Hojjat Naderi-Meshkin, Raheleh Amirkhah, Asieh Heirani-Tabasi, Muhammad Irfan-Maqsood
Novel findings on fabrication techniques for bioactive materials, discovering further basic knowledge about wound healing process, and availability of stem cells as alternative candidate for differentiated cells have highly encouraged scientists for developing new bioengineered skin substitutes (BSS) that offer an effective remedy for a specific wound type. However, technical, clinical, legislative and economic reasons hamper wide-spread commercialization and clinical translation of BSS. Among the various types of strategies that target skin repair and regeneration, tissue engineering with stem cells is most promising route. Tissue engineering by cooperation of several disciplines forms a context on which the commercial development of BSS is possible to provide benefits for patients who currently have limited or no cure options. The principles of tissue engineering are to initiate cell cultures in vitro, grow them in monolayer or on porous scaffolds and transplant the composite into a patient with a specific wound indication in vivo. The potential for creating of custom-designed biomaterials and availability of stem cells from either autologous or allogenic sources have helped to produce novel innovative BSS. Currently, wide range of skin substitutes are already being fabricated for clinical use in different wound indications but not yet definitively established. Therefore, many novel engineered constructs might be fabricated in the future. In this review, we describe the progress that has been made to date in the field of skin substitutes and the critical issues that are still hindering successful production and bench to bedside translation of BSS and restricting the availability of these innovative therapeutic constructs. Integrity of the science and technology, interdisciplinary expertise collaborations, and early interaction with regulatory entities such as Food and Drug Administration (FDA) and European Medicines Agency (EMA), together with other critical determinants, is vital to the successful commercialization of tissue engineering products into the marketplace/clinic.
Stem cells (SCs) are a population of undifferentiated cells with high self-renewing and differentiation potency. On the basis of origin, SCs are divided into four main groups: embryonic stem cells (ESCs), fetal stem cells (FSCs), induced pluripotent stem cells (iPSCs), and adult stem cells (ASCs). Interestingly, in different literatures, ASCs are considered as unipotent progenitor cells, multipotent stem cells or even pluripotent stem cells with variety of differentiation potential. ASCs reside in many adult tissues such as liver, bone marrow, adipose tissue, neural tissues, skin and etc. Among adult tissues, skin is considered as a fast self-renewing tissue which is capable to reconstruct itself during skin homeostasis and injuries. In fact, skin is mentioned as a pool of different types of SCs including keratinocyte stem cells (KSCs), hair follicle stem cells (HFSCs) and sebaceous gland stem cells (SGSCs). During skin regeneration, cooperation between these stem cells is essential for reconstruction of skin. Among these SCs, KSCs are most common cells in epidermis layer (mostly in basal layer) which are the important population of SCs for regeneration of epidermis. Herein, we reviewed different methods for skin stem cells isolation and characterization, and their potential for clinical application.
Metastasis is one the most leading cause of death from cancer and the chemokine receptor of CXCR4 has a critical role in cancer metastasis. Moreover, metastasis is always correlated with epithelial-mesenchymal transition (EMT). In this study, the correlation between expression of EMT-TF of ZEB1 and CXCR4 has been examined. The results revealed that in ZEB1 knocked out cells, the expression of CXCR4 decreased significantly. This indicated that ZEB1 might be one of the regulators of CXCR4 expression.
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Afsaneh Farokhi, Fatemeh Koohpeima, Mohammad Javad Mokhtari
Many studies have showed disadvantageous effect of ethanol exposure on stem cells. Ethanol exposure during development leads injury to various types of stem cells including neural stem cells (NSCs), dental pulp stem cells, mesenchymal stem cells, embryonic stem cells and etc. Because NSCs play a basic role in the development and maturation of the central nervous system, it is vital to understand the effect of ethanol on NSCs differentiation. Additionally, alcohol misusage appears lead to periodontal disease, tooth decay and mouth wounds that are potentially precancerous. Individuals who abuse alcohol are at high risk of having seriously destroyed teeth, gums and compromised oral health in general. Some of these adverse situations maybe are because of ethanol effects on stem cells. Therefore, here, ethanol effects on the various types of stem cells were reviewed.
Cutaneous wounds are known as the damages and injuries on the skin. Knowing the type of wound is very important before any kind of treatment or therapy being applied. Each type of wound is different from other due to the different structure, biology and pathophysiology, therefore, a kind of treatment for one wound cannot be specified for others. Considering the importance of types of wounds, these wounds are classified into different categories because of their different pathobiology. This manuscript would be a great piece of knowledge for the tissue engineer to develop specific skin substitute for specific wound which might help for the development of appropriate treatment strategies.