Complex cell cultures are more representative of in vivo conditions than conventionally used monolayer cultures, and are hence being investigated for predictive screening of therapeutic agents. Poly lactide co-glycolide (PLGA) polymer is frequently used in the development of porous substrates for complex cell culture. Substrates or scaffolds with highly interconnected, micrometric pores have been shown to positively impact tissue model formation by enhancing cell attachment and infiltration. We report a novel alginate microsphere (AMS)-based controlled pore formation method for the development of porous, biodegradable PLGA microspheres (PPMS), for tissue engineered lung tumor model development. The AMS porogen, non-porous PLGA microspheres (PLGAMS) and PPMS had spherical morphology (mean diameters: 10.3 ± 4, 79 ± 21.8, and 103 ± 30 μm, respectively). The PPMS had relatively uniform pores and a porosity of 45.5%. Degradation studies show that PPMS effectively maintained their structural integrity with time whereas PLGAMS showed shrunken morphology. The optimized cell seeding density on PPMS was 25 × 103 cells/mg of particles/well. Collagen coating on PPMS significantly enhanced the attachment and proliferation of co-cultures of A549 lung adenocarcinoma and MRC-5 lung fibroblast cells. Preliminary proof-of-concept drug screening studies using mono- and combination anti-cancer therapies demonstrated that the tissue-engineered lung tumor model had a significantly higher resistance to the tested drugs than the monolayer co-cultures. These studies indicate that the PPMS with controllable pore diameters may be a suitable platform for the development of complex tumor cultures for early in vitro drug screening applications.

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具有可控孔径的多孔聚合物微球用于组织工程肺肿瘤模型的开发

复杂细胞培养物比常规使用的单层培养物更能代表体内条件，因此正在研究用于治疗剂的预测筛选。聚丙交酯共乙交酯 (PLGA) 聚合物经常用于开发用于复杂细胞培养的多孔基质。具有高度互连的微孔的基质或支架已被证明通过增强细胞附着和浸润对组织模型形成产生积极影响。我们报告了一种新的基于藻酸盐微球 (AMS) 的受控孔形成方法，用于开发多孔、可生物降解的 PLGA 微球 (PPMS)，用于组织工程肺肿瘤模型的开发。AMS 致孔剂、无孔 PLGA 微球 (PLGAMS) 和 PPMS 具有球形形态（平均直径：10.3 ± 4、79 ± 21.8 和 103 ± 30 μm，分别）。PPMS 具有相对均匀的孔隙和 45.5% 的孔隙率。降解研究表明，随着时间的推移，PPMS 有效地保持了其结构完整性，而 PLGAMS 则显示出收缩的形态。PPMS 上优化的细胞接种密度为 25 × 103 个细胞/mg 颗粒/孔。PPMS 上的胶原涂层显着增强了 A549 肺腺癌和 MRC-5 肺成纤维细胞共培养物的附着和增殖。使用单一和联合抗癌疗法的初步概念验证药物筛选研究表明，组织工程肺肿瘤模型对测试药物的耐药性显着高于单层共培养物。