1
|
Zhang M, Xing J, Zhong Y, Zhang T, Liu X, Xing D. Advanced function, design and application of skin substitutes for skin regeneration. Mater Today Bio 2024; 24:100918. [PMID: 38223459 PMCID: PMC10784320 DOI: 10.1016/j.mtbio.2023.100918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 11/14/2023] [Accepted: 12/13/2023] [Indexed: 01/16/2024] Open
Abstract
The development of skin substitutes aims to replace, mimic, or improve the functions of human skin, regenerate damaged skin tissue, and replace or enhance skin function. This includes artificial skin, scaffolds or devices designed for treatment, imitation, or improvement of skin function in wounds and injuries. Therefore, tremendous efforts have been made to develop functional skin substitutes. However, there is still few reports systematically discuss the relationship between the advanced function and design requirements. In this paper, we review the classification, functions, and design requirements of artificial skin or skin substitutes. Different manufacturing strategies for skin substitutes such as hydrogels, 3D/4D printing, electrospinning, microfluidics are summarized. This review also introduces currently available skin substitutes in clinical trials and on the market and the related regulatory requirements. Finally, the prospects and challenges of skin substitutes in the field of tissue engineering are discussed.
Collapse
Affiliation(s)
- Miao Zhang
- The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, 266071, China
- Cancer Institute, Qingdao University, Qingdao 266071, China
| | - Jiyao Xing
- The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, 266071, China
- Cancer Institute, Qingdao University, Qingdao 266071, China
| | - Yingjie Zhong
- The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, 266071, China
- Cancer Institute, Qingdao University, Qingdao 266071, China
| | - Tingting Zhang
- The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, 266071, China
- Cancer Institute, Qingdao University, Qingdao 266071, China
| | - Xinlin Liu
- The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, 266071, China
- Cancer Institute, Qingdao University, Qingdao 266071, China
| | - Dongming Xing
- The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, 266071, China
- Cancer Institute, Qingdao University, Qingdao 266071, China
- School of Life Sciences, Tsinghua University, Beijing 100084, China
| |
Collapse
|
2
|
Min D, Ahn Y, Lee HK, Jung W, Kim H. A novel optical coherence tomography-based in vitro method of anti-aging skin analysis using 3D skin wrinkle mimics. Skin Res Technol 2023; 29:e13354. [PMID: 37357658 PMCID: PMC10209839 DOI: 10.1111/srt.13354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 05/08/2023] [Indexed: 06/27/2023]
Abstract
BACKGROUND Wrinkles represent a characteristic symptom of skin aging. In recent years, various studies have focused on their prevention and/or cure. However, clinical tests are still the only method available to directly detect and evaluate the anti-wrinkle efficacy of various substances. Moreover, no in vitro strategy for such anti-aging skin analysis has been reported. Therefore, in this study, we aimed to develop a novel technology to overcome these limitations. MATERIALS AND METHODS Full-thickness (FT) skin wrinkle mimics with various widths and depths were fabricated using a collagen stamping method. These were analyzed and compared using 2D and 3D Swept Source-Optical Coherence Tomography (SS-OCT) imaging technologies. RESULTS SS-OCT demonstrated superficial and cross-sectional images of the wrinkle mimics, and the size of the wrinkles was validated using image analysis. Retinoic acid treatment significantly decreased both the depth and width of wrinkles formed in the FT skin wrinkle mimics. CONCLUSIONS Using 3D tissue engineering and SS-OCT imaging technologies, we developed a novel in vitro technique that can directly detect skin wrinkles. This significantly efficient method could lead to an alternative strategy for animal experiments and preclinical anti-aging research on the skin.
Collapse
Affiliation(s)
- Daejin Min
- AMOREPACIFIC Research and Innovation CenterYonginRepublic of Korea
| | - Yujin Ahn
- Department of Biomedical EngineeringUlsan National Institute of Science and Technology (UNIST)UlsanRepublic of Korea
| | | | - Woonggyu Jung
- Department of Biomedical EngineeringUlsan National Institute of Science and Technology (UNIST)UlsanRepublic of Korea
| | - Hyoung‐June Kim
- AMOREPACIFIC Research and Innovation CenterYonginRepublic of Korea
| |
Collapse
|
3
|
Holman M, Tijani A, Klein J, Frempong D, Dinh S, Puri A. Penetration Enhancement Strategies for Intradermal Delivery of Cromolyn Sodium. AAPS PharmSciTech 2022; 23:171. [PMID: 35739411 DOI: 10.1208/s12249-022-02328-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 06/07/2022] [Indexed: 11/30/2022] Open
Abstract
This study aimed to explore the use of chemical and physical enhancement strategies for the intradermal delivery of cromolyn sodium (CS) for treatment of atopic dermatitis. CS gels were formulated to individually contain 2.5 and 9% salcaprozate sodium (SNAC) as a potential chemical enhancer. The effect of microneedles, alone and in combination with SNAC, was investigated via in vitro permeation studies. Skin impedance and FTIR evaluation of SNAC-treated stratum corneum (SC) was done and compared to the control. The amount of drug delivered in the dermis after 24 h by the 2.5% and 9% SNAC gels was 23.29 ± 1.89 µg/cm2 and 35.87 ± 2.23 µg/cm2, respectively, which were significantly higher than the control (p < 0.05) but were not remarkably different from each other (p > 0.05). Microneedles enhanced permeation in both the control and 2.5% SNAC groups (p < 0.05); however, no synergistic enhancement was observed when microneedle and SNAC treatments were combined (p > 0.05). Over 24 h of treating the SC with 2.5% SNAC, FTIR evaluation showed stretches on the CH2 asymmetric and symmetric stretching vibrations observed at 2920.23 cm-1 and 2850.79 cm-1 respectively in untreated SC, which shifted to higher wavenumbers and indicated some lipid fluidizing effect. However, no significant drop in skin impedance was seen with SNAC as compared to the control (p > 0.05). SNAC was concluded to have skin permeation enhancement effect on CS, while microneedles effectively enhanced CS permeation even in the absence of SNAC.
Collapse
Affiliation(s)
- Miranda Holman
- Department of Biological Sciences, College of Arts and Sciences, East Tennessee State University, Johnson City, TN, USA
| | - Akeemat Tijani
- Department of Pharmaceutical Sciences, Bill Gatton College of Pharmacy, East Tennessee State University, Johnson City, TN, USA
| | - Jeffrey Klein
- Department of Pharmaceutical Sciences, Bill Gatton College of Pharmacy, East Tennessee State University, Johnson City, TN, USA
| | - Dorcas Frempong
- Department of Pharmaceutical Sciences, Bill Gatton College of Pharmacy, East Tennessee State University, Johnson City, TN, USA
| | - Steven Dinh
- College of Arts, Sciences, and Education, Florida International University, Miami, FL, USA
| | - Ashana Puri
- Department of Pharmaceutical Sciences, Bill Gatton College of Pharmacy, East Tennessee State University, Johnson City, TN, USA.
| |
Collapse
|
4
|
Piaia L, Pittella CQP, Souza SSD, Berti FV, Porto LM. Incorporation of Aloe vera extract in bacterial nanocellulose membranes. POLIMEROS 2022. [DOI: 10.1590/0104-1428.210062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Lya Piaia
- Universidade Federal de Santa Catarina, Brasil
| | | | | | | | | |
Collapse
|
5
|
Lago JC, Puzzi MB. The effect of aging in primary human dermal fibroblasts. PLoS One 2019; 14:e0219165. [PMID: 31269075 PMCID: PMC6608952 DOI: 10.1371/journal.pone.0219165] [Citation(s) in RCA: 87] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 06/17/2019] [Indexed: 12/04/2022] Open
Abstract
Skin aging is a complex process, and alterations in human skin due to aging have distinct characteristic as compared to other organs. The aging of dermal cells and the biological mechanisms involved in this process are key areas to understand skin aging. A large number of biological mechanisms, such as decreasing of protein synthesis of extracellular matrix or increasing of degradation, are known to be altered through skin aging. However, environmental influence can accelerate this characteristic phenotype. In this study, we analyzed primary human dermal fibroblasts in three different in-vitro aging models—UVB irradiation and accelerated proliferation of human dermal fibroblasts from young donors as well as from elderly donors—for the gene expression of COL1A1, COL1A2, COL3A1, COL4A1, COL7A1, MMP1, MMP2, MMP3, MMP7, MMP8, MMP9, MMP10, MMP12, MMP13, MMP14, TIMP1, TIMP2, TIMP3, TIMP4, IL1B, IL1A, IL6, IL8, IL10, PTGS2, TP53, CASP3, LMNA, SIRT1. We compared the gene expression levels with young control. Furthermore, the behavior of skin fibroblasts was also evaluated using cell growth rate. The findings reveal that the gene expression levels in skin fibroblasts was altered in the process of aging in all three in-vitro aging models, and the cell growth rate was reduced, suggesting that these methods can be employed to understand skin aging mechanisms as well as drug discovery screening method.
Collapse
Affiliation(s)
- Juliana Carvalhães Lago
- Department of Dermatology, School of Medical Sciences, Laboratory of Skin Cell Cultures-Pediatric Research Center, University of Campinas – UNICAMP, Campinas, São Paulo, Brazil
- * E-mail:
| | - Maria Beatriz Puzzi
- Department of Dermatology, School of Medical Sciences, Laboratory of Skin Cell Cultures-Pediatric Research Center, University of Campinas – UNICAMP, Campinas, São Paulo, Brazil
| |
Collapse
|
6
|
Yu JR, Navarro J, Coburn JC, Mahadik B, Molnar J, Holmes JH, Nam AJ, Fisher JP. Current and Future Perspectives on Skin Tissue Engineering: Key Features of Biomedical Research, Translational Assessment, and Clinical Application. Adv Healthc Mater 2019; 8:e1801471. [PMID: 30707508 PMCID: PMC10290827 DOI: 10.1002/adhm.201801471] [Citation(s) in RCA: 99] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 01/04/2019] [Indexed: 12/20/2022]
Abstract
The skin is responsible for several important physiological functions and has enormous clinical significance in wound healing. Tissue engineered substitutes may be used in patients suffering from skin injuries to support regeneration of the epidermis, dermis, or both. Skin substitutes are also gaining traction in the cosmetics and pharmaceutical industries as alternatives to animal models for product testing. Recent biomedical advances, ranging from cellular-level therapies such as mesenchymal stem cell or growth factor delivery, to large-scale biofabrication techniques including 3D printing, have enabled the implementation of unique strategies and novel biomaterials to recapitulate the biological, architectural, and functional complexity of native skin. This progress report highlights some of the latest approaches to skin regeneration and biofabrication using tissue engineering techniques. Current challenges in fabricating multilayered skin are addressed, and perspectives on efforts and strategies to meet those limitations are provided. Commercially available skin substitute technologies are also examined, and strategies to recapitulate native physiology, the role of regulatory agencies in supporting translation, as well as current clinical needs, are reviewed. By considering each of these perspectives while moving from bench to bedside, tissue engineering may be leveraged to create improved skin substitutes for both in vitro testing and clinical applications.
Collapse
Affiliation(s)
- Justine R Yu
- Fischell Department of Bioengineering, University of Maryland, College Park, College Park, MD, 20742, USA
- NIH/NBIB Center for Engineering Complex Tissues, University of Maryland, College Park, College Park, MD, 20742, USA
- University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Javier Navarro
- Fischell Department of Bioengineering, University of Maryland, College Park, College Park, MD, 20742, USA
- NIH/NBIB Center for Engineering Complex Tissues, University of Maryland, College Park, College Park, MD, 20742, USA
| | - James C Coburn
- Fischell Department of Bioengineering, University of Maryland, College Park, College Park, MD, 20742, USA
- Division of Biomedical Physics, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD, 20903, USA
| | - Bhushan Mahadik
- Fischell Department of Bioengineering, University of Maryland, College Park, College Park, MD, 20742, USA
- NIH/NBIB Center for Engineering Complex Tissues, University of Maryland, College Park, College Park, MD, 20742, USA
| | - Joseph Molnar
- Wake Forest Baptist Medical Center, Winston-Salem, NC, 27157, USA
| | - James H Holmes
- Wake Forest Baptist Medical Center, Winston-Salem, NC, 27157, USA
| | - Arthur J Nam
- Division of Plastic, Reconstructive and Maxillofacial Surgery, R. Adams Cowley Shock Trauma Center, University of Maryland, Baltimore, Baltimore, MD, 21201, USA
| | - John P Fisher
- Fischell Department of Bioengineering, University of Maryland, College Park, College Park, MD, 20742, USA
- NIH/NBIB Center for Engineering Complex Tissues, University of Maryland, College Park, College Park, MD, 20742, USA
| |
Collapse
|
7
|
Yan WC, Davoodi P, Vijayavenkataraman S, Tian Y, Ng WC, Fuh JY, Robinson KS, Wang CH. 3D bioprinting of skin tissue: From pre-processing to final product evaluation. Adv Drug Deliv Rev 2018; 132:270-295. [PMID: 30055210 DOI: 10.1016/j.addr.2018.07.016] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Revised: 07/17/2018] [Accepted: 07/20/2018] [Indexed: 02/07/2023]
Abstract
Bioprinted skin tissue has the potential for aiding drug screening, formulation development, clinical transplantation, chemical and cosmetic testing, as well as basic research. Limitations of conventional skin tissue engineering approaches have driven the development of biomimetic skin equivalent via 3D bioprinting. A key hope for bioprinting skin is the improved tissue authenticity over conventional skin equivalent construction, enabling the precise localization of multiple cell types and appendages within a construct. The printing of skin faces challenges broadly associated with general 3D bioprinting, including the selection of cell types and biomaterials, and additionally requires in vitro culture formats that allow for growth at an air-liquid interface. This paper provides a thorough review of current 3D bioprinting technologies used to engineer human skin constructs and presents the overall pipelines of designing a biomimetic artificial skin via 3D bioprinting from the design phase (i.e. pre-processing phase) through the tissue maturation phase (i.e. post-processing) and into final product evaluation for drug screening, development, and drug delivery applications.
Collapse
|
8
|
Branco TM, Valério NC, Jesus VIR, Dias CJ, Neves MG, Faustino MA, Almeida A. Single and combined effects of photodynamic therapy and antibiotics to inactivate Staphylococcus aureus on skin. Photodiagnosis Photodyn Ther 2018; 21:285-293. [DOI: 10.1016/j.pdpdt.2018.01.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 12/19/2017] [Accepted: 01/03/2018] [Indexed: 01/08/2023]
|
9
|
Oliveira ACB, Morais TFL, Bernal C, Martins VCA, Plepis AMG, Menezes PFC, Perussi JR. Red light accelerates the formation of a human dermal equivalent. J Biomater Appl 2018; 32:1265-1275. [DOI: 10.1177/0885328218759385] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Anna CB Oliveira
- Programa de Pós-Graduação Interunidades Bioengenharia - EESC/FMRP/IQSC, Universidade São Paulo-São Carlos-SP, Brazil
| | - Thayz FL Morais
- Programa de Pós-Graduação Interunidades Bioengenharia - EESC/FMRP/IQSC, Universidade São Paulo-São Carlos-SP, Brazil
| | - Claudia Bernal
- Instituto de Química de São Carlos, Universidade de São Paulo-São Carlos-SP, Brazil
| | - Virginia CA Martins
- Instituto de Química de São Carlos, Universidade de São Paulo-São Carlos-SP, Brazil
| | - Ana MG Plepis
- Programa de Pós-Graduação Interunidades Bioengenharia - EESC/FMRP/IQSC, Universidade São Paulo-São Carlos-SP, Brazil
- Instituto de Química de São Carlos, Universidade de São Paulo-São Carlos-SP, Brazil
| | - Priscila FC Menezes
- Instituto de Física de São Carlos, Universidade de São Paulo-São Carlos-SP, Brazil
| | - Janice R Perussi
- Programa de Pós-Graduação Interunidades Bioengenharia - EESC/FMRP/IQSC, Universidade São Paulo-São Carlos-SP, Brazil
- Instituto de Química de São Carlos, Universidade de São Paulo-São Carlos-SP, Brazil
| |
Collapse
|
10
|
Russo FB, Pignatari GC, Fernandes IR, Dias JLRM, Beltrão-Braga PCB. Epithelial cells from oral mucosa: How to cultivate them? Cytotechnology 2016; 68:2105-14. [PMID: 26825681 PMCID: PMC5023582 DOI: 10.1007/s10616-016-9950-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 01/18/2016] [Indexed: 12/16/2022] Open
Abstract
Epithelial cells from oral mucosa (EOM) are responsible for important functions, like the primary protection of oral mucosa against external aggressions building a mechanical barrier against microorganisms, mechanical damage, toxic material, thermal regulation and secretion of different classes of inflammatory mediators. EOM could be an interesting tool for cellular and molecular biology research. Usually, EOM are collected by a painful and invasive process. In this study, we propose an alternative method to cultivate EOM collected by non-invasive scraping method of oral mucosa. Papanicolaou staining showed mainly two kinds of epithelial cell population after EOM scraping. As result of the five culture methods tested here, our results revealed that the EOM were successfully cultured on a murine feeder layer. In addition, EOM could be frozen and thawed, without morphology changes and loss of viability. Our findings suggest that EOM can be considered as a good cell source for many purposes, such as genetic studies, diagnosis and cell therapy.
Collapse
Affiliation(s)
- F. B. Russo
- Stem Cell Lab, Department of Surgery, School of Veterinary Medicine, University of São Paulo, 87 Prof. Dr. Orlando Marques de Paiva Av., São Paulo, 05508-270 Brazil
| | - G. C. Pignatari
- Stem Cell Lab, Department of Surgery, School of Veterinary Medicine, University of São Paulo, 87 Prof. Dr. Orlando Marques de Paiva Av., São Paulo, 05508-270 Brazil
- Center for Cellular and Molecular Therapy (NETCEM), School of Medicine, University of São Paulo, 455 Dr. Arnaldo Av., São Paulo, 01246-903 Brazil
| | - I. R. Fernandes
- Stem Cell Lab, Department of Surgery, School of Veterinary Medicine, University of São Paulo, 87 Prof. Dr. Orlando Marques de Paiva Av., São Paulo, 05508-270 Brazil
| | - J. L. R. M. Dias
- Stem Cell Lab, Department of Surgery, School of Veterinary Medicine, University of São Paulo, 87 Prof. Dr. Orlando Marques de Paiva Av., São Paulo, 05508-270 Brazil
| | - P. C. B. Beltrão-Braga
- Stem Cell Lab, Department of Surgery, School of Veterinary Medicine, University of São Paulo, 87 Prof. Dr. Orlando Marques de Paiva Av., São Paulo, 05508-270 Brazil
- Center for Cellular and Molecular Therapy (NETCEM), School of Medicine, University of São Paulo, 455 Dr. Arnaldo Av., São Paulo, 01246-903 Brazil
- Obstetrics Department, School of Arts, Sciences and Humanities, University of São Paulo, 100 Arlindo Béttio Av., São Paulo, 03828-100 Brazil
| |
Collapse
|
11
|
Modeling Barrier Tissues In Vitro: Methods, Achievements, and Challenges. EBioMedicine 2016; 5:30-9. [PMID: 27077109 PMCID: PMC4816829 DOI: 10.1016/j.ebiom.2016.02.023] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Revised: 02/09/2016] [Accepted: 02/11/2016] [Indexed: 12/24/2022] Open
Abstract
Organ-on-a-chip devices have gained attention in the field of in vitro modeling due to their superior ability in recapitulating tissue environments compared to traditional multiwell methods. These constructed growth environments support tissue differentiation and mimic tissue-tissue, tissue-liquid, and tissue-air interfaces in a variety of conditions. By closely simulating the in vivo biochemical and biomechanical environment, it is possible to study human physiology in an organ-specific context and create more accurate models of healthy and diseased tissues, allowing for observations in disease progression and treatment. These chip devices have the ability to help direct, and perhaps in the distant future even replace animal-based drug efficacy and toxicity studies, which have questionable relevance to human physiology. Here, we review recent developments in the in vitro modeling of barrier tissue interfaces with a focus on the use of novel and complex microfluidic device platforms.
Collapse
|
12
|
Helmo FR, Machado JR, Oliveira LF, Rocha LP, Cavellani CL, Teixeira VDPA, dos Reis MA, Corrêa RRM. Morphological and inflammatory changes in the skin of autopsied fetuses according to the type of stress. Pathol Res Pract 2015; 211:858-64. [PMID: 26384577 DOI: 10.1016/j.prp.2015.07.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2014] [Revised: 06/19/2015] [Accepted: 07/21/2015] [Indexed: 11/30/2022]
Abstract
INTRODUCTION The fetal skin acts on the development and activation of the immune response via immune-neuroendocrine communication coordinated by corticotropin-releasing hormone. OBJECTIVE This study aimed to evaluate the morphological and inflammatory changes in the skin due to acute stress and chronic stress, associated with perinatal asphyxia, ascending infection and congenital malformation. METHODS We measured dermal and epidermal thickness, the diameter of keratinocytes, and the percentage of collagen and elastic fibers. Immunohistochemistry was used to evaluate both Langerhans cell and mast cell density, and corticotropin-releasing hormone expression in the epidermis, sebaceous gland, sebaceous duct, sudoriparous gland and in the hair follicle. RESULTS The epidermis was thinner in the cases with perinatal asphyxia, ascending infection and chronic stress. The diameter of keratinocytes was smaller in ascending infection and chronic stress. Mast cell density showed an indirect correlation with gestational age. Corticotropin-releasing hormone expression was significantly higher in ascending infection and chronic stress. CONCLUSIONS Chronic stress is associated with immunological and morphological changes in the skin of fetuses with perinatal asphyxia and ascending infection. Thus, corticotropin-releasing hormone seems to play a vital role in the differentiation and activation of innate and adaptive immune cells of the skin of fetuses.
Collapse
Affiliation(s)
- Fernanda Rodrigues Helmo
- Discipline of General Pathology, Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil.
| | - Juliana Reis Machado
- Discipline of General Pathology, Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil.
| | - Lívia Ferreira Oliveira
- Discipline of General Pathology, Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil.
| | - Laura Penna Rocha
- Discipline of General Pathology, Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil.
| | | | | | - Marlene Antônia dos Reis
- Discipline of General Pathology, Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil.
| | - Rosana Rosa Miranda Corrêa
- Discipline of General Pathology, Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil.
| |
Collapse
|
13
|
Miller KJ, Brown DA, Ibrahim MM, Ramchal TD, Levinson H. MicroRNAs in skin tissue engineering. Adv Drug Deliv Rev 2015; 88:16-36. [PMID: 25953499 DOI: 10.1016/j.addr.2015.04.018] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Revised: 04/04/2015] [Accepted: 04/25/2015] [Indexed: 01/08/2023]
Abstract
35.2 million annual cases in the U.S. require clinical intervention for major skin loss. To meet this demand, the field of skin tissue engineering has grown rapidly over the past 40 years. Traditionally, skin tissue engineering relies on the "cell-scaffold-signal" approach, whereby isolated cells are formulated into a three-dimensional substrate matrix, or scaffold, and exposed to the proper molecular, physical, and/or electrical signals to encourage growth and differentiation. However, clinically available bioengineered skin equivalents (BSEs) suffer from a number of drawbacks, including time required to generate autologous BSEs, poor allogeneic BSE survival, and physical limitations such as mass transfer issues. Additionally, different types of skin wounds require different BSE designs. MicroRNA has recently emerged as a new and exciting field of RNA interference that can overcome the barriers of BSE design. MicroRNA can regulate cellular behavior, change the bioactive milieu of the skin, and be delivered to skin tissue in a number of ways. While it is still in its infancy, the use of microRNAs in skin tissue engineering offers the opportunity to both enhance and expand a field for which there is still a vast unmet clinical need. Here we give a review of skin tissue engineering, focusing on the important cellular processes, bioactive mediators, and scaffolds. We further discuss potential microRNA targets for each individual component, and we conclude with possible future applications.
Collapse
|
14
|
Bhardwaj N, Sow WT, Devi D, Ng KW, Mandal BB, Cho NJ. Silk fibroin–keratin based 3D scaffolds as a dermal substitute for skin tissue engineering. Integr Biol (Camb) 2015; 7:53-63. [DOI: 10.1039/c4ib00208c] [Citation(s) in RCA: 120] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Development of highly vascular dermal tissue-engineered skin substitutes with appropriate mechanical properties and cellular cues is in need for significant advancement in the field of dermal reconstruction.
Collapse
Affiliation(s)
- Nandana Bhardwaj
- School of Materials Science and Engineering
- Nanyang Technological University
- Singapore-639798
- Centre for Biomimetic Sensor Science
- Nanyang Technological University
| | - Wan Ting Sow
- School of Materials Science and Engineering
- Nanyang Technological University
- Singapore-639798
| | - Dipali Devi
- Seri-Biotechnology Unit
- Life Science Division
- Institute of Advanced Study in Science and Technology
- Guwahati-781035
- India
| | - Kee Woei Ng
- School of Materials Science and Engineering
- Nanyang Technological University
- Singapore-639798
| | - Biman B. Mandal
- Department of Biotechnology
- Indian Institute of Technology Guwahati
- Guwahati-781039
- India
| | - Nam-Joon Cho
- School of Materials Science and Engineering
- Nanyang Technological University
- Singapore-639798
- Centre for Biomimetic Sensor Science
- Nanyang Technological University
| |
Collapse
|
15
|
Duval C, Cohen C, Chagnoleau C, Flouret V, Bourreau E, Bernerd F. Key regulatory role of dermal fibroblasts in pigmentation as demonstrated using a reconstructed skin model: impact of photo-aging. PLoS One 2014; 9:e114182. [PMID: 25490395 PMCID: PMC4260844 DOI: 10.1371/journal.pone.0114182] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 10/17/2014] [Indexed: 12/30/2022] Open
Abstract
To study cutaneous pigmentation in a physiological context, we have previously developed a functional pigmented reconstructed skin model composed of a melanocyte-containing epidermis grown on a dermal equivalent comprising living fibroblasts. The present studies, using the same model, aimed to demonstrate that dermal fibroblasts influence skin pigmentation up to the macroscopic level. The proof of principle was performed with pigmented skins differing only in the fibroblast component. First, the in vitro system was reconstructed with or without fibroblasts in order to test the global influence of the presence of this cell type. We then assessed the impact of the origin of the fibroblast strain on the degree of pigmentation using fetal versus adult fibroblasts. In both experiments, impressive variation in skin pigmentation at the macroscopic level was observed and confirmed by quantitative parameters related to skin color, melanin content and melanocyte numbers. These data confirmed the responsiveness of the model and demonstrated that dermal fibroblasts do indeed impact the degree of skin pigmentation. We then hypothesized that a physiological state associated with pigmentary alterations such as photo-aging could be linked to dermal fibroblasts modifications that accumulate over time. Pigmentation of skin reconstructed using young unexposed fibroblasts (n = 3) was compared to that of tissues containing natural photo-aged fibroblasts (n = 3) which express a senescent phenotype. A stimulation of pigmentation in the presence of the natural photo-aged fibroblasts was revealed by a significant increase in the skin color (decrease in Luminance) and an increase in both epidermal melanin content and melanogenic gene expression, thus confirming our hypothesis. Altogether, these data demonstrate that the level of pigmentation of the skin model is influenced by dermal fibroblasts and that natural photo-aged fibroblasts can contribute to the hyperpigmentation that is associated with photo-aging.
Collapse
|
16
|
Bellini MZ, Caliari-Oliveira C, Mizukami A, Swiech K, Covas DT, Donadi EA, Oliva-Neto P, Moraes ÂM. Combining xanthan and chitosan membranes to multipotent mesenchymal stromal cells as bioactive dressings for dermo-epidermal wounds. J Biomater Appl 2014; 29:1155-66. [DOI: 10.1177/0885328214553959] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The association between tridimensional scaffolds to cells of interest has provided excellent perspectives for obtaining viable complex tissues in vitro, such as skin, resulting in impressive advances in the field of tissue engineering applied to regenerative therapies. The use of multipotent mesenchymal stromal cells in the treatment of dermo-epidermal wounds is particularly promising due to several relevant properties of these cells, such as high capacity of proliferation in culture, potential of differentiation in multiple skin cell types, important paracrine and immunomodulatory effects, among others. Membranes of chitosan complexed with xanthan may be potentially useful as scaffolds for multipotent mesenchymal stromal cells, given that they present suitable physico-chemical characteristics and have adequate tridimensional structure for the adhesion, growth, and maintenance of cell function. Therefore, the purpose of this work was to assess the applicability of bioactive dressings associating dense and porous chitosan-xanthan membranes to multipotent mesenchymal stromal cells for the treatment of skin wounds. The membranes showed to be non-mutagenic and allowed efficient adhesion and proliferation of the mesenchymal stromal cells in vitro. In vivo assays performed with mesenchymal stromal cells grown on the surface of the dense membranes showed acceleration of wound healing in Wistar rats, thus indicating that the use of this cell-scaffold association for tissue engineering purposes is feasible and attractive.
Collapse
Affiliation(s)
- Márcia Z Bellini
- School of Chemical Engineering, University of Campinas (UNICAMP), Campinas, SP, Brazil
- Integrated Adamantinenses Colleges (FAI), Adamantina, SP, Brazil
| | | | - Amanda Mizukami
- School of Medicine of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Kamilla Swiech
- School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Dimas T Covas
- School of Medicine of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Eduardo A Donadi
- School of Medicine of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Pedro Oliva-Neto
- School of Sciences and Languages of Assis, São Paulo State University (UNESP), Assis, SP, Brazil
| | - Ângela M Moraes
- School of Chemical Engineering, University of Campinas (UNICAMP), Campinas, SP, Brazil
| |
Collapse
|
17
|
Abstract
Fetal skin has the intrinsic capacity for wound healing, which is not correlated with the intrauterine environment. This intrinsic ability requires biochemical signals, which start at the cellular level and lead to secretion of transforming factors and expression of receptors, and specific markers that promote wound healing without scar formation. The mechanisms and molecular pathways of wound healing still need to be elucidated to achieve a complete understanding of this remodeling system. The aim of this paper is to discuss the main biomarkers involved in fetal skin wound healing as well as their respective mechanisms of action.
Collapse
|
18
|
Lee V, Singh G, Trasatti JP, Bjornsson C, Xu X, Tran TN, Yoo SS, Dai G, Karande P. Design and fabrication of human skin by three-dimensional bioprinting. Tissue Eng Part C Methods 2013; 20:473-84. [PMID: 24188635 DOI: 10.1089/ten.tec.2013.0335] [Citation(s) in RCA: 414] [Impact Index Per Article: 37.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Three-dimensional (3D) bioprinting, a flexible automated on-demand platform for the free-form fabrication of complex living architectures, is a novel approach for the design and engineering of human organs and tissues. Here, we demonstrate the potential of 3D bioprinting for tissue engineering using human skin as a prototypical example. Keratinocytes and fibroblasts were used as constituent cells to represent the epidermis and dermis, and collagen was used to represent the dermal matrix of the skin. Preliminary studies were conducted to optimize printing parameters for maximum cell viability as well as for the optimization of cell densities in the epidermis and dermis to mimic physiologically relevant attributes of human skin. Printed 3D constructs were cultured in submerged media conditions followed by exposure of the epidermal layer to the air-liquid interface to promote maturation and stratification. Histology and immunofluorescence characterization demonstrated that 3D printed skin tissue was morphologically and biologically representative of in vivo human skin tissue. In comparison with traditional methods for skin engineering, 3D bioprinting offers several advantages in terms of shape- and form retention, flexibility, reproducibility, and high culture throughput. It has a broad range of applications in transdermal and topical formulation discovery, dermal toxicity studies, and in designing autologous grafts for wound healing. The proof-of-concept studies presented here can be further extended for enhancing the complexity of the skin model via the incorporation of secondary and adnexal structures or the inclusion of diseased cells to serve as a model for studying the pathophysiology of skin diseases.
Collapse
Affiliation(s)
- Vivian Lee
- 1 Department of Biomedical Engineering, Rensselaer Polytechnic Institute , Troy, New York
| | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Wang HM, Chou YT, Wen ZH, Wang ZR, Chen CH, Ho ML. Novel biodegradable porous scaffold applied to skin regeneration. PLoS One 2013; 8:e56330. [PMID: 23762223 PMCID: PMC3677897 DOI: 10.1371/journal.pone.0056330] [Citation(s) in RCA: 107] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Accepted: 01/12/2013] [Indexed: 12/11/2022] Open
Abstract
Skin wound healing is an important lifesaving issue for massive lesions. A novel porous scaffold with collagen, hyaluronic acid and gelatin was developed for skin wound repair. The swelling ratio of this developed scaffold was assayed by water absorption capacity and showed a value of over 20 g water/g dried scaffold. The scaffold was then degraded in time- and dose-dependent manners by three enzymes: lysozyme, hyaluronidase and collagenase I. The average pore diameter of the scaffold was 132.5±8.4 µm measured from SEM images. With human skin cells growing for 7 days, the SEM images showed surface fractures on the scaffold due to enzymatic digestion, indicating the biodegradable properties of this scaffold. To simulate skin distribution, the human epidermal keratinocytes, melanocytes and dermal fibroblasts were seeded on the porous scaffold and the cross-section immunofluorescent staining demonstrated normal human skin layer distributions. The collagen amount was also quantified after skin cells seeding and presented an amount 50% higher than those seeded on culture wells. The in vivo histological results showed that the scaffold ameliorated wound healing, including decreasing neutrophil infiltrates and thickening newly generated skin compared to the group without treatments.
Collapse
Affiliation(s)
- Hui-Min Wang
- Department of Fragrance and Cosmetic Science, Kaohsiung Medical University, Kaohsiung, Taiwan
- Graduate Institute of Natural Products, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Yi-Ting Chou
- Department of Fragrance and Cosmetic Science, Kaohsiung Medical University, Kaohsiung, Taiwan
- Department of Physiology, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Zhi-Hong Wen
- Department of Marine Biotechnology and Resources, Asia-Pacific Ocean Research Center, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - Zhao-Ren Wang
- Department of Physiology, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- Orthopaedic Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Chun-Hong Chen
- Department of Marine Biotechnology and Resources, Asia-Pacific Ocean Research Center, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - Mei-Ling Ho
- Department of Physiology, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- Orthopaedic Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan
- * E-mail:
| |
Collapse
|
20
|
Cardinali G, Kovacs D, Picardo M. [Mechanisms underlying post-inflammatory hyperpigmentation: lessons from solar lentigo]. Ann Dermatol Venereol 2012; 139 Suppl 3:S96-101. [PMID: 23260525 DOI: 10.1016/s0151-9638(12)70118-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Hyperpigmentation of the skin is a common dermatologic condition in all skin types but most prominent in brown-skinned population. In skin of color any inflammation or injury can be accompanied by alterations in pigmentation (hyper/hypo-pigmentation). Postinflammatory hyperpigmentation (PIH) can be observed in many skin conditions including acne, eczema, and contact dermatitis. In the control of skin pigmentation, parallel to the cross-talk between keratinocytes and melanocytes, increasing evidence has underlined the crucial role exerted by the interactions between mesenchymal and epithelial cells through the release of fibroblast-derived growth factors. Among these factors, the keratinocyte growth factor (KGF), alone or in combination with interleukin-1α, induces melanin deposition in vitro and hyperpigmented lesions in vivo. Furthermore, a moderate increase of KGF and a high induction of its receptor have been shown in solar lentigo lesions, suggesting the involvement of this growth factor in the onset of the hyperpigmented spots. Several studies highlight the possible contribution of the fibroblast-derived melanogenic growth factors to the hyperpigmentated lesions, in the context of the mesenchymal - epithelial interactions modulating melanocyte functions.
Collapse
Affiliation(s)
- G Cardinali
- San Gallicano Dermatological Institute, IRCCS, Via Elio Chianesi 53, Rome 00144, Italie
| | | | | |
Collapse
|
21
|
Cardinali G, Kovacs D, Picardo M. Mechanisms underlying post-inflammatory hyperpigmentation: lessons from solar lentigo. Ann Dermatol Venereol 2012; 139 Suppl 4:S148-52. [DOI: 10.1016/s0151-9638(12)70127-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
22
|
Duval C, Chagnoleau C, Pouradier F, Sextius P, Condom E, Bernerd F. Human skin model containing melanocytes: essential role of keratinocyte growth factor for constitutive pigmentation-functional response to α-melanocyte stimulating hormone and forskolin. Tissue Eng Part C Methods 2012; 18:947-57. [PMID: 22646688 DOI: 10.1089/ten.tec.2011.0676] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
To study human skin pigmentation in a physiological in vitro model, we developed a pigmented reconstructed skin reproducing the three-dimensional architecture of the melanocyte environment and the interactions of melanocyte with its cellular partners, keratinocytes, and fibroblasts. Co-seeding melanocytes and keratinocytes onto a fibroblast-populated collagen matrix led to a correct integration of melanocytes within the epidermal basal layer, but melanocytes remained amelanotic even after supplementation with promelanogenic factors. Interestingly, normalization of keratinocyte differentiation using keratinocyte growth factor instead of epidermal growth factor finally allowed an active pigmentary system to develop, as shown by the expression of key melanogenic markers, the production, and transfer of melanosome-containing melanin into keratinocytes. Various degrees of constitutive pigmentation were reproduced using melanocytes from different skin phenotypes. Furthermore, induction of pigmentation was achieved by treatment with known propigmenting molecules, αMSH and forskolin, thus demonstrating the functionality of the pigmentary system. This pigmented full-thickness skin model therefore represents a highly relevant tool to study the role of cell-cell, cell-matrix, and mesenchymal-epithelial interactions in the control of skin pigmentation.
Collapse
|
23
|
Bellini MZ, Pires ALR, Vasconcelos MO, Moraes ÂM. Comparison of the properties of compacted and porous lamellar chitosan-xanthan membranes as dressings and scaffolds for the treatment of skin lesions. J Appl Polym Sci 2012. [DOI: 10.1002/app.36693] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
24
|
Marcelo D, Beatriz PM, Jussara R, Fabiana B. Tissue therapy with autologous dermal and epidermal culture cells for diabetic foot ulcers. Cell Tissue Bank 2011; 13:241-9. [DOI: 10.1007/s10561-011-9249-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2010] [Accepted: 03/09/2011] [Indexed: 11/28/2022]
|
25
|
Souto LRM, Vassallo J, Rehder J, Pinto GA, Puzzi MB. Immunoarchitectural characterization of a human skin model reconstructed in vitro. SAO PAULO MED J 2009; 127:28-33. [PMID: 19466292 PMCID: PMC10969314 DOI: 10.1590/s1516-31802009000100007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2007] [Revised: 12/29/2008] [Accepted: 01/28/2009] [Indexed: 11/21/2022] Open
Abstract
CONTEXT AND OBJECTIVE Over the last few years, different models for human skin equivalent reconstructed in vitro (HSERIV) have been reported for clinical usage and applications in research for the pharmaceutical industry. Before release for routine use as human skin replacements, HSERIV models need to be tested regarding their similarity with in vivo skin, using morphological (architectural) and immunohistochemical (functional) analyses. A model for HSERIV has been developed in our hospital, and our aim here was to further characterize its immunoarchitectural features by comparing them with human skin, before it can be tested for clinical use, e.g. for severe burns or wounds, whenever ancillary methods are not indicated. DESIGN AND SETTING Experimental laboratory study, in the Skin Cell Culture Laboratory, School of Medical Sciences, Universidade Estadual de Campinas. METHODS Histological sections were stained with hematoxylin-eosin, Masson's trichrome for collagen fibers, periodic acid-Schiff reagent for basement membrane and glycogen, Weigert-Van Gieson for elastic fibers and Fontana-Masson for melanocytes. Immunohistochemistry was used to localize cytokeratins (broad spectrum of molecular weight, AE1/AE3), high molecular weight cytokeratins (34betaE12), low molecular weight cytokeratins (35betaH11), cytokeratins 7 and 20, vimentin, S-100 protein (for melanocytic and dendritic cells), CD68 (KP1, histiocytes) and CD34 (QBend, endothelium). RESULTS Histology revealed satisfactory similarity between HSERIV and in vivo skin. Immunohistochemical analysis on HSERIV demonstrated that the marker pattern was similar to what is generally present in human skin in vivo. CONCLUSION HSERIV is morphologically and functionally compatible with human skin observed in vivo.
Collapse
Affiliation(s)
- Luís Ricardo Martinhão Souto
- MD, MSc. Postgraduate (PhD) student of Surgery, School of Medical Sciences, Universidade Estadual de Campinas (Unicamp), Campinas, São Paulo, Brazil.
| | - José Vassallo
- MD, PhD. Titular professor, Department of Pathological Anatomy, School of Medical Sciences, Universidade Estadual de Campinas (Unicamp), Campinas, São Paulo, Brazil.
| | - Jussara Rehder
- BSc. Chief biologist, Laboratory of Molecular Biology and Skin Cell Culture, School of Medical Sciences, Universidade Estadual de Campinas (Unicamp), Campinas, São Paulo, Brazil.
| | - Glauce Aparecida Pinto
- BSc, PhD. Biomedical researcher, Laboratory of Experimental Pathology, Women’s Full Healthcare Center, Universidade Estadual de Campinas (Unicamp), Campinas, São Paulo, Brazil.
| | - Maria Beatriz Puzzi
- MD, PhD. Associate professor of Dermatology, Department of Internal Medicine. Head of the Skin Cell Culture Laboratory, School of Medical Sciences, Universidade Estadual de Campinas (Unicamp), Campinas, São Paulo, Brazil.
| |
Collapse
|
26
|
Abstract
Stem cells are defined by their capacity of self-renewal and multilineage differentiation, which make them uniquely situated to treat a broad spectrum of human diseases. Based on a series of remarkable studies in several fields of regenerative medicine, their application is not too far from the clinical practice. Full-thickness burns and severe traumas can injure skin and its appendages, which protect animals from water loss, temperature change, radiation, trauma and infection. In adults, the normal outcome of repair of massive full-thickness burns is fibrosis and scarring without any appendages, such as hair follicles, sweat and sebaceous glands. Perfect skin regeneration has been considered impossible due to the limited regenerative capacity of epidermal keratinocytes, which are generally thought to be the key source of the epidermis and skin appendages. Currently, researches on stem cells, such as epidermal stem cells, dermal stem cells, mesenchymal stem cells from bone marrow, and embryonic stem cells, bring promise to functional repair of skin after severe burn injury, namely, complete regeneration of skin and its appendages. In this study, we present an overview of the most recent advances in skin repair and regeneration by using stem cells.
Collapse
|
27
|
Tfayli A, Piot O, Draux F, Pitre F, Manfait M. Molecular characterization of reconstructed skin model by Raman microspectroscopy: comparison with excised human skin. Biopolymers 2007; 87:261-74. [PMID: 17763468 DOI: 10.1002/bip.20832] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Human skin is directly exposed to different exogenous agents. Many research works have studied the diffusion, interactions, absorption mechanisms, and/or toxicity of these agents toward different cutaneous structures. With the use of living animals for such tests being more and more rejected; and the number of human volunteers being limited; different types of skin models are used. In the last few years, reconstructed epidermis from cell cultures has been frequently employed, and recent changes in the European chemical policy have approved and encouraged the use of these reconstructed models for skin-related research works and assessments. Among the techniques used actually to study the skin, Raman microspectroscopy is a rising and powerful nondestructive technique that detects characteristic molecular vibrations. In this study, we created a spectral database to index the vibration peaks and bands of a well-known reconstructed epidermis model, the Episkin. The comparison with a native epidermis signal enabled us to put in evidence several spectral differences associated with molecular and structural differences between the skin and the reconstructed model, both maintained in living conditions. In addition to that, we have showed the feasibility of tracking the penetration of a pharmaceutical molecule through the Episkin model. (
Collapse
Affiliation(s)
- Ali Tfayli
- MeDIAN Unit, CNRS UMR 6142, Faculty of Pharmacy, University of Reims Champagne-Ardenne, France
| | | | | | | | | |
Collapse
|