The use of Biobrane® as a delivery method for cultured epithelial autograft in burn patients

An eighteen-year review of intensive care requirements for paediatric burns in a regional burns service

INTRODUCTION

Advances in burns management have reduced mortality. Consequently, efficient resource management plays an increasingly important role in improving paediatric burns care. This study aims to assess the support requirements and outcomes of paediatric burns patients admitted to a burns centre intensive care unit in comparison to established benchmarks in burns care.

METHOD

A retrospective review of burns patients under the age of 16 years old, admitted to a regional burns service intensive care unit between March 1998 and March 2016 was conducted.

RESULTS

Our analysis included 234 patients, with the percentage of TBSA affected by burn injury ranging from 1.5% to 95.0%. The median (IQR) %TBSA was 20.0% (11.0-30.0), and the observed mortality rate was 2.6% (6/234). The median (IQR) length of stay was 0.7 days/%TBSA burn (0.4-1.2), 17.9% (41/229) required circulatory support and 2.6% (6/234) required renal replacement. Mortality correlated with smoke inhalation injury (P < 0.001), %TBSA burn (P = 0.049) and complications (P = 0.004) including infections (P = 0.013).

CONCLUSIONS

Among children with burn injuries who require intensive care, the presence of inhalational injury and the diagnosis of infection are positively correlated with mortality. Understanding the requirements for organ support can facilitate a more effective allocation of resources within a burns service.

Acute Management of Thermal Hand Burns in Adults: A 10-Year Review of the Literature

INTRODUCTION

Advances in the evidence base of acute thermal hand burns help to guide the management of these common injuries. The aim of this literature review was to evaluate recent evidence in the field over 10 years.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols methodology was used as a guide for this literature review. PubMed, MEDLINE, EMBASE, CINAHL, and Google Scholar were searched for English language articles related to hand burns published between 2009 and 2018 inclusive, and the Cochrane Library was reviewed. Exclusion criteria were as follows: participants younger than 18 years, scar or contracture management, rehabilitation, outcomes assessment, late reconstruction, and electrical or chemical burns.

RESULTS

An initial search retrieved 6493 articles, which was narrowed to 403 full-text articles that were reviewed independently by 3 of the authors and categorized. Of 202 included articles, there were 8 randomized controlled trials and 2 systematic reviews. Six evidence-based guidelines were reviewed. Referral of hand burns to specialist centers, use of telemedicine, early excision and grafting, and immediate static splintage have been recommended. Enzymatic debridement results in earlier intervention, more accurate burn assessment, preservation of vital tissue, and fewer skin grafts, and ideally requires regional anesthesia. Guidance on escharotomy emphasizes indication, technique and adequate intervention, and potential for enzymatic debridement. Inclusion of topical negative pressure, dermal regenerative templates, acellular dermal matrices, and noncellular skin substitutes in management has helped improve scar and functional outcomes.

DISCUSSION

The results of this literature review demonstrate that multiple national and international societies have published burns guidelines during the decade studied, with aspects directly relevant to hand burns, including the International Society for Burn Injuries guidelines. There are opportunities for evidence-based quality improvement across the field of hand burns in many centers.

CONCLUSIONS

More than 200 articles globally in 10 years outline advances in the understanding of acute management of thermal hand burns. Incorporating the evidence base into practice may facilitate optimization of triage referral pathways and acute management for hand burns.

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.

Current Concepts in Tissue Engineering: Skin and Wound

BACKGROUND

Pure regenerative healing with little to no donor morbidity remains an elusive goal for both surgeon and patient. The ability to engineer and promote the development of like tissue holds so much promise, and efforts in this direction are slowly but steadily advancing.

METHODS

Products selected and reviewed reflect historical precedence and importance and focus on current clinically available products in use. Emerging technologies we anticipate will further expand our therapeutic options are introduced. The topic of tissue engineering is incredibly broad in scope, and as such the authors have focused their review on that of constructs specifically designed for skin and wound healing. A review of pertinent and current clinically related literature is included.

RESULTS

Products such as biosynthetics, biologics, cellular promoting factors, and commercially available matrices can be routinely found in most modern health care centers. Although to date no complete regenerative or direct identical soft-tissue replacement exists, currently available commercial components have proven beneficial in augmenting and improving some types of wound healing scenarios. Cost, directed specificity, biocompatibility, and bioburden tolerance are just some of the impending challenges to adoption.

CONCLUSIONS

Quality of life and in fact the ability to sustain life is dependent on our most complex and remarkable organ, skin. Although pure regenerative healing and engineered soft-tissue constructs elude us, surgeons and health care providers are slowly gaining comfort and experience with concepts and strategies to improve the healing of wounds.

The Use of Dermal Skin Substitutes for the Treatment of the Burned Hand

The hand is commonly affected in burn injuries. Joints and extensor tendons are vulnerable given their superficial location. Durable coverage that permits relative frictionless tendon gliding and minimizes scar contracture is required to optimize functional outcomes. When soft tissue donor sites are limited, the use of dermal skin substitutes provides stable coverage with minimal scarring, good mobility, and acceptable appearance. A comprehensive review of dermal skin substitutes and their use with burn reconstruction of the hand is provided.

In Vivo Evaluation and Imaging of a Bilayered Self-Assembled Skin Substitute Using a Decellularized Dermal Matrix Grafted on Mice

As time to final coverage is the essence for better survival outcome in severely burned patients, we have continuously strived to reduce the duration for the preparation of our bilayered self-assembled skin substitutes (SASS). These SASS produced in vitro by the self-assembly approach have a structure and functionality very similar to native skin. Recently, we have shown that a decellularized dermal matrix preproduced by the self-assembly approach could be used as a template to further obtain self-assembled skin substitute using a decellularized dermal template (SASS-DM) in vitro. Thus, the production period with patient cells was then reduced to about 1 month. Herein, preclinical animal experiments have been performed to confirm the integration and evolution of such a graft and compare the maturation of SASS and SASS-DM in vivo. Both tissues, reconstructed from adult or newborn cells, were grafted on athymic mice. Green fluorescent protein-transfected keratinocytes were also used to follow grafted tissues weekly for 6 weeks using an in vivo imaging system (IVIS). Cell architecture and differentiation were studied with histological and immunofluorescence analyses at each time point. Graft integration, macroscopic evolution, histological analyses, and expression of skin differentiation markers were similar between both skin substitutes reconstructed from either newborn or adult cells, and IVIS observations confirmed the efficient engraftment of SASS-DM. In conclusion, our in vivo graft experiments on a mouse model demonstrated that the SASS-DM had equivalent macroscopic, histological, and differentiation evolution over a 6-week period, when compared with the SASS. The tissue-engineered SASS-DM could improve clinical availability and advantageously shorten the time necessary for the definitive wound coverage of severely burned patients.

Current wound healing procedures and potential care

In this review, we describe current and future potential wound healing treatments for acute and chronic wounds. The current wound healing approaches are based on autografts, allografts, and cultured epithelial autografts, and wound dressings based on biocompatible and biodegradable polymers. The Food and Drug Administration approved wound healing dressings based on several polymers including collagen, silicon, chitosan, and hyaluronic acid. The new potential therapeutic intervention for wound healing includes sustained delivery of growth factors, and siRNA delivery, targeting microRNA, and stem cell therapy. In addition, environment sensors can also potentially utilize to monitor and manage microenvironment at wound site. Sensors use optical, odor, pH, and hydration sensors to detect such characteristics as uric acid level, pH, protease level, and infection - all in the hopes of early detection of complications.

Wound healing: an update

Wounds, both chronic and acute, continue to be a tremendous socioeconomic burden. As such, technologies drawn from many disciplines within science and engineering are constantly being incorporated into innovative wound healing therapies. While many of these therapies are experimental, they have resulted in new insights into the pathophysiology of wound healing, and in turn the development of more specialized treatments for both normal and abnormal wound healing states. Herein, we review some of the emerging technologies that are currently being developed to aid and improve wound healing after cutaneous injury.

Cultivation of keratinocytes and fibroblasts in a three-dimensional bovine collagen-elastin matrix (Matriderm®) and application for full thickness wound coverage in vivo

New skin substitutes for burn medicine or reconstructive surgery pose an important issue in plastic surgery. Matriderm^® is a clinically approved three-dimensional bovine collagen-elastin matrix which is already used as a dermal substitute of full thickness burn wounds. The drawback of an avital matrix is the limited integration in full thickness skin defects, depending on the defect size. To further optimize this process, Matriderm^® has also been studied as a matrix for tissue engineering of skin albeit long-term cultivation of the matrix with cells has been difficult. Cells have generally been seeded onto the matrix with high cell loss and minimal time-consuming migration. Here we developed a cell seeded skin equivalent after microtransfer of cells directly into the matrix. First, cells were cultured, and microinjected into Matriderm^®. Then, cell viability in the matrix was determined by histology in vitro. As a next step, the skin substitute was applied in vivo into a full thickness rodent wound model. The wound coverage and healing was observed over a period of two weeks followed by histological examination assessing cell viability, proliferation and integration into the host. Viable and proliferating cells could be found throughout the entire matrix. The presented skin substitute resembles healthy skin in morphology and integrity. Based on this study, future investigations are planned to examine behaviour of epidermal stem cells injected into a collagen-elastin matrix under the aspects of establishment of stem cell niches and differentiation.