In the human body, the structure of the organ and tissue is its functional foundation. With the human body skin losing, the skin also loses its function. When the skin defect area is quite large, it is the question that the source of the autologous skin is deficient. But with the engineering research progressing, the application of artificial skin to repair the skin defect is possible. In order to make the tissue-engineered skin have "normal" skin function, the structure research also should make them approach as far as possible to be similar. This article reviews the constructs, properties and applications of the epidermal substitutes, the dermal substitutes and the skin substitutes. With continued development of multi-discipline and continued progress of basic and clinical research, the constituted tissue-engineered skin substitutes will more approach the normal skin in the structure and properties.

Exosomes are nano-vesicles released by many kinds of cells. Exosomes play a significant role in cell-to-cell communication and substance transportation through direct effect of signaling molecules on the cell membrane surface, intracellular regulation of cellular content during membrane fusion, or regulation of release of various bioactive molecules. Several studies have reported that culture supernatant of stem cells has some related exosomes to take part in wound repair. The secretion of exosomes is depended on the source and the physiological and pathological condition of deriving cells. How to stimulate the stem cells to produce exosomes maximally and their clinical application are worthy to explore. In this review, we summarize the biological function and application of exosomes derived from stem cells in wound repair.

Objective: To observe the safety and effects of application of analgesic and sedative drugs in severely burned patients during shock stage. Methods: One hundred and eighty patients with severe burns, conforming to the study criteria, were admitted to our unit from August 2014 to August 2016. Patients were divided into analgesia and sedation group and control group according to whether receiving analgesic and sedative treatment or not, with 90 cases in each group. Patients in control group received conventional treatment, while those in analgesia and sedation group received analgesic and sedative treatment for 24 hours besides conventional treatment. Before and at drug administration hour 2, 8, 16, and 24, pain degree of patients in two groups was scored by visual analogue scale (VAS). At drug administration hour 2, 8, 16, and 24, sedation degree of patients in two groups was scored by richmond agitation sedation scale, and the success rate of sedation was calculated. Mental state of patients within 24 hours of drug administration was observed, while pulse oxygen saturation (SpO₂), respiratory rate, heart rate, and blood pressure were observed and dynamically evaluated every 2 hours. The accidental extubation, tachycardia, hypertension, hypoxia, bradycardia, hypotension, urinary retention, and respiratory depression of patients within 24 hours of drug administration were monitored and recorded. Data were processed with analysis of variance for repeated measurement, one-way analysis of variance, t test, chi-square test, Wilcoxon rank sum test, and Fisher′s exact probability test. Results: (1) The VAS scores of patients in two groups were close before drug administration (t=0.675, P>0.05). The VAS scores of patients in analgesia and sedation group at drug administration hour 2, 8, 16, and 24 were (3.8±0.4), (3.9±0.6), (3.9±0.5), and (3.9±0.9) points, respectively, significantly lower than (6.0±0.9), (6.0±1.2), (6.2±0.6), and (6.3±0.4) points in control group (t=0.785, 0.730, 0.805, 0.895, P<0.05). The success rate of sedation of patients in analgesia and sedation group at drug administration hour 2, 8, 16, and 24 were 91.1% (82/90), 86.7% (78/90), 93.3% (84/90), and 90.0% (81/90), respectively, significantly higher than 7.8% (7/90), 6.7% (6/90), 14.4% (13/90), and 5.6% (5/90) in control group (Z=8.035, 7.946, 8.129, 8.014, P<0.05). (2) The respiratory rate of patients in analgesia and sedation group at drug administration hour 8, 16, and 24 were (15.78±0.69), (16.08±0.59), and (16.21±0.20) times per minute, and the heart rate were (87±9), (83±7), and (76±9) times per minute, respectively, significantly lower than (16.80±0.81), (17.09±0.50), and (17.02±0.61) times per minute and (89±8), (86±7), and (85±6) times per minute in control group (t=7.655, 7.022, 6.536, -6.931, -7.053, -10.196, P<0.01). There were no statistically significant difference in SpO₂, systolic blood pressure, and diastolic blood pressure before and at drug administration hour 2, 8, 16, and 24 between the two groups (t=3.417, -2.894, -6.501, -3.719, -4.573, 2.336, 3.315, 0.942, -1.583, 1.907, 1.147, -0.968, 0.931, -1.682, 1.076, P>0.05). (3) The rates of respiratory depression, hypoxia, bradycardia, urinary retention, and hypotension of patients in the two groups were close (χ²=0.310, P>0.05). The rates of hypertension, accidental extubation, and tachycardia of patients in analgesia and sedation group were significantly lower than those in control group (χ²=16.364, 5.143, 73.309, P<0.05 or P<0.01). Conclusions Proper application of analgesic and sedative drugs in severely burned patients during shock stage has good clinical effect with low incidence rates of complications.

On October 3rd, 2017, one male patient, aged 27 years, was admitted to our hospital 6 hours after hydrothermal scald of torso, buttocks, and limbs. The total area of burn was about 60% total body surface area, and the depth was from deep partial-thickness burn to full-thickness burn. Immediately after admission, the patient was given symptomatic support treatments, such as anti-shock, fluid replacement, and anti-infection, etc. After being treated by debridement and xenogenic (porcine) skin grafting for 2 times, the wounds were healed well. On the 12th day of admission, linezolid was used to prevent infection according to the results of microbial culture and drug sensitivity test, since when the level of his blood lactate continued to increase. After 8 days, linezolid was discontinued and vitamin B1 was given orally for 1 week, and the level of lactic acid gradually decreased to normal in result. This case was used mainly to analyze whether linezolid could directly cause hyperlacticemia and its important mechanism, aiming at reminding clinicians of being alert to the risk of hyperlacticemia when using linezolid. If hyperlacticemia occurs, linezolid should be discontinued immediately and vitamin B1 should be taken orally to correct the high lactic acid value, and the treatment plan should be adjusted if necessary.

OBJECTIVETo investigate the effects of recombinant human granulocyte macrophage colony-stimulating factor (rhGM-CSF) on wound healing and microRNA expression in diabetic rats.

METHODSEighteen male SD rats of clean grade were used to reproduce diabetes model. Four weeks later, a total of 64 full-thickness skin wounds were created on the back of 16 rats with established diabetes, with 4 wounds on each rat. Two symmetrical wounds on either side of the spine were created as a pair according to paired design. Then the wounds were divided into groups A and B according to the random number table and blind method (red and blue tags on the rhGM-CSF or the gel vehicle), with 32 wounds in each group. The ointment with red tag was applied on the wounds of group A and the blue one on group B. The application was conducted once a day, with a thickness of 3 mm, up to post injury day (PID) 14. Gross observation of wound healing was conducted on PID 3, 7, 14. The wound healing rate was determined on PID 3 and 7. On PID 3, 7, 14, tissues from 2, 4, and 8 wounds were harvested from each group respectively for the observation of the histopathological changes with HE staining, and also for analyzing the expression of proliferating cell nuclear antigen (PCNA) and CD31 with immunohistochemical staining (denoted as absorbance value). On PID 7, tissues from 6 wounds in each group were harvested for microarray gene chip to screen the differentially expressed microRNAs. Enrichment analysis of Kyoto encyclopedia of genes and genomes (KEGG) signaling pathway on the differentially expressed microRNAs were performed after the microRNA screening results were validated by real-time fluorescent quantitative RT-PCR. Data were processed with paired t test or two-sample t test.

RESULTS(1) On PID 3, the wound area was significantly decreased, and the wound granulation was significantly proliferated in both groups. On PID 7, the wound area was further decreased, and the wound area was almost filled by granulation in both groups; the conditions in group A were better. On PID 14, all the wounds in group A were almost healed, while a small area of raw wound with incrustation still remained in some wounds of group B. On PID 3 and 7, the wound healing rates of group A were (41 ± 5)% and (75 ± 4)%, significantly higher than those of group B [(31 ± 9)% and (71 ± 4)%, with t values respectively 10.13 and 8.06, P values below 0.001]. (2) On PID 3, the epidermal cells, endothelial cells, and Fbs in the wounds of 2 groups were sparse, with heavy infiltration of inflammatory cells. The above condition in the wounds was better in group A than in group B. On PID 7, the epidermal cells, endothelial cells, and Fbs were gradually well arranged in group A; infiltration of inflammatory cells decreased, and the condition was better than that of group B. On PID 14, the wounds of group A were completely covered by epidermis, while infiltration of inflammatory cells still remained in some wounds of group B. (3) On PID 3, 7, 14, the positive expressions of CD31 and PCNA in group A were respectively 0.275 ± 0.018, 0.345 ± 0.034, 0.305 ± 0.023; 0.406 ± 0.063, 0.223 ± 0.011, 0.045 ± 0.022. They were significantly higher than those of group B (0.222 ± 0.020, 0.229 ± 0.018, 0.197 ± 0.015; 0.324 ± 0.039, 0.162 ± 0.012, 0.018 ± 0.020, with t values from 2.281 to 9.652, P < 0.05 or P < 0.01). (4) According to the microRNAs detection and screening, as compared with group B, 18 microRNAs were up-regulated while 13 were down-regulated in the wounds of group A. (5) The results of real-time fluorescent quantitative RT-PCR had good consistency with the results of microRNAs detection. (6) Enrichment analysis of KEGG signaling pathway showed that among the 31 differentially expressed microRNAs, 4 took part in the MAPK signaling pathway, 3 took part in the Wnt signaling pathway, 1 took part in the TGF-β signaling pathway, 3 took part in the epidermal growth factor receptor signaling pathway, 2 took part in the cell cycle pathway, 5 took part in the axon guidance signaling pathway, 6 took part in the focal adhesion pathway, 3 took part in the regulation of actin cytoskeleton pathway, 1 took part in the extracellular cell matrix receptor pathway, 3 took part in the adherens junction pathway, and 1 took part in the cell adhesion molecules pathway. After disclosing the blind, it showed that the ointment with red tag was the rhGM-CSF gel and the blue one was gel vehicle.

CONCLUSIONSThe rhGM-CSF gel can promote wound healing in diabetic rats, producing significant differential microRNA expression in wounds, and they may be the target at gene post-transcriptional level of rhGM-CSF gel in promoting wound healing.

Animals ; Bacteria ; isolation & purification ; Burns ; drug therapy ; microbiology ; pathology ; Diabetes Mellitus, Experimental ; complications ; Granulocyte-Macrophage Colony-Stimulating Factor ; pharmacology ; Humans ; Male ; MicroRNAs ; genetics ; Proliferating Cell Nuclear Antigen ; metabolism ; Rats ; Recombinant Proteins ; Signal Transduction ; Wound Healing ; drug effects