Page 52 - IJB-9-5

International Journal of Bioprinting Precise fabrication of engineered vascular networks

Figure 5. Fabrication of 3D vasculature within the P/G hydrogel scaffolds by printing sacrificial templates with multiple layers.

increasing the vasculature density. For P/G hydrogel shown in Figure 5. P/G hydrogel and a 20-G needle were
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constructs, the diameter of vasculature was maintained used in this experiment. The images of the P/G hydrogel
at ~600 μm for Patterns 2 and 3, while the diameter of scaffolds at different time points were captured, and the
vasculature in Pattern 1 increased to 646.4 ± 15.9 μm. For red acrylic paint was injected into the vasculature to
P/G hydrogel constructs, the diameter of vasculature in verify its 3D structure. The top and side view images of
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Pattern 2 was similar to the designed size. The diameters the P/G hydrogel scaffolds indicate the connectivity of
of vasculature in Patterns 1 and 3 were 656.9 ± 19.5 and the fabricated vasculature before and after shrinking.
593.6 ± 2.8 μm, respectively. For P/G hydrogel constructs, Volume shrinkage of P/G hydrogel scaffolds with two and
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the diameters of vasculature for all patterns were above four layers of the vasculature at 37°C was observed, while
630 μm. This may be caused by the high surface area of no significant shrinkage was found for the P/G hydrogel
high-density vasculature that can facilitate the outflow of scaffold with six layers of vasculature. This is mainly due
the water in P/G hydrogel scaffolds. Thus, the size of the to the large volume of P/G hydrogel to encapsulate the
engineered vasculature can be tuned by adjusting the P/G sacrificial template with six layers, which makes it difficult
concentration and vasculature density. for the water inside the P/G hydrogel to be released.
However, the P/G hydrogel scaffolds with six layers of
3.4. Fabrication of 3D vasculature vasculature considerably shrunk at 37°C when P/G
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In Figure 1, the sacrificial template was printed on the P/G and P/G hydrogels were applied, as shown in Figure S5
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hydrogel film, exhibiting a two-dimensional vasculature. (Supplementary File). Thus, we can further confirm that
To investigate the potential of our method to fabricate the volume shrinkage degree of the P/G hydrogel scaffold
3D vasculature, sacrificial templates with multiple layers can be tuned by changing the hydrogel concentration,
were designed and printed on the P/G hydrogel film, as vasculature density, and vasculature structure to fabricate

Volume 9 Issue 5 (2023) 44 https://doi.org/10.18063/ijb.749