Cancer is the leading cause of mortality worldwide, and lung cancer is the most malignant. However, the high failure rate in oncology drug development from in vitro studies to in vivo preclinical models indicates that the modern methods of evaluating drug efficacies in vitro are not reliable. Traditional 2-dimensional (2D) cell culture has been proved inadequate to mimic real physiological conditions. Current 3-dimensional (3D) cell culture methods do not represent the delicate structure of lung alveoli. To mimic lung alveoli structure, a cell containing enzyme-cross-linked gelatin microbubble scaffold was produced by mixing surfactant-containing gelatin solution with microbial transglutaminase (mTGase)-mixed A549 cell suspension in a four-channel flow focusing microfluidic device. With uniform pore size of about 100 μm in diameter, this gelatin microbubble scaffold resembled the lung alveoli in structure and in mechanical properties with good biocompatibility. Effective gemcitabine concentration required to induce cell death in microbubble scaffolds was significantly higher than in 2D culture together with a longer treatment time. Cell death mechanisms were confirmed to be gemcitabine-induced cell apoptosis through Western blotting and real-time PCR. H&E staining and TUNEL assay showed rounded cells with DNA damage in drug-treated scaffolds. Taken together, the cell-containing microbubble scaffolds successfully mimicked lung alveoli in structure and cellular responses after gemcitabine treatment were similar to clinical regimen of treating lung carcinoma. The microbubble scaffold is promising to facilitate anticancer drug discovery by providing more accurate preclinical predictions.

中文翻译：

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模拟肺泡结构的含细胞微泡支架的制备，作为肺癌的3D药物筛选系统。

癌症是全球死亡的主要原因，肺癌是最恶性的。然而，从体外研究到体内临床前模型的肿瘤药物开发的高失败率表明，评估体外药物疗效的现代方法并不可靠。传统的二维（2D）细胞培养已被证明不足以模仿真实的生理条件。当前的3维（3D）细胞培养方法不能代表肺泡的微妙结构。为了模拟肺泡结构，通过将含有表面活性剂的明胶溶液与微生物转谷氨酰胺酶（mTGase）混合的A549细胞悬液在四通道流动聚焦微流控设备中混合来生产包含酶交联的明胶微泡支架的细胞。直径约100μm的均匀孔径 这种明胶微泡支架类似于肺泡的结构和机械特性，具有良好的生物相容性。微泡支架中诱导细胞死亡所需的有效吉西他滨浓度显着高于2D培养，同时处理时间更长。通过Western印迹和实时PCR证实细胞死亡机制是吉西他滨诱导的细胞凋亡。H＆E染色和TUNEL分析显示在药物处理的支架中圆形细胞具有DNA损伤。综上所述，含细胞的微泡支架成功地模仿了肺泡的结构，吉西他滨治疗后的细胞反应类似于治疗肺癌的临床方案。