Recent advances in 3D tissue models

Physiologically relevant tissue models that bridge the gap between 2D tissue culture and animal trials would be highly desirable to study the function of tissues in health and disease as well as for the validation of lead compounds during drug development. The field has made impressive advances in 3D culturing cells and organoids in naturally derived materials. Novel, rationally designed, biomimetic materials have been established, which allow the almost individual variation of matrix parameters, such as stiffness, cell adhesion, degradability, or growth factor binding and controlled release. The combination of innovative materials with novel technological platforms such as printing, microfluidics, and additive or preventive manufacturing provides a great potential to build unprecedented, complex tissue models. Here we review recent advances in the design of materials building blocks which allow the formation of 3D structured microenvironments. We will mainly focus on strategies to locally position cell-instructive molecular cues and discuss needs to generate models which would allow the investigator to controllably manipulate cells in their 3D context with the aim to generate complex but yet scalable tissue models