National Center for Advancing Translational Sciences, National Institute of Health, Rockville, MD, United States of America.
Biofabrication. 2020 Apr 9;12(3):035002. doi: 10.1088/1758-5090/ab76a1.
Three-dimensional (3D) biofabrication techniques enable the production of multicellular tissue models as assay platforms for drug screening. The increased cellular and physiological complexity in these 3D tissue models should recapitulate the relevant biological environment found in the body. Here we describe the use of 3D bioprinting techniques to fabricate skin equivalent tissues of varying physiological complexity, including human epidermis, non-vascularized and vascularized full-thickness skin tissue equivalents, in a multi-well platform to enable drug screening. Human keratinocytes, fibroblasts, and pericytes, and induced pluripotent stem cell-derived endothelial cells were used in the biofabrication process to produce the varying complexity. The skin equivalents exhibit the correct structural markers of dermis and epidermis stratification, with physiological functions of the skin barrier. The robustness, versatility and reproducibility of the biofabrication techniques are further highlighted by the generation of atopic dermatitis (AD)-disease like tissues. These AD models demonstrate several clinical hallmarks of the disease, including: (i) spongiosis and hyperplasia; (ii) early and terminal expression of differentiation proteins; and (iii) increases in levels of pro-inflammatory cytokines. We show the pre-clinical relevance of the biofabricated AD tissue models to correct disease phenotype by testing the effects of dexamethasone, an anti-inflammatory corticosteroid, and three Janus Kinase inhibitors from clinical trials for AD. This study demonstrates the development of a versatile and reproducible bioprinting approach to create human skin equivalents with a range of cellular complexity for disease modeling. In addition, we establish several assay readouts that are quantifiable, robust, AD relevant, and can be scaled up for compound screening. The results show that the cellular complexity of the tissues develops a more physiologically relevant AD disease model. Thus, the skin models in this study offer an in vitro approach for the rapid understanding of pathological mechanisms, and testing for efficacy of action and toxic effects of drugs.
三维（3D）生物制造技术可用于生产多细胞组织模型，作为药物筛选的分析平台。这些 3D 组织模型中增加的细胞和生理复杂性应能重现体内发现的相关生物学环境。在这里，我们描述了使用 3D 生物打印技术来制造不同生理复杂性的皮肤等效组织，包括人表皮、非血管化和血管化全厚皮肤组织等效物，在多孔平台上进行药物筛选。人角质形成细胞、成纤维细胞和周细胞，以及诱导多能干细胞衍生的内皮细胞被用于生物制造过程中，以产生不同的复杂性。皮肤等效物表现出真皮和表皮分层的正确结构标记物，具有皮肤屏障的生理功能。生物制造技术的稳健性、多功能性和可重复性进一步通过生成特应性皮炎（AD）疾病样组织得到了强调。这些 AD 模型表现出该疾病的几个临床特征，包括：（i）海绵形成和增生；（ii）早期和晚期分化蛋白的表达；和（iii）促炎细胞因子水平的增加。我们通过测试地塞米松（一种抗炎皮质类固醇）和三种来自 AD 临床试验的 Janus 激酶抑制剂的作用，显示了生物制造的 AD 组织模型对纠正疾病表型的临床前相关性。本研究证明了一种通用且可重复的生物打印方法的发展，可用于创建具有多种细胞复杂性的人类皮肤等效物，用于疾病建模。此外，我们建立了几种可量化、稳健、与 AD 相关且可扩展用于化合物筛选的测定读数。结果表明，组织的细胞复杂性开发出更具生理相关性的 AD 疾病模型。因此，本研究中的皮肤模型为快速了解病理机制以及测试药物的疗效和毒性作用提供了一种体外方法。
