Recent advances in defined hydrogels in organoid research.

Organoids are in vitro model systems that mimic the complexity of organs with multicellular structures and functions, which provide great potential for biomedical and tissue engineering. However, their current formation heavily relies on using complex animal-derived extracellular matrices (ECM), such as Matrigel. These matrices are often poorly defined in chemical components and exhibit limited tunability and reproducibility. Recently, the biochemical and biophysical properties of defined hydrogels can be precisely tuned, offering broader opportunities to support the development and maturation of organoids. In this review, the fundamental properties of ECM in vivo and critical strategies to design matrices for organoid culture are summarized. Two typically defined hydrogels derived from natural and synthetic polymers for their applicability to improve organoids formation are presented. The representative applications of incorporating organoids into defined hydrogels are highlighted. Finally, some challenges and future perspectives are also discussed in developing defined hydrogels and advanced technologies toward supporting organoid research.
Competing Interests: The authors declare no conflict of interest. All authors have read and approved the submission of this manuscript. And we also confirm that this manuscript, or its contents in some other form, has not been published previously by any of the authors and/or is not under consideration for publication in another journal at the time of submission.
(© 2023 The Authors.)