Key Laboratory of Tissue Repair and Regeneration of PLA, and Beijing Key Research Laboratory of Skin Injury, Repair and Regeneration, First Hospital Affiliated to General Hospital of PLA, Beijing 100048, P. R. China.
Department of Thoracic and Cardiovascular Surgery/Huiqiao Medical Center, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, P. R. China.
Sci Rep. 2016 Oct 3;6:34410. doi: 10.1038/srep34410.
3D bioprinting matrices are novel platforms for tissue regeneration. Tissue self-organization is a critical process during regeneration that implies the features of organogenesis. However, it is not clear from the current evidences whether 3D printed construct plays a role in guiding tissue self-organization in vitro. Based on our previous study, we bioprinted a 3D matrix as the restrictive niche for direct sweat gland differentiation of epidermal progenitors by different pore structure (300-μm or 400-μm nozzle diameters printed) and reported a long-term gradual transition of differentiated cells into glandular morphogenesis occurs within the 3D construct in vitro. At the initial 14-day culture, an accelerated cell differentiation was achieved with inductive cues released along with gelatin reduction. After protein release completed, the 3D construct guide the self-organized formation of sweat gland tissues, which is similar to that of the natural developmental process. However, glandular morphogenesis was only observed in 300-μm-printed constructs. In the absence of 3D architectural support, glandular morphogenesis was not occurred. This striking finding made us to identify a previously unknown role of the 3D-printed structure in glandular tissue regeneration, and this self-organizing strategy can be applied to forming other tissues in vitro.
3D 生物打印基质是组织再生的新型平台。组织自组织是再生过程中的一个关键过程，暗示了器官发生的特征。然而，目前的证据尚不清楚 3D 打印构建体是否在体外指导组织自组织中发挥作用。基于我们之前的研究，我们通过不同的孔结构（打印喷嘴直径为 300-μm 或 400-μm）生物打印了一个 3D 基质，作为表皮祖细胞直接分化为汗腺的限制小生境，并报告了体外 3D 构建体中分化细胞逐渐向腺体形态发生的长期转变。在最初的 14 天培养中，通过释放与明胶减少相关的诱导信号，实现了细胞的加速分化。蛋白质释放完成后，3D 构建体指导汗腺组织的自组织形成，类似于自然发育过程。然而，仅在 300-μm 打印构建体中观察到腺体形态发生。在没有 3D 结构支撑的情况下，不会发生腺体形态发生。这一惊人的发现使我们认识到 3D 打印结构在腺体组织再生中以前未知的作用，并且这种自组织策略可以应用于体外形成其他组织。
