A Synthetic Biodegradable Temporising Matrix in Degloving Lower Extremity Trauma Reconstruction: A Case Report

In Vivo Formation of Adrenal Organoids in a Novel Porcine Model of Adrenocortical Cell Transplantation

Recognizing the limitations of current therapies for Addison's disease, novel treatments that replicate dynamic physiologic corticosteroid secretion, under control of ACTH, are required. The aim of these experiments was to evaluate the feasibility of adrenocortical cell transplantation (ACT) in a large animal model, adapting methods successfully used for intracutaneous pancreatic islet cell transplantation, using a fully biodegradable temporizing matrix. Autologous porcine ACT was undertaken by bilateral adrenalectomy, cell isolation, culture, and intracutaneous injection into a skin site preprepared using a biodegradable temporizing matrix (BTM) foam. Hydrocortisone support was provided during adrenocortical cell engraftment and weaned as tolerated. Blood adrenocortical hormone concentrations were monitored, and the transplant site was examined at endpoint. Outcome measures included cellular histochemistry, systemic hormone production, and hydrocortisone independence. Transplanted adrenocortical cells showed a capability to survive and proliferate within the intracutaneous site and an ability to self-organize into discrete tissue organoids with features of the normal adrenal histologic architecture. Interpretation of systemic hormone levels was confounded by the identification of accessory adrenals and regenerative cortical tissue within the adrenal bed postmortem. Corticosteroids were unable to be completely ceased. ACT in a large animal model has not previously been attempted, yet it is an important step toward clinical translation. These results demonstrate rhe potential for ACT based on the development of adrenal organoids at the BTM site. However, the inability to achieve clinically relevant systemic hormone production suggests insufficient function, likely attributable to insufficient cells through delivered dose and subsequent proliferation.

Outcomes of Biodegradable Temporizing Matrix for Soft Tissue Reconstruction of the Hand and Extremities

Background

NovoSorb biodegradable temporizing matrix (BTM) is a novel, bilayer, synthetic skin substitute made of biodegradable polyurethane foam covered with a sealing membrane. BTM has demonstrated excellent outcomes in burn literature; however, few studies have been published for hand and extremity soft tissue reconstruction.

Methods

All patients who underwent extremity reconstruction with BTM from 2018 to 2023 were reviewed. Demographics, presentations, and clinical outcomes were recorded.

Results

A total of 86 cases from 54 patients (53.7% pediatric; age range: 0-81 years) were included. Common indications included trauma (36%), infection (18.6%), and malignancy (11.6%). BTM was placed over exposed tendon (38.4%), bone (19%), joints (12.8%), nerves (8.1%), and/or blood vessels (7%). BTM served as temporary wound coverage in 26 cases. Complications included hematoma (8.1%), infection (4.7%), and spontaneous delamination (4.7%). Wound closure was successfully obtained without flap use in 93.3%. Poor BTM take was associated with peripheral vascular disease, hypertension, immunosuppression, and BTM hematoma and infection (<0.05).

Conclusion

This study contributes to the growing body of evidence favoring BTM use in challenging reconstructive cases. Although prospective comparative studies are forthcoming, BTM likely has broad applications in reconstructive surgery.

The Application of a Synthetic Biodegradable Temporizing Matrix in Extensive Burn Injury: A Unicenter Experience of 175 Cases

Objectives: Addressing extensive and deep burn wounds poses considerable challenges for both patients and surgeons. The NovoSorb® Biodegradable Temporizing Matrix (BTM) emerged as a novel dermal substitute and has been subjected to evaluation in large burn wound cases, with a specific focus on identifying risk factors associated with suboptimal take rates. Methods: All patients with burn wounds greater than 10% body surface that underwent BTM treatment between March 2020 and November 2023 were eligible for inclusion. Univariate analyses and linear regression models were employed to discern risk factors and predictors influencing the take rates of both the BTM and split-thickness skin grafts (STSGs). Results: A total of 175 patients (mean age 56.2 ± 19.8 years, 70.3% male) were evaluated. The mean take rates of the BTM and STSGs were 82.0 ± 24.7% and 87.3 ± 19.0%, respectively. There were significant negative correlations between BTM take and the number of surgeries before BTM application (r = -0.19, p = 0.01), %TBSA and STSG take (r = -0.36, p = <0.001) and significant positive correlations between BTM and STSG take (r = 0.41, p ≤ 0.001) in addition to NPWT and STSG take (r = 0.21, p = 0.01). Multivariate regression analyses showed that a larger number of surgeries prior to BTM application (OR -3.41, 95% CI -6.82, -0.03, p = 0.04) was associated with poorer BTM take. Allograft treatment before BTM application (OR -14.7, 95% CI -23.0, -6.43,p = 0.01) and failed treatment with STSG before BTM application (OR -20.8, 95% CI -36.3, -5.23, p ≤ 0.01) were associated with poorer STSG take, whereas higher BTM take rates were associated with overall higher STSG take (OR -0.15, 95% 0.05, 0.26, p = 0.01). The Meek technique was used in 24 patients and showed similar take rates (BTM: 76.3 ± 28.0%, p = 0.22; STSG: 80.7 ± 21.1, p = 0.07). Conclusions: This study summarizes our findings on the application of a BTM in the context of large burn wounds. The results demonstrate that successful treatment can be achieved even in patients with extensive burns, resulting in satisfying take rates for both the BTM and STSG. The data underscore the importance of promptly applying a BTM to debrided wounds and indicate good results when using Meek.

Using BTM to reconstruct a complex dorsal hand wound with segmental loss of EDC tendon: Case report and review of the literature

We present the case of a 65 year old man who sustained a complex dorsal hand degloving injury with segmental loss of EDC tendon to middle finger, which was reconstructed using BTM. He returned to near full function despite not having a tendon reconstruction, and the uninjured tendons were able to glide without restriction beneath the BTM. We review the case and the literature surrounding the use of BTM in this clinical scenario.

Upper Extremity Wounds Treated with Biodegradable Temporizing Matrix versus Collagen-Chondroitin Silicone Bilayer

Objective  This study aims to compare outcomes between Novosorb Biodegradable Temporizing Matrix (BTM) and Integra collagen-chondroitin silicone for upper-extremity wound reconstruction. Methods  This retrospective study analyzed adult patients who underwent wound reconstruction with either BTM or Integra at our institution between 2015 and 2020. Results  Forty-eight patients were included: 31 (64.6%) BTM and 17 (35.4%) Integra. Mean age was 44.0 (range: 18-68) years. Age, race, sex, smoking, comorbidities, and defect size were similar between groups. Wound etiologies included 12 (25.0%) burn, 22 (45.8%) trauma, and others. Median template size was 133 cm 2 for BTM and 104 cm 2 for Integra ( p  = 0.526). Skin grafting was performed after 14 (45.2%) and 14 (82.4%) wounds treated with BTM and Integra, respectively ( p  = 0.028). Template complications of infection and dehiscence were comparable. Skin-graft complications occurred in five (35.7%) and three (21.4%) wounds in BTM and Integra, respectively ( p  = 0.031). Skin-graft failure rates were comparable ( p  = 0.121). Mean number of secondary procedures required after template placement was higher in the Integra group (BTM, 1.0; Integra, 1.9; p  = 0.090). Final healing was achieved in 17 (54.8%) BTM and 11 (64.7%) Integra wounds ( p  = 0.694). Median time to healing was 4.1 months after BTM and 2.6 months after Integra placement ( p  = 0.014). Conclusion  Compared with Integra, BTM achieved comparable wound healing and complication rates. Fewer secondary procedures and skin grafts were observed in BTM wounds, likely as a result of the coronavirus disease 2019 pandemic. At our institution, 100 cm 2 of product costs $850 for BTM and $3,150 for Integra, suggesting BTM as an economical alternative to fulfill the high functional and aesthetic requirements of upper-extremity wounds.

NovoSorb Biodegradable Temporizing Matrix for Reconstruction of Multiplanar Degloving Injury of the Upper Limb

Originally described as “wringer injuries” by MacCollum in 1938,¹ traumatic multiplanar degloving injuries that occur as the result of the hand, forearm or arm being drawn between the rollers of a machine are functionally devastating and present a significant reconstructive challenge. Revascularization and comprehensive excision of devitalized bone and soft tissue, followed by appropriate skeletal fixation and vascularized soft tissue cover are the mainstays of management. To date, published case series have described local flaps and free tissue transfer for coverage of wounds that involve exposed vital structures such as nerves, vessels, and tendons.² NovoSorb biodegradable temporizing matrix (BTM; PolyNovo Biomaterials Pty Ltd, Melbourne, Australia) is a bilayer bioabsorbable synthetic polymer dermal substitute, which has the ability to integrate into large wound beds and is resistant to infection.³ BTM comprises a bioabsorbable, polyurethane matrix that allows for cellular infiltration and a temporary nonbiodegradable, nonporous polyurethane layer, which limits moisture loss and provides a barrier to bacteria. Here we describe the successful use of BTM in the staged reconstruction of a high-energy industrial roller injury in an adolescent patient.

Biodegradable temporising matrix: use of negative pressure wound therapy shows a significantly higher success rate

OBJECTIVE

The purpose of this case series was to evaluate the efficacy of a synthetic biodegradable temporising matrix (BTM; PolyNovo Biomaterials Pty Ltd, Australia) and compare the outcome of BTM patients with and without negative pressure wound therapy (NPWT).

METHOD

A retrospective chart review was conducted on patients admitted with deep full-thickness burns, traumatic or complex wound injuries treated with BTM. Electronic medical records and images were evaluated by a team of clinical professionals. Endpoints included: the measure of successful BTM integration; and comparison between patients treated with and without NPWT. Additional measures were BTM total surface area, BTM sites, timeliness of BTM application and any complications.

RESULTS

A total of 28 patients were evaluated and 23 (82.1%) demonstrated overall successful BTM integration. Patients treated with BTM in conjunction with NPWT (n=16) demonstrated a significantly higher (p=0.046) integration rate compared to patients treated without NPWT (n=12) (93.8% versus 58.3%, respectively). Patients treated with BTM with NPWT continued to successfully integrate and sustain favourable outcomes despite the presence of severe infection or the development of haematomas.

CONCLUSION

A significantly higher integration rate was demonstrated when BTM was used in conjunction with NPWT. The results of this study further support the efficacy of successful integration of BTM as a replacement for tissue loss in the treatment of deep, full-thickness burns, traumatic and complex wound injuries, and particularly favourable outcomes with the use of NPWT. To the best of our knowledge, this is the first reported case series comparing the clinical outcomes of BTM with and without the use of NPWT.

Treatment of Complex Wounds with NovoSorb® Biodegradable Temporising Matrix (BTM)-A Retrospective Analysis of Clinical Outcomes

Complex and chronic wounds represent a highly prevalent condition worldwide that requires a multimodal and interdisciplinary treatment approach to achieve good functional and aesthetic outcomes. Due to increasing costs of health care, an aging population and an increase in difficult-to-treat microbial colonization of wounds, complex wounds will become a substantial clinical, social and economic challenge in the upcoming years. In plastic reconstructive surgery, a variety of dermal skin substitutes have been established for clinical use. Since its approval as a dermal skin substitute in Germany, NovoSorb^® Biodegradable Temporising Matrix (BTM) has become a valuable therapeutic option for the treatment of full-thickness wound defects. The clinical data published to date are limited to case reports and small-scale case series with the main focus on single wounds. The aim of this single-center study was a retrospective analysis of our own patient collective that has received treatment with BTM for complex wounds. Overall, BTM showed to be a reliable and versatile reconstructive option, especially for patients with multiple co-morbidities and microbiologically colonized wounds. Although the preliminary findings have produced promising results, further investigation and research are warranted regarding long-term outcomes and additional clinical applications.

Head and Neck Wound Reconstruction Using Biodegradable Temporizing Matrix Versus Collagen-Chondroitin Silicone Bilayer

BACKGROUND

Head and neck reconstruction is challenging because of the functional requirements of movement, sensation, and cosmesis of this highly visible region. This study is the first to compare Novosorb biodegradable temporizing matrix (BTM) and Integra collagen-chondroitin silicone (CCS) skin substitutes for reconstruction of soft tissue head and neck wounds.

METHODS

This retrospective review included adults who underwent wound reconstruction of the head/neck with either BTM or CCS between 2015 and 2020. Patient-level data, complications, and closure rates were compared.

RESULTS

The review identified 15 patients: 5 who received BTM and 10 who received CCS. Mean age at dermal template placement was 55 (range, 28-79) years. Race, sex, smoking status, medical comorbidities, defect size, radiation history, prior surgeries, and follow-up time were not significantly different between groups. Wound etiologies for BTM and CCS included burn (40% vs 60%), trauma (20% vs 20%), surgical wounds (20% vs 20%), and skin cancer (20% vs 0%), respectively (P = .026). Skin grafts were placed in 8 (80%) wounds after CCS placement, compared with 3 (60%) after BTM (P = .670). Template reapplication was required in 2 (40%) BTM wounds and 3 (30%) CCS wounds (P = 1.0). Infection, hematoma, and seroma were comparable between groups, although skin graft failure was higher in the CCS group at 3 (37.5%) compared with 0 for BTM (P = .506). More secondary procedures were required after CCS placement (CCS, 1.9 ± 2.2; BTM, 0.9 ± 0.8; P = .090). Definitive closure in patients not lost to follow-up occurred in 4 (100%) BTM and 6 (75%) CCS cases (P = 1.0).

CONCLUSIONS

Head and neck wounds treated with BTM had comparable closure and complication rates as CCS bilayer and required fewer secondary procedures and skin grafts. These findings suggest that BTM is safe and efficacious for application in head and neck wounds and may be considered as an economical alternative.

Use of a synthetic biodegradable temporising matrix after necrotising fasciitis infection of the thigh

Biodegradable temporising matrix (BTM NovoSorb; PolyNovo, Melbourne, Australia) is a novel synthetic polyurethane dermal substitute. Licensed in Europe in 2020, it was developed primarily for reconstruction of infected wounds. We present a case of a healthy man in his 60s with necrotising fasciitis of his left thigh. His medical history was significant for recurrent left thigh liposarcoma that was treated years earlier with surgical excision and adjuvant radiotherapy. The affected area was within the previously irradiated tissue, debrided down to fascia and dressed with a vacuum-assisted closure to help regenerate the wound bed. Reconstruction options were limited by having a circumferential thigh defect that was infected. Following the use of NovoSorb BTM, the area was dressed with Acticoat Flex 7 antimicrobial barrier dressing for 5 weeks. Patient mobilisation was permitted. The material integrated very well and formed a soft, pliable healthy dermal layer that was autografted with split thickness skin grafts. This resulted in durable cover of the thigh with good aesthetic contour and minimal contracture.

A novel use for the biodegradable temporizing matrix

Biodegradable Temporising Matrix (BTM), a skin substitute, has been recently developed as a novel adjunct to the plastic surgeon’s reconstructive repertoire. Its use has been described in literature in a variety of settings and complex wounds, including those that previously would have been described as “non-graftable”, with favourable outcomes. We present the case of a patient with a wound to the right foot and ankle following extravasation injury. Following surgical debridement, this injury was managed with BTM, which allowed granulation and production of a “neo-dermis”. A split-thickness skin graft was subsequently applied. The characteristics of the BTM allowed the resulting skin graft and scar to be pliable, avoiding tendon tethering and joint contracture. To the authors’ knowledge, this skin substitute has not been reported in a wound of this aetiology before. It is our hope that this report will provide evidence to colleagues that this is a valuable adjunct that may be used in complex wounds.

Level of evidence: Level V, therapeutic study.

Smart 3D Printed Hydrogel Skin Wound Bandages: A Review

Wounds are a major health concern affecting the lives of millions of people. Some wounds may pass a threshold diameter to become unrecoverable by themselves. These wounds become chronic and may even lead to mortality. Recently, 3D printing technology, in association with biocompatible hydrogels, has emerged as a promising platform for developing smart wound dressings, overcoming several challenges. 3D printed wound dressings can be loaded with a variety of items, such as antibiotics, antibacterial nanoparticles, and other drugs that can accelerate wound healing rate. 3D printing is computerized, allowing each level of the printed part to be fully controlled in situ to produce the dressings desired. In this review, recent developments in hydrogel-based wound dressings made using 3D printing are covered. The most common biosensors integrated with 3D printed hydrogels for wound dressing applications are comprehensively discussed. Fundamental challenges for 3D printing and future prospects are highlighted. Additionally, some related nanomaterial-based hydrogels are recommended for future consideration.

Biodegradeable temporising matrix use in a traumatic chest wound

The Welsh Centre for Burns and Plastic Surgery is responsible for a population of 10 million people in Wales and England. We describe the use of biodegradable temporising matrix (BTM) in a large traumatic chest wound in a 23-year-old woman. BTM is a synthetic dermal substitute and has been utilised to achieve soft tissue coverage in complex wounds. This wound was sustained after the patient fell from a tractor into a large silage rake, resulting in injuries to her chest and limbs. Following meticulous debridement, her resulting full thickness skin defect measured 30 × 30 cm extending from the sternal notch to the upper abdomen, with bone, muscle and breast tissue exposure. The central chest area is complex to reconstruct due to the contours of the breasts and tendency to contracture following skin graft reconstruction. We demonstrate the first reported use of BTM for breast reconstruction, as far as we are aware.

Scale-up of a Composite Cultured Skin Using a Novel Bioreactor Device in a Porcine Wound Model

Extensive deep-burn management with a two-stage strategy can reduce reliance on skin autografts; a biodegradable polyurethane scaffold to actively temporize the wound and later an autologous composite cultured skin (CCS) for definitive closure. The materials fulfilling each stage have undergone in vitro and in vivo pretesting in "small" large animal wounds. For humans, producing multiple, large CCSs requires a specialized bioreactor. This article reports a system used to close large porcine wounds. Three Large White pigs were used, each with two wounds (24.5 cm × 12 cm) into which biodegradable dermal scaffolds were implanted. A sample from discarded tissue allowed isolation/culture of autologous fibroblasts and keratinocytes. CCS production began by presoaking a 1-mm-thick biodegradable polyurethane foam in autologous plasma. In the bioreactor cassette, fibroblasts were seeded into the matrix with thrombin until established, followed by keratinocytes. The CCSs were applied onto integrated dermal scaffolds on day 35, alongside a sheet skin graft (30% of one wound). Serial punch biopsies, trans-epidermal water loss readings (TEWL), and wound measurements indicated epithelialization. During dermal scaffold integration, negligible wound contraction was observed (average 4.5%). After CCS transplantation, the control skin grafts were "taken" by day 11 when visible islands of epithelium were clinically observed on 2/3 CCSs. Closure was confirmed histologically, with complete epithelialization by day 63 post-CCS transplantation (CCS TEWL ~ normal skin average 11.9 g/m2h). Four of six wounds demonstrated closure with robust, stratified epithelium. Generating large pieces of CCS capable of healing large wounds is thus possible using a specialized designed bioreactor.

Engineering Bioactive Scaffolds for Skin Regeneration

Large skin wounds pose a major clinical challenge. Scarcity of donor site and postsurgical scarring contribute to the incomplete or partial loss of function and aesthetic concerns in skin wound patients. Currently, a wide variety of skin grafts are being applied in clinical settings. Scaffolds are used to overcome the issues related to the misaligned architecture of the repaired skin tissues. The current review summarizes the contribution of biomaterials to wound healing and skin regeneration and addresses the existing limitations in skin grafting. Then, the clinically approved biologic and synthetic skin substitutes are extensively reviewed. Next, the techniques for modification of skin grafts aiming for enhanced tissue regeneration are outlined, and a summary of different growth factor delivery systems using biomaterials is presented. Considering the significant progress in biomaterial science and manufacturing technologies, the idea of biomaterial-based skin grafts with the ability for scarless wound healing and reconstructing full skin organ is more achievable than ever.

Advances in Skin Tissue Bioengineering and the Challenges of Clinical Translation

Skin tissue bioengineering is an emerging field that brings together interdisciplinary teams to promote successful translation to clinical care. Extensive deep tissue injuries, such as large burns and other major skin loss conditions, are medical indications where bioengineered skin substitutes (that restore both dermal and epidermal tissues) are being studied as alternatives. These may not only reduce mortality but also lessen morbidity to improve quality of life and functional outcome compared with the current standards of care. A common objective of dermal-epidermal therapies is to reduce the time required to accomplish stable closure of wounds with minimal scar in patients with insufficient donor sites for autologous split-thickness skin grafts. However, no commercially-available product has yet fully satisfied this objective. Tissue engineered skin may include cells, biopolymer scaffolds and drugs, and requires regulatory review to demonstrate safety and efficacy. They must be scalable for manufacturing and distribution. The advancement of technology and the introduction of bioreactors and bio-printing for skin tissue engineering may facilitate clinical products' availability. This mini-review elucidates the reasons for the few available commercial skin substitutes. In addition, it provides insights into the challenges faced by surgeons and scientists to develop new therapies and deliver the results of translational research to improve patient care.

Early physiotherapy experience with a biodegradable polyurethane dermal substitute: Therapy guidelines for use

OBJECTIVE

The purpose of this study was to investigate and develop range of motion (ROM) and mobilisation guidelines in adult patients where a newly developed synthetic dermal substitute was applied in our adult burn centre.

METHOD

A retrospective case note audit was conducted on the first 20 acute burn injured patients who had a synthetic dermal substitute applied. Data collected included days to commencement of ROM, days to clearance for mobilisation, and joint ROM achieved after dermal substitute application (prior to delamination) and after split skin grafting (SSG) for the elbow, knee and shoulder joints. Scar assessments were completed at 12 months after injury using two scar assessment scales.

RESULTS

Clearance to mobilise occurred at mean 10.4 and 4.9 days after dermal substitute and after skin graft application to lower limbs respectively. ROM commenced at a mean of 9.9 (upper limbs) and 12.7 (lower limbs) days after dermal substitute application. Following skin grafting, ROM commenced at a mean of 6.6 and 6.5 days for upper limbs and lower limbs respectively. Prior to dermal substitute delamination mean flexion at the knee (86.3°), elbow (114.0°) and shoulder (143.4°) was achieved. Mean ROM continued to improve after grafting with knee (133.2°), elbow (126.1°) and shoulder (151.0°) flexion approaching normal ROM in most cases. Mean extension of the elbow (-4.6°) was maintained close to normal levels after skin grafting. There were no recorded instances of knee extension contracture. Patient and Observer Scar Assessment Scale and Matching Assessment of Photographs of Scars scores indicated good cosmetic outcomes with relatively low levels of itch and minimal pain reported at 12 months after injury.

CONCLUSION

A steep learning curve was encountered in providing therapy treatment for patients managed with this relatively new synthetic dermal substitute. Trends indicated that as experience with this new dermal substitute grew, patients progressed toward active therapy earlier. A guideline for therapy treatment has been developed but will continue to be evaluated and adjusted when required.

Lessons Learned From Two Survivors of Greater Than 90% TBSA Full-Thickness Burn Injuries Using NovoSorb Biodegradable Temporizing Matrix™ and Autologous Skin Cell Suspension, RECELL™: A Case Series

Since autologous split-thickness skin grafts are scarce and lab skin growth requires a significant amount of time, there are limited available treatment approaches for patients with full-thickness burns greater than 90% TBSA. Additionally, to achieve the primary goal of skin coverage and resuscitation, there must exist a balance between fluid loss and metabolic derangement. Allografts and xenografts have traditionally been used early in the process to achieve these goals. Currently, novel approaches to treatment consider the additional use of synthetic dermal substitutes and autologous skin cell suspension to improve outcomes. This case series describes the treatment course of patients with greater than 90% TBSA full-thickness burn injuries using a staged, multifaceted approach of using NovoSorb Biodegradable Temporizing Matrix™ as the primary dermal substitute in conjunction with a RECELL™ Autologous Cell Suspensions Device applied with autograft and allograft to achieve improved resuscitation, limiting fluid loss, and finally skin coverage. Allograft and NovoSorb Biodegradable Temporizing Matrix™ were used early to cover excised burns, resulting in improved metabolic control by limiting the systemic inflammatory response syndrome and fluid loss. Both patients survived using this approach.

Management of foot degloving injury with bilateral anterolateral thigh flaps

Foot degloving injuries are frequently encountered by reconstructive surgeons as there are more and more vehicles on the road. The separation between the deep facia and the superficial skin often damage the blood supply of the cutaneous tissue, resulting skin defect and digit necrosis. In order to manage these challenging situations, reconstructive surgeons have explored various types of techniques. Our team have managed to cure one such patient through bilateral anterolateral thigh flaps, in which the two flaps cover the dorsal and plantar side respectively. The flaps survived uneventfully and second stage operation of defatting was consequently arranged. The patient obtained protective sensation and felt satisfied with the cosmetic outcome. With the development of microsurgery, bilateral anterolateral thigh flaps could be effectively adopted to manage foot degloving injuries.

Advanced Hydrogels as Wound Dressings

Skin is the largest organ of the human body, protecting it against the external environment. Despite high self-regeneration potential, severe skin defects will not heal spontaneously and need to be covered by skin substitutes. Tremendous progress has been made in the field of skin tissue engineering, in recent years, to develop new skin substitutes. Among them, hydrogels are one of the candidates with most potential to mimic the native skin microenvironment, due to their porous and hydrated molecular structure. They can be applied as a permanent or temporary dressing for different wounds to support the regeneration and healing of the injured epidermis, dermis, or both. Based on the material used for their fabrication, hydrogels can be subdivided into two main groups—natural and synthetic. Moreover, hydrogels can be reinforced by incorporating nanoparticles to obtain “in situ” hybrid hydrogels, showing superior properties and tailored functionality. In addition, different sensors can be embedded in hydrogel wound dressings to provide real-time information about the wound environment. This review focuses on the most recent developments in the field of hydrogel-based skin substitutes for skin replacement. In particular, we discuss the synthesis, fabrication, and biomedical application of novel “smart” hydrogels.

A paradigm shift in practice-the benefits of early active wound temporisation rather than early skin grafting after burn eschar excision

After major burn injury, once survival is achieved by the immediate excision of all deep burn eschar, we are faced with a patient who is often physiologically well but with very extensive wounds. While very early grafting yields excellent results after the excision of small burns, it is not possible to achieve the same results once the wound size exceeds the available donor site. In patients where 50%-100% of the total body surface area is wound, we rely on serial skin graft harvest, from finite donor site resources, and the massive expansion of those harvested grafts to effect healing. The result is frequently disabling and dysaesthetic. Temporisation of the wounds both passively, with cadaver allograft, and actively, with dermal scaffolds, has been successfully employed to ameliorate some of the problems caused by our inability to definitively close wounds early. Recent advances in technology have demonstrated that superior functional and cosmetic outcomes can be achieved in actively temporised areas even when compared with definitive early closure with skin graft. This has several beneficial implications for both patient and surgeon, affecting the timing of definitive wound closure and creating a paradigm shift in the care of the burned patient.