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International Journal of Bioprinting 3D-printed scaffolds for osteochondral defect

Generally, the knee joints of small animals are in a Conflicts of interest
highly flexed position, unlike in humans. Additionally, The authors declare no competing interests.
196
humans engage in a wider range of movements—such
as walking, squatting, and stair climbing—that generate Authors’ Contributions
different mechanical stress patterns on the knee joint
compared to animals. Therefore, while experimental Conceptualization: Qi Wang, Wei Zhu
success in small animal models is valuable, a gap remains Writing-Original Draft: Qi Wang
in clinical translation. Writing-Review & Editing: Qi Wang, Wei Zhu
Investigation: Qi Wang, Ruoying Wang
In contrast, large animals such as pigs, goats, and horses Resources and supervision: Xisheng Weng
exhibit biomechanical features and joint sizes that are
more similar to humans. 194,197 Validation in these models Ethics Approval and Consent to Participate
can provide more clinically relevant data. Nevertheless,
significant interspecies differences persist. For example, Not applicable
only the human knee achieves full extension, a feature not Consent for Publication
observed in common large animal models. Therefore,
197
clinical translation of osteochondral repair strategies Not applicable
requires careful adaptation to human physiological and
biomechanical characteristics. Availability of Data
Not applicable
6. Conclusion

Osteochondral defects remain difficult to repair due References
to the complex structure and specialized function of
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This review has highlighted four key strategies—composite 2. He B, Wu JP, Kirk TB, Carrino JA, Xiang C, Xu J. High-
gradients, microarchitectural patterning, biochemical resolution measurements of the multilayer ultra-structure of
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approaches to achieving functional hierarchical design. Res Ther. 2014;16(2):205.
Despite progress, challenges like degradation mismatch, doi: 10.1186/ar4506
poor interface integration, and inflammatory responses still 3. Soderquist M, Barnes L. Osteochondral allograft
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the development of stimuli-responsive biomaterials, ballistic trauma. JSES Rev Rep Tech. 2024;4(3):540-546.
validation in large-animal models, and the integration of doi: 10.1016/j.xrrt.2024.04.008
multi-material bioprinting technologies to further advance 4. GBD 2021 Osteoarthritis Collaborators. Global, regional,
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Acknowledgment Burden of Disease Study 2021. Lancet Rheumatol.
2023;5(9):e508-e522.
The graphical abstract was created using BioRender.com. doi: 10.1016/s2665-9913(23)00163-7
Funding 5. Weng Q, Chen Q, Jiang T, et al. Global burden of early-onset
osteoarthritis, 1990-2019: results from the Global Burden of
This work was supported by the Natural Science Foundation Disease Study 2019. Ann Rheum Dis. 2024;83(7):915-925.
of Beijing, China (Grant No. 7232119), the Beijing Natural doi: 10.1136/ard-2023-225324
Science Foundation (Grant No. L232006), Peking Union 6. Abdulghani S, Morouço PG. Biofabrication for osteochondral
Medical College Hospital Talent Cultivation Program tissue regeneration: bioink printability requirements.
(Grant No. UHB11847), the National High Level Hospital J Mater Sci Mater Med. 2019;30(2):20.
Clinical Research Funding (No. 2022-PUMCH-C-036), doi: 10.1007/s10856-019-6218-x
and the National Natural Science Foundation Youth Fund 7. Brophy RH, Fillingham YA. AAOS clinical practice
(Grant No. 82102582). guideline summary: management of osteoarthritis of the

Volume 11 Issue 4 (2025) 22 doi: 10.36922/IJB025120100