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International Journal of Bioprinting 3D bioprinting of full-thickness skin with a rete ridge structure

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Figure 4. Observations of tissue sections to evaluate the influence of ultraviolet (UV) irradiation. Upon UV irradiation (25 and 50 mJ/cm ), conventional
full-thickness skin equivalents (FTSEs) exhibited notable stratum corneum collapse and a reduction in protein expression. Conversely, rete ridge FTSEs
demonstrated preserved stratum corneum and protein expression, particularly within the valley of the rete ridge structure. Scale bars: 200 μm. Abbreviation:
H&E: Hematoxylin & eosin.

discovery. Traditional skin research has primarily relied related approaches have focused solely on short-term
on epidermal models and FTSEs, which, despite their UV exposure of skin constructs or skin reconstruction
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utility in initial investigations and understanding basic techniques that do not represent the histological profile
skin functions, are limited in their ability to accurately of in vivo skin. To address the limitations associated
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replicate the complex topographical features of native with conventional methods, we used a preset extrusion
skin, particularly the rete ridges. These features are crucial bioprinting technique, utilizing SdECM-based bioinks to
for a realistic representation of skin, influencing cellular fabricate skin models with detailed rete ridge structures.
behaviors critical for skin health and disease. One major Unlike previous attempts that used molding or stamping
biological implication of the DEJ is its association with techniques prone to damaging delicate biomaterials such
aging; certain tissues are prone to become flatter with as collagen, our method overcomes these challenges
age. However, owing to technical limitations, most aging- by incorporating a “furrow step” to achieve the desired
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Volume 10 Issue 5 (2024) 496 doi: 10.36922/ijb.3961