Organoids and organs-on-a-chip (vascularized 3d culture) have seen rapid growth in recent years due to their importance in mimicking the shape and operation of human organs. At the moment, efforts to vascularized organoids and organ-on-a-chip have piqued the interest of researchers. Thick organ tissue necessitates a dense network of micro-vascular vessels to provide oxygen and nutrients while still removing metabolic waste. Vascularization, in particular for organoids-on-a-chip, allows one to study biochemical reactions and drug transfer in vascular tissue. In recent years, the literature has centered on angiogenesis regeneration in vitro.
Simultaneously, the micro-flow control device effectively simulates the exact management of the tissue micro-environment in many ways, as well as providing biochemical and mechanical shear force as a tool for in vitro vascular network development. As a result, the authors plan to build a macro-micro bridge by updating existing literature on micro-flow control technologies, proposing ideas for precise management of the dynamic tissue structure model of in vitro organ reshaping, and investigating the interaction of vascularization in different tissues. These ideas are crucial for the next wave of vascular tissue engineering and the advancement of personalized medicine.
Micro-environment conditions determine the growth and development of cells in organ-on-a-chip, among which micro-flow models, embedded hydrogels, and fluid shear forces are important conditions that affect the vascularization of organ chips.
Organoids and organoids-on-a-chip are important means for 3D culture in vitro. They overcome many shortcomings of traditional 2D culture and are better at restoring the specific function of organs.
The authors discuss that ”The use of human cells for the construction of 3D organ models in vitro based on cell self-assembly and engineering design has recently increased in popularity in the field of biological science. Although the organoids are able to simulate the structures and functions of organs in vitro, the 3D models have difficulty in forming a complex vascular network that can recreate the interaction between tissue and vascular systems. Therefore, organoids are unable to survive, due to the lack of oxygen and nutrients, as well as the accumulation of metabolic waste.
Organoids-on-a-chip provides a more controllable and favorable design platform for co-culture of different cells and tissue types in organoid systems, overcoming some of the limitations present in the organoid vascularized 3d culture. However, the majority of them have vascular networks that are not adequately elaborate to simulate signal communications between bionic microenvironment (e.g., fluid shear force) and multiple organs.
Here, we will review the technological progress of vascularization in organoids and organoids-on-a-chip and the development of intravital 3D and 4D bioprinting as a new way for vascularization, which can aid in further study on tissue or organ development, disease research and regenerative medicine.”
Keywords: organoid, organoids-on-a-chip, vascularization, advanced printing methods, micro-environment
Zhao X, Xu Z, Xiao L, et al. Review on the Vascularization of Organoids and Organoids-on-a-Chip. Front Bioeng Biotechnol. 2021;9:637048. Published 2021 Apr 12. doi:10.3389/fbioe.2021.637048