Page 310 - IJB-9-6

International Journal of Bioprinting Progress in bioprinted ear reconstruction

Table 2. Continued
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
• At 12 months, the reconstructed auricle • Multiple additional
presented high stiffness and low flexibility, surgical steps
whereas at 24 months, an obvious incorporated:
improvement in inflexibility with more • Tissue expanded
distinct structures were achieved. preoperatively for 3
• Among the total five cases, four cases showed months (psychosocial
obvious cartilage formation after 6 months impact)
post-implantation (one case was lost to • Split-thickness skin
follow-up). graft from groin was
• MRI conformed a significant portion of PCL required
has degraded (complete degradation of PCL • Scar revision
in vivo normally requires 2–4 years). Biopsied surgeries were
samples revealed formation of mature in vivo required at 6 and 18
cartilage at 6 months and 18 months post- months
operatively.
Abbreviations: ACM, ; ACMMA, methacrylate-modified acellular cartilage matrix; ASCs, adipose-derived stem cells; AuCPCs, auricular cartilage pro-
genitor cells; CAD, computer-aided design; CAM, computer-aided manufacturing; CPS, cell-printed structure; CSHS, cell-seeded hybrid scaffold; CSS,
cell-seeded scaffold; CT, computed tomography; DLP, digital light processing; DMEM, Dulbecco’s Modified Eagle Medium; ECM, extracellular matrix;
FDM, fused deposition modeling; GAG, glycosaminoglycan; GelMA, gelatin methacrylate; H&E, hematoxylin and eosin staining; HA, hyaluronic acid;
HAMA, hyaluronic acid methacrylate; MRI, magnetic resonance imaging; MSCs, mesenchymal stem cells; PBS, phosphate-buffered saline; PCL, poly-
caprolactone; PEG, polyethylene glycol; PEO, poly(ethylene oxide); PGA, polyglycolic acid; PGLA, poly(lactic-co-glycolic acid); PLA, polylactic acid; PPU,
perforated polyurethane; PRP, platelet-rich plasma; PU, polyurethane; SEM, scanning electron microscopy; SLS, selective laser sintering; UV, ultraviolet.

comparing scaffold materials and cartilage formation was
not possible.
4. Discussion

4.1. Overcoming current obstacles to clinical
translation
Auricular reconstruction is a challenging endeavor, partly
due to the complex 3D geometry of the auricle , so unique
[4]
to each individual that the pinna has been proposed as a
forensic identifier .
[5]
This review demonstrates that 3D printing has the
potential to have a significant impact on this relatively
niche but complex area of reconstructive surgery by
enhancing current surgical reconstructive options, and
before clinical translation can truly occur, this technology
requires optimization in multiple areas and large-scale
clinical trials.
The printed auricle’s desired anatomically detailed
shape should be ensured for a lifetime, even after
Figure 4. Time in vivo per scaffold type in experimental animal studies. postoperative inflammatory processes have attempted
Abbreviations: PCL, polycaprolactone; PLA, polylactic acid. to ravage the scaffold. Prevention of topographical
blunting and volume loss requires both excellent cellular
tomography (CT) scanning, and mechanical testing were performance and abundant cartilage matrix, organized
all used to assess the resulting tissue-engineered auricles. to mimic native elastic cartilage’s histological and
However, given the wide range of printing methods, biomechanical properties. A certain degree of scaffold
variable time in vivo, and heterogeneous use of outcome shrinkage is expected due to extrinsic compressive forces
measures in the included studies, meaningful meta-analysis exerted by the overlying soft tissue, myocontractile

Volume 9 Issue 6 (2023) 302 https://doi.org/10.36922/ijb.0898