Three-Dimensionally Printed Skin Substitute Using Human Dermal Fibroblasts and Human Epidermal Keratinocytes

Abstract

Introduction Wound healing affects millions of people annually. After injury, keratinocytes from the wound edge proliferate, migrate, and differentiate to recapitulate the 3-dimensional (3D) structure needed to provide a barrier function. If the wound is too large, skin grafting may be required. We are interested in discovering novel strategies to enhance the wound healing process. It may be possible to recreate a viable and histologically accurate skin tissue using 3D printing. We hypothesize that keratinocytes and dermal fibroblasts can be bioprinted into a viable skin substitute. Methods Adult human dermal fibroblasts (HDFa) and adult human epidermal keratinocytes (HEKa) were cultured and subsequently printed with a 3D bioprinter within a hydrogel scaffold. After printing the HDFa and HEKa separately, cell viability and histological appearance were determined by sectioning the printed tissue and performing hematoxylin and eosin staining. The stained histological sections were analyzed for tissue morphology. Results The HEKa and HDFa cells suspended in the hydrogel were successfully printed into 3D scaffolds that resembled skin with hematoxylin and eosin staining. Conclusions The HEKa and HDFa cells can be grown on 3D-printed hydrogels successfully. In addition, HEKa and HDFa cells can survive and grow when suspended in a hydrogel and 3D printed. Future potential applications of these results could lead to the creation of viable skin tissue for wound healing and surgical repair.

Recent Developments in 3D-(Bio)printed Hydrogels as Wound Dressings

“…Their physicochemical/mechanical properties and their composition need to be carefully selected in order to achieve high printability and high cell viability (Figure 8) and to assist cellular functions [135,137]. Bioinks need to be biocompatible to ease cell growth, exhibit controllable rheological properties (e.g., shear thinning) in order to flow effortlessly through the nozzle and possess enhanced shape fidelity after printing (i.e., redeem sufficient storage modulus after printing), biofunctionality to meet biomimicry requirements (i.e., they should mimic ECM regarding biochemical/biomechanical properties [136]) and mechanical stability [23,70,134,138,139], which can be difficult to accomplish with a single-component bioink [134]. Other important parameters that should be taken into consideration for the design and development of bioinks are their compatibility with various printing techniques, printing resolution, bioprintability, biodegradability, maintenance of cell viability and process scalability [137].…”

The 3D Bioprinted Scaffolds for Wound Healing

“…Especially, 3D printing technology allows the introduction of multiple cell types within specific positions in the scaffolds and the survival rates would be really high [3,5]. Indeed, adult human dermal fibroblasts and adult human epidermal keratinocytes can survive and grow after being 3D bioprinted with a hydrogel scaffold [234]. In addition, the efficacy in full-thickness burn wound healing in a rat model of a 3D bioprinted collagen and alginate scaffold was reported.…”

Epigenetic Modification of PD-1/PD-L1-Mediated Cancer Immunotherapy against Melanoma

“…The skin has a complex three-dimensional structure containing various component cells and is an organ located in the outmost layer of the human body. The skin is exposed to various influences from environmental alterations and stimuli, such as temperature, chemicals, microorganisms, and medications [1][2][3][4][5][6][7][8][9][10]. Indeed, representative inflammatory skin diseases such as psoriasis and atopic dermatitis are significantly influenced by various environmental factors [11][12][13][14][15].…”