School of Dentistry, University of Birmingham, Birmingham, B5 7EG, UK.
Department of Materials, University of Manchester, Manchester, M1 5GF, UK.
Adv Mater. 2023 Dec;35(52):e2301670. doi: 10.1002/adma.202301670. Epub 2023 Nov 2.
Advances in bioprinting have enabled the fabrication of complex tissue constructs with high speed and resolution. However, there remains significant structural and biological complexity within tissues that bioprinting is unable to recapitulate. Bone, for example, has a hierarchical organization ranging from the molecular to whole organ level. Current bioprinting techniques and the materials employed have imposed limits on the scale, speed, and resolution that can be achieved, rendering the technique unable to reproduce the structural hierarchies and cell-matrix interactions that are observed in bone. The shift toward biomimetic approaches in bone tissue engineering, where hydrogels provide biophysical and biochemical cues to encapsulated cells, is a promising approach to enhancing the biological function and development of tissues for in vitro modeling. A major focus in bioprinting of bone tissue for in vitro modeling is creating dynamic microenvironmental niches to support, stimulate, and direct the cellular processes for bone formation and remodeling. Hydrogels are ideal materials for imitating the extracellular matrix since they can be engineered to present various cues whilst allowing bioprinting. Here, recent advances in hydrogels and 3D bioprinting toward creating a microenvironmental niche that is conducive to tissue engineering of in vitro models of bone are reviewed.
生物打印技术的进步使得能够以高速和高分辨率制造复杂的组织构建体。然而，生物打印仍然无法复制组织中存在的显著结构和生物学复杂性。例如，骨骼具有从分子到整个器官水平的层次结构。当前的生物打印技术和所使用的材料对可以达到的规模、速度和分辨率施加了限制，使得该技术无法复制在骨骼中观察到的结构层次和细胞-基质相互作用。在骨组织工程中向仿生方法的转变，其中水凝胶为封装的细胞提供生物物理和生化线索，是增强组织体外建模的生物学功能和发育的有前途的方法。体外建模的骨组织生物打印的一个主要重点是创建动态的微环境龛，以支持、刺激和指导骨形成和重塑的细胞过程。水凝胶是模仿细胞外基质的理想材料，因为它们可以被设计为呈现各种线索，同时允许生物打印。在这里，综述了水凝胶和 3D 生物打印在创建有利于骨组织工程体外模型的微环境龛方面的最新进展。
