Page 295 - IJB-9-6

International Journal of Bioprinting Progress in bioprinted ear reconstruction

Study Aim of study Study Animal Study focus 3D printing Components Printed Printed Cell nature/type Notable post- Assessment Findings Limitations and suggested
setting model (if technique shape material printing of success/ improvements
any) modifications integration
Jang et al. To discover what happens In vitro; Rat Direct printing Extrusion Scaffold printed Resembling PCL Human ASCs and Incubation in Histopathology; • The proposed hybrid structure exhibited Unclear sample size
(2020) [8] when ASCs are co-cultured in vivo first and then pinna rabbit articular culture media at electron improved mechanical properties due to the
with chondrocytes in a 3D animal seeded with cells chondrocytes 37℃ with 5% CO 2 microscopy PCL framework and demonstrated reasonable
hybrid scaffold of PCL. chondrogenesis in vitro and in vivo.
• The compressive modulus of the alginate/PCL
hybrid scaffold was found to be around 2.64
± 0.34 MPa, similar to that of native auricular
tissue.
• Results suggest that chondrocytes
should be added to the scaffold when it
is implanted in the subcutaneous area
without any surrounding cartilage, as it is
difficult to regenerate cartilage using MSCs
alone without chondrocytes or cartilage
remnants.
Jia et al. To evaluate the In vitro; Mice Direct printing Multi-nozzle Cells in bioink + Resembling Bioink—A Bama miniature Two groups of cell- Histopathology; • By using multi-nozzle 3D bioprinting The feasibility of the
(2022) [11] effectiveness of a new in vivo extrusion by scaffold printed pinna; other microporous pigs’s auricular laden constructs micro-CT scan technology to control the distribution technology in large animal
approach for creating animal alternately together shape photo- cartilage were immersed in of chondrocyte-laden bioink and PCL, models is still yet to be
biological auricular printing type 1 crosslinkable a culture medium microporous auricular equivalents with optimized and verified by
equivalents using a (cell-laden bioink) bioactive for 24 h to dissolve precise shapes and satisfactory mechanical further experiments.
biomimetic microporous and type 2 (PCL) bioink based PEO to form strength were successfully fabricated.
photo-crosslinkable on cartilage- porous structures • Mature auricular cartilage tissue with high
cartilage-derived ECM derived morphological accuracy, good elasticity,
with precise shapes and ECM numerous cartilage lacunae, and cartilage-
a bioactive bioink based with the specific ECM deposition was successfully
on ACMMA, GelMA, assistance of regenerated in nude mice.
PEO, and PCL through GelMA and • The inclusion of PCL significantly improved
the use of multi-nozzle 3D PEO. the shape fidelity of auricular equivalents. The
bioprinting technology. modulus of regenerated auricular cartilage
without PCL support was over 65% of native
cartilage, while that of regenerated auricular
cartilage with PCL support was approximately
2.6 times greater than native cartilage.
• Although the PCL occupied space, it did not
affect the formation of mature cartilage tissue
in the bioink area while providing sufficient
strength and stiffness support.
Kim et al. To investigate whether In vitro; Mice Direct printing Extrusion Scaffold printed Resembling PU Tonsil-derived None Histopathology; • 3D-printed, implantable ear scaffolds made Further studies are needed
(2019) [30] customized 3D-printed in vivo first and then pinna MSC (for micro-CT scan; of PU are biomimetic, biocompatible, easily to clarify the long-term
PU scaffolds with adequate animal seeded with cells biocompatibility mechanical fabricated, and flexible. behavior of implanted,
microstructure provide testing only) testing; electron • The PPU scaffold used in this study was regular-sized, 3D-printed
biomechanical properties microscopy designed to have a specific microstructure in PPU scaffolds in terms of
suitable for reconstruction terms of pore size and uniform pore lattice shape and elasticity.
of congenital ear defects. architecture, which encouraged the ingrowth
of surrounding tissue. In comparison,
the Medpor scaffold had an irregular
microstructure (highly variable pore size and
distribution of pores) that did not allow for
close tissue interactions.
• Neovascularization was only observed in
PPU scaffolds, indicating that a pore size of
200 mm may be critical for promoting tissue
ingrowth after auricular reconstruction.
(Continued)

Volume 9 Issue 6 (2023) 287 https://doi.org/10.36922/ijb.0898