DNA-based hydrogels: Ideal biomaterials for cartilage organoids

Osteoarthritis (OA) is a common degenerative disease with high disability rate, imposing significant economic burdens on individuals and society. Due to the limited self-repair ability of articular cartilage, the existing treatment methods still cannot effectively treat OA. Organoids are multicellular structures differentiated from stem cells or organ progenitors and can be used to model disease. Future applications can provide alternative organ replacement strategies. Therefore, constructing cartilage organoids is expected to overcome the shortcomings of the existing treatment methods to achieve effective treatment of OA. The construction of organoids requires three-dimensional network scaffolds resembling extracellular matrix (ECM) to support cell expansion. Hydrogel has a hydrophilic natural network structure. Hence it can mimic the ECM, providing mechanical support and a favorable microenvironment for cell growth. DNA hydrogel is mainly formed by DNA. It preserves DNA's programmability, biocompatibility and biodegradability, and has unique mechanical properties. Thus, it is an ideal material for constructing cartilage organoids. This review summarized the preparation methods and discussed the use of DNA hydrogels in the construction of cartilage organoids, aiming to provide a reference for the construction and design of cartilage organoids based on DNA hydrogels.