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

Figure 5. 3D-printed triphasic and multiphasic scaffolds for osteochondral tissue engineering. (A) The graphical abstract of 3D-printed triphasic scaffolds.
(B) The constructdesign and printing. (Bi–Bv) The designing and development of the grid structure, and (Bvi) representative images of the printed
[98]
structures showing the threelayers. (C) Scanning electron microscope (SEM) images of 3D-printed multiphasic scaffolds . (Reproduced with permission
from Di Luca A, Lorenzo‐Moldero I, Mota C, et al., 2016, Adv Healthc Mater, John Wiley and Sons). (Di–Diii) Field emission scanning electron microscope
(FESEM) images of the printed structure showing the porous grid structure. Scale bar = 400 μm [103] . (Reproduced with permission from Singh YP, Moses
JC, Bandyopadhyay A, et al., Adv Healthc Mater, John Wiley and Sons).
and continuous gradient scaffolds prepared by emerging The osteochondral integrated scaffold is a good
technologies and traditional methods have achieved solution to some problems in conventional treatments, but
success in both chemical composition and structural it also has its corresponding shortcomings. For example,
properties, as summarized in this section. However, the there are currently no clinical trials using 3D-printed
studies on developing gradient scaffolds imitating the osteochondral scaffolds to repair osteochondral defects
osteochondral heterogeneities in anatomical, biological, in joints. Compared to other tissue engineering solutions,
physicochemical, and mechanical properties are still 3D printing allows for the construction of a personalized
limited and in the infancy stage. scaffold that matches the geometry of the defect on the
basis of magnetic resonance imaging (MRI) and computed
4. Conclusion and prospects tomography (CT) scans. Furthermore, the repair and
Osteochondral defects have been a widespread and serious regeneration mechanism of the osteochondral integrated
osteoarticular disease in clinical practice. The effective scaffold has not been investigated in depth, and it cannot
osteochondral defect repair has been a pressing challenge still be elucidated at a microscopic cellular and molecular
in the field of tissue engineering. This paper systematically level. Although the osteochondral integrated scaffold is
reviews the current problems faced by the conventional structurally and compositionally biomimetic, it is not
treatment of osteochondral defects and the current status comparable to normal osteochondral tissues at either the
of research on osteochondral integrated bionic scaffolds. biological or mechanical level. No special materials that
The osteochondral tissue-engineered scaffold imitates resemble natural osteochondral tissues have been found.
not only the normal osteochondral structure, but also the Finally, the CCZ and tideline play a crucial role in the
natural osteochondral composition, ultimately achieving osteochondral structure, which is not yet fully imitated by
effective repair of osteochondral defects. However, the the integrated bionic scaffold. Therefore, the problems of
complex anatomy and composition of osteochondral tissue cartilage layer calcification and easy separation between
and the dynamic changes of time and space in the defect layers of triphasic and multiphasic scaffolds have not
area indicate that the osteochondral repair is not a simple yet been well resolved. Nevertheless, it is believed that
filling of new tissue, but the formation of an integrated more suitable scaffold materials can be discovered or
bone–cartilage interface coupled with the simultaneous synthesized through novel fabrication technologies and
osteochondral regeneration. methods including 3D printing and electrostatic spinning.
Furthermore, multiple disciplines can be combined to

Volume 9 Issue 4 (2023) 139 https://doi.org/10.18063/ijb.724