Maloney Erin, Clark Casey, Sivakumar Hemamylammal, Yoo KyungMin, Aleman Julio, Rajan Shiny A P, Forsythe Steven, Mazzocchi Andrea, Laxton Adrian W, Tatter Stephen B, Strowd Roy E, Votanopoulos Konstantinos I, Skardal Aleksander
Department of Biomedical Engineering, Cornell University, Ithaca, NY 14853, USA.
Wake Forest Institute for Regenerative Medicine, Wake Forest School of Medicine, Winston Salem, NC 27101, USA.
Micromachines (Basel). 2020 Feb 18;11(2):208. doi: 10.3390/mi11020208.
The current drug development pipeline takes approximately fifteen years and $2.6 billion to get a new drug to market. Typically, drugs are tested on two-dimensional (2D) cell cultures and animal models to estimate their efficacy before reaching human trials. However, these models are often not representative of the human body. The 2D culture changes the morphology and physiology of cells, and animal models often have a vastly different anatomy and physiology than humans. The use of bioengineered human cell-based organoids may increase the probability of success during human trials by providing human-specific preclinical data. They could also be deployed for personalized medicine diagnostics to optimize therapies in diseases such as cancer. However, one limitation in employing organoids in drug screening has been the difficulty in creating large numbers of homogeneous organoids in form factors compatible with high-throughput screening (e.g., 96- and 384-well plates). Bioprinting can be used to scale up deposition of such organoids and tissue constructs. Unfortunately, it has been challenging to 3D print hydrogel bioinks into small-sized wells due to well-bioink interactions that can result in bioinks spreading out and wetting the well surface instead of maintaining a spherical form. Here, we demonstrate an immersion printing technique to bioprint tissue organoids in 96-well plates to increase the throughput of 3D drug screening. A hydrogel bioink comprised of hyaluronic acid and collagen is bioprinted into a viscous gelatin bath, which blocks the bioink from interacting with the well walls and provides support to maintain a spherical form. This method was validated using several cancerous cell lines, and then applied to patient-derived glioblastoma (GBM) and sarcoma biospecimens for drug screening.
目前，一种新药进入市场的药物研发流程大约需要15年，花费26亿美元。通常，药物在进入人体试验之前，会先在二维（2D）细胞培养物和动物模型上进行测试，以评估其疗效。然而，这些模型往往不能代表人体。二维培养会改变细胞的形态和生理机能，而动物模型的解剖结构和生理机能通常与人类有很大差异。使用基于生物工程的人类细胞类器官，可能会通过提供人类特异性的临床前数据，增加人体试验成功的概率。它们还可用于个性化医疗诊断，以优化癌症等疾病的治疗方案。然而，在药物筛选中使用类器官的一个限制是，难以创建大量与高通量筛选兼容的形状因子均匀的类器官（例如96孔板和384孔板）。生物打印可用于扩大此类类器官和组织构建体的沉积规模。不幸的是，由于孔与生物墨水之间的相互作用，将水凝胶生物墨水3D打印到小尺寸孔中一直具有挑战性，这种相互作用可能导致生物墨水扩散并润湿孔表面，而不是保持球形。在这里，我们展示了一种浸入式打印技术，用于在96孔板中生物打印组织类器官，以提高3D药物筛选的通量。一种由透明质酸和胶原蛋白组成的水凝胶生物墨水被生物打印到粘性明胶浴中，这可以阻止生物墨水与孔壁相互作用，并提供支撑以保持球形。该方法已通过几种癌细胞系进行了验证，然后应用于患者来源的胶质母细胞瘤（GBM）和肉瘤生物样本进行药物筛选。
