Human Tissue Models: Engineering 3D Hydrogels for Personalized In Vitro Human Tissue Models (Adv. Healthcare Mater. 4/2018)

Abstract

The use of hydrogel scaffolds for developing in vitro patient‐specific tissue and organ models using human‐derived cells is a powerful platform for studying the mechanism of disease initiation and progression, screening of potential drug candidates, and ultimately, the regeneration of fully functional tissues and organs. In article number https://doi.org/10.1002/adhm.201701165, Murat Guvendiren and co‐workers review the current developments in hydrogel‐based in vitro tissue models and fabrication techniques, with particular focus on liver and cancer tissues.

Bridging 2D and 3D culture: Probing impact of extracellular environment on fibroblast activation in layered hydrogels

“…Utilizing the capabilities afforded by photopolymerization, we then established an approach for creating a layered hydrogel geometry with these synthetic matrices, where cells are cultured at the interface between layers to create a 2.5D culture for comparison to and as a bridge between 2D and 3D cultures (Figure ). The term “2.5D” has been used for a variety of cell culture geometries that are not fully 3D cell encapsulations, and these systems been deployed for the culture of variety of cells types including hepatocytes, cancer cells, and fibroblasts . In 2.5D cell culture, fibroblasts can spread, allowing them to adopt a similar shape as is observed in 2D culture, but also interact with the hydrogel from multiple sides with different degrees of confinement based on the system used, which is more similar to 3D cell culture.…”

“…In 2.5D cell culture, fibroblasts can spread, allowing them to adopt a similar shape as is observed in 2D culture, but also interact with the hydrogel from multiple sides with different degrees of confinement based on the system used, which is more similar to 3D cell culture. For example, one of the more frequently deployed 2.5D approaches for the culture of fibroblasts is “sandwiching” the cells between two noninteracting hydrogel layers, allowing cell spreading, sensing of the matrix on both sides in the z ‐direction, and unrestricted movement in the x – y direction along the interface . Used to a lesser extent for studies of mechanotransduction, approaches also have been developed to encapsulate fibroblasts and other cell types at the interface between two hydrogels.…”

Hydrogels to engineer tumor microenvironmentsin vitro

“…Recent developments in materials engineering have resulted in the generation of hydrogels with tunable biophysical, biochemical and biological properties which recapitulate the in vivo tissue microenvironment with fidelity. 210…”

Polysaccharide-Based Hydrogels for Microencapsulation of Stem Cells in Regenerative Medicine

“…4D bioprinting could be used for ‘smart hydrogels’ fabrication and advanced stem cell microencapsulation. It offers capability to synthesis shape-programed and functional structured hydrogels in a regulated manner, leading to construction of active multilayered, functional tissues and disease models with dynamic and hierarchical structures ( Liaw et al, 2018 ). Under multiple stimuli, the complex shape transformation processes and functional transitions can facilitate tissue remodeling and maturation.…”