Bioprinting of biomimetic skin containing melanocytes

Abstract

This study reports a three-dimensional (3D) bioprinting technique that is capable of producing a full-thickness skin model containing pigmentation. Multiple layers of fibroblast (FB)-containing collagen hydrogel precursor were printed and crosslinked through neutralization using sodium bicarbonate, constituting the dermal layer. Melanocytes (MCs) and keratinocytes (KCs) were sequentially printed on top of the dermal layer to induce skin pigmentation upon subsequent air-liquid interface culture. Histological analysis was performed not only to confirm the formation of distinct skin layers, but also to identify the presence of pigmentation. The bioprinted skin structure showed the dermal and epidermal layers as well as the terminal differentiation of the KC that formed the stratum corneum. Moreover, the MC-containing epidermal layer showed freckle-like pigmentations at the dermal-epidermal junction, without the use of external ultraviolet light or chemical stimuli. The presented method offers the capability of producing engineered ephelides in biomimetic skin, thus rendering 3D bioprinting techniques as productive on-demand options for the creation of skin models available for therapeutic or research use.

The 3R approach to experimental dermatology

“…Original studies employing alternative methods have been frequently published in Experimental Dermatology in the last years . In line with this tradition, the present special issue also showcases a number of original contributions, which can be viewed as current examples for new developments in alternative methods. The advances in reproducing human skin features in vitro make it possible to recapitulate also human skin diseases, thus replacing the use of animals and/or reducing their number by integrating in vivo and in vitro data.…”

Skin microbiota and human 3D skin models

“…Compared to the prevalent “classical” 3D skin models, the development of novel complex next‐generation skin models based on induced pluripotent stem cells (iPSCs) and microfluidic technology (“skin‐on‐chip”) or using 3D bioprinting techniques will offer promising tools for the study of the microbiota‐skin interplay. For example, the use of iPSC‐derived cells such as keratinocytes, fibroblasts and melanocytes has already led to the successful generation of a complex 3D skin model .…”

Beyond 2D: 3D bioprinting for skin regeneration

“…Sequentially, KCs and MCs were printed on the top of the dermal layer and cultured on the subsequent air‐liquid interface to induce skin pigmentation. Through histological analysis, they identified the formation of different skin layers and the existence of pigmentation . Wei Long Ng et al also successfully used FBs, KCs, and MCs to product 3D‐pigmented human skin constructs …”