Design and fabrication of structured microfibers for the development of biomimetic tissues

在复杂的横截面结构中成形多种材料将在组织工程中提供许多优势，如精确控制不同生物材料的位置，以及不同生物材料之间的相互作用，从而促进细胞的增殖和分化。此外，多材料在有结构的横截面上的排列将导致在用于药物筛选的芯片上器官模型中模拟生物组织的分层结构。然而，目前的制造技术面临着在复杂形状中融合多种材料的挑战。在这个项目中，我们将提出一种用于制造结构化微纤维的微纤维技术，其中多种材料以复杂的横截面结构组织。通过将四种前驱体溶液通过3D打印微流控器件并用紫外光曝光固化，可以制备出规整的微纤维。该项目的目的将是通过调整微流控装置的设计和前体溶液的流速来设计超细纤维的横截面结构，从而建立材料相互作用的不同组合和集成区。首先，微流控装置将设计成八种横截面结构来成形多种材料，包括同心、堆叠、I型、T形、夹心、圆形、多芯和正芯横截面。其次，通过改变聚合物溶液、溶剂和光引发剂的组成制备聚合物前驱体溶液，并测定其材料性能。第三，对微流控装置进行了3D打印，建立了制备不同截面微纤维的实验装置。为制备均匀和非均匀截面结构的超细纤维，将优化实验条件。该项目的最终目标将是实现一种通过3D打印微流控装置控制制造微纤维特定横截面结构的策略。这个项目完成后，我们将把它扩大到体外组织模型的制造，这些模型将作为芯片上的器官模型用于药物筛选。

Shaping multiple materials in complex cross-sectional structures will provide numerous advantages in tissue engineering, such as precise control over the position, and interaction of different biomaterials, which will result in increasing the proliferation, and differentiation of cells. Moreover, multi-material arrangement in structured cross-sections will result in mimicking the hierarchical architecture of biological tissues in the organ-on-chip models for drug screening. However, the current fabrication technology face challenges in incorporating multiple materials in complex shapes. In this project, we will propose a microfiber technology for the fabrication of structured microfibers, with multiple materials organized in complex cross-sectional structures. By coflowing four precursor solutions through 3D printed microfluidic devices and curing them with UV exposure, the structured microfibers will be fabricated. The aim of this project will be to engineer the cross-sectional structures of microfibers by tailoring the design of microfluidic devices and the flow rate of precursor solutions in such a way that different combinations and integration areas of material interactions can be established. Firstly, microfluidic devices will be designed to shape multiple materials in eight cross-sectional structures, including concentric, stacked, I-shaped, T-shaped, sandwich, circular-core, multiple-cores, and plus-core cross-sections. Secondly, the polymer precursor solutions will be prepared by varying compositions of polymer solutions, solvent and photo-initiator and the material properties will be determined. Thirdly, the microfluidic devices will be 3D printed and the experimental setup will be established to fabricate microfibers with different cross-sections. The experimental conditions will be optimized to fabricate microfiber in uniform and non-uniform cross-sectional structures. The end goal of this project will be to realize a strategy for the controlled fabrication of a specific cross-sectional structure of microfiber through the 3D printed microfluidic device. After the completion of this project, we will be expanding it for the fabrication of in-vitro tissue models which will serve as organ-on-chip models for drug screening.