Kang Deni, Liu Zhen, Qian Chuanmu, Huang Junfei, Zhou Yi, Mao Xiaoyan, Qu Qian, Liu Bingcheng, Wang Jin, Hu Zhiqi, Miao Yong
Department of Plastic and Aesthetic Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, China; Department of Burns, Plastic, Cosmetology and Wound Repair Surgery, the Second Affiliated Hospital, School of Medicine, South China University of Technology, Guangzhou, Guangdong 510180, China.
Department of Plastic and Aesthetic Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, China.
Acta Biomater. 2023 Jul 15;165:19-30. doi: 10.1016/j.actbio.2022.03.011. Epub 2022 Mar 12.
Hair follicle (HF) regeneration remains challenging, principally due to the absence of a platform that can successfully generate the microenvironmental cues of hair neogenesis. Here, we demonstrate a 3D bioprinting technique based on a gelatin/alginate hydrogel (GAH) to construct a multilayer composite scaffold simulating the HF microenvironment in vivo. Fibroblasts (FBs), human umbilical vein endothelial cells (HUVECs), dermal papilla cells (DPCs), and epidermal cells (EPCs) were encapsulated in GAH (prepared from a mixture of gelatin and alginate) and respectively 3D-bioprinted into the different layers of a composite scaffold. The bioprinted scaffold with epidermis- and dermis-like structure was subsequently transplanted into full-thickness wounds in nude mice. The multilayer scaffold demonstrated suitable cytocompatibility and increased the proliferation ability of DPCs (1.2-fold; P < 0.05). It also facilitated the formation of self-aggregating DPC spheroids and restored DPC genes associated with hair induction (ALP, β-catenin, and α-SMA). The dermal and epidermal cells self-assembled successfully into immature HFs in vitro. HFs were regenerated in the appropriate orientation in vivo, which can mainly be attributed to the hierarchical grid structure of the scaffold and the dot bioprinting of DPCs. Our 3D printed scaffolds provide a suitable microenvironment for DPCs to regenerate entire HFs and could make a significant contribution in the medical management of hair loss. This method may also have broader applications in skin tissue (and appendage) engineering. STATEMENT OF SIGNIFICANCE: Hair loss remains a challenging clinical problem that influences quality of life. Three-dimensional (3D) bioprinting has become a useful tool for the fabrication of tissue constructs for transplantation and other biomedical applications. In this study, we used a 3D bioprinting technique based on a gelatin/alginate hydrogel to construct a multi-layer composite scaffold with cuticular and corium layers to simulate the microenvironment of dermal papilla cells (DPCs) in the human body. This new approach permits the controllable formation of self-aggregating spheroids of DPCs in a physiologically relevant extracellular matrix and the initiation of epidermal-mesenchymal interactions, which results in HF formation in vivo. The ability to regenerate entire HFs should have a significant impact on the medical management of hair loss.
毛囊（HF）再生仍然具有挑战性，主要原因是缺乏一个能够成功生成毛发新生微环境信号的平台。在此，我们展示了一种基于明胶/藻酸盐水凝胶（GAH）的3D生物打印技术，以构建模拟体内HF微环境的多层复合支架。将成纤维细胞（FBs）、人脐静脉内皮细胞（HUVECs）、真皮乳头细胞（DPCs）和表皮细胞（EPCs）封装在GAH（由明胶和藻酸盐的混合物制备而成）中，并分别3D生物打印到复合支架的不同层中。随后将具有表皮和真皮样结构的生物打印支架移植到裸鼠的全层伤口中。多层支架表现出合适的细胞相容性，并提高了DPCs的增殖能力（1.2倍；P < 0.05）。它还促进了自聚集DPC球体的形成，并恢复了与毛发诱导相关的DPC基因（碱性磷酸酶、β-连环蛋白和α-平滑肌肌动蛋白）。真皮和表皮细胞在体外成功自组装成未成熟的HF。HF在体内以适当的方向再生，这主要归因于支架的分层网格结构和DPCs的点状生物打印。我们的3D打印支架为DPCs再生整个HF提供了合适的微环境，并可能在脱发的医学治疗中做出重大贡献。这种方法在皮肤组织（和附属器）工程中也可能有更广泛的应用。重要性声明：脱发仍然是一个影响生活质量的具有挑战性的临床问题。三维（3D）生物打印已成为制造用于移植和其他生物医学应用的组织构建体的有用工具。在本研究中，我们使用基于明胶/藻酸盐水凝胶的3D生物打印技术构建了具有角质层和真皮层的多层复合支架，以模拟人体中真皮乳头细胞（DPCs）的微环境。这种新方法允许在生理相关的细胞外基质中可控地形成DPCs的自聚集球体，并启动表皮-间充质相互作用，从而在体内形成HF。再生整个HF的能力应该对脱发的医学治疗产生重大影响。
