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Background: Spina bifida cystica (SB) is one of the most common neural tube defects affecting 1 in 2,500 newborns worldwide. Due to the neurological deficits associated with SB, injuries from thermal exposure, trauma, or other etiology may be more severe rendering their treatment a challenge for a traditional approach to burn and wound management. Despite this relatively high disease incidence rate, few studies exist to evaluate wound development or the natural history of wound healing in patients with SB. Case presentation: We present a case of a pediatric patient with a history of SB who sustained a full thickness burn to the right plantar foot in February of 2023. The 8-year-old was riding an all-terrain vehicle when his right foot made contact with the hot tailpipe. The insensate neuropathy associated with the patient’s SB contributed to the extreme severity of thermal contact injury. We report the burn, treatments, the usage of a novel dermal replacement, and outcomes of this case. Conclusion: This case demonstrates successful limb salvage in a pediatric patient with severe plantar foot burns utilizing a novel collagen-elastin dermal matrix for tissue reconstruction. Limb salvage was the preferred treatment option over amputation and a prosthetic considering the patient’s age and need for future prostheses. Given the severity of the burn, the impaired wound healing due to his baseline neuropathy, and his baseline ambulatory status, the optimal outcome in this case was limb salvage, which was successfully achieved.

ABSTRACT Purpose: To analyze the cytotoxicity and cell in porcine-derived decellularized skin matrix. Methods: We analyzed the effect of multiple decellularization processes by histological analysis, DNA quantification, and flow cytometry. Subsequently, we analyzed the most appropriate hydrogel concentration to minimize cytotoxicity on fibroblast culture and to maximize cell proliferation. Results: After the fourth decellularization, the DNA quantification showed the lowest DNA concentration (< 50 ng/mg). Histological analysis showed no cell components in the hydrogel. Moreover, hematoxylin and eosin showed a heterogeneous structure of collagen fibers. The best hydrogel concentration ranged from 3 to 25%, and there was no significant difference between the 24 hours and seven days. Conclusions: The process of hydrogel production was effective for removing cells and DNA elements. The best hydrogel concentration ranged from 3 to 25%.

Objective: The clinical effects of artificial dermis in treating skin and soft tissue defects accompanied by bone or tendon exposure were assessed., Approach: A retrospective analysis was conducted on the clinical data of 45 cases of skin and soft tissue defects accompanied by bone or tendon exposure admitted to the trauma surgery department of Fujian Provincial Hospital between February 2018 and August 2020. They were divided into the artificial dermis and control groups. The wound was assessed using the Vancouver Scar Scale (mVSS), and the postoperative visual analogue scale (VAS) scores were recorded at 3, 6, 9, and 12 months after surgery. At the 12-month after surgery, skin sensation recovery was evaluated using the criteria of the British Medical Research Council (BMRC)., Results: The cases included 26 males and 19 females, aged 50 to 85 years. All patients were followed up for an average of 13.8 months (range: 12-18 months). Compared with controls, the wound healing time of the observation group was longer (35.8 ± 10.6 vs. 28.5 ± 4.8, P = 0.007), without significant differences for the number of operations and length of hospitalization. The mVSS scores were not different between groups (P group = 0.294), but the scores decreased with time (P time < 0.001), and the group×time interaction was significant (P interaction < 0.001). Similarly, the VAS scores were not different between groups (P group = 0.667), but the scores decreased with time (P time < 0.001); the group×time interaction was not significant (P interaction = 0.274). At the 12-month mark following the operation, in the artificial dermis group, the MCRR score was S3+ in 23 patients, while it ranged from S0 to S3 in two patients; in the control group, S3+ was observed in 17 patients, and S0-S3 in three (P = 0.815)., Conclusion: Artificial dermis treatment is considered a safe and effective alternative therapy for patients with skin and soft tissue defects accompanied by bone or tendon exposure who cannot tolerate or are unwilling to undergo autologous skin flap transplantation. It offers the advantages of minimal donor site trauma, simplicity in operation, and favorable postoperative functional recovery., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The Integra Ⓡ Dermal Regeneration Template (DRT) is a bioengineered dermal substitute that is becoming increasingly popular in the field of reconstruction. Its unique properties allow for immediate wound closure while providing a scaffold for tissue regeneration. Currently, it is commonly used to treat burns, ulcers, and complex wounds. In the setting of traumatic periocular tissue loss, only two prior reports have been published on its use for primary reconstruction. We present our institution's experience with a series of four young patients who received primary reconstruction with Integra Ⓡ DRT as a full-thickness skin substitute for their large traumatic periorbital skin defects.

Background: Secondary intention healing is an alternative to consider in large tumors or tumors located in areas of limited skin mobility, such as the scalp. To promote epithelialization, we can use Dermal Regeneration Matrix (DRM) or bone wax., Objective: This study aimed to compare the efficacy of DRM and bone wax in secondary intention healing of cutaneous scalp tumors in elderly patients with comorbidities., Materials and Methods: The medical records of 18 patients with cutaneous scalp tumor healing by secondary intention from February 2022 to April 2023 were analyzed for demographic variables, tumor and surgical characteristics, time from withdrawal of material to complete epithelialization, and need for subsequent surgical intervention., Results: Bone wax was used in 6 patients and DRM in 12. The mean patient age was 84.3 years, and the mean tumor size was 2.7 cm. There were no significant differences in demographics or postoperative complications between the groups. The median time to complete epithelization was 84.5 (60.2-108.7) days in the bone wax group and 105.0 (91.0-126.0) days in the DRM group, with no significant differences (P = 0.15)., Conclusions: Bone wax is a simple and economical material that can be used for secondary intention healing of scalp tumors in elderly patients with high surgical risk., (© 2024 the International Society of Dermatology.)

Electronic skins (E-Skins) are crucial for future robotics and wearable devices to interact with and perceive the real world. Prior research faces challenges in achieving comprehensive tactile perception and versatile functionality while keeping system simplicity for lack of multimodal sensing capability in a single sensor. Two kinds of tactile sensors, transient voltage artificial neuron (TVAN) and sustained potential artificial neuron (SPAN), featuring self-generated zero-biased signals are developed to realize synergistic sensing of multimodal information (vibration, material, texture, pressure, and temperature) in a single device instead of complex sensor arrays. Simultaneously, machine learning with feature fusion is applied to fully decode their output information and compensate for the inevitable instability of applied force, speed, etc, in real applications. Integrating TVAN and SPAN, the formed E-Skin achieves holistic touch awareness in only a single unit. It can thoroughly perceive an object through a simple touch without strictly controlled testing conditions, realize the capability to discern surface roughness from 0.8 to 1600 µm, hardness from 6HA to 85HD, and correctly distinguish 16 objects with temperature variance from 0 to 80 °C. The E-skin also features a simple and scalable fabrication process, which can be integrated into various devices for broad applications., (© 2024 Wiley‐VCH GmbH.)

Background: Non-graftable or composite defect reconstruction represents a major challenge to the reconstructive surgeon, with many wounds requiring local flap or free microvascular tissue transfer approaches. The recent advent of synthetic skin substitutes such as Biodegradable Temporizing Matrix (BTM) have revolutionized the management of complex defects including those caused by burns, trauma and infection, with low-morbidity and low-complexity surgery. However, limited data exist supporting their use in cancer reconstruction in Australia., Methods: We performed a prospective cohort study of patients undergoing cancer resection and reconstruction with BTM between February 2021 and February 2023 in our institution. Reported outcomes included matrix integration, infection, and return to theatre., Results: Twelve patients underwent reconstruction of primary or secondary defects following cancer resection during this period. Eight patients were male, four female, mean age at surgery was 70 years. Pathology resected included squamous cell carcinoma (SCC) and melanoma of the head and neck, sarcoma resection of the lower limb, and osteoradionecrosis (ORN) of the scalp. T-stage of primary tumours ranged from T2 to T4 and one in-transit metastasis of melanoma. Four patients were treated with radiotherapy, two of whom received postoperative radiotherapy (PORT) and two who received neoadjuvant radiotherapy, three additional patients had an intervention to a previously irradiated wound bed for recurrence or ORN. Overall matrix integration was 83% (10/12), with a 50% integration rate (2/4) observed in the post-radiotherapy group, requiring return to theatre for alternative reconstructive approaches., Conclusion: We report our experience with a synthetic dermal matrix (BTM) in cancer reconstruction, the largest cohort of this type in the Australian literature. BTM represents an exciting reconstructive tool for the cancer reconstructive surgeon, with a high rate of success and low morbidity., (© 2024 Royal Australasian College of Surgeons.)

Reconstructed epidermal equivalents (REEs) consist of two distinct cell layers - the stratum corneum (SC) and the keratinocyte layer (KL). The interplay of these layers is particularly crucial in pruritic inflammatory disorders, like psoriasis, where a defective SC barrier is associated with immune dysregulation. However, independent evaluation of the skin barrier function of the SC and KL in REEs is highly challenging because of the lack of quantitative methodologies that do not disrupt the counter layer. Here, a non-invasive impedance spectroscopy technique is introduced for dissecting the distinct contributions of the SC and KL to overall skin barrier function without disrupting the structure. These findings, inferred from the impedance spectra, highlight the individual barrier resistances and maturation levels of each layer. Using an equivalent circuit model, a correlation between impedance parameters and specific skin layers, offering insights beyond traditional impedance methods that address full-thickness skin only is established. This approach successfully detects subtle changes, such as increased paracellular permeability due to mild irritants and the characterization of an immature SC in psoriatic models. This research has significant implications, paving the way for detailed mechanistic investigations and fostering the development of therapies for skin irritation and inflammatory disorders., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

Background: This prospective study aimed to evaluate the outcomes of the use of dermal templates for lengthy volar soft tissue defects (1.5-4 cm) in the fingers., Methods: The volar soft tissue defects of 15 patients (19 fingers) were treated with Lando dermal template coverage between June 2022 and November 2022. We evaluated sensory recovery, scar formation, and overall appearance of the repair site at an average of 13 months (range, 12-17 months) of follow-up., Results: The defect healed in all cases. We found an average static 2-point discrimination of 7 mm (range 4 to 14 mm). Scar formation was evident in all cases. The repair did not restore the bulkiness of the volar finger, especially in the finger with the bony exposure. Nail deformities and joint contracture were observed in some cases., Conclusion: Dermal template repair does not restore normal sensation and inevitably leads to scar formation when the defect is longer (>1.5 cm). Bulkiness of the volar finger is not restored in most patients, especially when there was bone or tendon exposure in the initial wound site., (Copyright © 2024 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.)

The development of technologies for the generation and transplantation of living skin equivalents (LSEs) is a significant area of translational medicine. Such functional equivalents can be used to model and study the morphogenesis of the skin and its derivatives, to test drugs, and to improve the healing of chronic wounds, burns, and other skin injuries. The evolution of LSEs over the past 50 years has demonstrated the leap in technology and quality and the shift from classical full-thickness LSEs to principled new models, including modification of classical models and skin organoids with skin derived from human-induced pluripotent stem cells (iPSCs) (hiPSCs). Modern methods and approaches make it possible to create LSEs that successfully mimic native skin, including derivatives such as hair follicles (HFs), sebaceous and sweat glands, blood vessels, melanocytes, and nerve cells. New technologies such as 3D and 4D bioprinting, microfluidic systems, and genetic modification enable achievement of new goals, cost reductions, and the scaled-up production of LSEs., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2024 Andrei Riabinin et al.)

Lipid-based nanocarriers have been extensively utilized for the solubilization and cutaneous delivery of water-insoluble active ingredients in skincare formulations. However, their practical application is often limited by structural instability, leading to premature release and degradation of actives. Here we present highly robust multilamellar nanovesicles, prepared by the polyionic self-assembly of unilamellar vesicles with hydrolyzed collagen peptides, to stabilize all-trans-retinol and enhance its cutaneous delivery. Our results reveal that the reinforced multilayer structure substantially enhances dispersion stability under extremely harsh conditions, like freeze-thaw cycles, and stabilizes the encapsulated retinol. Interestingly, these multilamellar vesicles exhibit significantly lower cytotoxicity to human dermal fibroblasts than their unilamellar counterparts, likely due to their smaller particle number per weight, minimizing potential disruptions to cellular membranes. In artificial skin models, retinol-loaded multilamellar vesicles effectively upregulate collagen-related gene expression while suppressing the synthesis of metalloproteinases. These findings suggest that the robust multilamellar vesicles can serve as effective nanocarriers for the efficient delivery and stabilization of bioactive compounds in cutaneous applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Recent advances in cell and biofabrication technologies have contributed to the development of complex human organs. In particular, several skin substitutes are being generated using tissue engineering and regenerative medicine (TERM) technologies. However, recent studies mainly focus on the restoration of the dermis and epidermis layers rather than the regeneration of a fully functional innervated skin organ. Innervation is a critical step in functional tissue repair which has been overlooked in the current TERM studies. In the current study, we highlight the importance of sensation in the skin as the largest sensory organ in the human body. In large non-healing skin wounds, the skin sensation is severely diminished or completely lost and ultimately lead to chronic pain and wound healing process interruption. Current therapeutics for restoring skin sensation after trauma are limited. Recent regenerative medicine-based studies could successfully induce neural networks in skin substitutes, but the effectiveness of these technologies in enhancing sensory capability needs further investigation.

Partial-thickness burns are the most common form of burns, affecting the dermis and possibly resulting in scarring and infection. The Spincare System is a new device that uses electrospinning technology to create a temporary skin-like matrix that can be applied to wounds. This study evaluated the performance, safety, and efficacy of Spincare in treating superficial to partial-thickness burns not considered for surgery. A prospective single-arm, open-label, multicenter study was conducted in 3 adult burn units across Israel. Forty-four patients with superficial to intermediate burns of up to 10% of TBSA were enrolled. Spincare was applied to the wounds, and follow-up visits were performed on days 7, 14, and 21 and months 3 and 6 posttreatment. Thirty-one patients with 36 wounds completed the day 21 visit. The mean wound healing area on day 21 was 97.26 ± 9.41%, and the mean healing time was 12.8 ± 4.3 days. Only one moderate adverse event was observed concerning the treatment, and it is important to acknowledge the potential progression of this hypertrophic scar into a keloid. This study demonstrated that Spincare is a safe and effective device for treating superficial to intermediate partial-thickness burns. Spincare achieved rapid and complete wound healing with a low incidence of adverse events., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Burn Association.)

Bionic artificial skin which imitates the features and functions of human skin, has broad applications in wearable human-machine interfaces. However, equipping artificial materials with skin-like mechanical properties, self-healing ability, and high sensitivity remains challenging. Here, inspired by the structure of human skin, an artificial skin based on ionogel composites with tailored mechanical properties and robust interface is prepared. Combining finite element analysis and direct ink writing (DIW) 3D printing technology, an ionogel composite with a rigid skeleton and an ionogel matrix is precisely designed and fabricated, realizing the mechanical anisotropy and nonlinear mechanical response that accurately mimic human skin. Robust interface is created through co-curing of the skeleton and matrix resins, significantly enhancing the stability of the composite. The realization of self-healing ability and resistance to crack growth further ensure the remarkable durability of the artificial skin for sensing application. In summary, the bionic artificial skin mimics the characteristics of human skin, including mechanical anisotropy, nonlinear mechanical response, self-healing capability, durability and high sensitivity when applied as flexible sensors. These strategies provide strong support for the fabrication of tissue-like materials with adaptive mechanical behaviors., (© 2024 Wiley‐VCH GmbH.)

Background: Severe burn wounds face two primary challenges: dysregulated cellular impairment functions following infection and an unbalanced wound hydration microenvironment leading to excessive inflammation and collagen deposition. These results in hypertrophic scar contraction, causing significant deformity and disability in survivors., Methods: A three-dimensional (3D) printed double-layer hydrogel (DLH) was designed and fabricated to address the problem of scar formation after burn injury. DLH was developed using methacrylated silk fibroin (SFMA) and gelatin methacryloyl (GelMA) for the upper layer, and GelMA and hyaluronic acid methacryloyl (HAMA) for the lower layer. To combat infection, copper-epigallocatechin gallate (Cu-EGCG) was incorporated into the lower layer bioink, collectively referred to as DLS. To balance wound hydration levels, HaCaT cells were additionally encapsulated in the upper layer, designed as DLS/c., Findings: DLH demonstrated suitable porosity, appropriate mechanical properties, and excellent biocompatibility. DLS exhibited potent antimicrobial properties, exerted anti-inflammatory effects by regulating macrophage polarisation, and may enhance angiogenesis through the HIF-1α/VEGF pathway. In the DLS/c group, animal studies showed significant improvements in epidermal formation, barrier function, and epidermal hydration, accompanied by reduced inflammation. In addition, Masson's trichrome and Sirius red staining revealed that the structure and ratio of dermal collagen in DLS/c resembled that of normal skin, indicating considerable potential for scarless wound healing., Interpretation: This biomimetic matrix shows promise in addressing the challenges of burn wounds and aiming for scarless repair, with benefits such as anti-infection, epidermal hydration, biological induction, and optimised topological properties., Funding: Shown in Acknowledgements., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: The purpose of dermal substitutes is to mimic the basic properties of the extracellular matrix of human skin. The application of dermal substitutes to the defect reduces the formation of hypertrophic scars and improves the scar quality. This study aims to develop an original dermal substitute enriched with stable fibroblast growth factor 2 (FGF2-STAB®) and test it in an animal model., Methods: Dermal substitutes based on collagen/chitosan scaffolds or collagen/chitosan scaffolds with nanofibrous layer were prepared and enriched with FGF2-STAB® at concentrations of 0, 0.1, 1.0, and 10.0 µg ‧ cm -2 . The performance of these dermal substitutes was tested in vivo on artificially formed skin defects in female swine. The outcomes were evaluated using cutometry at 3 and 6 months. In addition, visual appearance was assessed based on photos of the scars at 1-month, 3-month and 6-month follow-ups using Yeong scale and Visual Analog Scale., Results: The dermal substitute was fully integrated into all defects and all wounds healed successfully. FGF2-STAB®-enriched matrices yielded better results in cutometry compared to scaffolds without FGF2. Visual evaluation at 1, 3, and 6 months follow-ups detected no significant differences among groups. The FGF2-STAB® effectiveness in improving the elasticity of scar tissues was confirmed in the swine model. This effect was independently observed in the scaffolds with nanofibres as well as in the scaffolds without nanofibres., Conclusion: The formation of scars with the best elasticity was exhibited by addition 1.0 µg ‧ cm -2 of FGF2-STAB® into the scaffolds, although it had no significant effect on visual appearance at longer follow-ups. This study creates the basis for further translational studies of the developed product and its progression into the clinical phase of the research., Competing Interests: Declaration of Competing Interest The authors declare that they have no competing interests., (Copyright © 2024 Elsevier Ltd and International Society of Burns Injuries. All rights reserved.)

The effective management of deep skin wounds remains a significant healthcare challenge that often deteriorates with bacterial infection, oxidative stress, tissue necrosis, and excessive production of wound exudate. Current medical approaches, including traditional wound dressing materials, cannot effectively address these issues. There is a great need to engineer advanced and multifunctional wound dressings to address this multifaceted problem effectively. Herein, a rationally designed composite cryogel composed of a Copper Metal-Organic Framework (Cu-MOF), tannic acid (TA), polyvinyl alcohol (PVA), and zein protein has been developed by freeze-thaw technique. Cryogels display a remarkable swelling capacity attributed to their interconnected microporous morphology. Moreover, dynamic mechanical behaviour with the characteristics of potent antimicrobial, antioxidant, and biodegradation makes it a desirable wound dressing material. It was further confirmed that the material is highly biocompatible and can release TA and copper ions in a controlled manner. In-vivo skin irritation in a rat model demonstrated that composite cryogel did not provoke any irritation/inflammation when applied to the skin of a healthy recipient. In a deep wound model, the composite cryogel significantly accelerates the wound healing rate. These findings highlight the multifunctional nature of composite cryogels and their promising potential for clinical applications as advanced wound dressings., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Three-dimensional (3D) bioprinting has advantages for constructing artificial skin tissues in replicating the structures and functions of native skin. Although many studies have presented improved effect of printing skin substitutes in wound healing, using hydrogel inks to fabricate 3D bioprinting architectures with complicated structures, mimicking mechanical properties, and appropriate cellular environments is still challenging. Inspired by collagen nanofibers withstanding stress and regulating cell behavior, a patterned nanofibrous film was introduced to the printed hydrogel scaffold to fabricate a composite artificial skin substitute (CASS). The artificial dermis was printed using gelatin-hyaluronan hybrid hydrogels containing human dermal fibroblasts with gradient porosity and integrated with patterned nanofibrous films simultaneously, while the artificial epidermis was formed by seeding human keratinocytes upon the dermis. The collagen-mimicking nanofibrous film effectively improved the tensile strength and fracture resistance of the CASS, making it sewable for firm implantation into skin defects. Meanwhile, the patterned nanofibrous film also provided the biological cues to guide cell behavior. Consequently, CASS could effectively accelerate the regeneration of large-area skin defects in mouse and pig models by promoting re-epithelialization and collagen deposition. This research developed an effective strategy to prepare composite bioprinting architectures for enhancing mechanical property and regulating cell behavior, and CASS could be a promising skin substitute for treating large-area skin defects.

Meeting the exacting demands of wound healing encompasses rapid coagulation, superior exudate absorption, high antibacterial efficacy, and imperative support for cell growth. In this study, by emulating the intricate structure of natural skin, we prepare a multifunctional porous bilayer artificial skin to address these critical requirements. The bottom layer, mimicking the dermis, is crafted through freeze-drying a gel network comprising carboxymethyl chitosan (CMCs) and gelatin (GL), while the top layer, emulating the epidermis, is prepared via electrospinning poly(l-lactic acid) (PLLA) nanofibers. With protocatechuic aldehyde and gallium ion complexation (PA@Ga) as cross-linking agents, the bottom PA@Ga-CMCs/GL layer featured an adjustable pore size (78-138 μm), high hemostatic performance (67s), and excellent bacterial inhibition rate (99.9%), complemented by an impressive liquid-absorbing capacity (2000% swelling rate). The top PLLA layer, with dense micronanostructure and hydrophobic properties, worked as a shield to effectively thwarted liquid or bacterial penetration. Furthermore, accelerated wound closure, reduced inflammatory responses, and enhanced formation of hair follicles and blood vessels are achieved by the porous artificial skin covered on the surface of wound. Bilayer artificial skin integrates the advantages of nanofibers and freeze-drying porous materials to effectively replicate the protective properties of the epidermal layer of the skin, as well as the cell migration and tissue regeneration of the dermis. This bioabsorbable artificial skin demonstrates structural and functional comparability to real skin, which would advance the field of wound care through its multifaceted capabilities.

Using a flap in a large wound with a very small area of exposed vital structures may be an excessive intrusion and cause unnecessary donor site morbidity. Dermal matrix (DuraGen) was applied onto critical areas where bone or tendons were exposed and a split skin graft was placed thereon. All patients had satisfactory wound closure without the need for a flap. DuraGen appears to be a safe, single-stage alternative, to a flap for the healing of complex wounds., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Skin regeneration attracts tremendous interest due to the important role of skin for human protection and beauty. Thus, methods allowing artificial skin to be carried out in a controllable fashion are potentially important for wound healing, which involves an intersection of materials, medicine, biology, and other disciplines. Herein, aiming at a new general methodology for fleshy materials, a new hydrogel-loaded hydrophobic-hydrophilic nanofiber fleshy artificial skin is designed and fabricated. The gradient hydrogel-loaded nanofiber artificial skin integrates both advantages of nanofiber and hydrogel, exhibiting fleshy feature (comparability to real skin in terms of appearance, texture, and function), excellent air permeability, compatibility, and good mechanical and antibacterial property. Interestingly, the efficient transport channels are formed throughout the hydrogel-loaded nanofiber structure, which is beneficial for water absorption and transfer. These advantages enable the establishment of a moist and favorable microenvironment; thus, greatly accelerating wound healing process. This work couples microfluidic electrospinning with reactive coating technique, which is in favor of material design and fabrication with controllable and uniform structures. The hydrogel-loaded nanofiber fleshy artificial skin shows comparability to real skin in terms of beauty, texture, and function, which would definitely provide new opportunities for the further optimization and upgrading of artificial skin., (© 2024 Wiley‐VCH GmbH.)

Keloid is a type of scar formed by the overexpression of extracellular matrix substances from fibroblasts following inflammation after trauma. The existing keloid treatment methods include drug injection, surgical intervention, light exposure, cryotherapy, etc. However, these methods have limitations such as recurrence, low treatment efficacy, and side effects. Consequently, studies are being conducted on the treatment of keloids from the perspective of inflammatory mechanisms. In this study, keloid models are created to understand inflammatory mechanisms and explore treatment methods to address them. While previous studies have used animal models with gene mutations, chemical treatments, and keloid tissue transplantation, there are limitations in fully reproducing the characteristics of keloids unique to humans, and ethical issues related to animal welfare pose additional challenges. Consequently, studies are underway to create in vitro artificial skin models to simulate keloid disease and apply them to the development of treatments for skin diseases. In particular, herein, scaffold technologies that implement three-dimensional (3D) full-thickness keloid models are introduced to enhance mechanical properties as well as biological properties of tissues, such as cell proliferation, differentiation, and cellular interactions. It is anticipated that applying these technologies to the production of artificial skin for keloid simulation could contribute to the development of inflammatory keloid treatment techniques in the future.

The multisensory responsiveness of hydrogels positions them as promising candidates for artificial skin, whereas the mismatch of modulus between soft hydrogels and hard electrodes as well as the poor adhesion and conductance at the interface greatly impairs the stability of electronics devices. Herein, we propose an in situ postprocessing approach utilizing electrochemical reactions between metals (Zn, etc.) and hydrogels to synergistically achieve strong adhesion of the hydrogel-electrode interface, low interfacial impedance, and local strain isolation due to the structural densification of the hydrogel network. The mechanism is that Zn electrochemically oxidizes to Zn 2+ and injects into the hydrogel, gradually forming a mechanically interlocked structure, Zn 2+ -polymer dual-helix structural nodes, and a high-modulus ZnO from the surface to the interior. Compared to untreated samples, the treated sample displays 8.7 times increased interfacial adhesion energy between the hydrogel and electrode (87 J/m 2 ), 95% decreased interfacial impedance (218.8 Ω), and a high-strain isolation efficiency (ε total /ε isolation > 400). Akin to human skin, the prepared sensor demonstrates multimodal sensing capabilities, encompassing highly sensitive strain perception and simultaneous perception of temperature, humidity, and oxygen content unaffected by strain interference. This easy on-chip preparation of hydrogel-based multimodal sensor array shows great potential for health and environment monitoring as artificial skin.

Skin injury repair is a dynamic process involving a series of interactions over time and space. Linking human physiological processes with materials' changes poses a significant challenge. To match the wound healing process, a spatiotemporal controllable biomimetic skin is developed, which comprises a three-dimensional (3D) printed membrane as the epidermis, a cell-containing hydrogel as the dermis, and a cytokine-laden hydrogel as the hypodermis. In the initial stage of the biomimetic skin repair wound, the membrane frame aids wound closure through pre-tension, while cells proliferate within the hydrogel. Next, as the frame disintegrates over time, cells released from the hydrogel migrate along the residual membrane. Throughout the process, continuous cytokines release from the hypodermis hydrogel ensures comprehensive nourishment. The findings reveal that in the rat full-thickness skin defect model, the biomimetic skin demonstrated a wound closure rate eight times higher than the blank group, and double the collagen content, particularly in the early repair process. Consequently, it is reasonable to infer that this biomimetic skin holds promising potential to accelerate wound closure and repair. This biomimetic skin with mechanobiological effects and spatiotemporal regulation emerges as a promising option for tissue regeneration engineering., (© 2024 Wiley‐VCH GmbH.)

Refractory wounds present a complex and serious clinical dilemma in plastic and reconstructive surgery. However, there are currently no standard guidelines for the treatment of refractory wounds. Artificial dermis (AD) has achieved some satisfactory results, but also has some limitations. Autologous platelet-rich plasma (PRP), as a cell-therapy material, was a valuable and safe treatment dressing for chronic non-healing wounds. This study aimed to evaluate the efficacies of artificial dermis (AD) with and without autologous platelet-rich plasma (PRP) in patients with refractory wounds. Sixteen patients with refractory wounds were randomly allocated to autologous PRP therapy combined with artificial dermis (PRP + AD [N = 8]) or an artificial dermis program only (AD [N = 8]). We compared the efficacies of the two methods in terms of times to wound healing, infection control, and AD vascularization, as well as hospitalization days and eventual clinical outcomes.13 patients achieved complete healing, including seven (87.5%) in the PRP + AD group and six (75.0%) in the AD group (P > .05). The times to wound healing, infection control, and AD vascularization, and hospitalization time after transfer were significantly shorter in the PRP + AD group compared with the AD group (P < .05). In conclusion, the combination of AD and PRP promoted refractory wound healing and shortened waiting times compared with simple dermal grafts., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

In developing three-dimensional (3D) human skin equivalents (HSEs), preventing dermis and epidermis layer distortion due to the contraction of hydrogels by fibroblasts is a challenging issue. Previously, a fabrication method of HSEs was tested using a modified solid scaffold or a hydrogel matrix in combination with the natural polymer coated onto the tissue culture surface, but the obtained HSEs exhibited skin layer contraction and loss of the skin integrity and barrier functions. In this study, we investigated the method of HSE fabrication that enhances the stability of the skin model by using surface plasma treatment. The results showed that plasma treatment of the tissue culture surface prevented dermal layer shrinkage of HSEs, in contrast to the HSE fabrication using fibronectin coating. The HSEs from plasma-treated surface showed significantly higher transepithelial electrical resistance compared to the fibronectin-coated model. They also expressed markers of epidermal differentiation (keratin 10, keratin 14 and loricrin), epidermal tight junctions (claudin 1 and zonula occludens-1), and extracellular matrix proteins (collagen IV), and exhibited morphological characteristics of the primary human skins. Taken together, the use of plasma surface treatment significantly improves the stability of 3D HSEs with well-defined dermis and epidermis layers and enhanced skin integrity and the barrier functions., (© 2024 Wiley Periodicals LLC.)

Syndactyly reconstruction often times leaves areas of skin deficit that require coverage for healing. Numerous techniques have been reported to address the deficits, including graftless technique, which utilizes mobilization of adjacent skin for coverage, full-thickness skin grafting, and skin substitute grafts. The technique described here demonstrates the ease of the use of skin substitutes for coverage in syndactyly reconstruction and reports the expected outcomes., Competing Interests: Conflicts of Interest and Source of Funding: The authors report no conflicts of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Chronic wounds pose a significant global public health challenge due to their suboptimal treatment efficacy caused by bacterial infections and microcirculatory disturbances. Inspired by the biofunctionality of natural skin, an artificial skin (HV@BC@TBG) is bioengineered with bacterial cellulose (BC) sandwiched between photosensitizers (PS) and functionalized living cells. Glucose-modified PS (TBG) and vascular endothelial growth factor (VEGF)-functionalized living cells (HV) are successively modified on each side of BC through biological metabolism and bio-orthogonal reaction. As the outermost layer, the TBG layer can generate reactive oxygen species (ROS) upon light illumination to efficiently combat bacterial infections. The HV layer is the inner layer near the diabetic wound, which servs as a living factory to continuously secrete VEGF to accelerate wound repair by promoting fibroblast proliferation and angiogenesis. The sandwiched structural artificial skin HV@BC@TBG is nontoxic, biocompatible, and demonstrated its ability to significantly accelerate the healing process of infected diabetic wounds, rendering it a promising next-generation medical therapy for chronic wound management., (© 2024 Wiley‐VCH GmbH.)

Human skin sensing of mechanical stimuli originates from transduction of mechanoreceptors that converts external forces into electrical signals. Although imitating the spatial distribution of those mechanoreceptors can enable developments of electronic skins capable of decoupled sensing of normal/shear forces and strains, it remains elusive. We report a three-dimensionally (3D) architected electronic skin (denoted as 3DAE-Skin) with force and strain sensing components arranged in a 3D layout that mimics that of Merkel cells and Ruffini endings in human skin. This 3DAE-Skin shows excellent decoupled sensing performances of normal force, shear force, and strain and enables development of a tactile system for simultaneous modulus/curvature measurements of an object through touch. Demonstrations include rapid modulus measurements of fruits, bread, and cake with various shapes and degrees of freshness.

As an emerging new manufacturing technology, Three-dimensional (3D) bioprinting provides the potential for the biomimetic construction of multifaceted and intricate architectures of functional integument, particularly functional biomimetic dermal structures inclusive of cutaneous appendages. Although the tissue-engineered skin with complete biological activity and physiological functions is still cannot be manufactured, it is believed that with the advances in matrix materials, molding process, and biotechnology, a new generation of physiologically active skin will be born in the future. In pursuit of furnishing readers and researchers involved in relevant research to have a systematic and comprehensive understanding of 3D printed tissue-engineered skin, this paper furnishes an exegesis on the prevailing research landscape, formidable obstacles, and forthcoming trajectories within the sphere of tissue-engineered skin, including: (1) the prevalent biomaterials (collagen, chitosan, agarose, alginate, etc.) routinely employed in tissue-engineered skin, and a discerning analysis and comparison of their respective merits, demerits, and inherent characteristics; (2) the underlying principles and distinguishing attributes of various current printing methodologies utilized in tissue-engineered skin fabrication; (3) the present research status and progression in the realm of tissue-engineered biomimetic skin; (4) meticulous scrutiny and summation of the extant research underpinning tissue-engineered skin inform the identification of prevailing challenges and issues., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Electronic skin (e-skin) capable of acquiring environmental and physiological information has attracted interest for healthcare, robotics, and human-machine interaction. However, traditional 2D e-skin only allows for in-plane force sensing, which limits access to comprehensive stimulus feedback due to the lack of out-of-plane signal detection caused by its 3D structure. Here, a dimension-switchable bioinspired receptor is reported to achieve multimodal perception by exploiting film kirigami. It offers the detection of in-plane (pressure and bending) and out-of-plane (force and airflow) signals by dynamically inducing the opening and reclosing of sensing unit. The receptor's hygroscopic and thermoelectric properties enable the sensing of humidity and temperature. Meanwhile, the thermoelectric receptor can differentiate mechanical stimuli from temperature by the voltage. The development enables a wide range of sensory capabilities of traditional e-skin and expands the applications in real life., (© 2024 Wiley‐VCH GmbH.)

Objectives: To develop and evaluate a novel human stratum corneum (SC) mimetic phospholipid vesicle-based permeation assay (PVPA SC ) model for in vitro permeation studies., Significance: Due to the increasing restrictions on the use of human and animal skins, artificial skin models have attracted substantial interest in pharmaceuticals and cosmetic industries. In this study, a modified PVPA SC model containing both SC lipids and proteins was developed., Methods: The PVPA SC model was optimized by altering the lipid composition and adding keratin in the formulation of large liposomes. The barrier properties were monitored by measuring the electrical resistance (ER) and permeability of Rhodamine B (RB). The modified PVPA SC model was characterized in terms of the surface topography, solvent influence and storage stability. The permeation studies of the active components in Compound Nanxing Zhitong Plaster (CNZP) were performed to examine the capability of PVPA SC in the application of skin penetration., Results: The ER and P app values of RB obtained from the optimized PVPA SC model indicated a similar barrier property to porcine ear skin. Scanning electron microscope analysis demonstrated a mimic 'brick-and-mortar' structure. The PVPA SC model can be stored for three weeks at -20 °C, and withstand the presence of different receptor medium for 24 h. The permeation studies of the active components demonstrated a good correlation ( r 2  = 0.9136) of P app values between the drugs' permeation through the PVPA SC model and porcine ear skin., Conclusion: Keratin contained composite phospholipid vesicle-based permeation assay models have been proven to be potential skin tools in topical/transdermal permeation studies.

Wounds pose significant challenges to public health, primarily due to the loss of the mechanical integrity and barrier function of the skin and impaired angiogenesis, causing physical morbidities and psychological trauma to affect patients. Reconstructing the vasculature of the wound bed is crucial for promoting wound healing, reducing scar formation and enhancing the quality of life for patients. The development of pro-angiogenic skin substitutes has emerged as a promising strategy to facilitate vascularization and expedite the healing process of burn wounds. This review provides an overview of the various types of skin substitutes employed in wound healing, explicitly emphasising those designed to enhance angiogenesis. Synthetic scaffolds, biological matrices and tissue-engineered constructs incorporating stem cells and primary cells, cell-derived extracellular vesicles (EVs), pro-angiogenic growth factors and peptides, as well as gene therapy-based skin substitutes are thoroughly examined. The review summarises the existing challenges, future directions and potential innovations in pro-angiogenic dressing for skin substitutes. It highlights the need for continued research to develop new technologies and combine multiple strategies and factors, and to overcome obstacles and advance the field, ultimately leading to improved outcomes for wound patients., (© 2024 The Wound Healing Society.)

Introduction: Extensive full-thickness soft-tissue defects remain a challenge in reconstructive surgery. NovoSorb® Biodegradable Temporising Matrix (BTM) represents a novel dermal substitute and was evaluated in wounds deriving from different aetiologies and to highlight risk factors for poor take rates., Methods: All patients treated with BTM at our department between March 2020 and October 2022 were included. Differences in univariate and linear regression models identified predictors and risk factors for take rates of BTM and split-thickness skin grafts (STSG)., Results: Three hundred patients (mean age 54.2 ± 20.1 years, 66.3% male, 59.7% burns, 19.7% trauma and 20.6% others) were evaluated. Mean take rates of BTM and STSG after BTM delamination were 82.7 ± 25.2% and 86.0 ± 22.6%, respectively. Multiple regression analyses showed that higher body mass index (BMI, OR 0.43, 95% CI 0.86, -0.01, p = 0.44), prior allograft transplantation (OR 15.12, 95% CI 26.98, -3.31, p = 0.041), longer trauma-to-BTM-application intervals (OR 0.01, 95% CI 0.001, -0.001, p = 0.038), positive wound swabs before BTM (OR 7.15, 95% CI 13.50, -0.80, p = 0.028) and peripheral artery disease (OR 10.80, 95% CI 18.63, -2.96, p = 0.007) were associated with poorer BTM take. Higher BMI (OR 0.40, 95% CI 0.76, -0.08, p = 0.026), increasing BTM graft surface areas (OR 0.58, 95% CI -1.00, -0.17, p = 0.005), prior allograft (OR 12.20, 95% CI -21.99, -2.41, p = 0.015) or autograft transplantations (OR 22.42, 95% CI 38.69, -6.14, p = 0.001), tumour as the aetiology of the wound (OR 37.42, 95% CI 57.41, -17.83, p = 0.001), diabetes (OR 6.64, 95% CI 12.80, -0.48, p = 0.035) and impaired kidney function (OR 5.90, 95% CI 10.94, -0.86, p = 0.021) were associated with poorer STSG take after delamination of BTM, whereas higher BTM take rates were associated with better STSG take (OR 0.40, 95% CI 0.31,0.50, p < 0.001)., Conclusion: Extensive complex wounds of different aetiologies unsuitable for immediate STSG can be successfully reconstructed by means of two-staged BTM application and subsequent skin grafting. Importantly, presence of wound contamination or infection and prior allograft coverage appear to jeopardise good BTM and STSG take., (Copyright © 2024. Published by Elsevier Ltd.)

Integra® (Integra LifeSciences) is a well-known dermal regeneration template used in partial and full-thickness wound reconstruction. It can be applied directly on to vascular tissue to create a bed for a skin graft, which is often placed in a second surgery. We present our experience of its novel use in oral and maxillofacial surgery patients, using it directly on bone and cartilage (avascular tissue) without further skin grafting. Patients who required full-thickness excision of lesions down to bone or cartilage and who were treated using Integra® were included. After scalp or ear lesion resection, the collagenous dermal layer of Integra® was placed directly on to bone or cartilage and, along with its outer silicone epidermal layer, secured to the defect with absorbable sutures and a bolster dressing. The wounds were kept dry for 14 days, at which point the dressing and silicone were removed and patients continued regular wound care. Seventeen patients were included, 15 of whom had squamous cell carcinoma. One was lost to follow up. The rest achieved complete healing of the defect. Histology showed epidermis developing on the Integra® surface and at one year, the appearance of normal scarred skin. This novel approach could redefine the uses of Integra®, avoiding the need for free-flap surgery or skin grafting when reconstructing large defects. Further resection of close margins or recurrence is easier after reconstruction using dermal regeneration material than after reconstruction with a local or free flap., (Copyright © 2024 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

Full-thickness wounds are severe cutaneous damages with destroyed self-healing function, which need efficient clinical interventions. Inspired by the hierarchical structure of natural skin, we have for the first time developed a biomimetic tri-layered artificial skin (TLAS) comprising silica gel-collagen membrane-collagen porous scaffold for enhanced full-thickness wound healing. The TLAS with the thickness of 3-7 mm displays a hierarchical nanostructure consisting of the top homogeneous silica gel film, the middle compact collagen membrane, and the bottom porous collagen scaffold, exquisitely mimicking the epidermis, basement membrane and dermis of natural skin, respectively. The 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide/N-Hydroxysuccinimide-dehydrothermal (EDC/NHS-DHT) dual-crosslinked collagen composite bilayer, with a crosslinking degree of 79.5 %, displays remarkable biocompatibility, bioactivity, and biosafety with no risk of hemolysis and pyrogen reactions. Notably, the extra collagen membrane layer provides a robust barrier to block the penetration of silica gel into the collagen porous scaffold, leading to the TLAS with enhanced biocompatibility and bioactivity. The full-thickness wound rat model studies have indicated the TLAS significantly facilitates the regeneration of full-thickness defects by accelerating re-epithelization, collagen deposition and migration of skin appendages. The highly biocompatible and bioactive tri-layered artificial skin provides an improved treatment for full-thickness wounds, which has great potential in tissue engineering., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Autologous skin grafting is a standard treatment for skin defects such as burns. No artificial skin substitutes are functionally equivalent to autologous skin grafts. The cultured epidermis lacks the dermis and does not engraft deep wounds. Although reconstituted skin, which consists of cultured epidermal cells on a synthetic dermal substitute, can engraft deep wounds, it requires the wound bed to be well-vascularized and lacks skin appendages. In this study, we successfully generate complete skin grafts with pluripotent stem cell-derived epidermis with appendages on p63 knockout embryos' dermis. Donor pluripotent stem cell-derived keratinocytes encroach the embryos' dermis by eliminating p63 knockout keratinocytes based on cell-extracellular matrix adhesion mediated cell competition. Although the chimeric skin contains allogenic dermis, it is engraftable as long as autologous grafts. Furthermore, we could generate semi-humanized skin segments by human keratinocytes injection into the amnionic cavity of p63 knockout mice embryos. Niche encroachment opens the possibility of human skin graft production in livestock animals., (© 2024. The Author(s).)

Background: Recently, micronized adipose tissue (MAT) grafts have shown promising results in wound healing, including diabetic ulcers., Objective: To assess the possibility of using 3D printed MAT niche grafts in the management of skin and soft tissue defects resulting from non-melanoma skin cancer (NMSC) resections., Materials and Methods: A retrospective feasibility study was conducted on patients with skin and soft tissue defects resulting from NMSC resections. Twenty-one patients were treated using either artificial dermis (n = 11) or MAT niche (n = 10) grafting. Healing time and POSAS scores were compared. The Mann-Whitney U test and the Pearson chi-square test were used in statistical analysis to compare between and within groups based on preoperative and postoperative measurements., Results: Wounds in the MAT niche group reepithelialized significantly faster than those in the artificial dermis group (mean [SD] 39.2 [11.4] days vs 63.7 [34.8] days; P = .04). In the 21 scar parameters evaluated, the MAT niche group demonstrated significantly superior outcomes in only 2 parameters based on operator assessment scores: relief (mean [SD] 1.6 [0.7] vs 2.2 [0.6]; P = .047) and scar contracture (mean [SD] 1.3 [0.5] vs 2.5 [1.0]; P = .011)., Conclusion: This study proves the feasibility of exploring the effects of MAT niche grafting following NMSC excision on healing time and specific parameters of scarring, including scar relief and scar contracture.

Large burns provoke profound pathophysiological changes. Survival rates of patients with large burns have improved significantly with the advancement of critical care and adaptation of early excision protocols. Nevertheless, care of large burn wounds remains challenging secondary to limited donor sites, prolonged time to wound closure, and immunosuppression. The development of skin substitutes and new grafting techniques decreased time to wound closure. Individually, these methods have limited success, but a combination of them may yield more successful outcomes. Early identification of patients with likely poor prognosis should prompt goals of care discussion and involvement of a palliative care team when possible., Competing Interests: Disclosure The authors have no disclosures., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Coverage of burn wounds is crucial to prevent sequalae including dehydration, wound infection, sepsis, shock, scarring, and contracture. To this end, numerous temporary and permanent options for coverage of burn wounds have been described. Temporary options for burn coverage include synthetic dressings, allografts, and xenografts. Permanent burn coverage can be achieved through skin substitutes, cultured epithelial autograft, ReCell, amnion, and autografting. Here, we aim to summarize the available options for burn coverage, as well as important considerations that must be made when choosing the best reconstructive option for a particular patient., Competing Interests: Disclosures No funding, financial disclosures, or sources of support., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Burns in the elderly are a significant cause of morbidity and mortality. Frailty is an important indicator of patient health and physiologic reserve. Comorbidities and typical age-related changes significantly impact the outcomes of elderly burn patients and decisions made during their burn care. It is essential to have early and thorough discussions about the goals of care and rehabilitation plans. Physiologic changes that occur from aging cause slower wound healing and may make operative treatment more challenging, although techniques such as autographing, skin substitutes, and flaps may all play a role in treating this patient population., Competing Interests: Disclosure The authors have no financial disclosures to state., (Published by Elsevier Inc.)

Dermal exposure to phosphorus flame retardants (PFRs) has received much attention as a major alternative exposure route in recent years. However, the information regarding dermal exposure via direct contact with a product is limited. In addition, in the commonly used dermal permeability test, the target substance is dissolved in a solvent, which is unrealistic. In this study, a dermal permeability test of PFRs in three car seats was performed using artificial skin. The PFR concentrations in the car seats are 0.12 wt% tris(2-chloroethyl) phosphate (TCEP), 0.030-0.25 wt% tris(2-chloroisopropyl) phosphate (TCPP), 0.15 wt% triphenyl phosphate (TPhP), 0.89 wt% cresyl diphenyl phosphate (CsDPhP), 0.074 wt% tricresyl phosphate (TCsP), and 0.46-4.7 wt% diethylene glycol bis [di (2-chloroisopropyl) phosphate (DEG-BDCIPP). The mean skin permeation rates for a contact time of 24 h are 14 (TCEP), 5.4-160 (TCPP), 0.67 (CsDPhP), 0.38 (TPhP), and 3.3-58 ng cm -2  h -1 (DEG-BDCIPP). The concentrations of TCsP in receptor liquid were lower than the limit of quantification at the contact time of 24 h. The skin permeation rates were significantly affected by the type of car seat (e.g., fabric or non-fabric). The potential dermal TCPP exposure rate for an adult via direct contact with the car seat during the average daily contact time (1.3 h), which was the highest value assessed in this study, was estimated to be 16,000 ng kg -1 day -1 , which is higher than that related to inhalation and dust ingestion reported as significant exposure route of PFRs in previous studies. These facts reveal that dermal exposure associated with direct contact with the product might be an important exposure pathway for PFRs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Aim: To determine the effectiveness of bilayered living cellular construct (BLCC) versus a fetal bovine collagen dressing (FBCD) in pressure injuries (PRIs). Methods: A real-world data study was conducted on 1352 PRIs analyzed digitally. 1046 and 306 PRIs were treated with BLCC and FBCD, respectively. Results: Cox healing for BLCC (n = 1046) was significantly greater (p < 0.0001) at week 4 (13 vs 7%), 8 (29 vs 17%), 12 (42 vs 27%), 24 (64 vs 45%), and 36 (73 vs 56%). The probability of healing increased by 66%, (hazard ratio = 1.66 [95% CI (1.38, 2.00)]; p < 0.0001. Time to healing was 162 days for FBCD and 103 days for BLCC showing a 36% reduction in time to healing with BLCC; (p < 0.0001). Conclusion: BLCC significantly improved healing of PRIs versus FBCD.

Technological advances have increasingly provided more and better treatment options for patients with severe burns. Here, we provide a bird's-eye view of the product development process for third-degree burn wounds with considerations of the critical interaction with regulatory bodies, existing technological gaps, and future directions for skin substitutes., Competing Interests: Declaration of interests None declared by authors., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Bioinspired artificial skins integrated with reliable human-machine interfaces and stretchable electronic systems have attracted considerable attention. However, the current design faces difficulties in simultaneously achieving satisfactory skin-like mechanical compliance and self-powered multimodal sensing. Here, this work reports a microphase-separated bicontinuous ionogel which possesses skin-like mechanical properties and mimics the multimodal sensing ability of biological skin by ion-driven stimuli-electricity conversion. The ionogel exhibits excellent elasticity and ionic conductivity, high toughness, and ultrastretchability, as well as a Young's modulus similar to that of human skin. Leveraging the ion-polymer interactions enabled selective ion transport, the ionogel can output pulsing or continuous electrical signals in response to diverse stimuli such as strain, touch pressure, and temperature sensitively, demonstrating a unique self-powered multimodal sensing. Furthermore, the ionogel-based I-skin can concurrently sense different stimuli and decouple the variations of the stimuli from the voltage signals with the assistance of a machine-learning model. The ease of fabrication, wide tunability, self-powered multimodal sensing, and the excellent environmental tolerance of the ionogels demonstrate a new strategy in the development of next-generation soft smart mechano-transduction devices., (© 2023 Wiley‐VCH GmbH.)

Chronic wounds are challenging to heal and increase global mortality. The effectiveness of skin graft is limited by rejection, fibrosis, and inadequate donor site. Multifunctionalised-hydrogel skin substitutes promoted higher wound healing by maintaining the moisture microenvironment and permit gas exchange/nourishment in prolong cell viability/activity. The purpose of this study was to evaluate a skin substitute using two strategies; via injectable and 3D bioprinting technique. New hydrogel formulations that composed of gelatin (GE) and polyvinyl-alcohol (PVA) were constructed using a pre-mix crosslinking approach with genipin (GNP) to generate the biodegradable and biocompatible skin substitute with reduced secondary traumatic wound. GPVA5&#95;GNP (6% GE: 5% PVA crosslinked with GNP) was the most stable hydrogel for wound healing application with the longest enzymatic degradation and stable hydrogel for absorption of excess wound exudates. Primary human dermal fibroblasts (HDFs) migrated extensively through 3D bioprinted hydrogels with larger average pore sizes and interconnected pores than injectable hydrogels. Moreover, 3D bioprinted GPVA hydrogels were biocompatible with HDFs and demonstrated > 90% cell viability. HDFs maintained their phenotype and positively expressed collagen type-I, vinculin, short and dense F-actin, alpha-smooth muscle actin, and Ki67. Additionally, the presence of GNP demonstrated antioxidant capacity and high-ability of angiogenesis. The utilisation of the 3D bioprinting (layer-by-layer) approach did not compromise the HDFs' growth capacity and biocompatibility with selected bioinks. In conclusion, it allows the cell encapsulation sustainability in a hydrogel matrix for a longer period, in promoting tissue regeneration and accelerating healing capacity, especially for difficult or chronic wound., (© 2023. Controlled Release Society.)

Non-healing wounds and skin losses constitute significant challenges for modern medicine and pharmacology. Conventional methods of wound treatment are effective in basic healthcare; however, they are insufficient in managing chronic wound and large skin defects, so novel, alternative methods of therapy are sought. Among the potentially innovative procedures, the use of skin substitutes may be a promising therapeutic method. Skin substitutes are a heterogeneous group of materials that are used to heal and close wounds and temporarily or permanently fulfill the functions of the skin. Classification can be based on the structure or type (biological and synthetic). Simple constructs (class I) have been widely researched over the years, and can be used in burns and ulcers. More complex substitutes (class II and III) are still studied, but these may be utilized in patients with deep skin defects. In addition, 3D bioprinting is a rapidly developing method used to create advanced skin constructs and their appendages. The aforementioned therapies represent an opportunity for treating patients with diabetic foot ulcers or deep skin burns. Despite these significant developments, further clinical trials are needed to allow the use skin substitutes in the personalized treatment of chronic wounds., Competing Interests: The authors declare no conflicts of interest.