­HYDROGEL-ECM GRANULAR COMPOSITES WITH VISCOUS INTERSTITIUM

­HYDROGEL-ECM GRANULAR COMPOSITES WITH VISCOUS INTERSTITIUM

Researchers at UCSF and CZ Biohub San Francisco have developed methods for making and using yield-stress composite matrix formulations for organoid printing.

Organoids are attractive models of health and disease as they recapture many important structural and physiological aspects of the mature organ. However, they lack certain developmental and anatomical context which leads to a high degree of heterogeneity in traditional 3D cultures. While some of this heterogeneity is biologically intrinsic, there are also significant external factors such as starting composition, microenvironment and neighboring organoids that contribute to morphogenic disparity. This can manifest in disparate response to treatments, therefore a substantial number of organoids are required to uncover statistically significant phenotypes.

The most flexible platform for generating on-demand, arbitrary tissues of defined composition is 3D bio printing. However, bio-printing assisted tissue emergence relies on pseudo-3D air-surface interfaces or a very limited print window for construction of large 3D tissues. In addition, Matrigel remains the gold-standard basement membrane for 3D organoid culture, however it is a poor bio printing material due to its steep transition from low viscosity fluid to predominantly elastic solid as a function of temperature, precluding the seeding of many organoids or complex architectures over long print times. These limitations highlight the need for better materials that enable high-fidelity bioprinting, while also supporting cell growth and morphogenesis using soft, viscoelastic extracellular matrices.

Stage of Research

The inventors have devised composite matrix materials comprising of a plurality of micro gel particles that provides advantageous yield-stress properties in combination with soft, viscoelastic properties to facilitate homogeneous organoid preparation. This disclosure provides methods for preparing such composite matrix materials and for preparing an organoid from these materials.

Applications

• Facilitating long sought applications of organoids in research and medicine.

Advantages

• Supporting long printing times (≥2 h) at 4 ℃ without compromising mechanical integrity or organoid viability.

• Promoting long-term cell growth by providing a matrix material that is soft and highly viscous over time scales of cell growth.
• Providing a matrix material with particle sizes on the order of the size of cells to allow for yielding behavior of the matrix to promote morphogenesis and organoid expansion.

Stage of Development

Research – in vitro

Keywords

Organoid, bioprinting

Technology Reference

CZ Biohub SF ref. no.: CZB-296F

UCSF ref .no.: SF2024-053