Split-thickness Skin Autografts Research Articles

Comparison of the Effectiveness of Methods for Obtaining and Application the Stromal-Vascular Fraction of Adipose Tissue in an Experimental Model of a Donor Wound in Burns

Introduction. The optimal method of obtaining and application a stromal-vascular fraction (SVF) of adipose tissue in the treatment of donor wounds in burned patients has not been determined.Objective — to compare the effectiveness of the stromal-vascular fraction of adipose tissue in the treatment of donor wounds, depending on the method of obtaining (mechanical and enzymatic) and the injection (subdermal, intradermal) into the tissue.Material and methods. Wistar rats (n = 30) were divided into 2 investigated groups: in the first group (eSVF) enzymatic processing of adipose tissue (n = 10) was used, in the second group (mSVF) mechanical processing was used (n = 10). Another 10 rats were used as adipose tissue donors’ group. A deep burn was created in all animals, and after 4 days two more donor wounds were created by taking a split thickness skin autograft: the stromal-vascular fraction was injected intradermally into one of the wounds, subdermally into the other. After 14 days, the area of epithelialization, the microcirculation index and the histological microstructure of the skin were evaluated.Results. The proportion of completely epithelized donor wounds in the eSVF-group was 85 %, in the mSVF-group — 55 % (p < 0.05). The index of microcirculation significantly decreased after intradermal injections in the eSVF-group (p < 0.01), and after subdermal injections — in the mSVF-group (p < 0.05). According to histomorphometry, with intradermal injections of eSVF, the thickness of the epidermis and the layer of granulation tissue is less than in the mSVF group (p < 0.01). At the same time, the relative density of collagen fibers in the granulation tissue was significantly higher after the injections of eSVF than after mSVF (p < 0.01). Comparison of injections of the stromal-vascular fraction showed: no significant differences were found when using eSVF; when using mSVF, the subdermal injections are preferable, since it was accompanied by a significantly lower thickness of granulation tissue (p < 0.01).Conclusions. The enzymatically obtained stromal-vascular fraction of adipose tissue has advantages over the mechanically obtained one: the efficiency of eSVF is equally high when used with intradermally and subdermally injections, which are confirmed by the structure and blood circulation in the newly formed skin. When using mSVF, intradermal injections are the least effective, and subdermal injections are accompanied by a moderately pronounced positive dynamic in the microstructure of the skin of donor wounds.

Higher serum prealbumin levels are associated with higher graft take and wound healing in adult burn patients: A prospective observational trial

IntroductionNutritional support is essential in burn care. There are few studies investigating the effect of nutrition on burn healing. The purpose of this study was to determine the relationship between perioperative serum prealbumin levels and the probability of autologous skin graft take in burned patients. Materials and methodsA prospective observational study was carried out with burned adults recruited consecutively from April 2019 until September 2021. Serum prealbumin was determined perioperatively. The percentage of graft take was evaluated over the first 5 postoperative dressing changes. Time until full epithelialization (absence of wounds) was also registered. ResultsA total of 60 patients were recruited, mostly middle-aged people with moderate flame burns. Serum prealbumin levels and graft take had a weak-moderate, nonlinear, statistically significant correlation. They were also an independent predictor of full epithelialization on the fifth dressing change, together with burn depth. Higher perioperative serum prealbumin levels were significantly associated with a reduction in time until full epithelialization. ConclusionsPerioperative serum prealbumin levels are significantly correlated with the probability of split-thickness skin autograft take in burned patients and with a reduced time to achieve complete epithelialization. They were an independent predictor of full graft take.

Artificial dermis combined with split-thickness skin autograft in the treatment of hand thermal compression wounds: a single center case-control study.

To explore the clinical effect of artificial dermis combined with split-thickness skin autograft in treating hand thermal compression wounds. Forty-two patients in our hospital from January 2016 to October 2022 with thermal compression wounds were divided into two groups. The survival rate of autologous skin grafts seven days after skin grafting, the number of operations, total hospital stay, total hospitalization cost, and bacterial culture results of secretions were recorded. The visual analog scale was used to evaluate the wound pain. The condition of skin graft rupture was recorded and the scar status of the donor site was evaluated by the Vancouver Scar Scale. It showed combination of artificial dermis, split-thickness skin autograft, and vacuum sealing drainage improves the treatment of hand thermal compression wounds by enhancing the survival rate of skin grafting (95.24% > 66.67%), reducing the number of operations (P < 0.001), relieving wound pain (P < 0.001), effectively controlling wound infection (4.76% < 9.52%), and reducing the skin graft rupture rate after surgery (4.8% < 28.6%). There was no evident scar hyperplasia in the donor (P = 0.003) and skin graft areas (P < 0.001), which had a good recovery of hand function (P = 0.037); however, this treatment strategy may prolong the hospital stay (P = 0.030) and increase the total hospitalization cost (P = 0.030). The composite transplantation of artificial dermis and split-thickness skin combined with the VSD significantly improves treatment and aesthetic outcomes in patients with thermal compression wounds to the hand, which is worth promoting and applying in clinical practice.

Cryoprecipitate and platelets-rich-plasma as a combined assisted therapy for burns: A promoted case series for future trials

IntroductionIn this paper, we present the first application of split-thickness skin autografts soaked in a combination of platelet-rich plasma (PRP) and cryoprecipitate for four cases of second and third-degree burns. Case presentationWe describe four cases of second and third-degree burns in males aged 35, 10, 24, and 5 years, respectively. The total body surface area (TBSA) affected in these cases ranged from 10 % to 35 %. The burn areas included the entire upper and lower back, the lower limbs, and the head, with involvement of the outer table of the calvarium according to Harrison's classification. To expedite wound healing, we applied split-thickness autografts soaked in a mixture of cryoprecipitate and PRP. Additionally, we covered the grafts with dressings soaked in the same mixture, resulting in successful graft acceptance and improved burn healing. DiscussionSkin wound healing involves increased angiogenesis, re-epithelialization, and modulation of inflammation. PRP has been shown to enhance re-epithelialization, a crucial process in skin wound healing. However, there is a lack of studies on the role of cryoprecipitate in re-epithelialization. Therefore, we propose the use of autologous skin grafts soaked in a combination of cryoprecipitate and PRP to expedite healing. ConclusionThis case series demonstrates that the use of split-thickness autografts soaked in a mixture of cryoprecipitate and PRP significantly improves and accelerates burn healing while contributing to acceptable graft outcomes.

Effectiveness of Autologous Platelet-Rich Plasma and Stromal Vascular Fraction in Autologous Skin Grafting

Introduction: Despite the medical advances, burns remain a serious challenge and require new and promising treatment options, such as biomedical technologies with a high potential for burn wound treatment. However, high cost and complexity of biotechnologies limit their routine use, but autologous tissues, such as stromal vascular fraction (SVF) and autologous platelet-rich plasma (PRP), overcome these shortcomings. Objective: To demonstrate a successful case of using a combination of adipose-derived SVF and autologous PRP during autologous skin grafting in a severely burned patient. Material and methods: We present a successful case of 84-year-old Patient B. treated at Saint Petersburg I. I. Dzhanelidze Research Institute of Emergency Medicine in September-October 2022. He was diagnosed with a 11% (6%) / II-III degree flame burn of the head, neck, trunk, and upper extremities and first-degree inhalation injury. At the first stage, the general condition of the patient was stabilized, and he was prepared for surgery. At the second stage, on day 25 of treatment we performed skin grafting using split-thickness autografts with rare perforations and application of SVF and autologous PRP on a burn wound. We evaluated the treatment effectiveness using planimetry, cytology, and histology. Results: We observed complete engraftment of the autograft with no lysis or rejection during the first dressing change on day 3 after surgery and complete skin restoration on day 11. Cytologic findings over time showed an active decrease in inflammatory cells and an increase in regenerative cells, indicating successful wound healing. Histology demonstrated formation of normal stratified squamous epithelium with areas of hyperkeratosis and young granulation tissue in the superficial layers of the dermis on day 6. Conclusions: Our case demonstrated that the combination of SVF and autologous PRP facilitates split-thickness skin autograft engraftment.

A prospective dual-centre intra-individual controlled study for the treatment of burns comparing dermis graft with split-thickness skin auto-graft

To investigate if donor and recipient site morbidity (healing time and cosmesis) could be reduced by a novel, modified split-thickness skin grafting (STSG) technique using a dermal component in the STSG procedure (DG). The STSG technique has been used for 150 years in surgery with limited improvements. Its drawbacks are well known and relate to donor site morbidity and recipient site cosmetic shortcomings (especially mesh patterns, wound contracture, and scarring). The Dermal graft technique (DG) has emerged as an interesting alternative, which reduces donor site morbidity, increases graft yield, and has the potential to avoid the mesh procedure in the STSG procedure due to its elastic properties. A prospective, dual-centre, intra-individual controlled comparison study. Twenty-one patients received both an unmeshed dermis graft and a regular 1:1.5 meshed STSG. Aesthetic and scar assessments were done using The Patient and Observer Scar Assessment Scale (POSAS) and a Cutometer Dual MPA 580 on both donor and recipient sites. These were also examined histologically for remodelling and scar formation. Dermal graft donor sites and the STSG donor sites healed in 8 and 14 days, respectively (p < 0.005). Patient-reported POSAS showed better values for colour for all three measurements, i.e., 3, 6, and 12 months, and the observers rated both vascularity and pigmentation better on these occasions (p < 0.01). At the recipient site, (n = 21) the mesh patterns were avoided as the DG covered the donor site due to its elastic properties and rendered the meshing procedure unnecessary. Scar formation was seen at the dermal donor and recipient sites after 6 months as in the standard scar healing process. The dermis graft technique, besides potentially rendering a larger graft yield, reduced donor site morbidity, as it healed faster than the standard STSG. Due to its elastic properties, the DG procedure eliminated the meshing requirement (when compared to a 1:1.5 meshed STSG). This promising outcome presented for the DG technique needs to be further explored, especially regarding the elasticity of the dermal graft and its ability to reduce mesh patterns.Trial registration: ClinicalTrials.gov Identifier (NCT05189743) 12/01/2022.

Composition and Performance of Autologous Engineered Skin Substitutes for Repair or Regeneration of Excised, Full-Thickness Burns.

Prompt and permanent wound closure after burn injuries remains a requirement for patient recovery. Historically, split-thickness skin autograft (STAG) has served as the prevailing standard of care for closure of extensive, deep burns. Because STAG availability may be insufficient in life-threatening burns, alternatives have been evaluated for safety and efficacy of wound closure. Since the 1970s, alternatives consisting of cultured epidermal keratinocytes, and/or acellular dermal substitutes were studied and translated into services and devices that facilitated wound closure, survival, and recovery after major burns. Cultured epithelial autografts (CEA) promoted epidermal closure of wounds but were not stable during long-term recovery. An acellular dermal substitute consisting of collagen and glycosaminoglycans (C-GAG) provided more uniform dermal repair, and reduced needs for epidermal harvesting but was subject to loss from microbial contamination. More recently, an autologous engineered skin substitute (ESS) has been reported and includes a C-GAG polymer populated with fibroblasts and keratinocytes which form basement membrane. ESS can be applied clinically over a vascularized dermal substitute and generates stable wound closure that is smooth, soft, and strong. Despite these advances, no current alternatives for permanent wound closure restore the anatomy and physiology of uninjured skin. Current alternatives act by mechanisms of wound healing, not by developmental biology by which skin forms in utero with pigment, hair, sweat and sebaceous glands, microvasculature, and nerve. Until full-thickness burns are restored with all of the normal structures and functions of uninjured skin, regenerative medicine of skin will remain an ambitious aspiration for future researchers and engineers to achieve.

Live Skin Allograft for Coverage of Deep and Extensive Burns: First Experience in Morocco

The gold standard for closure of excised full-thickness burns is split-thickness skin autograft. Patients with very large burns have limited donor sites for harvesting of autograft and may benefit from the use of skin Allografts. Taken from cadaveric or human skin as part of tissue donation. Allograft skin has been widely used for wound management in burn centers. Functional as biologic dressing, it can not only provide ideal temporary wound coverage in extensive burns when autograft is not immediately available but also prepare the wound bed for definitive autografting. In this study, we present the results of the use of allograft from living donors in three children, the use of this live skin allograft has permitted to keep the children’s alive in a balanced physiologic state until autologous skin graft or spontaneous healing closed all wounds. The procedure of live skin allograft is simple and replicable, and can be applied in settings where no skin bank is available in the management of deep burns.

Biofabrication and preclinical evaluation of a large-sized human self-assembled skin substitute

Severe skin burns are widely treated using split-thickness skin autografts. However, the accessibility of the donor site may be limited depending on the size of the injured surface. As an alternative to skin autografts, our laboratory is clinically investigating a model of human self-assembled skin substitute (SASS) with a standard size of 35 cm2. For the management of extensive skin wounds, multiple grafts are required to cover the entire wound bed. Even if SASSs could provide an adequate and efficient treatment, in some cases, the long-term follow-up of the skin graft site reveals the appearance of marks at the junction between SASSs. This study aims to produce a large-sized self-assembled skin substitute (L-SASS; 289 cm2) and evaluate its preclinical potential for skin wound coverage. The L-SASSs and SASSs shared similar contraction behavior on an agar surface, thickness, and epidermal differentiation in vitro. After grafting, similar histological results were obtained for skin substitutes produced with both methods. Hence, the self-assembly approach of tissue engineering is a scaffold-free method that allows the production of living skin substitutes in a large format.

Dehydrated Human Amnion Chorion Membrane as Treatment for Pediatric Burns.

Objective: Pediatric burns are a major source of injury and in the absence of adequate care can lead to lifelong functional loss and disfigurement. While split thickness skin autografts are the current standard of care for deep partial and full-thickness burns, this approach is associated with considerable morbidity. For this reason, alternative skin substitutes such as allografts have gained interest.Approach: In the present study, we present a case series of 30 children with various types of burns treated with dehydrated human amnion chorion membrane (dHACM).Results: We show that treatment with dHACM is associated with an excellent rate of healing comparable to split thickness skin grafts with less rate of hypertrophic scar and contracture.Innovation: Treatment with dHACM is particularly attractive as it consists of many tissue regenerative factors, such as growth factors and immune modulators, thus it will reduce the risk of scaring.Conclusion: While dHACM is associated with an increased upfront cost, treating patients with small to moderate-sized burns with dHACM in their regional centers works to decrease downstream costs such as management of prolonged pain from donor-site morbidity, revisional surgeries from scar and contractures of split thickness grafts, and avoiding the cost of transfer to higher level centers of care. Our findings challenge the current standard of care, suggesting that dHACM provides an alternative to the current use of split thickness skin grafting and is a safe, feasible, and potentially superior substitute for the management of small to moderate total body surface area partial and full-thickness pediatric burns.

Benefits of cryopreserved human amniotic membranes in association with conventional treatments in the management of full-thickness burns.

The use of split-thickness skin autografts (STSA) with dermal substitutes is the gold standard treatment for third-degree burn patients. In this article, we tested whether cryopreserved amniotic membranes could be beneficial to the current treatments for full-thickness burns. Swines were subjected to standardised full-thickness burn injuries, and then were randomly assigned to treatments: (a) STSA alone; (b) STSA associated with the dermal substitute, Matriderm; (c) STSA plus human amniotic membrane (HAM); and (d) STSA associated with Matriderm plus HAM. Clinical and histological assessments were performed over time. We also reported the clinical use of HAM in one patient. The addition of HAM to classic treatments reduced scar contraction. In the presence of HAM, skin wound healing displayed high elasticity and histological examination showed a dense network of long elastic fibres. The presence of HAM increased dermal neovascularization, but no effect was observed on the recruitment of inflammatory cells to the wound. Moreover, the use of HAM with classical treatments in one human patient revealed a clear benefit in terms of elasticity. These results give initial evidence to consider the clinical application of HAM to avoid post-burn contractures and therefore facilitate functional recovery after deep burn injury.

Autologous bilayered self-assembled skin substitutes (SASSs) as permanent grafts: a case series of 14 severely burned patients indicating clinical effectiveness.

Split-thickness skin autografts (AGs) are the standard surgical treatment for severe burn injuries. However, the treatment of patients with substantial skin loss is limited by the availability of donor sites for skin harvesting. As an alternative to skin autografts, our research group developed autologous self-assembled skin substitutes (SASSs), allowing the replacement of both dermis and epidermis in a single surgical procedure. The aim of the study was to assess the clinical outcome of the SASSs as a permanent coverage for full-thickness burn wounds. Patients were recruited through the Health Canada's Special Access Program. SASSs were grafted on debrided full-thickness wounds according to similar protocols used for AGs. The graft-take and the persistence of the SASS epithelium over time were evaluated. 14 patients received surgical care with SASSs. The mean percentage of the SASS graft-take was 98 % (standard deviation = 5) at 5 to 7 d after surgery. SASS integrity persisted over time (average follow-up time: 3.2 years), without noticeable deficiency in epidermal regeneration. Assessment of scar quality (skin elasticity, erythema, thickness) was performed on a subset of patients. Non-homogeneous pigmentation was noticed in several patients. These results indicated that the SASS allowed the successful coverage of full-thickness burns given its high graft-take, aesthetic outcome equivalent to autografting and the promotion of long-term tissue regeneration. When skin donor sites are in short supply, SASSs could be a valuable alternative to treat patients with full-thickness burns covering more than 50 % of their total body surface area.

Inflammatory response and biomechanical properties of coaxial scaffolds for engineered skin in vitro and post-grafting

Engineered skin (ES) offers many advantages over split-thickness skin autografts for the treatment of burn wounds. However, ES, both in vitro and after grafting, is often significantly weaker, less elastic and more compliant than normal human skin. Biomechanical properties of ES can be tuned in vitro using electrospun co-axial (CoA) scaffolds. To explore the potential for coaxial scaffold-based ES use in vivo, two CoA scaffolds were fabricated with bioactive gelatin shells and biodegradable synthetic cores of polylactic acid (PLA) and polycaprolactone (PCL), and compared with gelatin monofilament scaffolds. Fibroblast and macrophage production of inflammatory cytokines interleukin 6 (IL-6) and transforming growth factor β-1 was significantly higher when cultured on PLA and PCL monofilament scaffolds compared to gelatin monofilament scaffolds. The core-shell fiber configuration significantly reduced production of pro-inflammatory cytokines to levels similar to those of gelatin monofilament scaffolds. In vitro, ES mechanical properties were significantly enhanced using CoA scaffolds; however, after grafting CoA- and gelatin-based ES to full-thickness excisional wounds on athymic mice, the in vitro mechanical advantage of CoA grafts was lost. A substantially increased inflammatory response to CoA-based ES was observed, with upregulation of IL-6 expression and a significant M2 macrophage presence. Additionally, expression of matrix metalloproteinase I was upregulated and collagen type I alpha 1 was downregulated in CoA ES two weeks after grafting. These results suggest that while coaxial scaffolds provide the ability to regulate biomechanics in vitro, further investigation of the inflammatory response to core materials is required to optimize this strategy for clinical use. Statement of SignificanceEngineered skin has been used to treat very large burn injuries. Despite its ability to heal these wounds, engineered skin exhibits reduced biomechanical properties making it challenging to manufacture and surgically apply. Coaxial fiber scaffolds have been utilized to tune the mechanical properties of engineered skin while maintaining optimal biological properties but it is not known how these perform on a patient especially with regards to their inflammatory response. The current study examines the biomechanical and inflammatory properties of coaxial scaffolds and uniaxial scaffolds in vitro and in vivo. The results show that the biological response to the scaffold materials is a critical determinant of tissue properties after grafting with reduced inflammation and rapid scaffold remodeling leading to stronger skin.

From skin allograft coverage to allograft–micrograft sandwich method: A retrospective review of severe burn patients who received conjunctive application of cultured epithelial autografts

A 12-year retrospective review of severe burn patients who received cultured epithelial autografts (CEA) at the Singapore General Hospital Burns Centre from January 2005 to December 2016 was carried out. During this period, two different surgical modalities were employed to manage these burn injuries. In the earlier period, following early excision of the burn wounds, exposed surfaces were covered with a combination of split thickness skin autografts (STSG) and allografts. Surfaces covered with skin allografts were subsequently debrided of the allo-epidermis in about 3 weeks later, exposing the allodermis with granulating tissues for grafting of CEA; a technique known as the Cuono’s method. In the later period, allograft–autologous micrograft sandwich technique was used to graft on the early excised burns with subsequent CEA grafting. The former and latter groups represented by STSG/C (n=10) and M/CEA (n=14) respectively, were compared in terms of clinical profiles, outcomes, allograft/CEA usage and total graft cost. No significant differences were found based on mean age and presence of inhalation burns between the two treatment methods However, percentage total body surface area (TBSA) and Revised Baux Score were significantly higher (p<0.05) in the M/CEA group compared to the STSG/C group. Differences in clinical outcomes of mortality and length of hospital stay between the 2 groups were statistically insignificant. The average area amount of skin allografts used per patient in the M/CEA group was significantly lower compared to the STSG/C method group which contributed to lower total average cost of grafts used per % TBSA in the M/CEA method group. This might be attributed to the presence of micrografts which seemed to improve stabilization of the wound bed resulting in less operating procedures and improving CEA take. To conclude, the M/CEA method introduced was able to treat more severe burn patients at lower graft costs without compromising critical clinical outcomes significantly.

Stem cells, niches and scaffolds: Applications to burns and wound care.

The importance of skin to survival, and the devastating physical and psychological consequences of scarring following reparative healing of extensive or difficult to heal human wounds, cannot be disputed. We discuss the significant challenges faced by patients and healthcare providers alike in treating these wounds. New state of the art technologies have provided remarkable insights into the role of skin stem and progenitor cells and their niches in maintaining skin homeostasis and in reparative wound healing. Based on this knowledge, we examine different approaches to repair extensive burn injury and chronic wounds, including full and split thickness skin grafts, temporising matrices and scaffolds, and composite cultured skin products. Notable developments include next generation skin substitutes to replace split thickness skin autografts and next generation gene editing coupled with cell therapies to treat genodermatoses. Further refinements are predicted with the advent of bioprinting technologies, and newly defined biomaterials and autologous cell sources that can be engineered to more accurately replicate human skin architecture, function and cosmesis. These advances will undoubtedly improve quality of life for patients with extensive burns and difficult to heal wounds.

Free skin grafting in reconstructive surgery of burns in children

When performing reconstructive surgery in children suffering from extensive post-burn hypertrophic scars, the main problem is deficiency of donor intact skin.&#x0D; Aim. This study aimed to determine the possibility of using the expander skin balloon expansion method for obtaining free, large area split-thickness skin autografts.&#x0D; Materials and methods. A comparative analysis of treatment for 39 children with extensive post-burn hypertrophic scars was performed. In 16 children (experimental group), balloon skin expansion of a donor site for obtaining large area split-thickness skin grafts (more than 100 cm²) was performed. In 23 children (control group), the large area grafts were cut off without prior balloon skin expansion of the donor site.&#x0D; Results. In cases where it is necessary to close a wound defect over 100 cm², it is advisable to perform prior balloon skin expansion of the donor site. This technique enables attainment of an injury-resistant free implant full grafting material and also provides multiple uses of a donor site without disturbing the esthetics.

Adult onset dyschomatosis universalis.

Dear Editor: Dyschromatosis universalis hereditaria (DUH) is a rare hereditary skin disorder that is characterized by a mixture of small and irregularly sized hyperpigmented and hypopigmented macules of a mottled or reticulated pattern. The usual onset age of DUH is 6 years1. The common pattern of inheritance is generally autosomal dominant; however, rarely, a few cases show a sporadic pattern. Some authors named this form as dyschromatosis universalis (DU) instead of DUH2. We report a case of DU in a 29-year-old female patient with no family history and a late onset of the disease. A 29-year-old Korean woman presented with asymptomatic multiple pinhead to rice sized mottled hypopigmented macules with diffuse hyperpigmented patches on the abdomen and left upper arm (Fig. 1A). The hyperpigmented lesions, which had been noted 1 year previously, started initially on the abdomen and gradually spread to the left upper arm. She has no history of systemic disease or any previous cutaneous disease. She also denied any family history of skin discoloration or similar skin lesions. Fig. 1 (A) Multiple pinhead to rice sized mottled hypopigmented macules with diffuse hyperpigmented patches. (B) A closer view. (C) A biopsy specimen taken from a hyperpigmented lesion on the abdomen showed increased abundant melanin pigments in the epidermis ... A biopsy specimen taken from the hyperpigmented lesion on the abdomen showed increased abundant melanin pigments in the epidermis, with normal number and distribution of melanocytes on hematoxylin-eosin, Fontana Masson, and MART-1 stainning (Fig. 1B). In contrast, the histopathologic finding of a hypopigmented macule suggested a reduced amount of melanin pigments in the lesion area (Fig. 1C). On the basis of these findings, the diagnosis was concluded to be DU. We recommended treatment with Q-switched Nd:YAG laser for the hyperpigmented lesions; however, she refused the therapy. She has been followed without any changes. Rycroft et al.3 reported a case with no family history, but was associated with short stature and high tone deafness. In addition, Shono amd Toda4 reported a case with no family history and associated with photosensitivity and a neurosensory hearing defect. Also, Kim et al.2 reported a case that occurred in the patient at age 20 years, with a sporadic pattern and with no comorbid conditions. Some authors suggest that DU is a more appropriate name for the sporadic cases rather than DUH2. DU should be differentiated from other conditions showing both hyperpigmentation and hypopigmentation, such as generalized Dowling-Degos disease, xeroderma pigmentosum, dyskeratosis congenita and chronic radiodermatitis. DU generally does not involve a family history and present only dyschromatosis without systemic disorder. Various therapeutic trials, such as psoralen and ultraviolet A irradiation, thin split-thickness skin autograft, and Q-switched ruby laser have been tried to treat these lesions; however, there is no definitely effective treatment for both hyperpigmented and hypopigmented lesions. Recently, Kim et al.5 reported that they successfully treated the hyperpigmented lesions of DUH with a Q-switched Nd:YAG laser. Only a few cases of DU have been reported worldwide, and we could find only three cases in the Korean literature (Table 1)2,3,4. Particularly, adult-onset DU like our case is very unusual. Thus, we here report a case of DU occurring in a 29-year-old female patient with no family history. Table 1 Reported cases of dyschromatosis universalis in global literatures (including Korea)

Study of proliferation and 3D epidermal reconstruction from foreskin, auricular and trunk keratinocytes in children

ObjectiveSevere burns in children are conventionally treated with split-thickness skin autografts or epidermal sheets. An alternative approach is to graft isolated keratinocytes. We evaluated foreskin and other anatomic sites as donor sources for autologous keratinocyte graft in children. We studied in vitro capacities of isolated keratinocytes to divide and reconstitute epidermal tissue. MethodsKeratinocytes were isolated from foreskin, auricular skin, chest and abdominal skin by enzymatic digestion. Living cell recovery, in vitro proliferation, epidermal reconstruction capacities and differentiation status were analyzed. ResultsIn vitro studies revealed the higher yield of living keratinocyte recovery from foreskin and higher potential in terms of proliferative capacity, regeneration and differentiation.Cultured keratinocytes from foreskin express lower amounts of differentiation markers than those isolated from trunk and ear. Histological analysis of reconstituted human epidermis derived from foreskin and inguinal keratinocytes showed a structured multilayered epithelium, whereas those obtained from ear pinna-derived keratinocytes were unstructured. ConclusionOur studies highlight the potential of foreskin tissue for autograft applications in boys. A suitable alternative donor site for autologous cell transplantation in female paediatric burn patients remains an open question in our department. We tested the hypothesis that in vitro studies and RHE reconstructive capacities of cells from different body sites can be helpful to select an optimal site for keratinocyte isolation before considering graft protocols for girls.

Epidermal Healing in Burns

Background:Treatment of burned patients is a tricky clinical problem not only because of the extent of the physiologic abnormalities but also because of the limited area of normal skin available.Methods:Literature indexed in the National Center (PubMed) has been reviewed using combinations of key words (burns, children, skin graft, tissue engineering, and keratinocyte grafts). Articles investigating the association between burns and graft therapeutic modalities have been considered. Further literature has been obtained by analysis of references listed in reviewed articles.Results:Severe burns are conventionally treated with split-thickness skin autografts. However, there are usually not enough skin donor sites. For years, the question of how covering the wound surface became one of the major challenges in clinical research area and several procedures were proposed. The microskin graft is one of the oldest methods to cover extensive burns. This technique of skin expansion is efficient, but results remain inconsistent. An alternative is to graft cultured human epidermal keratinocytes. However, because of several complications and labor-intensive process of preparing grafts, the initial optimism for cultured epithelial autograft has gradually declined. In an effort to solve these drawbacks, isolated epithelial cells from selecting donor site were introduced in skin transplantation.Conclusions:Cell suspensions transplanted directly to the wound is an attractive process, removing the need for attachment to a membrane before transfer and avoiding one potential source of inefficiency. Choosing an optimal donor site containing cells with high proliferative capacity is essential for graft success in burns.

Fibrin biomatrix-conjugated platelet-derived growth factor AB accelerates wound healing in severe thermal injury

Controlled delivery of growth factors from biodegradable biomatrices could accelerate and improve impaired wound healing. The study aim was to determine whether platelet-derived growth factor AB (PDGF.AB) with a transglutaminase (TG) crosslinking substrate site released from a fibrin biomatrix improves wound healing in severe thermal injury. The binding and release kinetics of TG-PDGF.AB were determined in vitro. Third-degree contact burns (dorsum of Yorkshire pigs) underwent epifascial necrosectomy 24 h post-burn. Wound sites were covered with autologous meshed (3:1) split-thickness skin autografts and either secured with staples or attached with sprayed fibrin sealant (FS; n = 8/group). TG-PDGF.AB binds to the fibrin biomatrix using the TG activity of factor XIIIa, and is subsequently released through enzymatic cleavage. Three doses of TG-PDGF.AB in FS (100 ng, 1 µg and 11 µg/ml FS) were tested. TG-PDGF.AB was bound to the fibrin biomatrix as evidenced by western blot analysis and subsequently released by enzymatic cleavage. A significantly accelerated and improved wound healing was achieved using sprayed FS containing TG-PDGF.AB compared to staples alone. Low concentrations (100 ng-1 µg TG-PDGF.AB/ml final FS clot) demonstrated to be sufficient to attain a nearly complete closure of mesh interstices 14 days after grafting. TG-PDGF.AB incorporated in FS via a specific binding technology was shown to be effective in grafted third-degree burn wounds. The adhesive properties of the fibrin matrix in conjunction with the prolonged growth factor stimulus enabled by this binding technology could be favourable in many pathological situations associated with wound-healing disturbances. Copyright © 2013 John Wiley & Sons, Ltd.