Deanery of Biomedical Science and the Centre for Engineering Biology, University of Edinburgh, Edinburgh, United Kingdom.
Department of Biomedical Engineering, University of Strathclyde, Glasgow, United Kingdom.
Biofabrication. 2023 Jul 19;15(4). doi: 10.1088/1758-5090/ace2ed.
The bioassembly of layered tissue that closely mimics human histology presents challenges for tissue engineering. Existing bioprinting technologies lack the resolution and cell densities necessary to form the microscale cell-width layers commonly observed in stratified tissue, particularly when using low-viscosity hydrogels, such as collagen. Here we present rotational internal flow layer engineering (RIFLE), a novel, low-cost biofabrication technology for assembling tuneable, multi-layered tissue-like structures. Using high-speed rotating tubular moulds, small volumes of cell-laden liquids added to the inner surface were transitioned into thin layers and gelled, progressively building macroscale tubes composed of discrete microscale strata with thicknesses a function of rotational speed. Cell encapsulation enabled the patterning of high-density layers (10cells ml) into heterogenous constructs. RIFLE versatility was demonstrated through tunica media assembly, encapsulating human smooth muscle cells in cell-width (12.5m) collagen layers. Such deposition of discrete microscale layers, facilitates the biofabrication of composite structures mimicking the nature of native stratified tissue. This enabling technology has the potential to allow researchers to economically create a range of representative layered tissue.
层状组织的生物组装非常类似于人体组织学，这给组织工程带来了挑战。现有的生物打印技术缺乏形成常见于分层组织的微观细胞宽度层所需的分辨率和细胞密度，特别是在使用低粘度水凝胶（如胶原蛋白）时。在这里，我们提出了旋转内部流动层工程（RIFLE），这是一种新颖的、低成本的生物制造技术，可用于组装可调、多层状的类似组织的结构。使用高速旋转的管状模具，将添加到内表面的少量细胞负载液体转化为薄层并凝胶化，逐渐构建由离散微层组成的宏观管状结构，其厚度取决于旋转速度。细胞包封使得能够将高密度层（10 个细胞/ml）图案化为异质结构。通过中膜组装证明了 RIFLE 的多功能性，将人平滑肌细胞封装在细胞宽度（12.5μm）的胶原蛋白层中。这种离散微观层的沉积有助于模拟天然分层组织特性的复合材料结构的生物制造。这项使能技术有可能使研究人员能够经济地创建一系列有代表性的分层组织。
