 expression of Raw264.7 cells in IL-4-AuNP group was significantly higher than that in blank control group (t'=8.83, P<0.05).On the 16th day of treatment, there were no significant statistically differences in WBC, RBC, hemoglobin level, or platelet count and the level of AST, ALT, urea, or creatinine of mice between blank control group and IL-4-AuNP group (P>0.05). No obvious inflammation, bleeding or necrosis was observed in the heart, liver, spleen, lung, and kidney of important organs in IL-4-AuNP group, and no significant changes were observed compared with blank control group. On the 0 and 4th day of treatment, the wound area of diabetic mice in blank control group, AuNP alone group, and IL-4-AuNP group had no significant difference (P>0.05). On the 9th day of treatment, the wound areas both in AuNP alone group and IL-4-AuNP group were significantly smaller than that in blank control group (with q values of 9.45 and 14.87, respectively, P<0.05), the wound area in IL-4-AuNP group was significantly smaller than that in AuNP alone group (q=5.42, P<0.05). On the 15th day of treatment, the wound areas both in AuNP alone group and IL-4-AuNP group were significantly smaller than that in blank control group (with q values of 4.84 and 20.64, respectively, P<0.05), the wound area in IL-4-AuNP group was significantly smaller than that in AuNP alone group (q=15.80, P<0.05); moreover, inflammations such as redness and swelling were significantly reduced in IL-4-AuNP group compared with the other two groups. On the 9th day of treatment, compared with blank control group and AuNP alone group, the length of neonatal epithelium in the wound of diabetic mice in IL-4-AuNP group was significantly longer (all P<0.05), and the thickness of the granulation tissue in the wound was significantly increased (with q values of 11.33 and 9.65, respectively, all P<0.05). On the 15th day of treatment, compared with blank control group, ROS levels in wound tissue of diabetic mice in AuNP alone group and IL-4-AuNP group were significantly decreased (P<0.05). On the 15th day of treatment, the number of Arg-1 positive cells in the wounds of diabetic mice in IL-4-AuNP group was significantly more than that in blank control group and AuNP alone group, respectively (all P<0.05). Conclusions: IL-4-AuNP is safe in vivo, and can improve the oxidative microenvironment by removing ROS and induce macrophage polarization towards M2 phenotype, thus promote efficient diabetic wound healing and regeneration of full-thickness skin defects in diabetic mice.

[Influence of reactive oxygen species responsive self-assembled nanomicelle loaded with pyroptosis inhibitor on full-thickness skin defects in diabetic rats].

Objective: To investigate the influence of reactive oxygen species (ROS) responsive self-assembled nanomicelle loaded with pyroptosis inhibitor on full-thickness skin defects in diabetic rats. Methods: Experimental research methods were employed. A nucleotide-binding oligomerization domain (NOD) 1/2 inhibitor (NOD-IN-1) was encapsulated with nanomicelle polyethylene glycol-block-polypropylene sulfide (PEG-b-PPS), and the resulting product was called PEPS@NOD-IN-1. The morphology and hydration particle size of PEG-b-PPS and PEPS@NOD-IN-1 were observed by transmission electron microscope and particle size analyzer, respectively, and the encapsulation rate and drug loading rate of PEPS@NOD-IN-1 to NOD-IN-1 and the cumulative release rate of NOD-IN-1 by PEPS@NOD-IN-1 in phosphate buffer solution (PBS) alone and hydrogen peroxide-containing PBS within 40 h were measured and calculated by microplate reader, and the sample number was 3. Twenty-four male Sprague-Dawley rats aged 6-7 weeks were injected with streptozotocin to induce type 1 diabetes mellitus. Six full-thickness skin defect wounds were made on the back of each rat. The injured rats were divided into PBS group, NOD-IN-1 group, PEG-b-PPS group, and PEPS@NOD-IN-1 group with corresponding treatment according to the random number table, with 6 rats in each group. The wound healing was observed on post injury day (PID) 3, 7, and 12, and the wound healing rate was calculated. The ROS levels in wound tissue were detected by immunofluorescence method on PID 3. On PID 7, the granulation tissue thickness in wound was assessed by hematoxylin-eosin staining, the mRNA expressions of NOD1 and NOD2 were detected by real-time fluorescence quantitative reverse transcription polymerase chain reaction, and the protein expressions of NOD1, NOD2, and GSDMD-N terminals were detected by Western blotting. Six wounds from different rats in each group were taken for detection of the above indicators. Wound tissue (3 samples per group) was taken from rats in PBS group and PEPS@NOD-IN-1 group on PID 7, and transcriptome sequencing was performed using high-throughput sequencing technology platform. Differentially expressed genes (DEGs) significantly down-regulated in PEPS@NOD-IN-1 group as compared with PBS group were screened, and the enrichment analysis of Kyoto Encyclopedia of Genes and Genomes (KEGG) was performed. The DEG heatmap of the NOD-like receptor pathway, a pyroptosis-related pathway, was made. Protein-protein interaction (PPI) analysis of DEGs in heatmap was performed through the STRING database to screen key genes of PEPS@NOD-IN-1 regulating the NOD-like receptor pathway. Data were statistically analyzed with analysis of variance for repeated measurement, one-way analysis of variance, and Tukey test. Results: PEG-b-PPS and PEPS@NOD-IN-1 were in spherical structures of uniform size, with hydration particle sizes of (134.2±3.3) and (143.1±2.3) nm, respectively. The encapsulation rate of PEPS@NOD-IN-1 to NOD-IN-1 was (60±5)%, and the drug loading rate was (15±3)%. The release of NOD-IN-1 from PEPS@NOD-IN-1 in PBS alone was slow, and the cumulative release rate at 40 h was only (12.4±2.3)%. The release of NOD-IN-1 from PEPS@NOD-IN-1 in hydrogen peroxide-containing PBS within 10 h was very rapid, and the cumulative release rate at 10 h reached (90.1±3.6)%. On PID 3 and 7, the wounds of rats in the four groups were gradually healed, and the healing in PEPS@NOD-IN-1 group was better than that in the other three groups. On PID 12, the wound scab area in PBS group was large, the wound epithelialization in NOD-IN-1 group and PEG-b-PPS group was obvious, and the wound in PEPS@NOD-IN-1 group was close to complete epithelialization. Compared with those in PBS group, NOD-IN-1 group, and PEG-b-PPS group, the wound healing rates on PID 7 and 12 in PEPS@NOD-IN-1 group were significantly increased (P<0.05), the level of ROS in wound tissue on PID 3 was significantly decreased (P<0.05), the thickness of granulation tissue in wound on PID 7 was significantly thickened (P<0.05), and the mRNA expressions of NOD1 and NOD2 and the protein expressions of NOD1, NOD2, and GSDMD-N terminals in wound tissue on PID 7 were significantly decreased (P<0.05). KEGG pathway analysis showed that DEGs significantly down-regulated in PEPS@NOD-IN-1 group as compared with PBS group were significantly enriched in NOD-like receptors, hypoxia-inducible factors, mitogen-activated protein kinases, and tumor necrosis factor (TNF) pathways. In the DEG heatmap of NOD-like receptor pathway, the genes regulating pyroptosis mainly involved NOD1, NOD2, NOD-like receptor thermoprotein domain-related protein 3, Jun, signal transduction and transcriptional activator 1 (STAT1), TNF-α-induced protein 3. The PPI results showed that NOD1, NOD2, and STAT1 were the key genes of PEPS@NOD-IN-1 regulating the NOD-like receptor pathway. Conclusions: PEPS@NOD-IN-1 can down-regulate the level of local ROS in wounds and the expression of NOD1, NOD2, and GSDMD-N terminals, the key regulators of pyroptosis, thereby promoting the repair of full-thickness skin defect wounds in diabetic rats. PEPS@NOD-IN-1 can also significantly down-regulate the pyroptosis, inflammation, and hypoxia-related pathways of wounds, and regulate NOD-like receptor pathways by down-regulating key genes NOD1, NOD2, and STAT1.

[In situ monitoring and regulation of local reactive oxygen species levels to promote wound repair].

Local oxidative stress and inflammatory response are the essential procedures in wound repair, which determine the progress, prognosis, and quality of wound repair. Reactive oxygen species is one of the important indexes reflecting oxidative stress and inflammatory response of body, which is considered as a promising target to be regulated in wound inflammation. Recently, with the rapid development of nanomedicine, our research group and other research groups have successfully developed various diagnosis and treatment reagents for reactive oxygen species through interdisciplinary integration, to monitor and regulate reactive oxygen species in wounds in real time, and to finally achieve the goal of improving the speed and quality of wound repair, thus providing a new strategy and direction for the diagnosis and treatment of local inflammatory response in wounds. This article summarizes reactive oxygen species as the regulatory target of local inflammatory response in wounds, in situ monitoring and precise regulation of reactive oxygen species.

[Effect of P311 microspheres-loaded thermosensitive chitosan hydrogel on the wound healing of full-thickness skin defects in rats].

Objective: To explore the effect of P311 microspheres-loaded thermosensitive chitosan hydrogel on the wound healing of full-thickness skin defects in rats. Methods: The method of experimental study was adopted. The polyvinyl alcohol/sodium alginate microspheres (simple microspheres), P311 microspheres, and bovine serum albumin labeled with fluorescein isothiocyanate (FITC-BSA) microspheres were prepared by water-in-oil emulsification, and then their morphology was observed under a light microscope/inverted fluorescence microscope. Chitosan solution was prepared, chitosan solution and ß-glycerol phosphate disodium hydrate were mixed to prepare simple thermosensitive hydrogels, and thermosensitive hydrogels loaded with simple microspheres or P311 microspheres were prepared by adding corresponding substances in simple thermosensitive hydrogels. The morphological changes of the prepared four liquids in the state of tilt was observed at 37 ℃. After being freeze-dried, the micromorphology of the prepared four liquids was observed under a scanning electron microscope. Eighteen 3-4-week-old male Sprague-Dawley rats were divided into normal group without any treatment, dressing group, chitosan group, hydrogel alone group, simple microspheres-loaded hydrogel group, and P311 microspheres-loaded hydrogel group, which were inflicted with one full-thickness skin defect wound on both sides of the back spine and were dealt correspondingly, with 3 rats in each group. Rats with full-thickness skin defects in the five groups were collected, the wound healing was observed on post injury day (PID) 0 (immediately), 5, 10, and 15, and the wound healing rates on PID 5, 10, and 15 were calculated. The wound and wound margin tissue of rats with full-thickness skin defects in the five groups on PID 15 and normal skin tissue in the same site of rats in normal group were collected, hematoxylin and eosin staining was conducted to observe the histological changes, immunohistochemical staining was performed to observe the expressions of CD31 and vascular endothelial growth factor (VEGF), and Western blotting was conducted to detect the protein expressions of CD31 and VEGF. The number of samples was all three. Data were statistically analyzed with one-way analysis of variance, analysis of variance for repeated measurement, and Bonferroni correction. Results: Simple microspheres were spherical, with loose and porous surface. The surfaces of P311 microspheres and FITC-BSA microspheres were smooth without pores, and the FITC-BSA microspheres emitted uniform green fluorescence. The diameters of the three microspheres were basically consistent, being 33.1 to 37.7 µm. Compared with chitosan solution and simple thermosensitive hydrogel, the structures of the two microspheres-loaded hydrogels were more stable in the state of tilt at 37 ℃. The two microspheres-loaded hydrogels had denser network structures than those of chitosan solution and simple thermosensitive hydrogel, and in the cross section of which microspheres with a diameter of about 30 µm could be seen. Within PID 15, the wounds of rats in the five groups were healed to different degrees, and the wound healing of rats in P311 microspheres-loaded hydrogel group was the best. On PID 5, 10, and 15, the wound healing rates of rats in dressing group and chitosan group were (26.6±2.4)%, (38.5±3.1)%, (50.9±1.5)%, (47.6±2.0)%, (58.5±3.6)%, and (66.7±4.1)%, respectively, which were significantly lower than (59.3±4.8)%, (87.6±3.2)%, (97.2±1.0)% in P311 microspheres-loaded hydrogel group (P<0.05 or P<0.01). The wound healing rates of rats in hydrogel alone group on PID 10 and 15, and in simple microspheres-loaded hydrogel group on PID 15 were (76.0±3.3)%, (84.5±3.6)%, and (88.0±2.6)%, respectively, which were significantly lower than those in P311 microspheres-loaded hydrogel group (P<0.05). The epidermis, hair follicles, and sebaceous glands could be seen in the normal skin of rats in normal group, without positive expressions of CD31 or VEGF. The wounds of rats in P311 microspheres-loaded hydrogel group on PID 15 were almost completely epithelialized, with more blood vessels, hair follicles, sebaceous glands, and positive expressions of CD31 and VEGF in the wounds than those of rats with full-thickness skin defects in the other four groups, and more protein expressions of CD31 and VEGF than those of rats in the other five groups. Conclusions: The P311 microspheres-loaded thermosensitive chitosan hydrogel can release the encapsulated drug slowly, prolong the drug action time, and promote wound healing in rats with full-thickness skin defects by promoting wound angiogenesis and re-epithelialization.

[Summary of the 17th Chinese Symposium on Burn Medicine and the 2022 Congress of Burn Medicine Branch of China International Exchange and Promotion Association for Medical and Healthcare, and the 12th Academic Conference on Burn and Plastic Surgery in Five Provinces and One City in Southwest China].

The 17th Chinese Symposium on Burn Medicine and the 2022 Congress of Burn Medicine Branch of China International Exchange and Promotion Association for Medical and Healthcare, and the 12th Academic Conference on Burn and Plastic Surgery in Five Provinces and One City in Southwest China was successfully held in green city Nanning, from August 25th to 27th, 2022. The conference theme was "Burn treatment and wound repair", received nearly 200 submissions, nearly 1 100 online and offline registered delegates, and nearly 300 offline attendees. The meetings were held in one main venue and three branch venues, with combination of speaking offline and live and recorded broadcast, as well as whole process synchronous live broadcasting. During the meeting, key issues about burn treatment and wound repair were discussed, with warm academic atmosphere.

[Effects of P311 on the angiogenesis ability of human microvascular endothelial cell 1 in vitro and its molecular mechanism].

Objective: To explore the effects of P311 on the angiogenesis ability of human microvascular endothelial cell 1 (HMEC-1) in vitro and the potential molecular mechanism. Methods: The experimental research method was used. HMEC-1 was collected and divided into P311 adenovirus group and empty adenovirus group according to the random number table (the same grouping method below), which were transfected correspondingly for 48 h. The cell proliferation activity was detected using the cell counting kit 8 on 1, 3, and 5 days of culture. The residual scratch area of cells at post scratch hour 6 and 11 was detected by scratch test, and the percentage of the residual scratch area was calculated. The blood vessel formation of cells at 8 h of culture was observed by angiogenesis experiment in vitro, and the number of nodes and total length of the tubular structure were measured. The protein expressions of vascular endothelial growth factor receptor 2 (VEGFR2), phosphorylated VEGFR2 (p-VEGFR2), extracellular signal-regulated kinase 1/2 (ERK1/2), and phosphorylated ERK1/2 (p-ERK1/2) in cells were detected by Western blotting. HMEC-1 was collected and divided into P311 adenovirus+small interfering RNA (siRNA) negative control group, empty adenovirus+siRNA negative control group, P311 adenovirus+siRNA-VEGFR2 group, and empty adenovirus+siRNA-VEGFG2 group, which were treated correspondingly. The protein expressions of VEGFR2, p-VEGFR2, ERK1/2, and p-ERK1/2 in cells were detected by Western blotting at 24 h of transfection. The blood vessel formation of cells at 24 h of transfection was observed by angiogenesis experiment in vitro, and the number of nodes and total length of the tubular structure were measured. HMEC-1 was collected and divided into P311 adenovirus+dimethylsulfoxide (DMSO) group, empty adenovirus+DMSO group, P311 adenovirus+ERK1/2 inhibitor group, and empty adenovirus+ERK1/2 inhibitor group, which were treated correspondingly. The protein expressions of ERK1/2 and p-ERK1/2 in cells were detected by Western blotting at 2 h of treatment. The blood vessel formation of cells at 2 h of treatment was observed by angiogenesis experiment in vitro, and the number of nodes and total length of the tubular structure were measured. The sample number at each time point in each group was 6. Data were statistically analyzed with independent sample t test, analysis of variance for repeated measurement, one-way analysis of variance, and least significant difference test. Results: Compared with that of empty adenovirus group, the proliferation activity of cells in P311 adenovirus group did not show significant difference on 1, 3, and 5 days of culture (with t values of -0.23, -1.30, and -1.52, respectively, P>0.05). The residual scratch area percentages of cells in P311 adenovirus group were significantly reduced at post scratch hour 6 and 11 compared with those of empty adenovirus group (with t values of -2.47 and -2.62, respectively, P<0.05). At 8 h of culture, compared with those of empty adenovirus group, the number of nodes and total length of the tubular structure of cells in P311 adenovirus group were significantly increased (with t values of 4.49 and 4.78, respectively, P<0.01). At 48 h of transfection, compared with those of empty adenovirus group, the protein expressions of VEGFR2 and ERK1/2 of cells in P311 adenovirus group showed no obvious changes (P>0.05), and the protein expressions of p-VEGFR2 and p-ERK1/2 of cells in P311 adenovirus group were significantly increased (with t values of 17.27 and 16.08, P<0.01). At 24 h of transfection, the protein expressions of p-VEGFR2 and p-ERK1/2 of cells in P311 adenovirus+siRNA negative control group were significantly higher than those in empty adenovirus+siRNA negative control group (P<0.01). The protein expressions of VEGFR2, p-VEGFR2, and p-ERK1/2 of cells in P311 adenovirus+siRNA negative control group were significantly higher than those in P311 adenovirus+siRNA-VEGFR2 group (P<0.01). The protein expressions of VEGFR2 and p-ERK1/2 of cells in empty adenovirus+siRNA negative control group were significantly higher than those in empty adenovirus+siRNA-VEGFR2 group (P<0.05 or P<0.01). At 24 h of transfection, the number of nodes of the tubular structure in cells of P311 adenovirus+siRNA negative control group was 720±62, which was significantly more than 428±38 in empty adenovirus+siRNA negative control group and 364±57 in P311 adenovirus+siRNA-VEGFR2 group (with P values both <0.01). The total length of the tubular structure of cells in P311 adenovirus+siRNA negative control group was (21 241±1 139) µm, which was significantly longer than (17 005±1 156) µm in empty adenovirus+siRNA negative control group and (13 494±2 465) µm in P311 adenovirus+siRNA-VEGFR2 group (with P values both <0.01). The number of nodes of the tubular structure in cells of empty adenovirus+siRNA negative control group was significantly more than 310±75 in empty adenovirus+siRNA-VEGFR2 group (P<0.01), and the total length of the tubular structure of cells in empty adenovirus+siRNA negative control group was significantly longer than (11 600±2 776) µm in empty adenovirus+siRNA-VEGFR2 group (P<0.01). At 2 h of treatment, the protein expression of p-ERK1/2 of cells in P311 adenovirus+DMSO group was significantly higher than that in empty adenovirus+DMSO group and P311 adenovirus+ERK1/2 inhibitor group (with P values both <0.01), and the protein expression of p-ERK1/2 of cells in empty adenovirus+DMSO group was significantly higher than that in empty adenovirus+ERK1/2 inhibitor group (P<0.05). At 2 h of treatment, the number of nodes of the tubular structure in cells of P311 adenovirus+DMSO group was 726±72, which was significantly more than 421±39 in empty adenovirus+DMSO group and 365±41 in P311 adenovirus+ERK1/2 inhibitor group (with P values both <0.01). The total length of the tubular structure of cells in P311 adenovirus+DMSO group was (20 318±1 433) µm, which was significantly longer than (16 846±1 464) µm in empty adenovirus+DMSO group and (15 114±1 950) µm in P311 adenovirus+ERK1/2 inhibitor group (with P values both <0.01). The number of nodes of the tubular structure in cells of empty adenovirus+DMSO group was significantly more than 317±67 in empty adenovirus+ERK1/2 inhibitor group (P<0.01), and the total length of the tubular structure of cells in empty adenovirus+DMSO group was significantly longer than (13 188±2 306) µm in empty adenovirus+ERK1/2 inhibitor group (P<0.01). Conclusions: P311 can enhance the angiogenesis ability of HMEC-1 by activating the VEGFR2/ERK1/2 signaling pathway.

[Continuing the brilliance in response to the development trend of discipline: congratulations on the publication of Chinese Journal of Burns and Wounds].

At the beginning of 2022, the first issue of the renamed journal-Chinese Journal of Burns and Wounds is published successfully, the editor-in-chief, Prof. Gaoxing Luo, explains the purpose, reason and necessity in the frontispiece to change the name of the journal from Chinese Journal of Burns to Chinese Journal of Burns and Wounds. Meanwhile, the unshakable and authoritative academic function and position of the journal in the discipline of burns not only in China but also in the world is illustrated. In fact, wound repair and regeneration is one of the most important and skillful tasks for burn experts, which has been also the main published content of the journal since it was founded in 2000. In order to meet the needs of the development of the discipline of burns and wounds and to make the name of the journal much more consistent with the published content, the journal is renamed as the new one without any changes of aim or scope of the publication. We believe that the journal with the new name will grow better and faster, and will set up a much more valuable academic platform for the development and talent cultivation for the disciplines of burns and wounds in the future.

[Effects of porcine acellular dermal matrix combined with human epidermal stem cells on wound healing of full-thickness skin defect in nude mice].

Objective: To explore the effects of porcine acellular dermal matrix (ADM) combined with human epidermal stem cells (ESCs) on wound healing of full-thickness skin defect in nude mice. Methods: The morphology of porcine ADM was analyzed by photograph of digital camera, the cell residues in porcine ADM were observed by hematoxylin-eosin (HE) staining, the surface structure of porcine ADM was observed by scanning electron microscope, the secondary structure of porcine ADM was analyzed by infrared spectrometer, the porcine ADM particle size was analyzed by dynamic light scattering particle size analyzer, and the porcine ADM potential was analyzed by nano-particle size potentiometer. The morphology of porcine ADM was observed by inverted fluorescence microscope when it was placed in culture medium for 30 min, 1 d, and 5 d (n=2). The porcine ADM was divided into 5 min group, 10 min group, 20 min group, 30 min group, 60 min group, and 120 min group according to the random number table (the same grouping method below) in static state at normal temperature for the corresponding time to calculate the water absorption by weighing method (n=3). Swiss white mouse embryonic fibroblasts (Fbs) were divided into blank control group (culture medium only), and 50.0 g/L ADM extract group, 37.5 g/L ADM extract group, 25.0 g/L ADM extract group, 12.5 g/L ADM extract group, and 6.5 g/L ADM extract group which were added with the corresponding final concentrations of ADM extract respectively. At post culture hour (PCH) 24, 48, and 72, the cell survival rate was detected by cell counting kit 8 and the cytotoxicity was graded (n=5). The erythrocytes of a 6-week-old male Sprague-Dawley male rat were divided into normal saline group, ultra-pure water group, and 5 mg/mL ADM extract group, 10 mg/mL ADM extract group, and 15 mg/mL ADM extract group which were treated with the corresponding final concentrations of porcine ADM extract respectively. After reaction for 3 h, the absorbance value of hemoglobin was detected by microplate reader to represent the blood compatibility of porcine ADM (n=3). ESCs were isolated and cultured from the discarded prepuce of a 6-year-old healthy boy who was treated in the Department of Urology of the First Affiliated Hospital of Army Medical University (the Third Military Medical University) in July 2020, and then identified by flow cytometry. The porcine ADM particles of composite ESC (hereinafter referred to as ESC/ADM) were constructed by mixed culture. After 3 days of culture, the composite effect of ESC/ADM was observed by HE staining and laser scanning confocal microscope. Thirty-six 7-8-week-old male non-thymic nude mice were divided into phosphate buffer solution (PBS) alone group, ADM alone group, ESC alone group, and ESC/ADM group, with 9 mice in each group, and the wound model of full-thickness skin defect was established. Immediately after injury, the wounds were treated with the corresponding reagents at one time. On post injury day (PID) 1, 7, 11, and 15, the wound healing was observed and the wound healing rate was counted (n=3). On PID 7, the epithelialization of wounds was observed by HE staining and the length of un-epithelialized wound was measured (with this and the following sample numbers of 4). On PID 11, the dermal area and collagen deposition of wounds were observed by Masson staining and the dermal area of wound section was calculated, the number of cells expressing CD49f, a specific marker of ESC, was calculated with immunofluorescence staining, the mRNA expression of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) in ESC after wound transplantation was detected by real-time fluorescence quantitative reverse transcription polymerase chain reaction. Data were statistically analyzed with independent sample t test, one-way analysis of variance, analysis of variance for repeated measurement, and least significant difference t test. Results: The porcine ADM was white particles and composed of reticular structure, with no cells inside, disordered structure, and rough surface. The absorption peak of porcine ADM appeared at the wave numbers of 1 659, 1 549, and 1 239 cm-1, respectively. The main particle size distribution of porcine ADM in solution was 500 to 700 nm, with negative charge on the surface. The morphology of porcine ADM in static state at 30 min and on 1 and 5 d was relatively stable. The water absorption of porcine ADM remained relatively high level in static state from 30 min to 120 min. The cytotoxicity of mouse embryonic Fbs in 6.5 g/L ADM extract group, 12.5 g/L ADM extract group, and 25.0 g/L ADM extract group was grade 1 at PCH 24, and the cytotoxicity of the other groups was 0 grade at each time point. After reaction for 3 h, the absorbance value of hemoglobin of erythrocytes in ultra-pure water group was significantly higher than the values in normal saline group and 15 mg/mL ADM extract group (with t values of 8.14 and 7.96, respectively, P<0.01). After 3 days of culture, the cells of the fourth passage showed pebble-like morphology, with low expression of CD71 and high expression of CD49f, which were identified as ESCs. There was ESC attachment and growth on porcine ADM particles. On PID 1, the wound sizes of nude mice were almost the same in PBS alone group, ADM alone group, ESC alone group, and ESC/ADM group. On PID 7, 11, and 15, the wound contraction of nude mice in each group was observed, especially in ADM alone group, ESC alone group, and ESC/ADM group. On PID 7, the wound healing rates of nude mice in ESC alone group and ESC/ADM group were significantly higher than the rate in PBS alone group (with t values of 2.83 and 4.72 respectively, P<0.05 or P<0.01). On PID 11, the wound healing rate of nude mice in ESC/ADM group was significantly higher than that in PBS alone group (t=4.86, P<0.01). On PID 15, the wound healing rates of nude mice in ADM alone group, ESC alone group, and ESC/ADM group were significantly higher than the rate in PBS alone group (with t values of 2.71, 2.90, and 3.23 respectively, P<0.05). On PID 7, the length of un-epithelialized wound of nude mice in ADM alone group, ESC alone group, and ESC/ADM group was (816±85), (635±66), and (163±32) µm, respectively, which were significantly shorter than (1 199±43) µm in PBS alone group (with t values of 5.69, 10.19, and 27.54 respectively, P<0.01). On PID 11, the dermal areas of wound section of nude mice in ADM alone group, ESC alone group, and ESC/ADM group were significantly larger than the area in PBS alone group (with t values of 27.14, 5.29, and 15.90 respectively, P<0.01); the collagen production of nude mice in ADM alone group and ESC/ADM group was more obvious than that in PBS alone group, and the collagen production of nude mice in ESC alone group and PBS alone group was similar. On PID 11, in the wounds of nude mice in ESC alone group and ESC/ADM group, the cells with positive expression of CD49f were respectively 135±7 and 185±15, and the mRNA expressions of GAPDH were positive; while there were no expressions of CD49f nor mRNA of GAPDH in the wounds of nude mice in PBS alone group and ADM alone group. Conclusions: ESC/ADM particles can promote the wound healing of full-thickness skin defects in nude mice, which may be related to the improved survival rate of ESCs after transplantation and the promotion of dermal structure rearrangement and angiogenesis by ADM.

[Application effects of bundle nursing of citric acid extracorporeal anticoagulation on continuous renal replacement therapy of severe burn patients].

Objective: To explore the application effects of bundle nursing of citric acid extracorporeal anticoagulation on continuous renal replacement therapy (CRRT) of severe burn patients. Methods: A non-randomized controlled study was conducted. Forty-six patients who met the inclusion criteria and received regular nursing of citric acid extracorporeal anticoagulation during CRRT in the First Affiliated Hospital of Army Medical University (the Third Military Medical University) from January to December 2017 were included in regular nursing group (30 males and 16 females, aged 42.0 (38.7,47.0) years, with 201 times of CRRT performed), and 48 patients who met the inclusion criteria and received bundle nursing of citric acid extracorporeal anticoagulation during CRRT in the same hospital from January to December 2018 were included in bundle nursing group (32 males and 16 females, aged 41.0 (36.0,46.0) years, with 164 times of CRRT performed). The clinical data of all the patients in the two groups were recorded, including the length of intensive care unit (ICU) stay, total cost of treatment in ICU, cost of CRRT, unplanned ending of treatment, ending of treatment due to operation (with the rates of unplanned ending of treatment and ending of treatment due to operation calculated), times of disposable hemodialysis filter and supporting pipeline filter (hereinafter referred to as filter) with use time>24 h, times of CRRT, and lifetime of filter. For the patients in both groups who continuously received CRRT for 3 days or more from the first treatment, the prothrombin time (PT), activated partial thromboplastin time (APTT), international normalized ratio (INR), total calcium, ionic calcium (with the difference of total calcium or ionic calcium between before and after treatment calculated), creatinine, urea, ß2 microglobulin, cystatin C, platelet count, mean arterial pressure, pH value, oxygenation index, bicarbonate radical, and lactic acid levels before the first treatment (hereinafter referred to as before treatment) and 3 days after the first treatment (hereinafter referred to as after 3 days of treatment). The treatment-related complications of all patients in the two groups were recorded during hospitalization. Data were statistically analyzed with independent sample t test, Mann-Whitney U test, and chi-square test. Results: Compared with those in regular nursing group, the length of ICU stay was significantly shortened (Z=-4.71, P<0.01), the total cost of treatment in ICU was significantly reduced (t=-1.39, P<0.01), the cost of CRRT had no significant change (P>0.05), the rates of unplanned ending of treatment and ending of treatment due to operation were both significantly decreased (with χ2 values of 12.20 and 17.83, respectively, P<0.01), the times of filter service time>24 h was increased significantly (Z=-5.93, P<0.01), the times of CRRT were significantly reduced (Z=-4.75, P<0.01), and the filter service life was significantly prolonged (Z=-9.24, P<0.01) among patients in bundle nursing group. Thirty-one patients in bundle nursing group and 28 patients in regular nursing group continuously received CRRT for 3 days or more from the first treatment. Before treatment, PT, APTT, and INR of patients in bundle nursing group were 24.10 (16.08, 39.20) s, 38.81 (32.32, 45.50) s, and 1.17 (1.12, 1.19), respectively, similar to 31.75 (22.99, 40.96) s, 41.82 (35.05, 48.06) s, and 1.15 (1.11, 1.19) of patients in regular nursing group (P>0.05); the levels of total calcium and ionic calcium of patients in the two groups were similar (P>0.05). After 3 days of treatment, PT, APTT, and INR of patients in bundle nursing group and regular nursing group were 29.06 (20.11, 39.46) s, 35.25 (30.06, 40.28) s, 1.13 (1.09, 1.17) and 36.51 (26.64, 42.92) s, 39.89 (34.81, 46.62) s, 1.14 (1.10, 1.18), respectively, similar to those before treatment (P>0.05); the level of ionic calcium of patients in regular nursing group was significantly higher than that before treatment (Z=-2.08, P<0.05); the levels of total calcium and ionic calcium of patients in bundle nursing group were both significantly higher than those before treatment (with Z values of -3.55 and -3.69, respectively, P<0.01); compared with those in regular nursing group, APTT of patients was significantly shorter (Z=-2.29, P<0.05), while the total calcium level of patients was significantly higher in bundle nursing group (Z=-2.26, P<0.05). The difference of total calcium between before and after treatment of patients in bundle nursing group was significantly higher than that in regular nursing group (Z=-3.15, P<0.01). The differences of ionic calcium between before and after treatment of patients in the two groups were similar (P>0.05). Before treatment, the level of ß2 microglobulin of patients in bundle nursing group was significantly higher than that in regular nursing group (Z=-2.84, P<0.01), the platelet count of patients in bundle nursing group was significantly lower than that in regular nursing group (Z=-2.44, P<0.05), while the levels of creatinine, urea, cystatin C, mean arterial pressure, pH value, oxygenation index, bicarbonate radical, and lactic acid of patients in the two groups were similar (P>0.05). After 3 days of treatment, the levels of creatinine, urea, ß2 microglobulin, cystatin C, pH value, bicarbonate radical, and lactic acid of patients were all significantly lower than those before treatment (with Z values of -2.10, -2.90, -3.11, -2.02, -2.34, -2.63, and -2.84, respectively, P<0.05 or P<0.01), while the levels of platelet count, oxygenation index, and mean arterial pressure of patients were all significantly higher than those before treatment in bundle nursing group (with Z values of -6.65 and -2.40, respectively, t=-9.97, P<0.05 or P<0.01); the levels of creatinine, urea, ß2 microglobulin, cystatin C, platelet count, pH value, bicarbonate radical, and lactic acid of patients were all significantly lower than those before treatment (with Z values of -5.32, -2.31, -2.41, -2.21, -3.68, -2.93, -2.20, and -2.31, respectively, P<0.05 or P<0.01), while the oxygenation index and mean arterial pressure of patients were both significantly higher than those before treatment in regular nursing group (Z=-5.59, t=-7.74, P<0.01). After 3 days of treatment, compared with those in regular nursing group, the levels of creatinine, cystatin C, platelet count, oxygenation index, bicarbonate radical, and mean arterial pressure of patients were all significantly higher (with Z values of -2.93, -1.99, -6.39, -2.09, and -2.52, respectively, t=-3.28, P<0.05 or P<0.01), while the levels of urea, ß2 microglobulin, pH value, and lactic acid of patients were all significantly lower (with Z values of -3.87, -2.58, -4.24, and -2.75, respectively, P<0.05 or P<0.01) in bundle nursing group. During hospitalization, there were no treatment-related bleeding events or hypernatremia related to citric acid treatment of patients in the two groups. The ratio of total calcium to ionic calcium in one patient in bundle nursing group was >2.5, but there was no manifestation of citric acid accumulation poisoning; 1 patient had hypoionic calcemia, and 1 patient had severe metabolic alkalosis. Five patients had hypoionic calcemia and 2 patients had severe metabolic alkalosis in regular nursing group. Conclusions: The implementation of bundle nursing of citric acid extracorporeal anticoagulation during CRRT for severe burn patients shortens the length of ICU stay, reduces the total cost of treatment in ICU and the occurrence of treatment-related complications, relieves the economic burden of patients, and improves the continuity and quality of treatment.

[Burn injury should be considered as a chronic disease].

Burn is a special type of trauma, which initiates with skin injury and subsequently causes damages to various systems of the whole body. Burn was regarded as an acute injury in the past, while burn is also considered as a disease now. In recent years, more and more recent evidences have demonstrated that burn injury has a continuous and long-term influence on the life, work, and health status of burn survivors. Therefore, we proposed that burn should be considered as a chronic disease and briefly summarized the long-term effects of burns on mortality, psychology, metabolism, immune system, cardiovascular system, and occurrence of infection and tumor in discharged burn victims. We hope this work can improve the understanding of the long-term effects of burns among medical staff, burn patients and their relatives, and social workers.

[Research advances on the prevention and treatment strategies of burn wound progressive deepening].

The progressive deepening of burn wounds is one of the common clinical problems and difficulties in early burn treatment. At the present, it is believed that local ischemia and hypoxia, persistent inflammation, infection, unbalanced local microenvironment, cell necrosis, apoptosis, and autophagy are the main mechanisms of progressive deepening of burn wounds. In recent years, basic and clinical studies have proposed various new strategies for prevention and treatment of progressive deepening of burn wounds, mainly including correct cooling, improving blood perfusion of the wound, early debridement, improving the wound microenvironment, preventing and treating wound infection, reducing wound inflammation, and inhibiting the oxidative stress in the wound. This review focuses on the current progress of prevention and treatment strategies of burn wound progressive deepening, in order to provide references for the treatment of burn wounds.

[Application of functional materials to promote cutaneous wound healing].

Cutaneous wound is one of the common clinical diseases. Functional materials can provide targeted wound protection and promote wound healing through the structural adjustment and functional integration. Currently, functional materials have been widely used in the field of wound repair, becoming one of the important tools for clinical wound treatment. This paper summarizes the application of functional materials of following categories including hemostasis, antibacterial, anti-inflammation, vascularization, and regulation of wound microenvironment in wound repair.