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International Journal of Molecular... Nov 2020The skin plays an important role in the maintenance of the human's body physiological homeostasis. It acts as a coverage that protects against infective microorganism or... (Review)
Review
The skin plays an important role in the maintenance of the human's body physiological homeostasis. It acts as a coverage that protects against infective microorganism or biomechanical impacts. Skin is also implied in thermal regulation and fluid balance. However, skin can suffer several damages that impede normal wound-healing responses and lead to chronic wounds. Since the use of autografts, allografts, and xenografts present source limitations and intense rejection associated problems, bioengineered artificial skin substitutes (BASS) have emerged as a promising solution to address these problems. Despite this, currently available skin substitutes have many drawbacks, and an ideal skin substitute has not been developed yet. The advances that have been produced on tissue engineering techniques have enabled improving and developing new arising skin substitutes. The aim of this review is to outline these advances, including commercially available skin substitutes, to finally focus on future tissue engineering perspectives leading to the creation of autologous prevascularized skin equivalents with a hypodermal-like layer to achieve an exemplary skin substitute that fulfills all the biological characteristics of native skin and contributes to wound healing.
Topics: Adhesiveness; Allografts; Animals; Biomechanical Phenomena; Humans; Neovascularization, Pathologic; Regeneration; Skin; Skin Transplantation; Skin, Artificial; Subcutaneous Tissue; Tissue Engineering; Wound Healing
PubMed: 33147759
DOI: 10.3390/ijms21218197 -
Journal of Dental Research Jul 2012Advances in tissue engineering have permitted the three-dimensional (3D) reconstruction of human oral mucosa for various in vivo and in vitro applications.... (Review)
Review
Advances in tissue engineering have permitted the three-dimensional (3D) reconstruction of human oral mucosa for various in vivo and in vitro applications. Tissue-engineered oral mucosa have been further optimized in recent years for clinical applications as a suitable graft material for intra-oral and extra-oral repair and treatment of soft-tissue defects. Novel 3D in vitro models of oral diseases such as cancer, Candida, and bacterial invasion have been developed as alternatives to animal models for investigation of disease phenomena, their progression, and treatment, including evaluation of drug delivery systems. The introduction of 3D oral mucosal reconstructs has had a significant impact on the approaches to biocompatibility evaluation of dental materials and oral healthcare products as well as the study of implant-soft tissue interfaces. This review article discusses the recent advances in tissue engineering and applications of tissue-engineered human oral mucosa.
Topics: Absorbable Implants; Animals; Candidiasis, Oral; Cell Line, Transformed; Cleft Palate; Dental Implants; Dental Materials; Diagnostic Imaging; Drug Delivery Systems; Gingival Recession; Humans; Imaging, Three-Dimensional; Keratinocytes; Models, Biological; Models, Structural; Mouth Mucosa; Mouth Neoplasms; Skin, Artificial; Tissue Engineering; Tissue Scaffolds
PubMed: 22266525
DOI: 10.1177/0022034511435702 -
Cytotherapy Jan 2021The inability of two-dimensional cell culture systems to adequately map the structure and function of complex organs like skin necessitates the development of... (Review)
Review
The inability of two-dimensional cell culture systems to adequately map the structure and function of complex organs like skin necessitates the development of three-dimensional (3D) skin models. A diverse range of 3D skin equivalents have been developed over the last few decades for studying complex properties of skin as well as for drug discovery and clinical applications for skin regeneration in chronic wounds, such as diabetic foot ulcers, where the normal mechanism of wound healing is compromised. These 3D skin substitutes also serve as a suitable alternative to animal models in industrial applications and fundamental research. With the emergence of tissue engineering, new scaffolds and matrices have been integrated into 3D cell culture systems, along with gene therapy approaches, to increase the efficacy of transplanted cells in skin regeneration. This review summarizes recent approaches to the development of skin equivalents as well as different models for studying skin diseases and properties and current therapeutic applications of skin substitutes.
Topics: Animals; Humans; Regeneration; Skin, Artificial; Tissue Engineering; Tissue Scaffolds; Wound Healing
PubMed: 33189572
DOI: 10.1016/j.jcyt.2020.10.001 -
International Journal of Molecular... Apr 2022The skin is the largest organ in the human body, comprising the main barrier against the environment. When the skin loses its integrity, it is critical to replace it to...
The skin is the largest organ in the human body, comprising the main barrier against the environment. When the skin loses its integrity, it is critical to replace it to prevent water loss and the proliferation of opportunistic infections. For more than 40 years, tissue-engineered skin grafts have been based on the in vitro culture of keratinocytes over different scaffolds, requiring between 3 to 4 weeks of tissue culture before being used clinically. In this study, we describe the development of a polymerizable skin hydrogel consisting of keratinocytes and fibroblast entrapped within a fibrin scaffold. We histologically characterized the construct and evaluated its use on an in vivo wound healing model of skin damage. Our results indicate that the proposed methodology can be used to effectively regenerate skin wounds, avoiding the secondary in vitro culture steps and thus, shortening the time needed until transplantation in comparison with other bilayer skin models. This is achievable due to the instant polymerization of the keratinocytes and fibroblast combination that allows a direct application on the wound. We suggest that the polymerizable skin hydrogel is an inexpensive, easy and rapid treatment that could be transferred into clinical practice in order to improve the treatment of skin wounds.
Topics: Fibroblasts; Humans; Hydrogels; Skin; Skin Transplantation; Skin, Artificial; Tissue Engineering; Wound Healing
PubMed: 35563225
DOI: 10.3390/ijms23094837 -
The Journal of Surgical Research Jan 2020In the management of indeterminate-depth burns (IDB), common challenges include the ability to predict time to healing and regenerative potential, risk of burn wound... (Review)
Review
In the management of indeterminate-depth burns (IDB), common challenges include the ability to predict time to healing and regenerative potential, risk of burn wound progression, and timing of excision. Several technologies exist to aid in determination of the depth of a burn injury, yet surgeons continue to rely on the naked eye-visual assessment-as the standard of care. Newer and improved imaging technologies are closing in on the goal of inexpensive, accurate, noninvasive modalities for depth determination. Likewise, management of IDB is becoming more sophisticated as newer wound healing technologies continue to be developed. By describing what is meant by "indeterminate" depth burns, and their associated challenges, we hope to stimulate interest in research to develop new therapies and management strategies. The ultimate goal is to treat IDB without the need for autografts.
Topics: Burns; Debridement; Disease Progression; Humans; Patient Selection; Severity of Illness Index; Skin; Skin Transplantation; Skin, Artificial; Standard of Care; Time Factors; Treatment Outcome; Uncertainty; Wound Healing
PubMed: 31421361
DOI: 10.1016/j.jss.2019.07.063 -
Burns : Journal of the International... Nov 2018Half a million patients in the USA alone require treatment for burns annually. Following an extensive burn, it may not be possible to provide sufficient autografts in a... (Review)
Review
Half a million patients in the USA alone require treatment for burns annually. Following an extensive burn, it may not be possible to provide sufficient autografts in a single setting. Pig skin xenografts may provide temporary coverage. However, preformed xenoreactive antibodies in the human recipient activate complement, and thus result in rapid rejection of the graft. Because burn patients usually have some degree of immune dysfunction and are therefore at increased risk of infection, immunosuppressive therapy is undesirable. Genetic engineering of the pig has increased the survival of pig heart, kidney, islet, and corneal grafts in immunosuppressed non-human primates from minutes to months or occasionally years. We summarize the current status of research into skin xenotransplantation for burns, with special emphasis on developments in genetic engineering of pigs to protect the graft from immunological injury. A genetically-engineered pig skin graft now survives as long as an allograft and, importantly, rejection of a skin xenograft is not detrimental to a subsequent allograft. Nevertheless, currently, systemic immunosuppressive therapy would still be required to inhibit a cellular response, and so we discuss what further genetic manipulations could be carried out to inhibit the cellular response.
Topics: Animals; Animals, Genetically Modified; Burns; Cadaver; Complement Activation; Graft Rejection; Graft Survival; Humans; Immunosuppressive Agents; Primates; Skin Transplantation; Skin, Artificial; Swine; Transplantation, Heterologous; Transplantation, Homologous
PubMed: 29602717
DOI: 10.1016/j.burns.2018.02.029 -
Skin Research and Technology : Official... Jan 2022Make-up clumps, bumps and collapses are the three factors that determine how well make-up has been performed. The purpose of this study is to reduce the three factors...
PURPOSE
Make-up clumps, bumps and collapses are the three factors that determine how well make-up has been performed. The purpose of this study is to reduce the three factors mentioned above by using amphiphilic substances to increase the affinity between the skin and the make-up layer. In addition, it aims to evaluate the improvement of the make-up layer by developing an objective make-up layer evaluation method.
METHODS
Experiments were performed in an attempt to increase the affinity between the skin and the make-up layer by minimizing the difference in surface energy between the two. Multiple types of artificial skin (leather and bio-skin) were used and treated to form the liquid foundation layer. Qualitative evaluation of the make-up layer was conducted by analyzing the surface, cross-section, and fracture area of the make-up layer, using the evaluation method proposed in this study.
RESULTS
After applying this method and taking measurements by 3D surface analysis, the surface roughness of the make-up layer reduced by 46%, and the maximum thickness of the make-up layer reduced by about 50% in comparison with the control group (method not applied). In the case of the make-up layer to which this method was applied, two-dimensional cross-sectional Scanning Electron Microscope (SEM) image analysis confirmed that agglomeration was reduced, and the thickness of the make-up layer was also reduced by an average of 54%. According to this result, the technique of increasing the affinity between the skin and the make-up layer reduces the level of aggregation of make-up and encourages the formation of a uniform and thin make-up layer. Also, the fracture area after motion simulation was reduced by 33%. These results indicate that the method of increasing the affinity between skin/make-up membranes positively affects the formation of a uniform make-up layer.
CONCLUSION
Increasing the affinity by reducing the surface energy between the skin and the make-up layer plays an important role in forming a thin and uniform make-up layer by improving the problems of lifting, agglomeration, and collapse of the make-up. In addition, it has been confirmed that through this method, the quality of consumer experience related to make-up satisfaction can be improved. The results show that objective analyses of make-up help the understanding of the quality of consumer experience on make-up.
Topics: Cross-Sectional Studies; Dermis; Humans; Skin; Skin, Artificial
PubMed: 34455650
DOI: 10.1111/srt.13095 -
International Journal of Molecular... Mar 2024Non-healing wounds and skin losses constitute significant challenges for modern medicine and pharmacology. Conventional methods of wound treatment are effective in basic... (Review)
Review
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.
Topics: Humans; Skin, Artificial; Bioengineering; Biomedical Engineering; Diabetic Foot; Burns
PubMed: 38612513
DOI: 10.3390/ijms25073702 -
Actas Dermo-sifiliograficas Jan 2012Regenerative Medicine is an emerging field that combines basic research and clinical observations in order to identify the elements required to replace damaged tissues... (Review)
Review
Regenerative Medicine is an emerging field that combines basic research and clinical observations in order to identify the elements required to replace damaged tissues and organs in vivo and to stimulate the body's intrinsic regenerative capacity. Great benefits are expected in this field as researchers take advantage of the potential regenerative properties of both embryonic and adult stem cells, and more recently, of induced pluripotent stem cells. Bioengineered skin emerged mainly in response to a critical need for early permanent coverage of extensive burns. Later this technology was also applied to the treatment of chronic ulcers. Our group has established a humanized mouse model of skin grafting that involves the use of bioengineered human skin in immunodeficient mice. This model is suitable for the study of physiologic and pathologic cutaneous processes and the evaluation of treatment strategies for skin diseases, including protocols for gene and cell therapy and tissue engineering.
Topics: Adult Stem Cells; Animals; Bioengineering; Biological Dressings; Burns; Cells, Cultured; Disease Models, Animal; Epidermal Cells; Epidermolysis Bullosa; Fibroblasts; Humans; Keratinocytes; Mice; Mice, Nude; Psoriasis; Skin, Artificial; Species Specificity; Stem Cells; Wound Healing
PubMed: 22464599
DOI: 10.1016/j.adengl.2011.03.016 -
Journal of the American College of... Feb 1998
Review
Topics: Adult; Animals; Burns; Child; Combined Modality Therapy; Disease Models, Animal; Humans; Skin Transplantation; Skin, Artificial; Smoke Inhalation Injury
PubMed: 9482612
DOI: 10.1016/s1072-7515(98)00033-7