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Watt SM, Pleat JM. Stem cells, niches and scaffolds: Applications to burns and wound care. Adv Drug Deliv Rev 2018; 123:82-106. [PMID: 29106911 DOI: 10.1016/j.addr.2017.10.012] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2017] [Revised: 10/19/2017] [Accepted: 10/22/2017] [Indexed: 12/11/2022]
Abstract
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.
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Affiliation(s)
- Suzanne M Watt
- Stem Cell Research, Nuffield Division of Clinical Laboratory Medicine, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9BQ, UK.
| | - Jonathan M Pleat
- Department of Plastic and Reconstructive Surgery, North Bristol NHS Trust and University of Bristol, Westbury on Trym, Bristol BS9 3TZ, UK.
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52
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Hall C, Hardin C, Corkins CJ, Jiwani AZ, Fletcher J, Carlsson A, Chan R. Pathophysiologic Mechanisms and Current Treatments for Cutaneous Sequelae of Burn Wounds. Compr Physiol 2017; 8:371-405. [PMID: 29357133 DOI: 10.1002/cphy.c170016] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Burn injuries are a pervasive clinical problem. Extensive thermal trauma can be life-threatening or result in long-lasting complications, generating a significant impact on quality of life for patients as well as a cost burden to the healthcare system. The importance of addressing global or systemic issues such as resuscitation and management of inhalation injuries is not disputed but is beyond the scope of this review, which focuses on cutaneous pathophysiologic mechanisms for current treatments, both in the acute and long-term settings. Pathophysiological mechanisms of burn progression and wound healing are mediated by highly complex cascades of cellular and biochemical events, which become dysregulated in slow-healing wounds such as burns. Burns can result in fibroproliferative scarring, skin contractures, or chronic wounds that take weeks or months to heal. Burn injuries are highly individualized owing to wound-specific differences such as burn depth and surface area, in addition to patient-specific factors including genetics, immune competency, and age. Other extrinsic complications such as microbial infection can complicate wound healing, resulting in prolonged inflammation and delayed re-epithelialization. Although mortality is decreasing with advancements in burn care, morbidity from postburn deformities continues to be a challenge. Optimizing specialized acute care and late burn outcome intervention on a patient-by-patient basis is critical for successful management of burn wounds and the associated pathological scar outcome. Understanding the fundamentals of integument physiology and the cellular processes involved in wound healing is essential for designing effective treatment strategies for burn wound care as well as development of future therapies. Published 2018. Compr Physiol 8:371-405, 2018.
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Affiliation(s)
- Caroline Hall
- Quality Skin Collaborative for Advanced Reconstruction and Regeneration (Q-SCARRTM), Dental Craniofacial Trauma Research Division, US Army Institute of Surgical Research, Ft. Sam Houston, TX, USA
| | - Carolyn Hardin
- Quality Skin Collaborative for Advanced Reconstruction and Regeneration (Q-SCARRTM), Dental Craniofacial Trauma Research Division, US Army Institute of Surgical Research, Ft. Sam Houston, TX, USA
| | - Christopher J Corkins
- Quality Skin Collaborative for Advanced Reconstruction and Regeneration (Q-SCARRTM), Dental Craniofacial Trauma Research Division, US Army Institute of Surgical Research, Ft. Sam Houston, TX, USA.,Clinical Division and Burn Center, US Army Institute of Surgical Research, Ft. Sam Houston, TX, USA
| | - Alisha Z Jiwani
- Quality Skin Collaborative for Advanced Reconstruction and Regeneration (Q-SCARRTM), Dental Craniofacial Trauma Research Division, US Army Institute of Surgical Research, Ft. Sam Houston, TX, USA.,Clinical Division and Burn Center, US Army Institute of Surgical Research, Ft. Sam Houston, TX, USA
| | - John Fletcher
- Quality Skin Collaborative for Advanced Reconstruction and Regeneration (Q-SCARRTM), Dental Craniofacial Trauma Research Division, US Army Institute of Surgical Research, Ft. Sam Houston, TX, USA.,Clinical Division and Burn Center, US Army Institute of Surgical Research, Ft. Sam Houston, TX, USA
| | - Anders Carlsson
- Quality Skin Collaborative for Advanced Reconstruction and Regeneration (Q-SCARRTM), Dental Craniofacial Trauma Research Division, US Army Institute of Surgical Research, Ft. Sam Houston, TX, USA.,Clinical Division and Burn Center, US Army Institute of Surgical Research, Ft. Sam Houston, TX, USA
| | - Rodney Chan
- Quality Skin Collaborative for Advanced Reconstruction and Regeneration (Q-SCARRTM), Dental Craniofacial Trauma Research Division, US Army Institute of Surgical Research, Ft. Sam Houston, TX, USA.,Clinical Division and Burn Center, US Army Institute of Surgical Research, Ft. Sam Houston, TX, USA
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53
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Pripotnev S, Papp A. Split thickness skin graft meshing ratio indications and common practices. Burns 2017; 43:1775-1781. [DOI: 10.1016/j.burns.2017.04.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2016] [Revised: 04/15/2017] [Accepted: 04/20/2017] [Indexed: 10/19/2022]
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54
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Lotz C, Schmid FF, Oechsle E, Monaghan MG, Walles H, Groeber-Becker F. Cross-linked Collagen Hydrogel Matrix Resisting Contraction To Facilitate Full-Thickness Skin Equivalents. ACS APPLIED MATERIALS & INTERFACES 2017; 9:20417-20425. [PMID: 28557435 DOI: 10.1021/acsami.7b04017] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Full-thickness skin equivalents are gathering increased interest as skin grafts for the treatment of large skin defects or chronic wounds or as nonanimal test platforms. However, their fibroblast-mediated contraction and poor mechanical stability lead to disadvantages toward their reproducibility and applicability in vitro and in vivo. To overcome these pitfalls, we aimed to chemically cross-link the dermal layer of a full-thickness skin model composed of a collagen type I hydrogel. Using a noncytotoxic four-arm succinimidyl glutarate polyethylene glycol (PEG-SG), cross-linking could be achieved in cell seeded collagen hydrogels. A concentration of 0.5 mg of PEG-SG/mg of collagen led to a viability comparable to non-cross-linked collagen hydrogels and no increased release of intracellular lactate dehydrogenase. Cross-linked collagen hydrogels were more mechanically stable and less prone to enzymatic degradation via collagenase when compared with non-cross-linked collagen hydrogels. Remarkably, during 21 days, cross-linked collagen hydrogels maintain their initial surface area, whereas standard dermal models contracted up to 50%. Finally, full-thickness skin equivalents were generated by seeding human epidermal keratinocytes on the surface of the equivalents and culturing these equivalents at an air-liquid interface. Immunohistochemical stainings of the cross-linked model revealed well-defined epidermal layers including an intact stratum corneum and a dermal part with homogeneously distributed human dermal fibroblasts. These results indicate that cross-linking of collagen with PEG-SG reduces contraction of collagen hydrogels and thus increases the applicability of these models as an additional tool for efficacy and safety assessment or a new generation of skin grafts.
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Affiliation(s)
- Christian Lotz
- Department of Tissue Engineering & Regenerative Medicine (TERM), University Hospital Würzburg , Würzburg 97070, Germany
| | - Freia F Schmid
- Translational Center Würzburg 'Regenerative Therapies in Oncology and Musculoskeletal Diseases', Würzburg Branch of the Fraunhofer Institute for Interfacial Engineering and Biotechnology , Würzburg 97070, Germany
| | - Eva Oechsle
- Translational Center Würzburg 'Regenerative Therapies in Oncology and Musculoskeletal Diseases', Würzburg Branch of the Fraunhofer Institute for Interfacial Engineering and Biotechnology , Würzburg 97070, Germany
| | - Michael G Monaghan
- Department of Cell and Tissue Engineering, Fraunhofer Institute for Interfacial Engineering and Biotechnology , Stuttgart 70569, Germany
| | - Heike Walles
- Department of Tissue Engineering & Regenerative Medicine (TERM), University Hospital Würzburg , Würzburg 97070, Germany
- Translational Center Würzburg 'Regenerative Therapies in Oncology and Musculoskeletal Diseases', Würzburg Branch of the Fraunhofer Institute for Interfacial Engineering and Biotechnology , Würzburg 97070, Germany
| | - Florian Groeber-Becker
- Translational Center Würzburg 'Regenerative Therapies in Oncology and Musculoskeletal Diseases', Würzburg Branch of the Fraunhofer Institute for Interfacial Engineering and Biotechnology , Würzburg 97070, Germany
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55
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Ramos RR, Ferreira LM. Sub fascial flap based on the supraclavicular artery in reconstruction of neck burn contractures. Burns 2017; 43:e1-e4. [PMID: 28506509 DOI: 10.1016/j.burns.2017.03.031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Revised: 03/29/2017] [Accepted: 03/30/2017] [Indexed: 11/19/2022]
Abstract
This study presents 3 cases of women ages ranged from 25 to 52 years with anterior cervical contractures caused by burns that resulted in functional and aesthetic deficit. Contracture release in 3 patients and reconstruction was done using a sub-fascial flap whose main pedicle was the supraclavicular artery and the occipito-postero-cervical vessels that were preserved. The flap was designed differently from the classically described that uses the skin of the shoulder but which presents differences of color and texture with relation to the skin of the neck. The results were satisfactory and no complications such as infections or necrosis.
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Affiliation(s)
| | - Lydia Masako Ferreira
- Division of Plastic Surgery, UNIFESP, São Paulo, SP, Brazil; Federal University of São Paulo, Division of Plastic Surgery, São Paulo, SP, Brazil
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56
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Stekelenburg CM, Marck RE, Verhaegen PDHM, Marck KW, van Zuijlen PPM. Perforator-based flaps for the treatment of burn scar contractures: a review. BURNS & TRAUMA 2017; 5:5. [PMID: 28261622 PMCID: PMC5329961 DOI: 10.1186/s41038-017-0071-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 02/08/2017] [Indexed: 11/17/2022]
Abstract
Patients with burn scars often experience functional problems because of scar contractures. Surgical treatment may be indicated for those burn scar contractures. If the contractures are small and linear, the contraction bands can be treated with local transposition flaps like the Z-plasty. Broader, diffuse contractures are more challenging and require a different surgical approach, such as the use of local tissue. The use of perforator-based flaps is promising; however, their true clinical significance for this type of burn reconstructions still needs to be determined. Therefore, we performed a review to evaluate the role of perforator-based flaps for burn scar contracture treatment. Electronic databases were searched using a predefined search strategy. Studies evaluating the long-term outcome of perforator-based flaps for the treatment of burn scar contractures were included. The methodological quality was tested and data was summarized. Five hundred and ten papers were identified of which eleven met the inclusion criteria. One study was a randomized controlled trial; ten were cohort studies of a pre-postoperative design. The papers described outcomes of free flaps and local flaps. Most studies had methodological shortcomings and used inappropriate statistical methods. Perforator-based interposition flaps appear to be highly relevant for burn scar contracture treatment. However, due to the paucity and low quality of the studies that were assessed, no definitive conclusions about the true clinical significance could be reached. And therefore, only recommendations could be given for improvement of the quality of further primary research on the effectiveness of perforator-based flaps for burn scar contracture release.
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Affiliation(s)
- C M Stekelenburg
- Burn Center and Department of Plastic, Reconstructive, and Hand Surgery, Red Cross Hospital, Vondellaan 13, 1942 LE Beverwijk, The Netherlands.,Department of Plastic, Reconstructive, and Hand Surgery, University Medical Center, Utrecht, The Netherlands
| | - R E Marck
- Burn Center and Department of Plastic, Reconstructive, and Hand Surgery, Red Cross Hospital, Vondellaan 13, 1942 LE Beverwijk, The Netherlands.,Department of Plastic, Reconstructive, and Hand Surgery, Academical Medical Center, Amsterdam, The Netherlands.,Department of Plastic, Reconstructive, and Hand Surgery, MOVE Research Institute, VU University Medical Center, Amsterdam, The Netherlands
| | - P D H M Verhaegen
- Burn Center and Department of Plastic, Reconstructive, and Hand Surgery, Red Cross Hospital, Vondellaan 13, 1942 LE Beverwijk, The Netherlands.,Department of Plastic, Reconstructive, and Hand Surgery, MOVE Research Institute, VU University Medical Center, Amsterdam, The Netherlands.,Department of Plastic, Reconstructive, and Hand Surgery, Isala, Zwolle, The Netherlands
| | - K W Marck
- Department of Plastic Surgery, Medisch Centrum Leeuwarden, Leeuwarden, The Netherlands
| | - P P M van Zuijlen
- Burn Center and Department of Plastic, Reconstructive, and Hand Surgery, Red Cross Hospital, Vondellaan 13, 1942 LE Beverwijk, The Netherlands.,Department of Plastic, Reconstructive, and Hand Surgery, MOVE Research Institute, VU University Medical Center, Amsterdam, The Netherlands
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57
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Successful treatment of postburn flexion contracture in fingers of early childhood with dynamic splint therapy after operation: long-term follow-up. EUROPEAN JOURNAL OF PLASTIC SURGERY 2017. [DOI: 10.1007/s00238-017-1288-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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58
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Koppenol DC, Vermolen FJ. Biomedical implications from a morphoelastic continuum model for the simulation of contracture formation in skin grafts that cover excised burns. Biomech Model Mechanobiol 2017; 16:1187-1206. [PMID: 28181018 PMCID: PMC5511621 DOI: 10.1007/s10237-017-0881-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 01/25/2017] [Indexed: 12/20/2022]
Abstract
A continuum hypothesis-based model is developed for the simulation of the (long term) contraction of skin grafts that cover excised burns in order to obtain suggestions regarding the ideal length of splinting therapy and when to start with this therapy such that the therapy is effective optimally. Tissue is modeled as an isotropic, heterogeneous, morphoelastic solid. With respect to the constituents of the tissue, we selected the following constituents as primary model components: fibroblasts, myofibroblasts, collagen molecules, and a generic signaling molecule. Good agreement is demonstrated with respect to the evolution over time of the surface area of unmeshed skin grafts that cover excised burns between outcomes of computer simulations obtained in this study and scar assessment data gathered previously in a clinical study. Based on the simulation results, we suggest that the optimal point in time to start with splinting therapy is directly after placement of the skin graft on its recipient bed. Furthermore, we suggest that it is desirable to continue with splinting therapy until the concentration of the signaling molecules in the grafted area has become negligible such that the formation of contractures can be prevented. We conclude this study with a presentation of some alternative ideas on how to diminish the degree of contracture formation that are not based on a mechanical intervention, and a discussion about how the presented model can be adjusted.
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Affiliation(s)
- Daniël C Koppenol
- Delft Institute of Applied Mathematics, Delft University of Technology, Delft, The Netherlands.
| | - Fred J Vermolen
- Delft Institute of Applied Mathematics, Delft University of Technology, Delft, The Netherlands
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59
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Stekelenburg CM, Simons JM, Tuinebreijer WE, van Zuijlen PP. Analyzing contraction of full thickness skin grafts in time: Choosing the donor site does matter. Burns 2016; 42:1471-1476. [DOI: 10.1016/j.burns.2016.02.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Revised: 02/01/2016] [Accepted: 02/02/2016] [Indexed: 12/29/2022]
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60
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Vijayavenkataraman S, Lu WF, Fuh JYH. 3D bioprinting of skin: a state-of-the-art review on modelling, materials, and processes. Biofabrication 2016; 8:032001. [DOI: 10.1088/1758-5090/8/3/032001] [Citation(s) in RCA: 151] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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61
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62
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Tam J, Wang Y, Vuong LN, Fisher JM, Farinelli WA, Anderson RR. Reconstitution of full-thickness skin by microcolumn grafting. J Tissue Eng Regen Med 2016; 11:2796-2805. [PMID: 27296503 PMCID: PMC5697650 DOI: 10.1002/term.2174] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 02/11/2016] [Accepted: 02/15/2016] [Indexed: 12/23/2022]
Abstract
In addition to providing a physical barrier, skin also serves a diverse range of physiological functions through different specialized resident cell types/structures, including melanocytes (pigmentation and protection against ultraviolet radiation), Langerhans cells (adaptive immunity), fibroblasts (maintaining extracellular matrix, paracrine regulation of keratinocytes), sweat glands (thermoregulation) and hair follicles (hair growth, sensation and a stem cell reservoir). Restoration of these functional elements has been a long-standing challenge in efforts to engineer skin tissue, while autologous skin grafting is limited by the scarcity of donor site skin and morbidity caused by skin harvesting. We demonstrate an alternative approach of harvesting and then implanting μm-scale, full-thickness columns of human skin tissue, which can be removed from a donor site with minimal morbidity and no scarring. Fresh human skin microcolumns were used to reconstitute skin in wounds on immunodeficient mice. The restored skin recapitulated many key features of normal human skin tissue, including epidermal architecture, diverse skin cell populations, adnexal structures and sweat production in response to cholinergic stimulation. These promising preclinical results suggest that harvesting and grafting of microcolumns may be useful for reconstituting fully functional skin in human wounds, without donor site morbidity. © 2016 The Authors Journal of Tissue Engineering and Regenerative Medicine Published by John Wiley & Sons Ltd.
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Affiliation(s)
- Joshua Tam
- Wellman Center for Photomedicine, Massachusetts General HospitalBostonMAUSA
- Department of DermatologyHarvard Medical SchoolBostonMAUSA
| | - Ying Wang
- Wellman Center for Photomedicine, Massachusetts General HospitalBostonMAUSA
- Department of DermatologyHarvard Medical SchoolBostonMAUSA
| | - Linh N. Vuong
- Wellman Center for Photomedicine, Massachusetts General HospitalBostonMAUSA
| | - Jeremy M. Fisher
- Wellman Center for Photomedicine, Massachusetts General HospitalBostonMAUSA
| | | | - R. Rox Anderson
- Wellman Center for Photomedicine, Massachusetts General HospitalBostonMAUSA
- Department of DermatologyHarvard Medical SchoolBostonMAUSA
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63
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Cell-Assisted Skin Grafting: Improving Texture and Elasticity of Skin Grafts through Autologous Cell Transplantation. Plast Reconstr Surg 2016; 137:58e-66e. [PMID: 26710061 DOI: 10.1097/prs.0000000000001949] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Full-thickness skin grafts are widely used in plastic and reconstructive surgery. Their poor textural durability and associated contracture make them less desirable than skin flaps. Currently, stromal vascular fraction cells hold great promise because of their angiogenic potential, which may ameliorate the hypoxic period after skin grafting. In this study, autologous transplantation of stromal vascular fraction cells was used in combination with skin grafts to determine whether it improved the texture and other physical property of skin grafts. METHODS Stromal vascular fraction cells were isolated and injected under full-thickness skin grafts in a cohort of 20 rats; a second cohort of 20 rats served as controls. Skin grafts were harvested and analyzed on days 14, 30, and 90 after injections. Bioluminescent imaging with luciferase-stromal vascular fraction cells was used for cell tracing. Contracture ratios, elasticity modulus, and the stiffness of each graft were evaluated. Angiogenesis was evaluated using immunohistochemical techniques against vascular endothelial growth factor. Blood flow signals of the graft were also measured, and expression of vascular endothelial growth factor, hepatocyte growth factor, and basic fibroblast growth factor was assessed in all grafts. RESULTS Stromal vascular fraction cells markedly decreased the contracture of skin grafts and improved their resilience and elasticity after 1 month. Histologically, the cells enhanced skin thickness and skin vascularization. Moreover, expression of vascular endothelial growth factor, basic fibroblast growth factor, and hepatocyte growth factor also increased in the stromal vascular fraction group. CONCLUSION Autologous stromal vascular fraction cell transplantation enhances angiogenesis after skin grafting and improves the texture and elasticity of skin grafts.
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64
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Sinha I, Zhu D, Ojomo K, Gfrerer L, Sawh-Martinez R, Patel A, Chan RK, Watkins JF. Functional and subjective assessment of burn contracture release in a mission setting. Burns 2016; 42:466-70. [PMID: 26778704 DOI: 10.1016/j.burns.2015.07.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Revised: 05/26/2015] [Accepted: 07/16/2015] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Burns and subsequent contractures are common in developing nations. Contracture release is performed to treat such patients with functional limitations. The aim of this study is to evaluate post-operative functional and psychosocial outcomes following contracture release in a mission setting. METHODS During a surgical mission in Mumbai, India, 39 patients burn contractures underwent surgical release. A total of 31 patients (64% female, mean age 27 years) chose to participate in the study. Patients were scored preoperatively and postoperatively using a SF-36 validated survey and AMA impairment guideline assessment. RESULTS Thirty-one patients completed questionnaires pre-operative and 6-weeks post operatively. Twenty-four patients completed a survey 3-months post operatively (77.4%). Among those enrolled, 67% were women with the majority sustaining <20% total body surface area burns (70.7%) but had multiple contractures (80.6%). SF-36 physical component score increased from a mean score of 49.8 preoperatively to 55.6 by 3 months following contracture release (P<0.001). The SF-36 mental component score similarly increased from 38.8 to 51.1 by 3 months (P<0.001). AMA Whole Person Impairment (WPI) scores improved from 40.3% impairment pre-operative to 26.6% at 6-weeks post-operative (P<0.001). CONCLUSIONS Patients SF-36 and WPI scores improved following burn contracture release, confirming both functional and psychologic improvement following surgery. During the acute post-operative period, this study suggests that contracture release in a mission setting is of benefit to patients.
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Affiliation(s)
- Indranil Sinha
- Division of Plastic Surgery, Brigham and Women's Hospital, Boston, MA 02115, United States; Division of Trauma and Burn Surgery, Brigham and Women's Hospital, Boston, MA 02115, United States.
| | - Dagny Zhu
- Department of Ophthalmology, University of Southern California, Los Angeles, CA 90089, United States
| | - Kristin Ojomo
- Division of Plastic Surgery, Brigham and Women's Hospital, Boston, MA 02115, United States; Division of Trauma and Burn Surgery, Brigham and Women's Hospital, Boston, MA 02115, United States
| | - Lisa Gfrerer
- Division of Plastic Surgery, Massachusetts General Hospital, Boston, MA 02114, United States
| | - Rajendra Sawh-Martinez
- Division of Plastic Surgery, Yale University School of Medicine, New Haven, CT 06520, United States
| | - Anup Patel
- Division of Plastic Surgery, Yale University School of Medicine, New Haven, CT 06520, United States
| | - Rodney K Chan
- Clinical Division and Burn Center, San Antonio Military Medical Center, San Antonio, TX 78234, United States
| | - James F Watkins
- Division of Trauma and Critical Care, VA Eastern Colorado Healthcare System, Denver, CO 80220, United States
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65
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Challenging the Conventional Therapy: Emerging Skin Graft Techniques for Wound Healing. Plast Reconstr Surg 2016; 136:524e-530e. [PMID: 26397272 DOI: 10.1097/prs.0000000000001634] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Split-thickness skin grafting is the current gold standard for treatment of major traumatic skin loss. However, split-thickness skin grafting is limited by donor-skin availability, especially in large burns. In addition, the donor-site wound is associated with pain and scarring. Multiple techniques have been developed in the past to overcome these limitations but have been unable to achieve clinical relevance. In this study, the authors examine the novel emerging skin grafting techniques, aiming to improve the utility of split-thickness skin grafting. METHODS An extensive literature review was conducted on PubMed, MEDLINE, and Google Scholar to look for new skin grafting techniques. Special focus was given to techniques with potential for large expansion ratio and decreased donor-site pain. RESULTS The new modalities of modified skin grafting technique, discussed in this article, include (1) Xpansion Micrografting System, (2) fractional skin harvesting, (3) epidermal suction blister grafting, and (4) ReCell technology. These techniques are able to achieve significantly increased expansion ratios compared with conventional split-thickness skin grafting and also have decreased donor-site morbidity. CONCLUSIONS These techniques can be used separately or in conjunction with split-thickness skin grafting to overcome the associated pitfalls. Further studies and clinical trials are needed to define the utility of these procedures and where they fit into routine clinical practice.
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66
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Abstract
The surgical management of melanoma has undergone considerable changes over the past several decades, as new strategies and treatments have become available. Surgeons play a pivotal role in all aspects of melanoma care: diagnostic, curative, and palliative. There is a high potential for cure in patients with early-stage melanoma and the selection of an appropriate operation is very important for this reason. Staging the nodal basin has become widespread since the adoption of sentinel lymph node biopsy (SLNB) for the management of melanoma. This operation provides the best prognostic information that is currently available for patients with melanoma. The surgeon plays a central role in the palliation of symptoms resulting from nodal disease and metastases, as melanoma has a propensity to spread to almost any site in the body.
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Affiliation(s)
- Vadim P Koshenkov
- Division of Surgical Oncology, Rutgers Cancer Institute of New Jersey, 195 Little Albany St., Suite 3001, New Brunswick, NJ, 08901, USA.
| | - Joe Broucek
- Division of Surgical Oncology, Rutgers Cancer Institute of New Jersey, 195 Little Albany St., Suite 3001, New Brunswick, NJ, 08901, USA
| | - Howard L Kaufman
- Division of Surgical Oncology, Rutgers Cancer Institute of New Jersey, 195 Little Albany St., Suite 3001, New Brunswick, NJ, 08901, USA
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67
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Strategies to promote healing of split thickness skin grafts: an integrative review. J Wound Ostomy Continence Nurs 2015; 41:335-9; quiz E1-2. [PMID: 24988511 DOI: 10.1097/won.0000000000000035] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Skin grafts are commonly used to promote healing of shallow wounds and burns, and wound care nurses play an important role in management of wounds treated with grafting. The purpose of this article was to review recent findings regarding strategies to promote healing of split-thickness skin grafts including topical phenytoin or platelet-rich plasma prior to graft application, fibrin sealant, or negative pressure wound therapy to stabilize a graft and to promote close adherence of the graft to the underlying wound bed and adjunctive therapies such as laser.
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68
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Autologous Graft Thickness Affects Scar Contraction and Quality in a Porcine Excisional Wound Model. PLASTIC AND RECONSTRUCTIVE SURGERY-GLOBAL OPEN 2015; 3:e468. [PMID: 26301157 PMCID: PMC4527642 DOI: 10.1097/gox.0000000000000426] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 05/28/2015] [Indexed: 11/26/2022]
Abstract
BACKGROUND Texture, color, and durability are important characteristics to consider for skin replacement in conspicuous and/or mobile regions of the body such as the face, neck, and hands. Although autograft thickness is a known determinant of skin quality, few studies have correlated the subjective and objective characters of skin graft healing with their associated morphologic and cellular profiles. Defining these relationships may help guide development and evaluation of future skin replacement strategies. METHODS Six-centimeter-diameter full-thickness wounds were created on the back of female Yorkshire pigs and covered by autografts of variable thicknesses. Skin quality was assessed on day 120 using an observer scar assessment score and objective determinations for scar contraction, erythema, pigmentation, and surface irregularities. Histological, histochemical, and immunohistochemical assessments were performed. RESULTS Thick grafts demonstrated lower observer scar assessment score (better quality) and decreased erythema, pigmentation, and surface irregularities. Histologically, thin grafts resulted in scar-like collagen proliferation while thick grafts preserves the dermal architecture. Increased vascularity and prolonged and increased cellular infiltration were observed among thin grafts. In addition, thin grafts contained predominately dense collagen fibers, whereas thick grafts had loosely arranged collagen. α-Smooth muscle actin staining for myofibroblasts was observed earlier and persisted longer among thinner grafts. CONCLUSIONS Graft thickness is an important determinant of skin quality. High-quality skin replacements are associated with preserved collagen architecture, decreased neovascularization, and decreased inflammatory cellular infiltration. This model, using autologous skin as a metric of quality, may give a more informative analysis of emerging skin replacement strategies.
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69
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Prospective, randomised controlled trial comparing Versajet™ hydrosurgery and conventional debridement of partial thickness paediatric burns. Burns 2015; 41:700-7. [DOI: 10.1016/j.burns.2015.02.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 01/07/2015] [Accepted: 02/02/2015] [Indexed: 11/18/2022]
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70
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MacNeil S. Can you whistle? Then I'll come: stem cells home to where they're needed. Br J Dermatol 2015; 172:1183-4. [PMID: 25963207 DOI: 10.1111/bjd.13733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- S MacNeil
- Department of Materials Science & Engineering, Kroto Research Institute, University of Sheffield, North Campus, Broad Lane, Sheffield, S3 7HQ, U.K..
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71
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Ding JP, Fang L, Wang LZ. The use of micro-plasma radiofrequency technology in secondary skin graft contraction: 2 case reports. J COSMET LASER THER 2015; 17:301-3. [DOI: 10.3109/14764172.2015.1027230] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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72
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Bonvallet PP, Schultz MJ, Mitchell EH, Bain JL, Culpepper BK, Thomas SJ, Bellis SL. Microporous dermal-mimetic electrospun scaffolds pre-seeded with fibroblasts promote tissue regeneration in full-thickness skin wounds. PLoS One 2015; 10:e0122359. [PMID: 25793720 PMCID: PMC4368828 DOI: 10.1371/journal.pone.0122359] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 02/16/2015] [Indexed: 11/19/2022] Open
Abstract
Electrospun scaffolds serve as promising substrates for tissue repair due to their nanofibrous architecture and amenability to tailoring of chemical composition. In this study, the regenerative potential of a microporous electrospun scaffold pre-seeded with dermal fibroblasts was evaluated. Previously we reported that a 70% collagen I and 30% poly(Ɛ-caprolactone) electrospun scaffold (70:30 col/PCL) containing 160 μm diameter pores had favorable mechanical properties, supported fibroblast infiltration and subsequent cell-mediated deposition of extracellular matrix (ECM), and promoted more rapid and effective in vivo skin regeneration when compared to scaffolds lacking micropores. In the current study we tested the hypothesis that the efficacy of the 70:30 col/PCL microporous scaffolds could be further enhanced by seeding scaffolds with dermal fibroblasts prior to implantation into skin wounds. To address this hypothesis, a Fischer 344 (F344) rat syngeneic model was employed. In vitro studies showed that dermal fibroblasts isolated from F344 rat skin were able to adhere and proliferate on 70:30 col/PCL microporous scaffolds, and the cells also filled the 160 μm pores with native ECM proteins such as collagen I and fibronectin. Additionally, scaffolds seeded with F344 fibroblasts exhibited a low rate of contraction (~14%) over a 21 day time frame. To assess regenerative potential, scaffolds with or without seeded F344 dermal fibroblasts were implanted into full thickness, critical size defects created in F344 hosts. Specifically, we compared: microporous scaffolds containing fibroblasts seeded for 4 days; scaffolds containing fibroblasts seeded for only 1 day; acellular microporous scaffolds; and a sham wound (no scaffold). Scaffolds containing fibroblasts seeded for 4 days had the best response of all treatment groups with respect to accelerated wound healing, a more normal-appearing dermal matrix structure, and hair follicle regeneration. Collectively these results suggest that microporous electrospun scaffolds pre-seeded with fibroblasts promote greater wound-healing than acellular scaffolds.
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Affiliation(s)
- Paul P. Bonvallet
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Matthew J. Schultz
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Elizabeth H. Mitchell
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Jennifer L. Bain
- Department of Periodontology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Bonnie K. Culpepper
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Steven J. Thomas
- Department of Surgery, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Susan L. Bellis
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- * E-mail:
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73
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Osman NI, Hillary C, Bullock AJ, MacNeil S, Chapple CR. Tissue engineered buccal mucosa for urethroplasty: progress and future directions. Adv Drug Deliv Rev 2015; 82-83:69-76. [PMID: 25451857 DOI: 10.1016/j.addr.2014.10.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Revised: 09/22/2014] [Accepted: 10/03/2014] [Indexed: 01/15/2023]
Abstract
PURPOSE Autologous buccal mucosa is commonly utilized in the surgical treatment of urethral strictures. Extensive strictures require a larger quantity of tissue, which may lead to donor site morbidity. This review assesses progress in producing tissue engineered buccal mucosa as an alternative graft material. RESULTS Few clinical studies have introduced cells onto biological or synthetic scaffolds and implanted resulting constructs in patients. The available studies show that buccal mucosa cells on acellular human dermis or on collagen matrix lead to good acute stage tissue integration. Urothelial cells on a synthetic substrate also perform well. However while some patients do well many years post-grafting, others develop stricture recurrence. Acellular biomaterials used to treat long urethral defects in animals commonly lead to fibrosis. CONCLUSIONS Tissue engineered buccal mucosa shows promise as a substitute for native tissue. The fibrosis which occurs months post-implantation may reflect the underlying disease process recurring in these patients.
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Affiliation(s)
- N I Osman
- Kroto Research Institute, University of Sheffield, Sheffield, UK; Department of Urology, Royal Hallamshire Hospital, Sheffield, UK
| | - C Hillary
- Kroto Research Institute, University of Sheffield, Sheffield, UK; Department of Urology, Royal Hallamshire Hospital, Sheffield, UK
| | - A J Bullock
- Kroto Research Institute, University of Sheffield, Sheffield, UK
| | - S MacNeil
- Kroto Research Institute, University of Sheffield, Sheffield, UK
| | - C R Chapple
- Department of Urology, Royal Hallamshire Hospital, Sheffield, UK.
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Wu JC, Rose LF, Christy RJ, Leung KP, Chan RK. Full-Thickness Thermal Injury Delays Wound Closure in a Murine Model. Adv Wound Care (New Rochelle) 2015; 4:83-91. [PMID: 25713750 DOI: 10.1089/wound.2014.0570] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Accepted: 08/17/2014] [Indexed: 11/12/2022] Open
Abstract
Objective: The contemporary treatment of a full-thickness burn consists of early eschar excision followed by immediate closure of the open wound using autologous skin. However, most animal models study burn wound healing with the persistence of the burn eschar. Our goal is to characterize a murine model of burn eschar excision to study wound closure kinetics. Approach: C57BL/6 male mice were divided into three groups: contact burn, scald burn, or unburned control. Mice were burned at 80°C for 5, 10, or 20 s. After 2 days, the eschar was excised and wound closure was documented until postexcision day 13. Biopsies were examined for structural morphology and α-smooth muscle actin. In a subsequent interval-excision experiment (80°C scald for 10 s), the burn eschar was excised after 5 or 10 days postburn to determine the effect of a prolonged inflammatory focus. Results: Histology of both contact and scald burns revealed characteristics of a full-thickness injury marked by collagen coagulation and tissue necrosis. Excision at 2 days after a 20-s burn from either scald or contact showed significant delay in wound closure. Interval excision of the eschar, 5 or 10 days postburn, also showed significant delay in wound closure. Both interval-excision groups showed prolonged inflammation and increased myofibroblasts. Innovation and Conclusions: We have described the kinetics of wound closure in a murine model of a full-thickness burn excision. Both contact and scald full-thickness burn resulted in significantly delayed wound closure. In addition, prolonged interval-excision of the eschar appeared to increase and prolong inflammation.
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Affiliation(s)
- Jesse C. Wu
- Dental and Trauma Research Detachment, U.S. Army Institute of Surgical Research, Fort Sam Houston, Texas
- U.S. Army Institute of Surgical Research, Fort Sam Houston, Texas
| | - Lloyd F. Rose
- Dental and Trauma Research Detachment, U.S. Army Institute of Surgical Research, Fort Sam Houston, Texas
- U.S. Army Institute of Surgical Research, Fort Sam Houston, Texas
| | | | - Kai P. Leung
- Dental and Trauma Research Detachment, U.S. Army Institute of Surgical Research, Fort Sam Houston, Texas
- U.S. Army Institute of Surgical Research, Fort Sam Houston, Texas
| | - Rodney K. Chan
- Dental and Trauma Research Detachment, U.S. Army Institute of Surgical Research, Fort Sam Houston, Texas
- U.S. Army Institute of Surgical Research, Fort Sam Houston, Texas
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Rakar J, Krammer MP, Kratz G. Human melanocytes mitigate keratinocyte-dependent contraction in an in vitro collagen contraction assay. Burns 2014; 41:1035-42. [PMID: 25466959 DOI: 10.1016/j.burns.2014.10.034] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 10/28/2014] [Accepted: 10/31/2014] [Indexed: 01/30/2023]
Abstract
Scarring is an extensive problem in burn care, and treatment can be especially complicated in cases of hypertrophic scarring. Contraction is an important factor in scarring but the contribution of different cell types remains unclear. We have investigated the contractile behavior of keratinocytes, melanocytes and fibroblasts by using an in vitro collagen gel assay aimed at identifying a modulating role of melanocytes in keratinocyte-mediated contraction. Cells were seeded on a collagen type I gel substrate and the change in gel dimensions were measured over time. Hematoxylin & Eosin-staining and immunohistochemistry against pan-cytokeratin and microphthalmia-associated transcription factor showed that melanocytes integrated between keratinocytes and remained there throughout the experiments. Keratinocyte- and fibroblast-seeded gels contracted significantly over time, whereas melanocyte-seeded gels did not. Co-culture assays showed that melanocytes mitigate the keratinocyte-dependent contraction (significantly slower and 18-32% less). Fibroblasts augmented the contraction in most assays (approximately 6% more). Non-contact co-cultures showed some influence on the keratinocyte-dependent contraction. Results show that mechanisms attributable to melanocytes, but not fibroblasts, can mitigate keratinocyte contractile behavior. Contact-dependent mechanisms are stronger modulators than non-contact dependent mechanisms, but both modes carry significance to the contraction modulation of keratinocytes. Further investigations are required to determine the mechanisms involved and to determine the utility of melanocytes beyond hypopigmentation in improved clinical regimes of burn wounds and wound healing.
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Affiliation(s)
- Jonathan Rakar
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden; Center for Integrative Regenerative Medicine, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
| | - Markus P Krammer
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - Gunnar Kratz
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden; Department of Hand and Plastic Surgery and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
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76
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Turner NJ, Pezzone D, Badylak SF. Regional variations in the histology of porcine skin. Tissue Eng Part C Methods 2014; 21:373-84. [PMID: 25205147 DOI: 10.1089/ten.tec.2014.0246] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Porcine skin is commonly used as a model for human skin injury and as a source material for biologic scaffold materials. Although remarkable similarities between porcine and human skin exist, regional anatomic variations present in human skin are also present in porcine skin. The objective of this study was to evaluate the structure of porcine skin from 11 different anatomic regions in the American Yorkshire crossbreed. Both qualitative and quantitative methods were used, with emphasis on epidermal and dermal thickness, hair follicle density, and collagen and elastin composition and distribution. The results showed that significant regional differences in skin histology exist, particularly with regard to the thickness of the dermis and epidermis and the amount of collagen and elastin within each tissue. Differences were also seen in the distribution of type I and type III collagen within the dermis. Therefore, while porcine skin shares many similarities with human skin, distinct regional differences in composition and morphology exist. This study highlights the importance of appreciating these regional differences to avoid misinterpretation of experimental results when using porcine skin as a human analogue.
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Affiliation(s)
- Neill J Turner
- 1 McGowan Institute for Regenerative Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania
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77
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AlQahtani SM, Alzahrani MM, Carli A, Harvey EJ. Burn Management in Orthopaedic Trauma: A Critical Analysis Review. JBJS Rev 2014; 2:01874474-201410000-00001. [PMID: 27490295 DOI: 10.2106/jbjs.rvw.n.00010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Saad M AlQahtani
- 1Division of Orthopaedic Surgery, McGill University Health Center, Montreal General Hospital, 1650 Cedar Avenue, Room B5.159.5, Montreal, Quebec, Canada H3G 1A4
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78
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Kuo JH, Cuevas I, Chen A, Dunn A, Kuri M, Boudreau N. Secreted HoxA3 Promotes Epidermal Proliferation and Angiogenesis in Genetically Modified Three-Dimensional Composite Skin Constructs. Adv Wound Care (New Rochelle) 2014; 3:605-613. [PMID: 25302136 DOI: 10.1089/wound.2013.0474] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2013] [Accepted: 06/21/2013] [Indexed: 01/21/2023] Open
Abstract
Objective: Homeobox (HOX) transcription factors coordinate gene expression in wound repair and angiogenesis. Previous studies have shown that gene transfer of HoxA3 to wounds of diabetic mice accelerates wound healing, increasing angiogenesis and keratinocyte migration. In this study, we examined whether HoxA3 can also improve angiogenesis, epidermal integrity, and viability of composite skin grafts. Approach: To determine the effects of HoxA3 on composite skin grafts, we constructed bilayered composite grafts incorporating fibroblasts engineered to constitutively secrete HoxA3. We then transplanted these composite grafts in vivo. Results: The composite grafts produced a stratified epidermal layer after seventeen days in culture and following transplantation in vivo, these grafts exhibit normal epidermal differentiation and reduced contraction compared to controls. In addition, HoxA3 grafts showed increased angiogenesis. Quantitative polymerase chain reaction (PCR) analyses of HoxA3 graft tissue reveal an increase in the downstream HoxA3 target genes MMP-14 and uPAR expression, as well as a reduction in CCL-2 and CxCl-12. Innovation: Expression of secreted HoxA3 in composite grafts represents a comprehensive approach that targets both keratinocytes and endothelial cells to promote epidermal proliferation and angiogenesis. Conclusion: Secreted HoxA3 improves angiogenesis, reduces expression of inflammatory mediators, and prolongs composite skin graft integrity.
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Affiliation(s)
- Jennifer H. Kuo
- Department of Surgery, University of California Davis, Sacramento, California
| | - Ileana Cuevas
- Surgical Research Laboratory, University of California San Francisco, San Francisco, California
| | - Amy Chen
- Surgical Research Laboratory, University of California San Francisco, San Francisco, California
| | - Ashley Dunn
- Surgical Research Laboratory, University of California San Francisco, San Francisco, California
| | - Mauricio Kuri
- Surgical Research Laboratory, University of California San Francisco, San Francisco, California
| | - Nancy Boudreau
- Surgical Research Laboratory, University of California San Francisco, San Francisco, California
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79
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Hur GY, Seo DK, Lee JW. Contracture of skin graft in human burns: effect of artificial dermis. Burns 2014; 40:1497-503. [PMID: 25270084 DOI: 10.1016/j.burns.2014.08.007] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 07/11/2014] [Accepted: 08/11/2014] [Indexed: 11/29/2022]
Abstract
BACKGROUND Skin grafts with an artificial dermis have been widely used as a part of the efforts to minimize contractures and reduce donor-site scars. We conducted a prospective randomized clinical trial to study the effect of a dermal substitute by measuring the size of the graft after surgery for months. METHOD The artificial dermis (Matriderm, Dr. Suwelack Skin and Health Care AG, Billerbeck, Germany) was applied in combination with a split-thickness autograft in 40 patients with acute burn wounds or scar reconstruction. Demographic and medical data were collected on each patient. We directly measured the graft size by using a transparent two-ply film (Visitrak Grid, Smith & Nephew Wound Management, Inc, Largo, FL, USA) intraoperatively and 1, 2, 3, and 6 months postoperatively. For effective data comparison, the size of the graft at the time of surgery was taken to be "100%." Then, the size in each phase was estimated in percentage (%). RESULT During the 1st month, the average size was 89%. The figure decreased to 86% and 82% in the 2nd and 3rd months, respectively. In the 6th month, it slightly rebounded to 85% but failed to return to the original state. The size of patients with acute burns was smaller than the size of scar patients as follows: 85-91% in the 2nd month, 81-87% in the 3rd month, and 85-96% in the 6th month. CONCLUSION This study examined the progress of skin grafts through the measurement of graft size in the human body. The grafted skin underwent contracture and remodeling for 3-6 months. In terms of skin contraction, an acute burn was more serious than scar reconstruction. The use of an artificial dermis that contains elastin is very effective from the functional and esthetic perspective by minimizing contractures and enhancing skin elasticity.
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Affiliation(s)
- Gi-Yeun Hur
- Department of Plastic and Reconstructive Surgery, Hangang Sacred Heart Hospital, Hallym University Medical Center, Seoul, Republic of Korea
| | - Dong-Kook Seo
- Department of Plastic and Reconstructive Surgery, Hangang Sacred Heart Hospital, Hallym University Medical Center, Seoul, Republic of Korea
| | - Jong-Wook Lee
- Department of Plastic and Reconstructive Surgery, Hangang Sacred Heart Hospital, Hallym University Medical Center, Seoul, Republic of Korea.
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Abstract
Vascularization is one of the great challenges that tissue engineering faces in order to achieve sizeable tissue and organ substitutes that contain living cells. There are instances, such as skin replacement, in which a tissue-engineered substitute does not absolutely need a preexisting vascularization. However, tissue or organ substitutes in which any dimension, such as thickness, exceeds 400 μm need to be vascularized to ensure cellular survival. Consistent with the wide spectrum of approaches to tissue engineering itself, which vary from acellular synthetic biomaterials to purely biological living constructs, approaches to tissue-engineered vascularization cover numerous techniques. Those techniques range from micropatterns engineered in biomaterials to microvascular networks created by endothelial cells. In this review, we strive to provide a critical overview of the elements that must be considered in the pursuit of this goal and the major approaches that are investigated in hopes of achieving it.
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Affiliation(s)
- François A Auger
- Centre LOEX de l'Université Laval, Regenerative Medicine section of the FRQS Research Center of the CHU de Québec, Quebec, QC, Canada.
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81
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Lagus H, Sarlomo-Rikala M, Böhling T, Vuola J. Prospective study on burns treated with Integra®, a cellulose sponge and split thickness skin graft: comparative clinical and histological study--randomized controlled trial. Burns 2013; 39:1577-87. [PMID: 23880091 DOI: 10.1016/j.burns.2013.04.023] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Revised: 04/18/2013] [Accepted: 04/19/2013] [Indexed: 01/23/2023]
Abstract
BACKGROUND The aim of this study was to compare three different methods to cover excised burn wounds in a randomized controlled trial. METHODS Fascially excised burn wounds, measuring 10 cm × 5 cm, were covered with Integra(®), split thickness skin graft (STSG), and a viscose cellulose sponge Cellonex™ in each of ten adult patients. Integra(®) and Cellonex™ treated areas were covered with thin STSG on day 14. Biopsies were taken 3, 7, 14, and 21 days, 3 months, and 12 months after surgery, and samples were subjected to a range of immunohistochemical stains, in addition to hematoxylin and eosin (HE). Scar assessment was performed 3 and 12 months post-operatively with the Vancouver Scar Scale (VSS). RESULTS Inflammation was not substantial in any of the study areas, but Cellonex™ had the most neutrophils, histiocytes, and lymphocytes with significant differences on days 7 and 14. Complete vascularization of Integra(®) seemed to occur later compared to the other materials. STSG had the most myofibroblasts on day 14 (p = 0.012). In VSS the quality of the scar improved in all materials from 3 to 12 months. CONCLUSIONS The final results for all treatments after 12 months demonstrate equal clinical appearance, as well as histological and immunohistochemical findings.
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Affiliation(s)
- Heli Lagus
- Department of Surgery, Hyvinkää Hospital, Hyvinkää, Finland.
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82
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Jor JWY, Parker MD, Taberner AJ, Nash MP, Nielsen PMF. Computational and experimental characterization of skin mechanics: identifying current challenges and future directions. WILEY INTERDISCIPLINARY REVIEWS-SYSTEMS BIOLOGY AND MEDICINE 2013; 5:539-56. [PMID: 23757148 DOI: 10.1002/wsbm.1228] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Revised: 04/25/2013] [Accepted: 04/26/2013] [Indexed: 12/21/2022]
Abstract
The characterization of skin mechanics has many clinical implications and has been an active area of research for the past few decades. Biomechanical models have evolved from earlier empirical models to state-of-the-art structural models that provide linkage between tissue microstructure and macroscopic stress-strain response. To maximize the accuracy and predictive capabilities of such computational models, there is a need to reliably identify often a large number of unknown model parameters. This is critically dependent on the availability of experimental data that cover an extensive range of different deformation modes, and quantification of internal structural features, such as collagen orientation. To this end, future challenges should include the ongoing development of noninvasive instrumentation and imaging modalities for in vivo skin measurements. We highlight the important concept of tightly integrating computational models, instrumentation, and imaging modalities into a single platform to investigate skin biomechanics.
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Affiliation(s)
- Jessica W Y Jor
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
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83
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Sharpe JR, Martin Y. Strategies Demonstrating Efficacy in Reducing Wound Contraction In Vivo.. Adv Wound Care (New Rochelle) 2013; 2:167-175. [PMID: 24527340 DOI: 10.1089/wound.2012.0378] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Indexed: 01/27/2023] Open
Abstract
SIGNIFICANCE Scarring continues to present a significant clinical problem. Wound contraction leads to scarring and is mediated by myofibroblasts and contractile forces across the wound bed. Contracture formation can have a significant impact on the quality of life of the patient, particularly where function and appearance are affected. RECENT ADVANCES Novel tissue-engineered matrices, cell-based therapies, and medicinal therapeutics have shown significant reduction in wound contraction in in-vivo models, particularly at early time points. These have been accompanied in many cases by reduced numbers of myofibroblasts, and in some by increased angiogenesis and improved neodermal architecture. CRITICAL ISSUES There are no animal models that replicate all aspects of wound healing as seen in patients. Therefore, information obtained from in vivo studies should be assessed critically. Additional studies, in particular those that seek to elucidate the mechanisms by which novel therapies reduce contraction, are needed to gain sufficient confidence to move into clinical testing. FUTURE DIRECTIONS The use of knockout mouse models in particular has generated significant advances in knowledge of the mechanisms behind myofibroblast conversion and other factors involved in generating tension across the wound. Medicinal therapeutics and tissue-engineering approaches that seek to disrupt/alter these pathways hold much promise for future development and translation to clinical practice.
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Affiliation(s)
- Justin R. Sharpe
- Blond McIndoe Research Foundation, Queen Victoria Hospital, East Grinstead, United Kingdom
| | - Yella Martin
- Blond McIndoe Research Foundation, Queen Victoria Hospital, East Grinstead, United Kingdom
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84
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Lootens L, Brusselaers N, Beele H, Monstrey S. Keratinocytes in the treatment of severe burn injury: an update. Int Wound J 2013; 10:6-12. [PMID: 22958654 PMCID: PMC7950461 DOI: 10.1111/j.1742-481x.2012.01083.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Burns are among the most life-threatening physical injuries, in which fast wound closure is crucial. The surgical burn care has evolved considerably throughout the past decennia resulting in a shift of therapeutic goals. Therapies aiming to provide coverage of the burn have been replaced by treatments that have both functional as aesthetic outcomes. The standard in treating severe burns is still early excision followed by skin grafting. The use of cultured keratinocytes to cover extensive burn wounds appeared very promising at first, but the technique still has several limitations of which the long time to culture, the major costs, the risk of infection and the need for an adequate dermal layer limit clinical application. The introduction of dermal substitutes, composite grafts, tissue engineering based on stem cell application have been advocated. The aim of this review is to assess the use of cultured keratinocytes in terms of technical aspects, clinical application, limitations and future perspectives. Cultured keratinocytes are expected to keep playing a role in wound healing, especially in the field of chronic wounds. In severe burns, despite its limitations, keratinocytes can be beneficial if implemented as one of the elements in a broader wound management.
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Affiliation(s)
- Liesbeth Lootens
- Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
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Abstract
Postburn contracture is a source of significant morbidity in India, even though its occurrence can be reduced significantly by comprehensive postburn injury care, including surgical intervention. This study investigates whether limited access to initial medical care after burn injury has been associated with increased contracture formation among lower socioeconomic class patients in Mumbai, India. During a surgical mission in Mumbai, India, patients presenting with functionally debilitating burn contractures and minimal income were surveyed for initial care received immediately after burn injury. The survey consisted of questions regarding the history of burn injury and details of any initial treatment. Demographic data were collected by chart review. Thirty-eight patients from the state of Maharashtra participated in the study (mean age 28.1 years). The most common etiology of burn injury was from kerosene stove blasts (74%), and the most common morbidities were contractures of the neck and upper extremity. On average, time elapsed since the original injury was 2.8 years. Nearly all patients sought initial medical care at hospitals (97%) with the majority receiving only dressing changes for their full-thickness or deep-dermal burns (61%). The most common reason for not seeking out delayed burn reconstruction was perceived cost (65%). Ultimately, 60 operations were performed, of which 9 (15%) developed postsurgical complications. These data suggest that a subset of lower socioeconomic class burn patients in Maharashtra received suboptimal initial intervention. Comprehensive initial therapy after burn injury may provide better outcomes and limit the number of patients requiring delayed reconstruction.
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86
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Orlando G, Wood KJ, De Coppi P, Baptista PM, Binder KW, Bitar KN, Breuer C, Burnett L, Christ G, Farney A, Figliuzzi M, Holmes JH, Koch K, Macchiarini P, Mirmalek Sani SH, Opara E, Remuzzi A, Rogers J, Saul JM, Seliktar D, Shapira-Schweitzer K, Smith T, Solomon D, Van Dyke M, Yoo JJ, Zhang Y, Atala A, Stratta RJ, Soker S. Regenerative medicine as applied to general surgery. Ann Surg 2012; 255:867-80. [PMID: 22330032 PMCID: PMC3327776 DOI: 10.1097/sla.0b013e318243a4db] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The present review illustrates the state of the art of regenerative medicine (RM) as applied to surgical diseases and demonstrates that this field has the potential to address some of the unmet needs in surgery. RM is a multidisciplinary field whose purpose is to regenerate in vivo or ex vivo human cells, tissues, or organs to restore or establish normal function through exploitation of the potential to regenerate, which is intrinsic to human cells, tissues, and organs. RM uses cells and/or specially designed biomaterials to reach its goals and RM-based therapies are already in use in several clinical trials in most fields of surgery. The main challenges for investigators are threefold: Creation of an appropriate microenvironment ex vivo that is able to sustain cell physiology and function in order to generate the desired cells or body parts; identification and appropriate manipulation of cells that have the potential to generate parenchymal, stromal and vascular components on demand, both in vivo and ex vivo; and production of smart materials that are able to drive cell fate.
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Affiliation(s)
- Giuseppe Orlando
- Wake Forest Institute for Regenerative Medicine, Winston Salem, NC, USA.
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87
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The effects of combined application of autogenous fibroblast cell culture and full-tissue skin graft (FTSG) on wound healing and contraction in full-thickness tissue defects. Burns 2012; 38:225-31. [DOI: 10.1016/j.burns.2011.08.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Revised: 08/17/2011] [Accepted: 08/22/2011] [Indexed: 11/15/2022]
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88
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Minimal contraction for tissue-engineered skin substitutes when matured at the air-liquid interface. J Tissue Eng Regen Med 2012; 7:452-60. [DOI: 10.1002/term.543] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2011] [Revised: 08/01/2011] [Accepted: 11/03/2011] [Indexed: 11/07/2022]
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89
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Sima LE, Buruiana EC, Buruiana T, Matei A, Epurescu G, Zamfirescu M, Moldovan A, Petrescu SM, Dinescu M. Dermal cells distribution on laser‐structured ormosils. J Tissue Eng Regen Med 2011; 7:129-38. [DOI: 10.1002/term.507] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Revised: 06/13/2011] [Accepted: 07/26/2011] [Indexed: 12/31/2022]
Affiliation(s)
- L. E. Sima
- Institute of Biochemistry Romanian Academy Splaiul Independentei 296 060031 Bucharest 17 Romania
| | - E. C. Buruiana
- Petru Poni Institute of Macromolecular Chemistry Grigore Ghica Voda 41A 6600 Iasi Romania
| | - T. Buruiana
- Petru Poni Institute of Macromolecular Chemistry Grigore Ghica Voda 41A 6600 Iasi Romania
| | - A. Matei
- National Institute for Lasers Plasma and Radiation Physics Atomistilor 409 76900 Bucharest‐Magurele Romania
| | - G. Epurescu
- National Institute for Lasers Plasma and Radiation Physics Atomistilor 409 76900 Bucharest‐Magurele Romania
| | - M. Zamfirescu
- National Institute for Lasers Plasma and Radiation Physics Atomistilor 409 76900 Bucharest‐Magurele Romania
| | - A. Moldovan
- National Institute for Lasers Plasma and Radiation Physics Atomistilor 409 76900 Bucharest‐Magurele Romania
| | - S. M. Petrescu
- Institute of Biochemistry Romanian Academy Splaiul Independentei 296 060031 Bucharest 17 Romania
| | - M. Dinescu
- National Institute for Lasers Plasma and Radiation Physics Atomistilor 409 76900 Bucharest‐Magurele Romania
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90
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Methods to Reduce the Contraction of Tissue-Engineered Buccal Mucosa for Use in Substitution Urethroplasty. Eur Urol 2011; 60:856-61. [DOI: 10.1016/j.eururo.2011.07.045] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2011] [Accepted: 07/15/2011] [Indexed: 11/19/2022]
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91
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Schouten HJ, Nieuwenhuis MK, van Zuijlen PPM. A review on static splinting therapy to prevent burn scar contracture: do clinical and experimental data warrant its clinical application? Burns 2011; 38:19-25. [PMID: 21831527 DOI: 10.1016/j.burns.2011.06.003] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2010] [Revised: 01/21/2011] [Accepted: 06/19/2011] [Indexed: 11/18/2022]
Abstract
BACKGROUND Static splinting therapy is widely considered an essential part in burn rehabilitation to prevent scar contractures in the early phase of wound healing. However, scar contractures are still a common complication. In this article we review the information concerning the incidence of scar contracture, the effectiveness of static splinting therapy in preventing scar contractures, and specifically focus on the - possible - working mechanism of static-splinting, i.e. mechanical load, at the cellular and molecular level of the healing burn wound. METHOD A literature search was done including Pubmed, Cochrane library, CINAHL and PEDRO. RESULTS Incidence of scar contracture in patients with burns varied from 5% to 40%. No strong evidence for the effectiveness of static splinting therapy in preventing scar contracture was found, whereas in vitro and animal studies demonstrated that mechanical tension will stimulate the myofibroblast activity, resulting in the synthesis of new extracellular matrix and the maintenance of their contractile activity. CONCLUSION The effect of mechanical tension on the wound healing process suggests that static splinting therapy may counteract its own purpose. This review stresses the need for randomised controlled clinical trials to establish if static splinting to prevent contractures is a well-considered intervention or just wishful thinking.
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Affiliation(s)
- H J Schouten
- Association of Dutch Burn Centres, Beverwijk, The Netherlands.
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92
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93
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Abstract
The mortality and morbidity from burns have diminished tremendously over the last six to seven decades. However, these do not truly reflect whether the victim could go back to society as a useful person or not and lead a normal life because of the inevitable post-burn scars, contractures and other deformities which collectively have aesthetic and functional considerations. This article gives an overview of the post-burn scars and scar contractures, especially their prevention, minimisation and principles of management.
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Affiliation(s)
- Arun Goel
- Departments of Burns, Plastic, Maxillofacial & Microvascular Surgery, Lok Nayak Hospital & Associated Maulana Azad Medical College, New Delhi - 110 002, India
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94
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Lee K, Kim H, Kim JM, Chung YH, Lee TY, Lim HS, Lim JH, Kim T, Bae JS, Woo CH, Kim KJ, Jeong D. Nacre-driven water-soluble factors promote wound healing of the deep burn porcine skin by recovering angiogenesis and fibroblast function. Mol Biol Rep 2011; 39:3211-8. [PMID: 21688145 DOI: 10.1007/s11033-011-1088-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Accepted: 06/11/2011] [Indexed: 11/26/2022]
Abstract
To assess the recovery effect of water-soluble components of nacre on wound healing of burns, water-soluble nacre (WSN) was obtained from powdered nacre. Alterations to WSN-mediated wound healing characteristics were examined in porcine skin with deep second-degree burns; porcine skin was used as a proxy for human. When WSN was applied to a burned area, the burn-induced granulation sites were rapidly filled with collagen, and the damaged dermis and epidermis were restored to the appearance of normal skin. WSN enhanced wound healing recovery properties for burn-induced apoptotic and necrotic cellular damage and spurred angiogenesis. Additionally, WSN-treated murine fibroblast NIH3T3 cells showed increased proliferation and collagen synthesis. Collectively, the findings indicate that WSN improves the process of wound healing in burns by expeditiously restoring angiogenesis and fibroblast activity. WSN may be useful as a therapeutic agent, with superior biocompatibility to powdered nacre, and evoking less discomfort when applied to a wounded area.
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Affiliation(s)
- Kyunghee Lee
- Department of Microbiology, Yeungnam University College of Medicine, Daegu 705-717, Korea
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95
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Rnjak J, Wise SG, Mithieux SM, Weiss AS. Severe Burn Injuries and the Role of Elastin in the Design of Dermal Substitutes. TISSUE ENGINEERING PART B-REVIEWS 2011; 17:81-91. [DOI: 10.1089/ten.teb.2010.0452] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Jelena Rnjak
- School of Molecular Bioscience, University of Sydney, Sydney, Australia
| | - Steven G. Wise
- School of Molecular Bioscience, University of Sydney, Sydney, Australia
| | | | - Anthony S. Weiss
- School of Molecular Bioscience, University of Sydney, Sydney, Australia
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96
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97
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Potential use of botulinum toxin type A for controlling contraction of skin grafts. Med Hypotheses 2011; 76:303. [DOI: 10.1016/j.mehy.2010.11.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2010] [Accepted: 11/14/2010] [Indexed: 11/18/2022]
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98
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Lin YH, Huang CC, Wang SH. Quantitative assessments of burn degree by high-frequency ultrasonic backscattering and statistical model. Phys Med Biol 2011; 56:757-73. [PMID: 21239847 DOI: 10.1088/0031-9155/56/3/014] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
An accurate and quantitative modality to assess the burn degree is crucial for determining further treatments to be properly applied to burn injury patients. Ultrasounds with frequencies higher than 20 MHz have been applied to dermatological diagnosis due to its high resolution and noninvasive capability. Yet, it is still lacking a substantial means to sensitively correlate the burn degree and ultrasonic measurements quantitatively. Thus, a 50 MHz ultrasound system was developed and implemented to measure ultrasonic signals backscattered from the burned skin tissues. Various burn degrees were achieved by placing a 100 °C brass plate onto the dorsal skins of anesthetized rats for various durations ranged from 5 to 20 s. The burn degrees were correlated with ultrasonic parameters, including integrated backscatter (IB) and Nakagami parameter (m) calculated from ultrasonic signals acquired from the burned tissues of a 5 × 1.4 mm (width × depth) area. Results demonstrated that both IB and m decreased exponentially with the increase of burn degree. Specifically, an IB of -79.0 ± 2.4 (mean ± standard deviation) dB for normal skin tissues tended to decrease to -94.0 ± 1.3 dB for those burned for 20 s, while the corresponding Nakagami parameters tended to decrease from 0.76 ± 0.08 to 0.45 ± 0.04. The variation of both IB and m was partially associated with the change of properties of collagen fibers from the burned tissues verified by samples of tissue histological sections. Particularly, the m parameter may be more sensitive to differentiate burned skin due to the fact that it has a greater rate of change with respect to different burn durations. These ultrasonic parameters in conjunction with high-frequency B-mode and Nakagami images could have the potential to assess the burn degree quantitatively.
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Affiliation(s)
- Yi-Hsun Lin
- Department of Computer Science and Information Engineering, National Cheng Kung University, Tainan City, Taiwan
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99
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MacNeil S, Shepherd J, Smith L. Production of tissue-engineered skin and oral mucosa for clinical and experimental use. Methods Mol Biol 2011; 695:129-153. [PMID: 21042970 DOI: 10.1007/978-1-60761-984-0_9] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Since the early 1990s, our understanding of how epithelial and stromal cells interact in 3D tissue-engineered constructs has led to tissue-engineered skin and oral mucosa models, which are beginning to deliver benefit in the clinic (usually in small-scale reconstructive surgery procedures) but have a great deal to offer for in vitro investigations. These 3D tissue-engineered models can be used for a wide variety of purposes such as dermato- and mucotoxicity, wound healing, examination of pigmentation and melanoma biology, and in particular, a recent development from this laboratory, as a model of bacterially infected skin. Models can also be used to investigate specific skin disease processes. In this chapter, we describe the basic methodology for producing 3D tissue-engineered skin and oral mucosa based on de-epidermised acellular human dermis, and we give examples of how these models can be used for a variety of applications.
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Affiliation(s)
- Sheila MacNeil
- Department of Materials Science and Engineering, Kroto Research Institute, University of Sheffield, Sheffield, UK
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100
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The role of R-spondin2 in keratinocyte proliferation and epidermal thickening in keloid scarring. J Invest Dermatol 2010; 131:644-54. [PMID: 21160497 DOI: 10.1038/jid.2010.371] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Keloids are found only in humans and the underlying biochemical mechanisms of their pathogenesis remain unknown. R-spondins (Rspos) are a relatively new group of secreted proteins known to be Wnt/β-catenin signaling agonists, but their role in keloids has yet to be elucidated. We investigated the expression levels of R-spondin2 (Rspo2) in cell lysates and conditioned media of monocultures and co-cultures of fibroblasts and keratinocytes derived from keloids and normal skin. In this study we found increased protein expression and secretion of Rspo2 in respective monocultures of keloid fibroblasts and keratinocytes when compared with their normal counterparts. Double-chamber co-culture experiments implicated the role of keloid keratinocytes (KKs) in the induction of Rspo2 secretion from fibroblasts because of epithelial-mesenchymal interactions. Addition of recombinant human Rspo2 in culture increased the proliferation of keratinocytes and it acted synergistically with Wnt3a through the canonical Wnt/β-catenin pathway. Overexpression of Rspo2 in normal fibroblasts brought about thicker epidermis when compared with control fibroblasts in a skin organotypic culture model. This observation coincides with the hyperproliferative phenotype of thickened epidermis seen in keloids. Taken together, the results suggest the possible double paracrine action of KKs in inducing higher expression of Rspo2 in fibroblasts that promotes keratinocyte proliferation and epidermal thickening.
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