Clinical application of a tissue-cultured skin autograft: an alternative for the treatment of non-healing or slowly healing wounds?

The efficacy and safety of autologous epidermal cell suspensions for re-epithelialization of skin lesions: A systematic review and meta-analysis of randomized trials

BACKGROUND

Successful usage of autologous skin cell suspension (ASCS) has been demonstrated in some clinical trials. However, its efficacy and safety have not been verified. This latest systematic review and meta-analysis aim to examine the effects of autologous epidermal cell suspensions in re-epithelialization of skin lesions.

METHODS

Relevant articles were retrieved from PubMed, Embase, Cochrane Database, Web of Science, International Clinical Trials Registry Platform, China National Knowledge Infrastructureris, VIP Database for Chinese Technical Periodicals and Wanfang database. The primary output measure was the healing time, and the secondary outputs were effective rate, size of donor site for treatment, size of study treatment area, operation time, pain scores, repigmentation, complications, scar scale scores and satisfaction scores. Data were pooled and expressed as relative risk (RR), mean difference (MD) and standardized mean difference (SMD) with a 95% confidence interval (CI).

RESULTS

Thirty-one studies were included in this systematic review and meta-analysis, with 914 patients who received autologous epidermal cell suspensions (treatment group) and 883 patients who received standard care or placebo (control group). The pooled data from all included studies demonstrated that the treatment group has significantly reduced healing time (SMD = -0.86; 95% CI: -1.59-0.14; p = 0.02, I2 = 95%), size of donar site for treatment (MD = -115.41; 95% CI: -128.74-102.09; p<0.001, I2 = 89%), operation time (MD = 25.35; 95% CI: 23.42-27.29; p<0.001, I2 = 100%), pain scores (SMD = -1.88; 95% CI: -2.86-0.90; p = 0.0002, I2 = 89%) and complications (RR = 0.59; 95% CI: 0.36-0.96; p = 0.03, I2 = 66%), as well as significantly increased effective rate (RR = 1.20; 95% CI: 1.01-1.42; p = 0.04, I2 = 77%). There were no significant differences in the size of study treatment area, repigmentation, scar scale scores and satisfaction scores between the two groups.

CONCLUSION

Our meta-analysis showed that autologous epidermal cell suspensions is beneficial for re-epithelialization of skin lesions as they significantly reduce the healing time, size of donar site for treatment, operation time, pain scores and complications, as well as increased effective rate. However, this intervention has minimal impact on size of treatment area, repigmentation, scar scale scores and satisfaction scores.

Novel electro-spun fabrication of blended polymeric nanofibrous wound closure materials loaded with catechin to improve wound healing potential and microbial inhibition for the care of diabetic wound

Diabetic wound infections caused by the multiplication of infectious pathogens and their antibiotic resistance. Wound infection evident by bacterial colonization and other factors, such as the virulence and host immune factors. In this context, we need discover appropriate treatment and effective antibiotics for wound infection control. Considering this, we synthesized catechin-loaded polyvinyl alcohol/Chitosan (PVA/CS) based nanofiber for multifunctional wound healing. The physicochemical and biological properties of fabricated nanofiber, were systematically evaluated by various spectroscopy and microscopy techniques. The CA@PVA/CS nanofiber exhibited a high level of antibacterial and antioxidant effects. The nanofibers showed effective control in gram-positive and negative wound infectious bacterial multiplication at the lowest concentration. Based on the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell viability study CA@PVA/CS nanofiber shows excellent biocompatibility against L929 cells. In wound, scratch assay results revealed that the CA@PVA/CS treated group shows enhanced cell migration and cell proliferation within 48 h. The synthesis of antioxidant, antibacterial, and biocompatible nanofiber exposes their potential for effective wound healing. Current research hypothesized catechin loaded PVA/CS nanofiber could be a multifunctional and low-cost material for diabetic wound care application. Fabricated nanofiber would be improved skin tissue regeneration and public health hygiene.

3D bioprinting bioglass to construct vascularized full-thickness skin substitutes for wound healing

Constructing three-dimensional (3D) bioprinted skin tissues that accurately replicate the mechanical properties of native skin and provide adequate oxygen and nutrient support remains a formidable challenge. In this study, we incorporated phosphosilicate calcium bioglasses (PSCs), a type of bioactive glass (BG), into the bioinks used for 3D bioprinting. The resulting bioink exhibited mechanical properties and biocompatibility that closely resembled those of natural skin. Utilizing 3D bioprinting technology, we successfully fabricated full-thickness skin substitutes, which underwent comprehensive evaluation to assess their regenerative potential in treating full-thickness skin injuries in rats. Remarkably, the skin substitutes loaded with PSCs exhibited exceptional angiogenic activity, as evidenced by the upregulation of angiogenesis-related genes in vitro and the observation of enhanced vascularization in wound tissue sections in vivo. These findings conclusively demonstrated the outstanding efficacy of PSCs in promoting angiogenesis and facilitating the repair of full-thickness skin wounds. The insights garnered from this study provide a valuable reference strategy for the development of skin tissue grafts with potent angiogenesis-inducing capabilities.

Perspectives on the Current State of Bioprinted Skin Substitutes for Wound Healing

Human skin is particularly vulnerable to external damaging influences such as irradiation, extreme temperatures, chemical trauma, and certain systemic diseases, which reduce the skin's capacity for regeneration and restoration and can possibly lead to large-scale skin defects. To restore skin continuity in severe cases, surgical interventions such as the transplantation of autologous tissue are needed. Nevertheless, the coverage of larger skin defects caused by severe third-grade burns or extensive irradiation therapy is limited due to the depletion of uninjured autologous tissue. In such cases, many of the patient's epidermal cells can become available using biofabricated skin grafts, thereby restoring the skin's vital functions. Given the limited availability of autologous skin grafts for restoring integrity in large-scale defects, using bioprinted constructs as skin graft substitutes could offer an encouraging therapeutic alternative to conventional therapies for large-scale wounds, such as the transplantation of autologous tissue. Using layer-by-layer aggregation or volumetric bioprinting, inkjet bioprinting, laser-assisted bioprinting, or extrusion-based bioprinting, skin cells are deposited in a desired pattern. The resulting constructs may be used as skin graft substitutes to accelerate wound healing and reconstitute the physiological functions of the skin. In this review, we aimed to elucidate the current state of bioprinting within the context of skin tissue engineering and introduce and discuss different bioprinting techniques, possible approaches and materials, commonly used cell types, and strategies for graft vascularization for the production of bioprinted constructs for use as skin graft substitutes.

A Newly Developed Chemically Defined Serum-Free Medium Suitable for Human Primary Keratinocyte Culture and Tissue Engineering Applications

In our experience, keratinocytes cultured in feeder-free conditions and in commercially available defined and serum-free media cannot be as efficiently massively expanded as their counterparts grown in conventional bovine serum-containing medium, nor can they properly form a stratified epidermis in a skin substitute model. We thus tested a new chemically defined serum-free medium, which we developed for massive human primary keratinocyte expansion and skin substitute production. Our medium, named Surge Serum-Free Medium (Surge SFM), was developed to be used alongside a feeder layer. It supports the growth of keratinocytes freshly isolated from a skin biopsy and cryopreserved primary keratinocytes in cultured monolayers over multiple passages. We also show that keratin-19-positive epithelial stem cells are retained through serial passaging in Surge SFM cultures. Transcriptomic analyses suggest that gene expression is similar between keratinocytes cultured with either Surge SFM or the conventional serum-containing medium. Additionally, Surge SFM can be used to produce bilayered self-assembled skin substitutes histologically similar to those produced using serum-containing medium. Furthermore, these substitutes were grafted onto athymic mice and persisted for up to six months. In conclusion, our new chemically defined serum-free keratinocyte culture medium shows great promise for basic research and clinical applications.

Bioactive inorganic particles-based biomaterials for skin tissue engineering

The challenge for treatment of severe cutaneous wound poses an urgent clinical need for the development of biomaterials to promote skin regeneration. In the past few decades, introduction of inorganic components into material system has become a promising strategy for improving performances of biomaterials in the process of tissue repair. In this review, we provide a current overview of the development of bioactive inorganic particles-based biomaterials used for skin tissue engineering. We highlight the three stages in the evolution of the bioactive inorganic biomaterials applied to wound management, including single inorganic materials, inorganic/organic composite materials, and inorganic particles-based cell-encapsulated living systems. At every stage, the primary types of bioactive inorganic biomaterials are described, followed by citation of the related representative studies completed in recent years. Then we offer a brief exposition of typical approaches to construct the composite material systems with incorporation of inorganic components for wound healing. Finally, the conclusions and future directions are suggested for the development of novel bioactive inorganic particles-based biomaterials in the field of skin regeneration.

3D Printing of Strontium Silicate Microcylinder-Containing Multicellular Biomaterial Inks for Vascularized Skin Regeneration

The reconstruction of dermal blood vessels is essential for skin regeneration process. However, the lack of vascular structure, insufficient angiogenesis induction, and ineffective graft-host anastomosis of the existing skin substitutes are major bottle-necks for permanent skin replacement in tissue engineering. In this study, the uniform strontium silicate (SS) microcylinders are successfully synthesized and integrated into the biomaterial ink to serve as stable cell-induced factors for angiogenesis, and then a functional skin substitute based on a vascularization-induced biomimetic multicellular system is prepared via a "cell-writing" bioprinting technology. With an unprecedented combination of vascularized skin-mimicking structure and vascularization-induced function, the SS-containing multicellular system exhibits outstanding angiogenic activity both in vitro and in vivo. As a result, the bioprinted skin substitutes significantly accelerate the healing of both acute and chronic wounds by promoting the graft-host integration and vascularized skin regeneration in three animal models. Therefore, the study provides a referable strategy to fabricate biomimetic multicellular constructs with angiogenesis-induced function for regeneration of vascularized complex and hierarchical tissues.

Improvement of the Wound-Healing Process by Curcumin-Loaded Chitosan/Collagen Blend Electrospun Nanofibers: In Vitro and In Vivo Studies

Chronic wounds have become a major health problem worldwide. Curcumin (Cur), with strong anti-inflammatory and anti-infective properties, is introduced as a unique molecule for wound dressing applications. In the present study, Cur-loaded chitosan/poly(ethylene oxide)/collagen (Cho/PEO/Col) nanofibers were developed for wound dressing applications by the blend-electrospinning process. Structural, mechanical, and biological properties of nanofibers were evaluated using SEM, FTIR, tensile testing, in vitro release study, Alamar blue cytotoxicity assay, and in vivo study in a rat model. According to the results, Cur was successfully released up to 3 days without any significant cytotoxicity of the above hybrid to human dermal fibroblasts. In vivo studies on full-thickness wounds in the rat model indicated significant improvement in the mean wound area closure by applying Cur-loaded Cho/PEO/Col nanofibers. The electrospun Cho/PEO/Col nanofibers loaded with Cur could be considered as a promising type of wound dressing in the wound-healing process.

3D Bioprinting of Functional Skin Substitutes: From Current Achievements to Future Goals

The aim of this review is to present 3D bioprinting of skin substitutes as an efficient approach of managing skin injuries. From a clinical point of view, classic treatments only provide physical protection from the environment, and existing engineered scaffolds, albeit acting as a physical support for cells, fail to overcome needs, such as neovascularisation. In the present work, the basic principles of bioprinting, together with the most popular approaches and choices of biomaterials for 3D-printed skin construct production, are explained, as well as the main advantages over other production methods. Moreover, the development of this technology is described in a chronological manner through examples of relevant experimental work in the last two decades: from the pioneers Lee et al. to the latest advances and different innovative strategies carried out lately to overcome the well-known challenges in tissue engineering of skin. In general, this technology has a huge potential to offer, although a multidisciplinary effort is required to optimise designs, biomaterials and production processes.

Advances in the Research of Bioinks Based on Natural Collagen, Polysaccharide and Their Derivatives for Skin 3D Bioprinting

The skin plays an important role in protecting the human body, and wound healing must be set in motion immediately following injury or trauma to restore the normal structure and function of skin. The extracellular matrix component of the skin mainly consists of collagen, glycosaminoglycan (GAG), elastin and hyaluronic acid (HA). Recently, natural collagen, polysaccharide and their derivatives such as collagen, gelatin, alginate, chitosan and pectin have been selected as the matrix materials of bioink to construct a functional artificial skin due to their biocompatible and biodegradable properties by 3D bioprinting, which is a revolutionary technology with the potential to transform both research and medical therapeutics. In this review, we outline the current skin bioprinting technologies and the bioink components for skin bioprinting. We also summarize the bioink products practiced in research recently and current challenges to guide future research to develop in a promising direction. While there are challenges regarding currently available skin bioprinting, addressing these issues will facilitate the rapid advancement of 3D skin bioprinting and its ability to mimic the native anatomy and physiology of skin and surrounding tissues in the future.

Normal and keloid fibroblasts are differentially influenced by IFN-γ and triamcinolone as well as by their combination

Impaired wound healing as well as imbalanced cell proliferation and extracellular matrix synthesis and degeneration can cause aberrant scarring. The most severe impacts of such scarring on patients' lives are stigmatization and physical restriction. Although, a broad variety of combinatorial approaches with, e.g., glucocorticoids, chemotherapeutics, and immunomodulators are used, there is still a high recurrence rate of keloids. The aim of this study was to investigate which influence interferon γ (IFN-γ, 1.000-10.000 IU/mL) and/or triamcinolone acetonide (TA, 1 μg/mL) have on proliferation, cell viability, collagen type I synthesis, and cytokine secretion in healthy and keloid fibroblasts. It was shown that mono-treatment with IFN-γ or TA for 2 days induced a severe reduction of the proliferative potential in both cell species. The combinatory treatment (IFN-γ plus TA) of keloid fibroblasts enhanced the anti-proliferative effect of the mono-treatments, whereas no additional anti-proliferative effect was observed in normal fibroblasts. Furthermore, we observed that the combinatory treatment regimen reduced the expression of α-smooth muscle actin (α-SMA), an actin isotype contributing to cell-generated mechanical tension, in keloid fibroblasts. In normal fibroblasts, α-SMA was reduced by the mono-treatment with IFN-γ as well as by the combinatory treatment. The analysis of collagen-type I synthesis revealed that TA did not reduce collagen type I synthesis in normal fibroblasts but in keloid fibroblasts. IFN-γ reduced in both cell species the collagen type I synthesis. The combination of TA and IFN-γ intensified the previously observed collagen type I synthesis reduction in keloid fibroblasts. The herein presented data suggest the combinatory application of IFN-γ and TA as a promising therapy concept for keloids.

Assessment of Melanogenesis in a Pigmented Human Tissue-Cultured Skin Equivalent

Background:

Organotypic tissue-cultured skin equivalents are used for a broad range of applications either as possible substitute for animal tests or for transplantation in patient-centered care.

Aims:

In this study, we implemented melanocytes in a tissue-cultured full-thickness skin equivalent, consisting of epidermis and dermis. The versatility of this skin-like model with respect to pigmentation and morphological criteria was tested.

Materials and Methods:

Pigmented skin equivalents were morphologically characterized, and melanogenesis was evaluated after treatment with kojic acid – a tyrosinase inhibitor and forskolin – a well-known activator of the cyclic adenosine 3,5-monophosphate pathway. Pigmentation was measured either by determination of the extinction at 400 nm after melanin extraction with KOH correlated to a melanin standard curve or by reflectance colorimetric analysis, monitoring reflectance of 660 nm and 880 nm emitting diodes.

Results:

The morphological analysis revealed characteristic epidermal stratification with melanocytes located at the basal layer. Stimulation with forskolin increased the pigmentation, whereas treatment with kojic acid caused bleaching.

Conclusion:

The present study demonstrates that the herein-introduced organotypic tissue-cultured skin equivalent is comparable to the normal human skin and its versatility in tests regarding skin pigmentation. Therefore, this model might help understand diseases with dysfunctional pigmentation such as melasma, vitiligo, and postinflammatory hyperpigmentation.

Extrinsic or Intrinsic Apoptosis by Curcumin and Light: Still a Mystery

Curcumin—a rhizomal phytochemical from the plant Curcuma longa—is well known to inhibit cell proliferation and to induce apoptosis in a broad range of cell lines. In previous studies we showed that combining low curcumin concentrations and subsequent ultraviolet A radiation (UVA) or VIS irradiation induced anti-proliferative and pro-apoptotic effects. There is still debate whether curcumin induces apoptosis via the extrinsic or the intrinsic pathway. To address this question, we investigated in three epithelial cell lines (HaCaT, A431, A549) whether the death receptors CD95, tumor necrosis factor (TNF)-receptor I and II are involved in apoptosis induced by light and curcumin. Cells were incubated with 0.25–0.5 µg/mL curcumin followed by irradiation with 1 J/cm² UVA. This treatment was combined with inhibitors specific for distinct membrane-bound death receptors. After 24 h apoptosis induction was monitored by quantitative determination of cytoplasmic histone-associated-DNA-fragments. Validation of our test system showed that apoptosis induced by CH11 and TNF-α could be completely inhibited by their respective antagonists. Interestingly, apoptosis induced by curcumin/light treatment was reversed by none of the herein examined death receptor antagonists. These results indicate a mechanism of action independent from classical death receptors speaking for intrinsic activation of apoptosis. It could be speculated that a shift in cellular redox balance might prompt the pro-apoptotic processes.

SIKVAV-Modified Chitosan Hydrogel as a Skin Substitutes for Wound Closure in Mice

Skin wound healing is a complex and dynamic process that involves angiogenesis and growth factor secretion. Newly formed vessels can provide nutrition and oxygen for skin wound healing. Growth factors in skin wounds are important for keratinocytes and fibroblasts proliferation, epithelialization, extracellular matrix remodeling, and angiogenesis, which accelerate skin wound healing. Therefore, treatment strategies that enhance angiogenesis and growth factors secretion in skin wounds can accelerate skin wound healing. This study investigated the effects of a SIKVAV (Ser-Ile-Lys-Val-Ala-Val) peptide-modified chitosan hydrogel on skin wound healing. Hematoxylin and eosin (H&E) staining demonstrated that the SIKVAV-modified chitosan hydrogel accelerated the re-epithelialization of wounds compared with that seen in the negative and positive controls. Masson's trichrome staining showed that more collagen fibers were deposited in the skin wounds treated with the SIKVAV-modified chitosan hydrogel than in the negative and positive controls. Immunohistochemistry assays demonstrated that more myofibroblasts were deposited and more angiogenesis occurred in skin wounds treated with the SIKVAV-modified chitosan hydrogel than in the negative and positive controls. In addition, ELISA assays showed that the SIKVAV-modified chitosan hydrogels promoted the secretion of growth factors in skin wounds. Taken together, these results suggest that the SIKVAV-modified chitosan hydrogel has the potential to be developed as synthesized biomaterials for the treatment of skin wounds.

Skin bioprinting: a novel approach for creating artificial skin from synthetic and natural building blocks

Significant progress has been made over the past few decades in the development of in vitro-engineered substitutes that mimic human skin, either as grafts for the replacement of lost skin, or for the establishment of in vitro human skin models. Tissue engineering has been developing as a novel strategy by employing the recent advances in various fields such as polymer engineering, bioengineering, stem cell research and nanomedicine. Recently, an advancement of 3D printing technology referred as bioprinting was exploited to make cell loaded scaffolds to produce constructs which are more matching with the native tissue. Bioprinting facilitates the simultaneous and highly specific deposition of multiple types of skin cells and biomaterials, a process that is lacking in conventional skin tissue-engineering approaches. Bioprinted skin substitutes or equivalents containing dermal and epidermal components offer a promising approach in skin bioengineering. Various materials including synthetic and natural biopolymers and cells with or without signalling molecules like growth factors are being utilized to produce functional skin constructs. This technology emerging as a novel strategy to overcome the current bottle-necks in skin tissue engineering such as poor vascularization, absence of hair follicles and sweat glands in the construct.

Directing adipose-derived stem cells into keratinocyte-like cells: impact of medium composition and culture condition

BACKGROUND

Adipose-derived stem cells (ASC) are known to transdifferentiate into a wide range of different cell species in vitro including along the epidermal lineage. This property makes them a promising tool for regenerative medicine to restore the epidermal barrier.

OBJECTIVE

This study is dedicated to identify in vitro conditions enabling transdifferentiation to a keratinocyte-like phenotype. In particular, the impact of different culture conditions (media compositions, 2D, 3D cultures) and extracellular matrix (ECM) molecules was evaluated.

METHODS

Adipose-derived stem cells derived from subcutaneous abdominal fat were characterized by stemness-associated markers and subjected to different media. Epithelial differentiation in 2D cultures was monitored by pan-cytokeratin expression using flow cytometry and immunocytochemistry. To evaluate the impact of different ECM molecules on epidermal stratification, 3D cultures were produced, lifted to the air-liquid interface (ALI) and examined by histological analysis and quantitative real-time RT-PCR.

RESULTS

We identified a medium composition containing retinoic acid, hydrocortisone, ascorbic acid and BMP-4 enabling maximum pan-cytokeratin expression in 2D cultures. Moreover, adhesion to type IV collagen further promotes the pan-cytokeratin expression. When cultures were lifted to the ALI, significant stratification was observed, particularly in supports coated with type IV collagen or fibronectin. Moreover, epidermal differentiation markers (involucrin, cytokeratin 1 and 14) become induced.

CONCLUSION

Conditions with hampered wound healing such as non-healing ulcers demand new treatment regimes. The here introduced optimized protocols for transdifferentiation of ASC into keratinocyte-like cells may help to establish more effective treatment procedures.

Skin Wound Healing Is Accelerated by a Lipid Mixture Representing Major Lipid Components of Chamaecyparis obtusa Plant Extract

In chronic nonhealing wounds, the healing process is disrupted and wounds are often infected with bacteria. About 85% of lower extremity amputations in diabetes are attributed to deep infection of foot ulcers. Therefore, infection control is critical for wound care. In this study, we analyzed lipid composition of Chamaecyparis obtusa extract, and we describe the wound-healing properties of its combination of 10 major lipid components. A 10-lipid mixture up-regulated HBD-3 and LL-37 through the olfactory receptor 2AT4 and induced phosphorylation of extracellular signal-regulated kinases and p38 mitogen-activated protein kinases in primary human keratinocytes. In addition, the 10-lipid mixture had direct bactericidal effects against Staphylococcus aureus and Streptococcus pyogenes and protected against staphylococcal α-toxin-induced keratinocyte cell death. In an animal model, the 10-lipid mixture accelerated skin wound healing and was also effective in healing wounds superinfected with S. aureus. We suggest that the 10-lipid mixture, because of its wound-healing and antimicrobial properties, can be beneficial for wound treatment.

Epidermal Stem Cells in Skin Wound Healing

Significance: Skin serves as a protective barrier for mammals. Epidermal stem cells are responsible for maintaining skin homeostasis. When cutaneous injuries occur, skin homeostasis and integrity are damaged, leading to dire consequences such as acute, chronic, or infected wounds. Skin wound healing is an intrinsic self-saving chain reaction, which is crucial to facilitating the replacement of damaged or lost tissue. Recent Advances: An immense amount of research has uncovered the underlying mechanisms behind the complex and highly regulated wound healing process. In this review, we will dissect the biological process of adult skin wound healing and emphasize the importance of epidermal stem cells during the wound healing. Critical Issues: We will comprehensively discuss the current clinical practices used on patients with cutaneous wounds, including both traditional skin grafting procedures and advanced grafting techniques with cultured skin stem cells. The majority of these leading techniques still retain some deficiencies during clinical use. Moreover, the regeneration of skin appendages after severe injuries remains a challenge in treatment. Future Directions: Understanding epidermal stem cells and their essential functions during skin wound healing are fundamental components behind the development of clinical treatment on patients with cutaneous wounds. It is important to improve the current standard of care and to develop novel techniques improving patient outcomes and long-term rehabilitation, which should be the goals of future endeavors in the field of skin wound healing.

Modeling Physiological Events in 2D vs. 3D Cell Culture

Cell culture has become an indispensable tool to help uncover fundamental biophysical and biomolecular mechanisms by which cells assemble into tissues and organs, how these tissues function, and how that function becomes disrupted in disease. Cell culture is now widely used in biomedical research, tissue engineering, regenerative medicine, and industrial practices. Although flat, two-dimensional (2D) cell culture has predominated, recent research has shifted toward culture using three-dimensional (3D) structures, and more realistic biochemical and biomechanical microenvironments. Nevertheless, in 3D cell culture, many challenges remain, including the tissue-tissue interface, the mechanical microenvironment, and the spatiotemporal distributions of oxygen, nutrients, and metabolic wastes. Here, we review 2D and 3D cell culture methods, discuss advantages and limitations of these techniques in modeling physiologically and pathologically relevant processes, and suggest directions for future research.

Retrospektive Analyse von56 Weichteildefekten nach einzeitiger Rekonstruktion unter Verwendung von Dermisersatzpräparaten

HINTERGRUND

Der Verschluss von Wunden mit ausgeprägtem Weichteilschaden stellt eine chirurgische Herausforderung dar und erfordert häufig umfangreiche plastische Operationen sowie freie Lappenplastiken. Die Kombination von Dermisersatzpräparaten und Spalthauttransplantationen ist eine innovative Methode die zur Versorgung von komplexen Verletzungen der Extremitäten angewandt werden kann. Wir haben diese Technik in das Standard-Handwerkszeug bei komplexen Verletzungen der Extremitäten aufgenommen. Die klinischen Ergebnisse von 56 behandelten Patienten werden vorgestellt.

PATIENTEN UND METHODEN

In 44 Fällen (78,6 %) wurde die beschriebene Methode an Defekten der unteren Extremitäten verwendet, einschließlich sieben Personen (12,5 %), die sich einer Stumpfdeckung nach Amputation unterzogen. Zwölf Defekte (21,4 %) befanden sich an den oberen Extremitäten. In zwei Fällen (3,6 %) wurde die Matriderm(®) -Matrix verwendet, um Nerven von unmittelbar angrenzenden chirurgischen Implantaten zu schützen.

ERGEBNISSE

Bei 41 Patienten (73,2 %) kam es zur Einheilung des Transplantats ohne Komplikationen. Fünfzehn Patienten (26,8 %) zeigten eine gestörte Wundheilung nach Defektverschluss, die unter konservativer Therapie zur Ausheilung gebracht werden konnte. Ein Patient (1,8 %) zeigte ein Transplantatversagen, was eine Revisionsoperation erforderlich machte. Umfangreiche plastische Rekonstruktionen mussten bei keinem Patienten angewandt werden.

SCHLUSSFOLGERUNGEN

Bei Fällen, in denen ausgedehnte plastische Operationen nicht möglich oder nicht erwünscht sind, ist die Verwendung von Dermisersatzpräparaten in Kombination mit Spalthauttransplantationen eine vielversprechende Alternative zum Wundverschluss bei ausgedehnten Weichteilschäden.

Skin tissue engineering advances in severe burns: review and therapeutic applications

Current advances in basic stem cell research and tissue engineering augur well for the development of improved cultured skin tissue substitutes: a class of products that is still fraught with limitations for clinical use. Although the ability to grow autologous keratinocytes in-vitro from a small skin biopsy into sheets of stratified epithelium (within 3 to 4 weeks) helped alleviate the problem of insufficient donor site for extensive burn, many burn units still have to grapple with insufficient skin allografts which are used as intermediate wound coverage after burn excision. Alternatives offered by tissue-engineered skin dermal replacements to meet emergency demand have been used fairly successfully. Despite the availability of these commercial products, they all suffer from the same problems of extremely high cost, sub-normal skin microstructure and inconsistent engraftment, especially in full thickness burns. Clinical practice for severe burn treatment has since evolved to incorporate these tissue-engineered skin substitutes, usually as an adjunct to speed up epithelization for wound closure and/or to improve quality of life by improving the functional and cosmetic results long-term. This review seeks to bring the reader through the beginnings of skin tissue engineering, the utilization of some of the key products developed for the treatment of severe burns and the hope of harnessing stem cells to improve on current practice.

Development and Characterization of an Engraftable Tissue-Cultured Skin Autograft: Alternative Treatment for Severe Electrical Injuries

BACKGROUND/AIMS

Optimizing the treatment regimens of extensive or nonhealing defects is a constant challenge. Tissue-cultured skin autografts may be an alternative to mesh grafts and keratinocyte suspensions that are applied during surgical defect coverage.

METHODS

Autologous epidermal and dermal cells were isolated, in vitro expanded and seeded on collagen-elastin scaffolds. The developed autograft was immunohistochemically and electron microscopically characterized. Subsequently, it was transplanted onto lesions of a severely burned patient.

RESULTS

Comparability of the skin equivalent to healthy human skin could be shown due to the epidermal strata, differentiation, proliferation markers and development of characteristics of a functional basal lamina. Approximately 2 weeks after skin equivalent transplantation the emerging new skin correlated closely to the adjacent normal skin.

CONCLUSION

The present study demonstrates the comparability of the developed organotypic skin equivalent to healthy human skin and its versatility for clinical applications.