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International Journal of Bioprinting 3D-bioprinted respiratory disease model

Figure 7. Live/dead staining of constructs: (A) day 1, static conditions; (B) day 1, dynamic conditions; (C) day 28, static conditions; and (D) day 28,
dynamic conditions. Scale bars: 1000 µm.

both significantly upregulated IP-10 mRNA as well. IL-29 appears to have stabilized at the 24-h mark, as there are no
mRNA was upregulated to the greatest extent by HBEpCs, significant changes in cytokine release between 24 and 48
followed by IL-8, while HPFs upregulated IP-10 to the h. Generally, at 24 and 48 h, all cytokine mRNAs of interest
greatest extent. are upregulated in the static condition; however, Il-1β
and IL-8 mRNAs are not significantly upregulated in the
Similarly, Figure 12 demonstrates that the upregulation
of these cytokines in the infected constructs was dynamic condition with nanoparticles.
determined over the 48-h infection period for the three 3.9. Plaque assays for viral titre
different culture conditions with a mock infection used to Plaque assays were used to determine the viral titer in
normalize the results for each condition (fold change of 1). each condition at 6, 24, and 48 HPI (Figure 13). From the
At 6 h post-infection, the highest cytokine mRNA fold original diluted supernatant, the viral titer increased from
7
5
change is exhibited by IL-29, with a fold change of around ~8 × 10 at 6 HPI to ~1.1 × 10 PFU/mL by 24 HPI; the
49 in the dynamic condition with nanoparticles. IL-29 viral titer then decreased slightly by the 48-h timepoint.
mRNA is maintained as the cytokine that undergoes the
greatest increase; by 24 hours, the static condition exhibits 4. Discussion
the highest average mRNA fold change of IL-29, reaching Mechanical characterization, consisting of rheological
120; however, its fold change is less significant than that analysis, printability analysis, compression testing, and
of both dynamic conditions. Cytokine mRNA production tensile testing, all demonstrated that the synthesized

Volume 10 Issue 6 (2024) 421 doi: 10.36922/ijb.3895