Wake Forest Institute for Regenerative Medicine, Wake Forest School of Medicine, 391 Technology Way, Winston-Salem, NC 27101, United States of America.
Department of Biomedical Engineering, Wake Forest School of Medicine, 575 Patterson Avenue, Winston-Salem, NC 27101, United States of America.
Biomed Mater. 2022 Dec 2;18(1). doi: 10.1088/1748-605X/aca05d.
Organoids, and in particular patient-derived organoids, have emerged as crucial tools for cancer research. Our organoid platform, which has supported patient-derived tumor organoids (PTOs) from a variety of tumor types, has been based on the use of hyaluronic acid (HA) and collagen, or gelatin, hydrogel bioinks. One hurdle to high throughput PTO biofabrication is that as high-throughput multi-well plates, bioprinted volumes have increased risk of contacting the sides of wells. When this happens, surface tension causes bioinks to fall flat, resulting in 2D cultures. To address this problem, we developed an organoid immersion bioprinting method-inspired by the FRESH printing method-in which organoids are bioprinted into support baths in well plates. The bath-in this case an HA solution-shields organoids from the well walls, preventing deformation. Here we describe an improvement to our approach, based on rheological assessment of previous gelatin baths versus newer HA support baths, combined with morphological assessment of immersion bioprinted organoids. HA print baths enabled more consistent organoid volumes and geometries. We optimized the printing parameters of this approach using a cell line. Finally, we deployed our optimized immersion bioprinting approach into a drug screening application, using PTOs derived from glioma biospecimens, and a lung adenocarcinoma brain metastasis. In these studies, we showed a general dose dependent response to an experimental p53 activator compound and temozolomide (TMZ), the drug most commonly given to brain tumor patients. Responses to the p53 activator compound were effective across all PTO sets, while TMZ responses were observed, but less pronounced, potentially explained by genetic and epigenetic states of the originating tumors. The studies presented herein showcase a bioprinting methodology that we hope can be used in increased throughput settings to help automate biofabrication of PTOs for drug development-based screening studies and precision medicine applications.
类器官，特别是患者来源的类器官，已成为癌症研究的重要工具。我们的类器官平台支持来自多种肿瘤类型的患者来源肿瘤类器官（PTO），该平台基于使用透明质酸（HA）和胶原或明胶水凝胶生物墨水。高通量 PTO 生物制造的一个障碍是，由于高通量多孔板的体积增加，与孔壁接触的风险增加。当这种情况发生时，表面张力会导致生物墨水平铺，从而导致 2D 培养。为了解决这个问题，我们开发了一种类器官浸入式生物打印方法，该方法受 FRESH 打印方法的启发，即将类器官打印到孔板中的支持浴中。在这种情况下，浴液——HA 溶液——可以保护类器官免受孔壁的影响，防止变形。在这里，我们描述了我们方法的改进，该方法基于对以前的明胶浴和更新的 HA 支撑浴的流变学评估，以及对浸入式生物打印类器官的形态学评估。HA 打印浴使类器官的体积和形状更加一致。我们使用细胞系优化了这种方法的打印参数。最后，我们将优化后的浸入式生物打印方法应用于药物筛选应用，使用源自神经胶质瘤生物样本的 PTO 和肺腺癌脑转移模型。在这些研究中，我们展示了一种对实验性 p53 激活剂化合物和替莫唑胺（TMZ）的一般剂量依赖性反应，TMZ 是最常用于脑肿瘤患者的药物。所有 PTO 组均对 p53 激活剂化合物有反应，而 TMZ 的反应较弱，这可能是由于起源肿瘤的遗传和表观遗传状态。本文介绍的研究展示了一种生物打印方法，我们希望该方法可以在增加通量的设置中使用，以帮助自动化 PTO 的生物制造，用于基于药物开发的筛选研究和精准医学应用。
