Deep Partial-thickness Burn Wounds Research Articles

Effects of Hair Follicle Stem Cells on Partial-Thickness Burn Wound Healing and Tensile Strength

Background:The recent improvements in wound healing have led to new strategies in regenerative medicine. Burn wound healing is an important issue in skin regeneration and has multiple indications for stem cell therapy. HFSCs are a highly promising source of stem cells for healing use, as these cells are accessible, active and pluripotent adult stem cells. Methods:HFSCs of the rat whisker were isolated, cultured, and labeled with DiI. Flow cytometry method was used to detect special markers of HFSCs. Deep partial-thickness burn wound was created, and labeled HFSCs were injected around the wound bed. Wound closure was recorded via digital photographs. The inflicted rats were sacrificed at 3, 7, or 14 days post burn and used for subsequent histological and tensiometry analysis. Results:Our results indicated that HFSCs were positive for Nestin and CD34 markers, but negative for Kr15. Morphological and histological photographs revealed that wound closure rate was accelerated in stem cell-treated group compared with other groups. In addition, faster re-epithelialization and collagen deposition were observed. The immunohistochemical analysis suggested that CD31 expression and vascular density enhanced in the stem cell-treated group. Further, tissue tensile strength increased in HFSCs-treated rats in comparison to the control group. Conclusion:The present study demonstrates that HFSCs could accelerate burn wound healing as well as tensile strength in rats.

The Role of Autologous PRP on Deep Partial-Thickness Burn Wound Healing in Bama Pigs.

In this study, we aimed to evaluate the therapeutic effects of autologous platelet-rich plasma (PRP) on deep partial-thickness burns in Bama pigs. Deep partial-thickness burn wounds were created on the back of Bama pigs. The reepithelialization time was compared between the PRP and control groups. The mean score of Ki67 (+) cells and α-SMA (+) vessels, the mean thickness of epidermis and dermis of the healing wounds were determined via H&E staining and immunohistochemical assay. The levels of the growth factors epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), and vascular endothelial growth factor (VEGF) were examined by ELISA. Our data showed that the time to wound reepithelialization was shorter in the PRP group compared with the control group. The thickness of the epidermis was larger in the PRP group compared with the control group. On the 7th and 14th days after the treatment, the mean score of Ki67 (+) cells and α-SMA (+) vessels were higher in the PRP group compared with the control group. The PRP group showed higher levels of growth factors (EGF, bFGF, and VEGF) compared with the control group by ELISA. The results indicated that PRP could improve wound healing process of deep partial-thickness burns in Bama pigs. The PRP increased the thickness of epidermis of the healed wounds, cell proliferation, and angiogenesis. We demonstrated that applying PRP had a greater potential for the treatment of deep partial-thickness burns.

Adipose-derived stem cells-induced burn wound healing and regeneration of skin appendages in a novel skin island rat model.

The study of effectiveness of adipose-derived stem cells (ASCs) in treating burn wounds is still a developing field. The process of wound contraction in areas of loose skin is a major confounding factor in the evaluation and study of burn wound healing in animal models. To evaluate the effect of local ASCs administration, deep partial thickness burn wounds were induced by 30 s application of hot copper plates in a novel skin island burn wound rat model to avoid interference from primary wound contraction. Skin islands were divided into two treatment groups-control group (n = 9) injected with PBS and ASCs-treated group (n = 9) injected with 5 × 10 ASCs intradermally. Progress in wound healing was checked at regular intervals after injury (on 1st, 2nd, 3rd, and 4th week) by measuring the mean wound area and analyzing the wound histologically and immunohistochemically, after unstitching the overlaying skin to expose the skin island. It was found that local intradermal injection of ASCs improved burn wound healing at all given time points when compared with control groups, especially in the first 2 weeks (p < 0.05). The percentage of live follicles increased gradually in the ASCs-treated groups compared with control groups between the 3rd and 4th weeks (p < 0.05). The vascular density and proliferating cell nuclear antigen index were also significantly increased in the ASCs-treated groups. Thus, in this study, a novel burn wound rat model with reduced interference from wound contraction has been put forth to investigate the therapeutic effects of local administration of ASCs on burn wound healing. Local injection of ASCs not only improved burn wound recovery but also enhanced angiogenesis and skin appendage regeneration.

Use of NexoBrid for Treatment of Acute Deep Partial and Full Thickness Burn Injuries

Use of NexoBrid for Treatment of Acute Deep Partial and Full Thickness Burn Injuries

Bioactive peptide amphiphile nanofiber gels enhance burn wound healing

BackgroundBurns are physically debilitating and potentially fatal injuries. The standard-of-care for burn wounds is the coverage with gauze dressings designed to minimize trauma to the regenerating epidermis and dermis during dressing changes. However, deep partial- and full-thickness burns always heal slowly when standard wound care alone is performed. We have previously reported that peptide amphiphile (PA) gels, pH-induced self-assembling nanostructured fibrous scaffolds, promote cell proliferation and have great potential in regenerative medicine for rapid repair of tissues. In this study, we hypothesized that the PA gels are capable of accelerating wound healing in burn injury. MethodsArtificially generated thermally damaged fibroblasts and human umbilical vein endothelial cells were seeded onto the various PA nanofiber gels including bioactive and nonbioactive peptide sequences. Cell proliferation was assessed at different time points, and thermally damaged fibroblasts and HUVECs manifested increased proliferation with time when cultured with various PA gels. To determine in vivo effects, burn wounds of rats were treated with the bioactive Arg-Gly-Asp-Ser (RGDS)-modified gel that showed greater cell proliferation in vitro. The wound closure was observed, and skin samples were harvested for histologic evaluation. ResultsCell proliferation using the RGDS-PA gel was significantly higher than that observed in other gels. The RGDS-PA gel significantly enhanced re-epithelialization during the burn wound healing process between days 7 and 28. Application of PA gels accelerates the recovery of deep partial-thickness burn wounds by stimulation of fibroblasts and the creation of an environment conducive to epithelial cell proliferation and wound closure. ConclusionsThis biomaterial represents a new therapeutic strategy to overcome current clinical challenges in the treatment of injuries resulting from burns.

Discordance between histologic and visual assessment of tissue viability in excised burn wound tissue

The regenerative capacity of burn wounds, and the need for surgical intervention, depends on wound depth. Clinical visual assessment is considered the gold standard for burn depth assessment but it remains a subjective and inaccurate method for tissue evaluation. The purpose of this study was to compare visual assessment with microscopic and molecular techniques for human burn depth determination, and illustrate differences in the evaluation of tissue for potential regenerative capacity. Using intraoperative visual assessment, patients were identified as having deep partial thickness or full thickness burn wounds. Tangential excisions of burn tissue were processed with hematoxylin and eosin to visualize tissue morphology, lactate dehydrogenase assay to ascertain cellular viability, and Keratin-15 and Ki67 to identify epidermal progenitor cells and proliferative capacity, respectively. RNA from deep partial and full thickness burn tissue as well as normal tissue controls were submitted for RNA sequencing. Lactate dehydrogenase, Keratin-15, and Ki67 were found throughout the excised burn wound tissue in both deep partial thickness burn tissues and in the second tangential excision of full thickness burn tissues. RNA sequencing demonstrated regenerative capacity in both deep partial and full thickness burn tissue, however a greater capacity for regeneration was present in deep partial thickness compared with full thickness burn tissues. In this study, we highlight the discordance that exists between the intraoperative clinical identification of burn injury depth, and microscopic and molecular determination of viability and regenerative capacity. Current methods utilizing visual assessment for depth of injury are imprecise, and can lead to removal of viable tissue. Additionally, hematoxylin and eosin microscopic analysis should not be used as the sole method in research or clinical determination of depth, as there are no differences in staining between viable and nonviable tissue.

On-Demand Dissolvable Self-Healing Hydrogel Based on Carboxymethyl Chitosan and Cellulose Nanocrystal for Deep Partial Thickness Burn Wound Healing.

Deep partial thickness burn wounds present big challenges due to the long healing time, large size and irregular shape, pain and reinjury at wound dressing changes, as well as scarring. The clinically effective therapy to alleviate pain at wound dressing changes, and the scar left on the skin after the healing of wound is still unavailable. To combat this, we develop a nanocomposite self-healing hydrogel that can be injected into irregular and deep burn wound beds and subsequently rapidly self-heal to reform into an integrated piece of hydrogel that thoroughly fills the wound area and protects the wound site from external environment, finally being painlessly removed by on-demand dissolving using amino acid solution at wound dressing changes, which accelerates deep partial thickness burn wound healing and prevents scarring. The hydrogel is made out of naturally occurring polymers, namely, water-soluble carboxymethyl chitosan (CMC) and rigid rod-like dialdehyde-modified cellulose nanocrystal (DACNC). They are cross-linked by dynamic Schiff-base linkages between amines from CMC and aldehydes from DACNC. The large aspect ratio and specific surface area of DACNC raise massive active junctions within the hydrogel, which can be readily broken and reformed, allowing hydrogel to rapidly self-heal. Moreover, DACNC serves as nanoreinforcing fillers to improve the hydrogel strength, which also restricts the "soft" CMC chains' motion when soaked in aqueous system, endowing high fluid uptake capacity (350%) to hydrogel while maintaining integrity. Cytotoxicity assay and three-dimensional cell culture demonstrate excellent biocompatibility of the hydrogel and capacity as extracellular matrix to support cell growth. This work opens a novel pathway to fabricate on-demand dissolvable self-healing hydrogels to speed deep partial thickness burn wound healing and eliminate pain at wound dressing changes and prevent scar formation.

Effects of minimally invasive tangential excision in treating deep partial-thickness burn wounds on trunk and limbs in pediatric patients in the early stage post burn

Objective: To observe the effects of minimally invasive tangential excision in treating deep partial-thickness burn wounds on trunk and limbs in pediatric patients in the early stage post burn. Methods: Clinical data of 40 children with deep partial-thickness burn wounds on trunk and limbs, admitted to our burn ward from January 2016 to June 2017, conforming to the study criteria, were retrospectively analyzed. They were divided into conventional treatment group (CT, n=19) and minimally invasive tangential excision group (MITE, n=21) according to the different treatments. The patients in group CT were treated with eschar-reserving therapy firstly. When tangential excision was performed, the roller knife was used, and no necrotic tissue left on the wound bed was considered the proper depth of excision. Razor-thickness skin grafting was performed to cover the wound when adipose tissue exposed markedly after tangential excision. Dressing change was performed within 48 h after the operation and repeated every 2 days. Unhealed wounds were covered by razor-thickness skin grafting. The patients in group MITE were treated with tangential excision in the early stage post burn. The tangential excision was operated with electric dermatome, and the thickness was set at 0.1 mm to excise the surface of eschar until the sporadic punctate hemorrhage on wound surface was observed and some necrotic tissue was left on the wound bed. Porcine acellular dermal matrix was applied after tangential excision. The first dressing change was often performed about 1 week after the operation. Razor-thickness skin grafting was performed to cover the unhealed wounds. The length of wound healing, high fever, antibiotic usage, and hospital stay, times of later operation, and hospitalization expenses of patients in the 2 groups were recorded. The excisional eschar and wound bed tissue of patients in group MITE were harvested for pathological observation. Data were processed with t test and Fisher's exact probability test. Results: (1) There were no statistically significant differences in length of high fever and length of hospital stay and hospitalization expenses between patients in the 2 groups (t=-1.67, -1.93, 0.31, P>0.05). The lengths of wound healing [(24.8±2.5) d] and antibiotic usage [(4.4±0.7) d] of patients in group MITE were significantly shorter than those in group CT [(33.3±2.5) and (7.0±0.7) d, t=-2.44, -2.44, P<0.05], and times of later operation of patients in group MITE [(0.29±0.14) times] were significantly less than those in group CT [(0.79±0.21) times, t=-2.03, P<0.05]. (2) The thickness of the excisional eschar of patients in group MITE was about 150 μm. The eschar has epidermis and upper dermis. Some necrotic tissue was left on the wound bed. Conclusions: The treatment for pediatric deep partial-thickness burn wounds on trunk and limbs with minimally invasive tangential excision using electric dermatome in the early stage post burn can accelerate wound healing, shorten length of antibiotic usage, and reduce times of later operations.

Development of Pseudomonas aeruginosa Biofilms in Partial-Thickness Burn Wounds Using a Sprague-Dawley Rat Model.

We used a modified Walker–Mason scald burn rat model to demonstrate that Pseudomonas aeruginosa, a common opportunistic pathogen in the burn ward and notable biofilm former, establishes biofilms within deep partial-thickness burn wounds in rats.Deep partial-thickness burn wounds, ~10% of the TBSA, were created in anesthetized male Sprague-Dawley rats (350–450 g; n = 84). Immediately post-burn, 100 µl of P. aeruginosa in phosphate-buffered saline at 1 × 103, 1 × 104, or 1 × 105 cells/wound was spread over the burn surface . At 1, 3, 7, and 11 days post-burn, animals were euthanized and blood and tissue were collected for complete blood counts, colony-forming unit (CFU) counts, biofilm gene expression, histology, scanning electron microscopy (SEM), and myeloperoxidase activity in the burn eschar. P. aeruginosa developed robust biofilm wound infections, plateauing at ~1 × 109 CFU/g burn tissue within 7 days regardless of inoculum size. Expression of Pseudomonas alginate genes and other virulence factors in the infected wound indicated formation of mature P. aeruginosa biofilm within the burn eschar. Compared to un-inoculated wounds, P. aeruginosa infection caused both local and systemic immune responses demonstrated by changes in systemic neutrophil counts, histology, and myeloperoxidase activity within the burn wound. Additionally, SEM showed P. aeruginosa enmeshed within an extracellular matrix on the burn surface as well as penetrating 500–600 µm deep into the eschar. P. aeruginosa establishes biofilms within deep partial-thickness burn wounds and invades deep into the burned tissue. This new in vivo biofilm infection model is valuable for testing novel anti-biofilm agents to advance burn care.

Effects of hydrotherapy with traditional Chinese medicine and magnetotherapy on treatment of scars after healing of deep partial-thickness burn wounds in children

Objective: To study the effects of hydrotherapy with traditional Chinese medicine combined with magnetotherapy on treatment of scars after healing of deep partial-thickness burn wounds in children. Methods: Forty-eight children with scars after healing of deep partial-thickness burn wounds admitted to the Burn Department of Air Force General Hospital from January to December in 2016 met the criteria for inclusion in this study, and their medical records were analyzed retrospectively. Within one month after the wound was completely healed, 24 children were treated with silicone cream for 2 times per day and wore elastic sleeves all day long according to the wishes of the children and their families, and they were enrolled in routine treatment group. The other 24 children were treated by hydrotherapy with traditional Chinese medicine Fuchunsan No. 2 once every 2 days for 30 min each time on the basis of treatment methods of routine treatment group, plus magnetotherapy using pulse magnetotherapy apparatus in the morning and evening of each day for 30-60 min each time, and they were enrolled in hydrotherapy+ magnetotherapy group. Before treatment and 12 weeks after treatment, the Vancouver Scar Scale was used to assess the scar condition of children, the Wong-Baker Facial Expression Scale was used to assess the degree of scar pain of children, the Numerical Rating Scale was used to assess the degree of scar itching of children, the modified Barthel Index was used to assess the activity of daily living (ADL) of children, and the Motor Function Evaluation Scale was used to assess the dysfunction condition of limbs with scar. After 12 weeks of treatment, the incidence of deformity of children was calculated. Data were processed with t test and chi-square test. Results: Before treatment, the scores of scar condition of children between routine treatment group and hydrotherapy+ magnetotherapy group were similar (t=0.517, P=0.721). After 12 weeks of treatment, the score of scar condition of children in hydrotherapy+ magnetotherapy group was (2.8±0.8) points, which was significantly lower than (3.9±0.8) points of routine treatment group (t=5.725, P<0.01). Before treatment, the scores of scar pain and itching degree of children between routine treatment group and hydrotherapy+ magnetotherapy group were similar (t=0.373, 0.241, P=0.712, 0.631). After 12 weeks of treatment, the scores of scar pain and itching degree of children in hydrotherapy+ magnetotherapy group were (0.52±0.21) and (0.7±0.4) points, respectively, which were obviously lower than (1.13±0.32) and (1.3±0.4) points of routine treatment group (t=6.057, 5.259, P<0.01). Before treatment, the ADL scores of children between routine treatment group and hydrotherapy+ magnetotherapy group were similar (t=0.082, P=0.964). After 12 weeks of treatment, the ADL score of children in hydrotherapy+ magnetotherapy group was (67±13) points, which was significantly higher than (48±10) points of routine treatment group (t=5.378, P<0.01). Before treatment, the dysfunction scores of limbs with scar of children between routine treatment group and hydrotherapy+ magnetotherapy group were similar (t=0.261, P=0.720). After 12 weeks of treatment, the dysfunction score of limbs with scar of children in hydrotherapy+ magnetotherapy group was (62±9) points, which was significantly higher than (47±8) points of routine treatment group (t=14.463, P<0.05). After 12 weeks of treatment, the incidence of deformity of children in hydrotherapy+ magnetotherapy group was 8.3% (2/24), which was significantly lower than 37.5% (9/24) of routine treatment group (χ(2)=4.25, P<0.05). Conclusions: On the basis of topical anti-scarring drugs and compression therapy, supplementing hydrotherapy with traditional Chinese medicine and magnetotherapy can significantly reduce the hyperplasia degree, pain degree, itching degree of scars formed after healing of deep partial-thickness burn wounds in children, improve the ADL, promote functional recovery, and reduce the incidence of deformity of children.

Pirfenidone Ointment Modulates the Burn Wound Bed in C57BL/6 Mice by Suppressing Inflammatory Responses.

An inflammatory response is the normal response to a burn-induced injury. The burn-associated inflammation can lead to further tissue damage as the tissue tries to repair the damage. Prolonged or excessive inflammation is associated with increased fibrosis of burn wounds and the development of hypertrophic scars. The high incidence of hypertrophic scar formation is one of the many challenges to treating deep partial-thickness burns. Prophylactic treatment to improve burn-induced hypertrophic scarring is lacking. For this reason, we evaluated prophylactic treatment of deep partial-thickness burns with pirfenidone in C57BL/6 mice. Pirfenidone is an FDA-approved anti-fibrotic drug for systemic use in the treatment of idiopathic lung fibrosis and other fibrotic disorders. Additionally, pirfenidone has anti-inflammatory activity. We tested treatment efficacy of pirfenidone using a mouse model of deep partial-thickness burns. Inflammatory cytokines including IL-1β, IL-2, IL-6, IL-13, G-CSF, and MIP-1α, along with neutrophil infiltration, were significantly reduced in wounds when mice were treated during the inflammatory phase of burn wound healing. Additionally, pirfenidone significantly reduced expression of αSMA 12days after the induction of burns and modestly reduced hydroxyproline in 22-day-old burn wounds. Results show that pirfenidone treatment modulated the inflammatory response of the burn wound. The findings in this study indicate that further examination is required to validate the use of pirfenidone for prophylactic treatment to improve long-term outcomes of scarring and contracture in deep partial-thickness burn wounds.

Predominance of CD14+ Cells in Burn Blister Fluids.

Burn blister fluid contains several angiogenic factors to promote wound neovascularization. In our previous study, we found that deep partial-thickness burn (DPTB) wounds showed higher expression levels of angiogenin to enhance vascularization compared with superficial partial-thickness burn wounds. Neovascularization is a complex process that involves an interaction between circulating angiogenic cells and mediators. We hypothesized that in addition to angiogenic factors burn blisters may contain specific cell types. The aim of the present study was to characterize the specific cells present in burn blisters. Twenty-four burn blister fluid samples were obtained with informed consent from patients with superficial partial-thickness burn (n = 16) or DPTB (n = 8) wounds. Blister cells were isolated from individual intact blisters and characterized with flow cytometry analysis using CD14, CD34, vascular endothelial growth factor receptor 2, and CD133 markers. CD14 and CD34 blister cells were also isolated using a magnetic-activated cell sorting system to examine their potential for endothelial differentiation. Angiogenin levels in the burn blister fluids were evaluated with enzyme-linked immunosorbent assay. CD14 cells were the most highly represented cell type in the burn fluids of both groups, although a significantly greater percentage of CD14 cells were observed in DPTB fluids. CD14 blister cells had a higher potency to differentiate into functional endothelial cells as compared with CD34 cells. The proportion of CD14 cells gradually increased after burn injury. In contrast to CD14 cells, angiogenin showed the highest expression levels at day 1 postburn. With regard to burn wound neovascularization, angiogenin expression was partially correlated with CD14 blister cells in the burn fluids. We provide the first report on the characterization of blister cells in burn fluids. Our data suggest that CD14 blister cells may play a role in burn wound neovascularization. Measurement of CD14 blister cells serves as a possible tool for assessing burn wound status.

Cell-spray auto-grafting technology for deep partial-thickness burns: Problems and solutions during clinical implementation

Cell-spray autografting is an innovative early treatment option for deep partial-thickness burn wounds. As an alternative to non-operative management, cell-spray autografting can achieve rapid wound re-epithelialization, particularly in large wounds. When compared to traditional mesh autografting for deep partial-thickness burn wounds, cell-spray autografting can accomplish re-epithelialization with a much smaller donor site. In this review, we describe the development of a biomedical engineering method for isolation and immediate distribution of autologous, non-cultured, adult epidermis-, and adult dermis-derived stem cells. We present data on cell isolation procedures in 44 patients with deep partial-thickness burns performed over five years under an innovative practice IRB. Treated patients presented with a variety of burn wound etiologies and a wide range of TBSA. Overall clinical results were very satisfying. The average hospital length of stay following treatment was seven days. Over the time period, the donor-site to burn-wound surface area ratio was enhanced from 1:80 to 1:100. A detailed analysis of all process-related biotechnology and operative problems, pitfalls, and solutions was performed and is reported herein. Strategies for future clinical studies are discussed.

Comparison of Laser Doppler Imaging (LDI) and clinical assessment in differentiating between superficial and deep partial thickness burn wounds

Purpose of presentation/studyTo compare the accuracy of Laser Doppler Imaging (LDI) and clinical assessment in differentiating between superficial and deep partial thickness burns to decide whether early tangential excision and grafting or conservative management should be employed to optimize burn and patient management. Study periodMarch 2015 to November 2016. Methods/procedure detailsNinety two wounds in 34 patients reporting within 5days of less than 40% burn surface area were included. Unstable patients, pregnant females and those who expired were excluded. The wounds were clinically assessed and LDI done concomitantly Plastic Surgeons blinded to each other’s findings. Wound appearance, color, blanching, pain, hair follicle dislodgement were the clinical parameters that distinguished between superficial and deep partial thickness burns. On day 21, the wounds were again assessed for the presence of healing by the same plastic surgeons. The findings were correlated with the initial findings on LDI and clinical assessment and the results statistically analyzed. Results/outcomeThe data of 92 burn wounds was analyzed using SPSS (ver. 17). Clinical assessment correctly identified the depth of 75 and LDI 83 wounds, giving diagnostic accuracies of 81.52% and 90.21% respectively. The sensitivity of clinical assessment was 81% and of LDI 92.75%, whereas the specificity was 82% for both. The positive predictive value was 93% for clinical assessment and 94% for LDI while the negative predictive value was 59% and 79% respectively. ConclusionsPredictive accuracy of LDI was found to be better than clinical assessment in the prediction of wound healing, the gold standard for wound healing being 21 days. As such it can prove to be a reliable and viable cost effective alternative per se to clinical assessment.

Effects of functional training combined with self-made hand flexing training band in treatment of scar contracture after burn injury of dorsal hand

Objective: To observe the effects of functional training combined with self-made hand flexing training band in treatment of scar contracture after burn injury of dorsal hand. Methods: Forty-six patients with scar contracture after deep partial-thickness or full-thickness burn injury of dorsal hand hospitalized in our department from March 2013 to February 2015 were divided into routine training group (RT, n=18) and comprehensive training group (CT, n=28) according to their willingness. Two weeks after the wounds were healed, patients in group RT were treated with functional training of hands and self-made pressure gloves, while patients in group CT were treated with self-made hand flexing training band (consisting of nylon strap, flexing band, and velcro) on the basis of those in group RT. All patients were treated for 3 months. Before and after treatment, scar condition of affected hands was assessed with Vancouver Scar Scale (VSS). The range of motion of joints of affected hands was measured by Total Active Movement (TAM) Scale. The function of affected hands was evaluated by Carroll Upper Extremity Function Test. Data were processed with t test, chi-square test, and Mann-Whitney U test. Results: (1) The score of VSS in patients of group RT was (10.0±1.9) points before treatment and (4.4±1.4) points after treatment, with the improved score of (5.6±1.0) points. The score of VSS in patients of group CT was (10.5±1.8) points before treatment and (4.6±1.4) points after treatment, with the improved score of (5.9±1.2) points. There was no statistically significant difference in the improved score of patients between the two groups (t=0.834, P>0.05). The score of VSS in patients of groups RT and CT after treatment was significantly lower than that before treatment (with t values respectively 14.014 and 10.003, P values below 0.01). (2) Before treatment, the ratios of excellent and good results according to TAM were 2/9 in patients of group RT and 3/14 in group CT, with no statistical differences between them (χ(2)=2.140, P>0.05). After treatment, the ratio of excellent and good results according to TAM in patients of group CT (6/7) was higher than that in group RT (5/9, χ(2)=0.023, P=0.038). The ratios of excellent and good results according to TAM in patients of groups RT and CT after treatment were significantly higher than those before treatment (with Z values respectively -2.023 and -4.780, P values below 0.05). (3) The improved score of hand function in patients of group CT was (26±12) points, which was higher than (15±7) points in group RT (t=3.278, P=0.002). The score of hand function in patients of groups RT and CT after treatment was significantly higher than that before treatment (with t values respectively 2.628 and 6.125, P values below 0.05). There were no significant differences in grades of hand function of patients between the two groups before treatment (Z=-0.286, P>0.05). After treatment, the grade of hand function in patients of group CT was higher than that in group RT(Z=-1.993, P=0.046). The grades of hand function in patients of groups RT and CT after treatment were significantly higher than those before treatment (with Z values respectively -2.717 and -4.998, P values below 0.01). Conclusions: For patients with scar contracture after burn injury of dorsal hand, early functional training combined with hand flexing training band can improve the range of motion of hand joints and functional recovery of hand, and the result was better than functional training alone.

Steel Wool-Aided Dermabrasion of Deep Partial-Thickness Burns.

Early tangential excision of the burn wound is essential for removal of necrotic tissue and promotion of burn wound healing process. However, the depth of the burn wound is not easily assessed during the tangential excision performed by hand-held dermatomes, and it may be possible to excise unburned vital dermis unnecessarily, which aids in primary epithelization of the burn wound by adnexal structures. We herein present early clinical results of steel wool-aided dermabrasion in patients with deep partial-thickness burns. This is a retrospective case study of 23 consecutive hospitalized patients with deep partial-thickness burns. All of the steel wool-aided dermabrasions were performed under general anesthesia within 48 hours after injury. Patients were excluded from the study if the admission was not within 24 hours after injury, and if the burn wound was entirely superficial partial- or full-thickness. Thirteen male and 10 female patients with a mean age of 26.2 ± 17.1 years were enrolled in the study. During the follow-up period, all of the patients had burn wounds primary epithelized on postburn day 15.1 ± 1.8, without any complications. None of the patients exhibited a mortal course, and redebridement or skin grafting of the previously dermabraded deep partial-thickness burn wounds were not required in any of the patients. Steel wool-aided dermabrasion is an easy, cost-effective, and reliable technique for the treatment of deep partial-thickness burns, which provides complete removal of necrotic tissue, preserves the vital dermis, reduces the requirement for skin grafting, and decreases length of hospital stay.

Calculations for reproducible autologous skin cell-spray grafting

Non-cultured, autologous cell-spray grafting is an alternative to mesh grafting for larger partial- and deep partial-thickness burn wounds. The treatment uses a suspension of isolated cells, from a patient's donor site skin tissue, and cell-spray deposition onto the wound that facilitates re-epithelialization. Existing protocols for therapeutic autologous skin cell isolation and cell-spray grafting have defined the donor site area to treatment area ratio of 1:80, substantially exceeding the coverage of conventional mesh grafting. However, ratios of 1:100 are possible by maximizing the wound treatment area with harvested cells from a given donor site skin tissue according to a given burn area. Although cell isolation methods are very well described in the literature, a rational approach addressing critical aspects of these techniques are of interest in planning clinical study protocols. We considered in an experimental study the cell yield as a function of the donor site skin tissue, the cell density for spray grafting, the liquid spray volume, the sprayed distribution area, and the percentage of surface coverage. The experimental data was then used for the development of constants and mathematical equations to give a rationale for the cell isolation and cell-spray grafting processes and in planning for clinical studies.

Effects of hydrogen sulfide on the secretion of cytokines in macrophages of deep partial-thickness burn wound in rats

To analyze the effects of exogenous hydrogen sulfide on the secretion of growth factors basic fibroblast growth factor (bFGF) and transforming growth factor β1 (TGF-β1), as well as inflammatory mediators tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β) in macrophages of deep partial-thickness burn wound in rats. Seventy-eight SD rats were divided into normal control group (n=6), pure burn group, sodium hydrosulfide group, propargylglycine (PPG) group, and sodium hydrosulfide+ PPG group according to the random number table, with 18 rats in each of the latter four groups. Rats in normal control group did not receive any treatment, while rats in the other four groups were inflicted with 5% total burn surface area deep partial-thickness scald (hereinafter referred to as burn) on the back. Immediately after burn, rats in pure burn group, sodium hydrosulfide group, and group PPG were intraperitoneally injected with saline 2 mL/kg, sodium hydrosulfide 56 μmol/kg, and PPG 45 mg/kg respectively, while those in sodium hydrosulfide+ PPG group were intraperitoneally injected with sodium hydrosulfide 56 μmol/kg and PPG 45 mg/kg, once a day till the day before harvesting specimen. Six rats of normal control group fed for one week, and 6 rats from each of the rest four groups on post injury day (PID) 3, 7, 14 were collected respectively. Normal skin on the back of rats in normal control group and tissue in the base of wound of rats in the other four groups were harvested to isolate macrophages, and then the content of bFGF, TGF-β1, TNF-α, and IL-1β in culture supernatant of macrophages was detected with enzyme-linked immunosorbent assay. Data were processed with one-way analysis of variance, analysis of variance of factorial design, and LSD test. Compared with that of normal control group [(42.6±2.5) and (18±4) pg/mL], the content of bFGF and TGF-β1 in culture supernatant of macrophages of rats in pure burn group was obviously increased at each time point (with P values below 0.01), peaking on PID 14 at (141.6±7.7) and (580±16) pg/mL respectively. Compared with that of pure burn group, the content of bFGF and TGF-β1 in culture supernatant of macrophages of rats in sodium hydrosulfide group was obviously increased at each time point (with P values below 0.01), peaking on PID 14 at (193.7±10.9) and (793±12) pg/mL respectively, while the content of bFGF and TGF-β1 in culture supernatant of macrophages of rats in group PPG was obviously decreased at each time point (with P values below 0.01), reaching the nadir on PID 3 at (62.0±7.1) and (170±10) pg/mL respectively. The content of bFGF and TGF-β1 in culture supernatant of macrophages of rats in sodium hydrosulfide+ PPG group was obviously lower than that of sodium hydrosulfide group but obviously higher than that of group PPG at each time point (with P values below 0.01), peaking on PID 14 at (151.3±9.0) and (579±9) pg/mL respectively. Compared with that of normal control group [(97±6) and (31±6) pg/mL], the content of TNF-α and IL-1β in culture supernatant of macrophages of rats in pure burn group was obviously increased at each time point (with P values below 0.01), peaking on PID 3 at (924±8) and (290±10) pg/mL respectively. Compared with that of pure burn group, the content of TNF-α and IL-1β in culture supernatant of macrophages of rats in sodium hydrosulfide group was obviously decreased at each time point (with P values below 0.01), reaching the nadir on PID 14 at (346±10) and (120±5) pg/mL respectively, while the content of TNF-α and IL-1β in culture supernatant of macrophages of rats in group PPG was obviously increased at each time point (with P values below 0.01), peaking on PID 3 at (1 232±13) and (410±10) pg/mL respectively. The content of TNF-α and IL-1β in culture supernatant of macrophages of rats in sodium hydrosulfide+ PPG group was obviously higher than that of sodium hydrosulfide group but obviously lower than that of group PPG at each time point (with P values below 0.01), reaching the nadir on PID 14 at (488±16) and (144±6) pg/mL respectively. Supplementation of exogenous hydrogen sulfide in small dosage can increase the secretion of growth factors bFGF and TGF-β1 in macrophages of wound in rats with deep partial-thickness burn in the early stage and reduce the release of inflammatory mediators TNF-α and IL-1β in the meantime, thus affecting the healing of wound.

Preparation of asiaticoside-loaded coaxially electrospinning nanofibers and their effect on deep partial-thickness burn injury.

Sodium alginate and chitosan were in favor of wound healing. However, the two polymers were not compatible in one formulation due to the electrostatic interaction. Coaxially electrospinning technology could make two or more noneletrospun polymers to be electrospun in independent core and shell layer. Asiaticoside-loaded coaxially electrospinning nanofibers of alginate, polyvinyl alcohol (PVA) and chitosan (alginate/PVA/chitosan) were prepared and evaluated. Morphologies and microstructure of nanofibers were observed with scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Drug release in vitro of coaxial nanofibers was also evaluated. Deep partial-thickness burn injury were established and used to evaluate the improved healing effect of asiaticoside-loaded coaxial nanofibers. Drug-loaded coaxial nanofibers prepared with the optimized formulations and technologies had the obvious core-shell structure. Coaxial nanofibers showed faster drug release profiles in vitro and this facilitated wound healing. Its healing effect on rats with deep partial-thickness burn injury was also significant based on morphology, wound healing ratio, and pathological sections. Positive expression of vascular endothelial growth factor (VEGF), cluster of differentiation 31 (CD31), and proliferating cell nuclear antigen (PCNA), and down regulation of tumor necrosis factor (TNF) and interleukin-6 (IL-6) also validated the improved effect of wound healing. In general, the asiaticoside-loaded coaxial nanofibers had obvious core-shell structure with smooth surface and uniform diameter. Its healing effect on deep partial-thickness burn injury of rats was obvious. Asiaticoside-loaded coaxial nanofibers provide a novel promising option for treatment of deep partial-thickness burn injury.

Clinical efficacy of negative-pressure wound therapy combined with porcine acellular dermal matrix for repairing deep burn wounds in limbs

Clinical efficacy of negative-pressure wound therapy combined with porcine acellular dermal matrix for repairing deep burn wounds in limbs