Li Yuehong, Huang Danyang, Zhang Yuting, Xiao Yun, Zhang Xingdong
National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, 610064, China; College of Biomedical Engineering, Sichuan University, Chengdu, 610064, China.
National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, 610064, China; College of Biomedical Engineering, Sichuan University, Chengdu, 610064, China.
Acta Biomater. 2025 Jun 1;199:1-17. doi: 10.1016/j.actbio.2025.05.023. Epub 2025 May 9.
Hydrogels have emerged as a promising 3D cell culture scaffold owing to their structural similarity to the extracellular matrix (ECM) and their tunable physicochemical properties. Recent advances in microfluidic technology have enabled the fabrication of hydrogels into precisely controlled microspheres and microfibers, which serve as modular units for scalable 3D tissue assembly. Furthermore, advances in 3D bioprinting have allowed facile and precise spatial engineering of these hydrogel-based structures into complex architectures. When integrated with microfluidics, these systems facilitate microscale heterogeneity, dynamic shear flow, and gradient generation-critical features for advancing organoids and organ-on-a-chip systems. In this review, we will discuss (1) microfluidic strategies for the preparation of hydrogel microspheres and microfibers, (2) the integration of microfluidics with 3D bioprinting technologies, and (3) their transformative applications in organoids and organ-on-a-chip systems. STATEMENT OF SIGNIFICANCE: Microfluidic-assisted preparation and assembly of hydrogel microspheres and microfibers have enabled unprecedented precision in size, morphology and compositional control. The diverse configurations of these hydrogel modules offer the opportunities to generate 3D constructs with microscale complexity-recapitulating critical features of native tissues such as compartmentalized microenvironments, cellular gradients, and vascular networks. In this review, we discuss the fundamental microfluidic principles governing the generation of hydrogel microspheres (0D) and microfibers (1D), their hierarchical assembly into 3D constructs, and their integration with 3D bioprinting platforms to generate and culture organoids and organ-on-a-chip systems. The synergistic integration of microfluidics and bioprinting overcomes longstanding limitations of conventional 3D culture, such as static microenvironments and poor spatial resolution. Advances in microfluidic design offer tunable hydrogel biophysical and biochemical properties that regulate cell behaviors dynamically. Looking forward, the growing mastery of these principles paves the way for next-generation organoids and organ-on-a-chip systems with improved cellular heterogeneity, integrated vasculature, and multicellular crosstalk, closing the gap between in vitro models and human pathophysiology.
水凝胶因其与细胞外基质（ECM）的结构相似性以及可调节的物理化学性质，已成为一种很有前景的3D细胞培养支架。微流控技术的最新进展使得水凝胶能够被制造成精确控制的微球和微纤维，这些微球和微纤维作为可扩展3D组织组装的模块化单元。此外，3D生物打印技术的进步使得这些基于水凝胶的结构能够轻松且精确地进行空间工程设计，形成复杂的架构。当与微流控技术相结合时，这些系统有助于实现微尺度异质性、动态剪切流以及梯度生成，这些都是推进类器官和芯片上器官系统的关键特征。在本综述中，我们将讨论：（1）制备水凝胶微球和微纤维的微流控策略；（2）微流控技术与3D生物打印技术的整合；（3）它们在类器官和芯片上器官系统中的变革性应用。重要性声明：微流控辅助制备和组装水凝胶微球和微纤维在尺寸、形态和成分控制方面实现了前所未有的精度。这些水凝胶模块的多样配置为生成具有微尺度复杂性的3D构建体提供了机会，重现了天然组织的关键特征，如分隔的微环境、细胞梯度和血管网络。在本综述中，我们讨论了控制水凝胶微球（0D）和微纤维（1D）生成的基本微流控原理、它们分级组装成3D构建体以及它们与3D生物打印平台的整合，以生成和培养类器官和芯片上器官系统。微流控技术和生物打印技术的协同整合克服了传统3D培养的长期局限性，如静态微环境和较差的空间分辨率。微流控设计的进步提供了可调节的水凝胶生物物理和生化特性，可动态调节细胞行为。展望未来，对这些原理的日益精通为下一代类器官和芯片上器官系统铺平了道路，这些系统具有改善的细胞异质性、整合的脉管系统和多细胞串扰，缩小了体外模型与人类病理生理学之间的差距。
