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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
• PCL scaffolds maintained good shape
retention both immediately after printing and
after 30 days of in vitro culture.
• The hybrid ear-shaped construct produced
cartilage-specific components in abundance.
• 400 μm and 800 μm scaffolds are relatively
stiff and inflexible, while 1000 μm and 1200
μm scaffolds allow for more bending when
manipulated by hand. However, using wider
strand spacings also reduces control over the
fine architecture of the structure.
Visscher et al. To create a rapid In vitro N/A Direct printing Extrusion Scaffold only Other shape PCL Goat mesenchymal Printing is paused Histopathology; • A novel cage construct consisting of a No in vivo testing of this
(2016) [50] production pathway stem cells, half-way to insert mechanical combined hydrogel and collagen I/III scaffold method yet
and mechanically stable chondrocytes and a collagen I/III testing within a 3D-printed synthetic PCL cage can
scaffold structures with an perichondrocytes. scaffold into the prevent in vitro scaffold contraction.
optimal biochemical ECM PCL cage. Then • Six PCL cage constructs can be produced and
environment for generating after printing, printed in 2 h with good printing accuracy
and maintaining proper ear hydrogel is added and minimal oozing effects.
cartilage. on top of that. • Cell-seeded hydrogels showed significant
contraction in vitro, reducing to 15–48% of
their original volume after 28 days of culture
depending on the cell type.
• Histological evidence of GAG deposition was
present in all scaffolds and internal scaffolds.
• Chondrocyte- and chondrocytes
perichondrocyte (CP)-seeded scaffolds
produced the most collagen, while adipose-
derived stem cells and chondrocytes had
lower GAG production than other cell types.
• The Young’s modulus of all scaffolds and
internal scaffolds increased by 50% after 28
days of in vitro culture compared to 14 days
of culture.
Visscher et al. To design and 3D-print an In vitro N/A Direct printing Extrusion – 3D Cells in bioink + Resembling PCL Chondrocytes Molds were Histopathology; • It was found that a porous synthetic outer Long-term in vivo
(2018) [51] easily-assembled cartilage printing a two- scaffold printed pinna from Dutch milk disinfected with Mechanical layer with high mechanical strength was experiments are required to
implant for auricular part PCL mold together; scaffold goats 70% ethanol for 1 h, testing needed to withstand forces during in vivo test preclinical applicability
reconstruction. in the shape of printed first and washed with sterile tissue maturation.
human auricular then seeded with PBS and dried in a • An inner “natural” core made of a biomimetic
cartilage and cells sterile incubator. environment for cartilage tissue formation
injecting this All parts were was an effective way to achieve biointegration.
construct with a coated with sterile • Beads cultured in chondrogenic medium had
mixture of alginate gelatin to block higher levels of GAGs and type II collagen
and chondrocytes the pores and deposition.
before culturing create a sealed
the final construct mold. Once placed
in vitro. in proliferation
medium at
37°C, the gelatin
liquefied and left
the pores, allowing
for nutrient and
oxygen exchange
through the mold
pores.

(Continued)

Volume 9 Issue 6 (2023) 283 https://doi.org/10.36922/ijb.0898