About this Research Topic
These models have the strong potential to increase the significance of scientific and clinical outcomes and to reduce animal experimentation. Moreover, they also preclude the need for repeated patient biopsies. The generation of more complex 3D skin models will help decipher further relevant patho-mechanisms and uncover new therapeutic approaches in a broad range of skin pathologies. Moreover, they will help optimize delivery systems to skin and test new skin antiaging molecules.
Several models are already composed of various skin cell types such as Langerhans cells, melanocytes, T cells, macrophages and endothelial cells. Immortalized keratinocytes, such as HaCaT and N/TERT cells, can also be advantageously utilized for drug testing. Moreover, human mesenchymal stem cells from adipose tissue or bone marrow or germline-derived pluripotent stem cells have been employed to generate or improve full-skin models. Epidermal equivalents have already been established with induced pluripotent stem cells (iPSCs), generated from human skin fibroblasts. However, epidermal equivalents and full-skin models can reach higher levels of sophistication and be utilized in a broader range of skin pathologies, including some relevant for veterinary research.
Furthermore, the complex interplay between the gamut of skin cell types, which is crucial for the cross-talk between the physical, immunological and microbial barriers of the skin, is still missing to capture the complexity of the structure and function of native skin and adequately reflect processes such as skin ageing, skin pathologies and wound healing.
Additional current drawbacks of most existing organotypic models are the lack of (i) cutaneous vascular, lymphatic and nervous systems, (ii) relative longevity critical in many studies (e.g. chronic exposure to various molecules, chronic diseases), and (iii) skin appendages and macrostructures such as sebaceous or sweat glands and hair. Moreover, there is a need to develop ethical and sustainable reagents required for the elaboration of organotypic skin models and of new scaffolds for 3D-skin bio-printing.
Indeed, it is nowadays important to increase accountability for plastic waste reduction while advancing the quality of research by boosting research on alternative scaffolds, including melt-electrospun writing, bio-inks from renewable sources (e.g., natural polymers), optimise hydrogels, which do not influence the immune response or cell phenotype, and develop bioreactor fluidic systems.
In silico computational skin models represent a promising alternative to animal experimentation and an advantageous cost-effective approach for drug/cosmetic screening, but they are still in early stages of development.
Thus, there is still a large room for innovations in the field of skin models and Frontiers in Physiology–Skin will give the opportunity to a broad range of scientists, including computer scientists and bioengineers to publish their work.
Topic Editors declare no conflict of interest.
Keywords: Skin models, ex-vivo skin tissues, in-vitro skin models, in-silico skin models, computational skin models, 3D-skin bio-printing, alternative skin scaffolds, drug/cosmetic screening, skin ageing, skin pathologies, wound healing.
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