Clinical trials of amniotic membranes in burn wound care

Four test conditions of increasing complexity were used to evaluate the clinical efficacy of amniotic membranes as biologic dressings on donor sites and burn wounds in children. These were the clean-skin donor-site wound, the uncontaminated shallow partial-thickness burn wound, the bed of freshly excised full-thickness wounds, and the granulating surface of colonized burn wounds. The rate of epithelialization under amniotic membranes was the same as that under 5% scarlet red ointment or 0.5% silver nitrate solution dressings. Preservation of a healthy excised wound bed and maintenance of a low bacterial count in contaminated wounds paralleled the experience with human allograft dressings despite technical difficulties and the absence of vascularization of amniotic membrane and its fragile structure. Tentative conclusions are drawn as to the mechanisms by which biologic dressings exert their beneficial effects.     

Effect of topical phenytoin on burn wound healing in rats

To evaluate the effect of phenytoin on burn wounds and to compare the effect of the combination of topical phenytoin preparation in dexamethasone treated burn wounds in rats, partial thickness thermal burn wounds were inflicted upon five groups of six rats each. Group I was assigned as control, Group II received the standard silver sulphadiazine, Group III was given topical phenytoin and Group IV received injection dexamethasone, Group V received the combination of the phenytoin and the dexamethasone. The parameters observed were epithelialization period, percentage of wound contraction and histopathological analysis as indicative of the process of healing. Phenytoin group showed significant improvement in burn wound contraction in comparison to standard silver sulphadiazine group, the combination group of topical phenytoin and dexamethasone also showed significant contraction compared to dexamethasone group. The period of epithelialization also decreased significantly in groups II, III and V. In conclusion, phenytoin promotes burn wound healing as evidenced by decrease in period of epithelialization and faster wound contraction.     

Wound‐healing evaluation of entrapped active agents into protein microspheres over cellulosic gauzes

The use of active ingredients in wound management have evolved alongside the pharmaceutical agents and dressings used to deliver them. However, the development of gauzes, dressings with specific properties, still remains a challenge for several medical applications. A new methodology for the controlled release of active components for the healing of burn wounds is proposed herein. Cotton and non‐woven bandages have been cationised to promote the attachment of protein microspheres. The active agents, piroxicam and vegetable oil, were entrapped into the microspheres using ultrasound energy. Active agents were released from the microspheres by a change in pH. Wound healing was assessed through the use of standardised burn wounds induced by a cautery in human full‐thickness skin equivalents (EpidermFT). The best re‐epithelialisation and fastest wound closure was observed in wounds treated with proteinaceous microspheres attached to gauzes, after six days of healing, in comparison with commercial collagen dressing and other controls. Furthermore, the ability of these materials to reduce the inflammation process, together with healing improvement, makes these biomaterials suitable for wound‐dressing applications.     

CXC chemokines and their receptors: a case for a significant biological role in cutaneous wound healing

Wound healing requires a complex series of reactions and interactions among cells and their mediators, resulting in an overlapping series of events including coagulation, inflammation, epithelialization, formation of granulation tissue, matrix and scar formation. Cytokines and chemokines promote inflammation, angiogenesis, facilitate the passage of leukocytes from circulation into the tissue, and contribute to the regulation of epithelialization. They integrate inflammatory events and reparative processes that are important for modulating wound healing. Thus both cytokines and chemokines are important targets for therapeutic intervention. The chemokine-mediated regulation of angiogenesis is highly sophisticated, fine tuned, and involves pro-angiogenic chemokines, including CXCL1-3, 5-8 and their receptors, CXCR1 and CXCR2. CXCL1 and CXCR2 are expressed in normal human epidermis and are further induced during the wound healing process of human burn wounds, especially during the inflammatory, epithelialization and angiogenic processes. Human skin explant studies also show CXCR2 is expressed in wounded keratinocytes and Th/1/Th2 cytokine modulation of CXCR2 expression correlates with proliferation of epidermal keratinocytes. Murine excision wound healing, chemical burn wounds and skin organ culture systems are valuable models for examining the role of inflammatory cytokines and chemokines in wound healing.     

Effect of a Synthetic Dressing Formed on a Burn Wound in Rats: a Comparison of Allografts, Collagen Sheets, and Polyhydroxyethylmethacrylate in the Control of Wound Infection

Allograft dressings to control Pseudomonas wound infections in rats were studied on surgical wounds and escharectomized burn wounds. The effects of allografts were compared with a collagen sheet (Aviderm) and a synthetic dressing, polyhydroxyethylmethacrylate (Hydron), formed on the wound by mixing the polymer and the solvent. The results indicated that infections in surgical wounds were more easily controlled by dressings than similar contaminations in burn wounds. A procedure was described for the formation of a synthetic dressing directly on the wound from a mixture of polymer and solvent. This type of preparation completely filled the wound area and sealed the edges, preventing further contamination, and gave excellent coverage of the wound. With 24 h of coverage of escharectomized burn wounds, allografts provided the best dressing for reduction of wound organisms. At 96 h of coverage, Hydron and Aviderm produce significant reductions in the Pseudomonas resident in the burn wound. The results support the thesis that suitable dressings promote local host defense processes which kill the contaminating bacteria.     

The effects of topical treatment with curcumin on burn wound healing in rats

The present study was designed to determine the role of topical treatment with curcumin (Cur) on burn wound healing in rats. The Wistar-albino rats were randomly allotted into one of three experimental groups: 4th, 8th and 12th day (post burn) and all groups include subgroups which Burn and Burn + Cur. Each group contains 12 animals. Burn wounds were made on the back of rat and Cur was administered topically. At the end of the study, all animals were sacrificed and the wound tissues removed for analyse to biochemical and histopathological changes. There was a significant increase in the hydroxyproline levels in the skin of the Cur groups. Cur treated wounds were found to heal much faster as indicated by improved rates of inflammatory cells, collagen deposition, angiogenesis, granulation tissue formation and epithelialization which were also confirmed by histopathological and biochemical examinations. Our data also indicate that there is a rise in the expression of proliferating cell nuclear antigen in skin tissues of Cur-treated rats in the Burn group. The results clearly substantiate the beneficial effects of the topical application of Cur in the acceleration of wound healing.     

Comparative evaluation of aloe vera in the management of burn wounds in guinea pigs

An experimental study was designed using Hartley guinea pigs, who received full-thickness burns covering 3 percent of their body surface area by direct contact with a hot plate. A total of 40 animals were equally divided among four modalities of closed burn wound management as follows: group I: silver sulfadiazine (Silvadine); group II: aloe vera gel extract (Carrington Dermal Wound Gel); group III: salicylic acid cream (aspirin); and group IV: plain gauze occlusive dressing only. The dressings were changed daily, and the size and appearance of each burn wound were recorded until complete healing. On the sixth postburn day, quantitative burn wound cultures were made. The average time to complete healing in the control group was 50 days, and the only significant difference was found in the aloe vera-treated animals, which healed on an average of 30 days (p less than 0.02). Wound bacterial counts were effectively decreased by silver sulfadiazine (p = 0.015) and by aloe vera extract (p = 0.015). From our data it appears that aloe gel extracts permit a faster healing of burn wounds.     

A prospective, blinded, randomized, controlled clinical trial of topical negative pressure use in skin grafting

Topical negative pressure has been demonstrated to improve graft take in a number of noncomparative studies. This study aimed to assess whether split-thickness skin graft take is improved qualitatively or quantitatively with topical negative pressure therapy compared with standard bolster dressings. A blinded, prospective, randomized trial was conducted of 22 adult inpatients of Liverpool Hospital between July of 2001 and July of 2002 who had wounds requiring skin grafting. After grafting, each wound half was randomized to receive either a standard bolster dressing or a topical negative pressure dressing. Skin graft assessment was performed at 2 weeks by a single observer blinded to the randomization. Two patients were lost to follow-up and were excluded from the study. There were 20 patients (12 men and eightwomen) in the study group. The median patient age was 64 years (range, 27 to 88 years), and the mean wound size was 128 cm2 (range, 35 to 450 cm2). The wound exposed subcutaneous fat in eight patients, muscle in six patients, paratenon in four patients, and deep fascia in two patients. At 2 weeks, wounds that received a topical negative pressure dressing had a greater degree of epithelialization in six cases (30 percent), the same degree of epithelialization in nine cases (45 percent), and less epithelialization in five cases (25 percent) compared with their respective control wounds. Graft quality following topical negative pressure therapy was subjectively determined to be better in 10 cases (50 percent), equivalent in seven cases (35 percent), and worse in three cases (15 percent). Although the quantitative graft take was not significant, the qualitative graft take was found to be significantly better with the use of topical negative pressure therapy (p < 0.05). Topical negative pressure significantly improved the qualitative appearance of split-thickness skin grafts as compared with standard bolster dressings.     

A Randomized and Controlled Multicenter Prospective Study of the Chinese Medicinal Compound Fufang Xuelian Burn Ointment for the Treatment of Superficial and Deep Second-Degree Burn Wounds

The objective of this study was to evaluate the efficacy and safety of a traditional Chinese medicine, Fufang Xuelian Burn Ointment (FXBO), to treat superficial and deep second-degree burn wounds. A four-center, randomized, controlled, and prospective study was conducted. Overall, 240 patients with either superficial or deep second-degree burn wounds were enrolled consecutively in this study. Patients who were randomly assigned to the control group (superficial: 72, deep: 48) underwent common burn wound therapy, whereas those randomized to the treatment group (superficial: 72, deep: 48) received common burn wound therapy plus topical FXBO. The healing rate, healing time, effective rate, and safety data were compared between the two groups. The baseline characteristics were comparable for the two groups. The healing rate was 94.79(±7.50) in the control group and 98.60(±5.69) in the FXBO group after 14 days for patients with superficial second-degree burn wounds (P = 0.000), and 95.17(±9.68) versus 97.44(±9.81) at 28 for deep second-degree burn wounds (P = 0.025). The median healing time in the FXBO group were 9 and 21 days for superficial and deep second-degree burns, respectively, compared to 10.5 and 22.5 days, respectively, in control group (P _superficial = 0.000 and P _deep = 0.009). The results of the effective rate showed that comprehensive efficacy of the FXBO group was improved compared to the control group for either superficial or deep second-degree burns (P _superficial = 0.035 and P _deep = 0.003). There were no reported drug-related adverse events in both groups. Therefore, FXBO was well tolerated and more effective than control group for treating superficial and deep second-degree burn wounds.     

枯草芽胞杆菌活菌制剂促进烧伤创面愈合的实验研究

目的　探讨枯草芽胞杆菌活菌制剂对烧伤创面愈合的影响。方法　通过大鼠深Ⅱ°烧伤模型,使用枯草芽胞杆菌活菌制剂,观察烧伤创面愈合过程中,成纤维细胞增殖周期的变化,以及测定羟脯氨酸（OHP）的含量,同时记录烧伤创面愈合时间,从而评价该制剂对烧伤创面愈合的影响。结果　应用枯草芽胞杆菌活菌制剂可促进成纤维细胞分裂、增殖,胶原含量提高,创面愈合时间明显缩短。结论　枯草芽胞杆菌活菌制剂具有促进烧伤创面愈合的作用。     

Aerosolization of epidermal cells with fibrin glue for the epithelialization of porcine wounds with unfavorable topography

Aerosolized epidermal cell suspension was previously found to be effective for the epithelialization of full-thickness wounds. This suspension is less expensive than and requires a shorter preparation time than the currently used cultured epithelial autografts. Still, convex and irregular wounds present unfavorable conditions for homogenous dispersion of the aerosolized cell suspension. The authors hypothesized that the addition of fibrin glue to the aerosol of cells would reduce cell movement and ensure homogenous dispersion of the cells, thereby promoting wound epithelialization. The objectives of the study were to evaluate the healing of wounds with unfavorable topography after autotransplantation of an epidermal cell aerosol with and without fibrin glue.Six Yorkshire piglets were studied. An epidermal suspension was made from full-thickness groin skin. Dispase was used to separate the epidermis from the dermis, and trypsin was used to separate the epidermal cells from one another. Twenty-four hours later, full-thickness wounds with unfavorable topography were created adjacent to the vertebral column of six pigs. Twelve wounds were treated with an aerosol of epidermal cell suspension mixed with fibrin glue (study group), and 12 wounds were treated with the same suspension without the fibrin glue (control group). The percentages of total wound contraction and the epithelialized and nonepithelialized areas were evaluated 1, 2, 3, and 4 weeks after aerosolization. The histologic characteristics of the newly formed skin were examined by light microscopy using slides stained with hematoxylin and eosin.Study wounds were characterized by central epithelialization, whereas control wounds were characterized by peripheral epithelialization. Study wounds contracted at a slower rate than control wounds, but wound size was the same in both groups after 4 weeks. The addition of fibrin glue facilitated epithelialization: Study wounds showed 75.5 +/- 22.4 percent (mean +/- SD) and 94.2 +/- 8.8 percent epithelialization after 3 and 4 weeks, respectively, compared with 46.3 +/- 9.5 percent and 47.9 +/- 13.1 percent epithelialization of the control wounds at the same times. These differences between the study and control groups were statistically significant (p < 0.001, paired t test).The addition of fibrin glue to an aerosol of epidermal cells significantly enhances the epithelialization of wounds with unfavorable topography in pigs.     

Rhinophyma: treatment with electrocautery and silver-impregnated porcine xenograft

A typical case of advanced rhinophyma is reported. Partial excision reduced the size of the nose by two-thirds, leaving a thin layer of dermis. This was covered with silver-impregnated porcine xenograft, which allowed efficient drainage and remained adherent in its initial application for 2 weeks. A total of four applications of silver-impregnated porcine xenografts--the last two involving only very small areas--were required for complete epithelialization at 5 weeks after surgery. We believe that this xenograft is an ideal dressing for wounds resulting from partial excision of rhinophymatous tissue, providing the beneficial effects of biological dressings, including the hemostatic effects of collagen with the added benefit of silver's potent antibacterial properties. Silver-impregnated porcine xenograft reduces patient discomfort and results in rapid healing with excellent cosmetic results.     

Wound dressings for a proteolytic-rich environment

Wound dressings have experienced continuous and significant changes over the years based on the knowledge of the biochemical events associated with chronic wounds. The development goes from natural materials used to just cover and conceal the wound to interactive materials that can facilitate the healing process, addressing specific issues in non-healing wounds. These new types of dressings often relate with the proteolytic wound environment and the bacteria load to enhance the healing. Recently, the wound dressing research is focusing on the replacement of synthetic polymers by natural protein materials to delivery bioactive agents to the wounds. This article provides an overview on the novel protein-based wound dressings such as silk fibroin keratin and elastin. The improved properties of these dressings, like the release of antibiotics and growth factors, are discussed. The different types of wounds and the effective parameters of healing process will be reviewed.     

The use of allogeneic cultivated keratinocytes for the early coverage of deep dermal burns – indications, results and problems

Since 1995, keratinocytes are grown into cultures and used as allografts for the coverage of deep dermal defects in our burn unit. Donor skin samples are mostly acquired from other burn patients. In addition, special methods of skin preservation allow us the use of skin, which has been taken in redundancy for split thickness skin grafting from nonburned patients.Thirty five patients with deep partial thickness burns in the face were treated since 1996 according to the following concept: Dermabrasion or tangential excision was performed before the 5(th) day following trauma. If viable dermis was present, the wounds were covered with sheets of allogeneic cultivated keratinocytes. In cases of deeper defects, autologous skin grafts were applied. In 23 cases, epithelialisation was achieved within 10 days, in 8 patients, a prolonged duration until complete healing was observed. In 5 faces, coverage of residual defects with skin grafts was necessary. The mentioned problems of wound healing occurred from infection, incomplete excision of burn eschar and a depth of the wound which was retrospectively seen too deep for the treatment with keratinocytes. At follow up, patients were examined clinically and functionally with Frey's faciometer(R), which is an instrument for quantification of mimic movements. In cases of uncomplicated healing, a nearly complete restitution was found.Other indications include deep dermal burns in children and the coverage of early excised wounds in adults, with a reasonable amount of viable dermis remaining, both resulting in a significant reduction of donor-site morbidity. In severely burned adults with limited donor sites, it offers the possibility of immediate definite coverage of large areas.     

Permanent restoration of human skin treated with cultured epithelium grafting--wound healing by stem cell based tissue engineering--

The technique of epidermal cell culture developed by Green and colleagues made a breakthrough in the treatment of massive wounds in vivo with grown cells in vitro. In the past two decades, progress of culture methods and clinical practice have been made and now it is possible to treat extensive skin defect with large amounts of cultured epithelium. Since 1985, we have been successfully used cultured epidermis as autografts for the permanent coverage of full-thickness burn wounds or excised burn scars, giant nevi, tattoos and so on. Furthermore, cultured epidermis has been available as allografts to promote the healing of chronic skin ulcers or deep dermal burn. In this paper we describe our clinical experience of cultured epithelium grafting for the treatment of wounds and predict new trial of wound management and regeneration based on tissue engineering concept.     

VSD联合金因肽治疗手足外科难愈性伤口的临床研究

目的:观察封闭式负压引流技术(VSD)联合金因肽治疗手足外科难愈性伤口的临床疗效,为临床联合运用提供依据。方法:86例手足外科难愈性伤口患者随机分为治疗组和对照组各43例,治疗组采用VSD联合金因肽治疗,对照组采用常规换药治疗,观察两组临床疗效和上皮化时间、愈合时间、创面愈合率、换药次数、伤口疼痛评分、住院费用差异。结果:治疗组总有效率90.70%;对照组总有效率72.09%;两组比较,有显著性差异(P0.05);治疗组上皮化时间、愈合时间、创面愈合率、换药次数、伤口疼痛评分、住院费用较对照组相比明显缩短,差异有统计学意义(P0.05)。结论:VSD联合金因肽治疗手足外科难愈性伤口疗效确切,能更好促进损伤组织的修复,加速创面愈合,值得临床推广应用。     

Adipose-derived stem cells for wound healing

Wound healing is a complex but a fine-tuned biological process in which human skin has the ability to regenerate itself following damage. However, in particular conditions such as deep burn or diabetes the process of wound healing is compromised. Despite investigations on the potency of a wide variety of stem cells for wound healing, adipose-derived stem cells (ASCs) seem to possess the least limitations for clinical applications, and literature showed that ASCs can improve the process of wound healing very likely by promoting angiogenesis and/or vascularisation, modulating immune response, and inducing epithelialization in the wound. In the present review, advantages and disadvantages of various stem cells which can be used for promoting wound healing are discussed. In addition, potential mechanisms of action by which ASCs may accelerate wound healing are summarised. Finally, clinical studies applying ASCs for wound healing and the associated limitations are reviewed.     

新型抗菌凝胶敷料治疗深II度烧伤创面的疗效评价

目的:评价新型抗菌凝胶敷料普朗特联合磺胺嘧啶银霜治疗深Ⅱ度烧伤创面的临床疗效和安全性。方法:采用前瞻性随机对照的方法将2015年3月至2016年5月来我科初次就诊的深Ⅱ度烧伤患者74例分为两组:试验组38例采用新型抗菌凝胶敷料普朗特联合磺胺嘧啶银霜治疗,对照组36例采用磺胺嘧啶银霜治疗。两组均采用规定的标准化创面处理方式,其余治疗均按常规进行。分别统计和比较两组的创面愈合时间、愈合率、创面细菌培养阳性率、换药时的疼痛程度,同时定期监测患者在用药期间有无实验室指标异常及不良反应的发生。结果:试验组创面愈合时间(21.11 3.13)d,明显短于对照组(25.28 4.50)d(P0.01)。治疗后7 d、14 d、21 d,试验组创面愈合率分别为(26.63 5.21)%、(63.32 5.32)%、(92.66 4.19)%,均显著高于对照组(P0.05)。治疗后7 d、14 d,试验组分别有5例(13.16%)和1例(2.63%)创面细菌培养阳性,明显低于对照组的12例(33.33%)和8例(22.22%)(P0.05)。治疗后7 d、14 d、21 d,试验组换药时的疼痛评分均明显低于对照组(P0.05)。两组治疗期间实验室检查指标均无异常波动,均未见明显不良反应。结论:新型抗菌凝胶敷料普朗特联合磺胺嘧啶银霜治疗深Ⅱ度烧伤创面能缩短愈合时间,提高愈合率,减少创面感染发生,减轻患者痛苦。     

Efficacy of l-proline administration on the early responses during cutaneous wound healing in rats

Proline (Pro) plays a versatile role in cell metabolism and physiology. Pro and hydroxypro are major imino acids present in collagen, an important connective tissue protein, essential for wound healing, which is a primary response to tissue injury. This study explains the role of l-pro on cutaneous wound healing in rats when administered both topically and orally. Open excision wounds were made on the back of rats, and 200 μl (200 mg) of pro was administered topically and orally once daily to the experimental rats until the wounds healed completely. The control wounds were left untreated. Granulation tissues formed were removed after day 4 and 8 of post excision wounding, and biochemical parameters such as total protein, collagen, hexosamine, and uronic acid were estimated. Levels of enzymatic and non-enzymatic antioxidants such as catalase, superoxide dismutase, glutathione peroxidase, ascorbic acid, and reduced glutathione were evaluated along with lipid peroxides in the granulation tissues. Tensile strength and period of epithelialization were also measured. It was observed that the treated wounds healed very fast as evidenced by augmented rates of epithelialization and wound contraction, which was also confirmed by histological examinations. The results strappingly authenticate the beneficial effects of the topical administration of l-proline in the acceleration of wound healing than the oral administration and control.     

Stimulation of skin wound contraction and epithelialization by soluble collage]

It is found that local applications of the unguent with soluble collagen, but not solution of the collagen, stimulate healing of erosions and full-thickness excision wounds in the rat skin. Not all the stages of healing were stimulated, but only two of them--contraction and epithelialization.