Skin covers the outermost surface of the body and protects internal organs. The skin has various functions, including protecting against pathogens, absorbing and storing water, regulating body temperature, and excreting body waste2. Skin grafts can be classified depending on the skin source; grafts using skin from another donor are termed allografts, and grafts using the patient’s own skin are autografts. Although an autograft is the preferred treatment due to its low rejection risk, skin biopsies are difficult to perform on patients with severe lesions or an insufficient number of skin cells. In patients with severe burns, three times the number of skin cells are necessary to cover large areas. The limited availability of skin cells from a patient’s body results in situations where allogenous transplantation is necessary. An allograft is temporarily used until autologous transplantation can be performed since it is usually rejected by the host’s immune system after approximately 1 week3. To overcome rejection by the patient’s immune system, grafts must come from a source with the same immune identity as the patient4.
Human iPSCs are an emerging source of cells for stem cell therapy5. Human iPSCs are generated from somatic cells, using reprogramming factors such as OCT4, SOX2, Klf4, and c-Myc6. Using human iPSCs overcomes the ethical and immunological issues of embryonic stem cells (ESCs)7,8. Human iPSCs have pluripotency and can differentiate into three germ layers9. The presence of HLA, a critical factor in regenerative medicine, determines the immune response and the possibility of rejection10. The use of patient-derived iPSCs resolves the problems of cell-source limitation and immune system rejection. CBMCs have also emerged as an alternative cell source for regenerative medicine11. Mandatory HLA typing, which occurs during CBMC banking, can easily be used for research and transplantation. Further, homozygous HLA-type iPSCs can widely apply to various patients12. A CBMC-iPSC bank is a novel and efficient strategy for cell therapy and allogenic regenerative medicine12,13,14. In this study, we use CBMC-iPSCs, differentiated into keratinocytes and fibroblasts, and generate stratified 3D skin layers. Results from this study suggest that a CBMC-iPSC-derived 3D skin organoid is a novel tool for in vitro and in vivo dermatologic research.