Inner ear organoids: From three-dimensional bioprinting to vascularization

Abstract

The inner ear is essential for auditory perception and balance, yet damage to cochlear hair cells remains a major cause of irreversible hearing loss worldwide. As the number of individuals affected by sensorineural deafness continues to rise, there is a growing need for deeper pathophysiological insight and the development of effective therapies. Inner ear organoids, which recapitulate key aspects of the in vivo inner ear microenvironment, have emerged as powerful platforms for disease modeling, high-throughput drug screening, and regenerative medicine. This review summarizes recent progress in the development of inner ear organoids, with a focus on strategies to improve their structural complexity and functional maturity. In particular, we highlight innovations in vascularization and three-dimensional bioprinting that are advancing organoid scalability and integration potential. Meanwhile, commonly used biomaterials in three-dimensional bioprinting for inner ear organoids are systematically compared. Finally, we discuss current challenges and future directions for translating these technologies into clinical applications.

Keywords

Inner ear / Organoids / Vascularization / Three-dimensional bioprinting / Biomaterials / Hair cell regeneration

Acknowledgments

None.

Funding

The work was financially supported by the National Natural Science Foundation of China (22174121, 22211530067, and T2250710180), the 2022 Natural Science Foundation of Guangdong Provincial Basic and Applied Basic Research Fund (Guangdong Hybribio, the Guangdong Pearl River Talent Program (2021CX02Y066), Shenzhen Bay Open Laboratory Fund 2021, the CUHKSZ-Boyalife Joint Laboratory Fund, the University Development Fund (UDF01002012), 1+1+1 CUHK-CUHK(SZ)-GDSTC Joint Collaboration Fund, and the Guangdong Basic Research Center of Excellence for Aggregate Science Fund.

Conflict of interest

The authors declare they have no competing interests.

Author contributions

Conceptualization: Guozhen Liu

Funding acquisition: Guozhen Liu

Methodology: Jianxia Chen

Project administration: Guozhen Liu

Supervision: Guozhen Liu

Visualization: Fuzheng Li, Kexin Yang

Writing-original draft: Fuzheng Li

Writing-review & editing: Fuzheng Li, Kexin Yang, Mohsen Asadnia, Jianxia Chen

Ethics approval and consent to participate

Not applicable.

Consent for publication

Not applicable.

Availability of data

Data will be available upon request.

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