Bhattacharjee Tapomoy, Gil Carmen J, Marshall Samantha L, Urueña Juan M, O'Bryan Christopher S, Carstens Matt, Keselowsky Benjamin, Palmer Glyn D, Ghivizzani Steve, Gibbs C Parker, Sawyer W Gregory, Angelini Thomas E
Department of Mechanical & Aerospace Engineering, 571 Gale Lemerand Drive, University of Florida, Gainesville, Florida 32611, United States.
Department of Chemical Engineering, University of Florida, 1030 Center Drive, Gainesville, Florida 32611, United States.
ACS Biomater Sci Eng. 2016 Oct 10;2(10):1787-1795. doi: 10.1021/acsbiomaterials.6b00218. Epub 2016 Jun 20.
The demands of tissue engineering have driven a tremendous amount of research effort in 3D tissue culture technology and, more recently, in 3D printing. The need to use 3D tissue culture techniques more broadly in all of cell biology is well-recognized, but the transition to 3D has been impeded by the convenience, effectiveness, and ubiquity of 2D culture materials, assays, and protocols, as well as the lack of 3D counterparts of these tools. Interestingly, progress and discoveries in 3D bioprinting research may provide the technical support needed to grow the practice of 3D culture. Here we investigate an integrated approach for 3D printing multicellular structures while using the same platform for 3D cell culture, experimentation, and assay development. We employ a liquid-like solid (LLS) material made from packed granular-scale microgels, which locally and temporarily fluidizes under the focused application of stress and spontaneously solidifies after the applied stress is removed. These rheological properties enable 3D printing of multicellular structures as well as the growth and expansion of cellular structures or dispersed cells. The transport properties of LLS allow molecular diffusion for the delivery of nutrients or small molecules for fluorescence-based assays. Here, we measure viability of 11 different cell types in the LLS medium, we 3D print numerous structures using several of these cell types, and we explore the transport properties in molecular time-release assays.
组织工程的需求推动了在3D组织培养技术以及最近在3D打印方面的大量研究工作。在整个细胞生物学领域更广泛地使用3D组织培养技术的必要性已得到充分认识，但向3D的转变受到2D培养材料、检测方法和方案的便利性、有效性和普遍性的阻碍，以及这些工具缺乏3D对应物的影响。有趣的是，3D生物打印研究的进展和发现可能为3D培养实践的发展提供所需的技术支持。在这里，我们研究了一种用于3D打印多细胞结构的综合方法，同时使用相同的平台进行3D细胞培养、实验和检测方法开发。我们采用了一种由填充的颗粒级微凝胶制成的类液固（LLS）材料，该材料在集中施加应力时局部且暂时流化，并在去除施加的应力后自发固化。这些流变特性使得能够3D打印多细胞结构以及细胞结构或分散细胞的生长和扩展。LLS的传输特性允许分子扩散，用于输送营养物质或用于基于荧光的检测的小分子。在这里，我们测量了11种不同细胞类型在LLS培养基中的活力，我们使用其中几种细胞类型3D打印了许多结构，并在分子缓释检测中探索了传输特性。
