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International Journal of Bioprinting Bioprinted stem cell niche regenerates muscles

Figure 3. Persistence of bioprinted Fc fusion proteins on 3D construct. (A) We performed protein binding experiments to demonstrate that Fc fusion proteins
can be stably bioprinted and biopatterned on artificial 3D construct, made of DermaMatrix. Cy3-labelled human IgG Fc was printed onto DermaMatrix
construct, with varying number of OP (overprints/repeated prints). Fluorescent images were taken immediately postprinting (before washing with PBS
for 15 min) and 5 days postprinting. Incubation was performed in simulated interstitial fluid (10% serum MEM culture media containing 25 mM HEPES
and 0.1% sodium azide). Following the removal of unbound IgG Fc, the printed pattern persisted throughout the incubation period. (B) Over 18 days after
rinsing and incubation in simulated interstitial fluid, the levels of IgG bound to the DermaMatrix construct were very consistent. (C) GFP-labeled WT
MPCs (GFP-WT MPCs) were seeded in the DermaMatrix construct with DLL1-printed or nonprinted areas to compare their growth rate.

dimensions). Cell seeding was performed by injecting of engraftment when constructs are implanted into skeletal
0.2 × 10 GFP-labeled MPCs into both the DLL1-bioprinted muscle.
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DermaMatrix constructs and control DermaMatrix
constructs (IgG Fc) and cultured in medium. Three days 3.6. Implantation of GFP-MPC-seeded DLL1-
after cell seeding, DermaMatrix constructs were placed bioprinted DermaMatrix constructs into mdx mice
in the Matrigel-coated upper chamber of an electrode- resulted in improved cell engraftment
impedance-based invasion assay system (xCELLigence) MPCs were virally transfected to express GFP protein
(Figure 4A) . The 3D Matrigel layer was made of Matrigel and seeded into DermaMatrix constructs with or without
[39]
dissolved in medium (1 mg/mL). The numbers of cells bioprinted DLL1 (4 × 10 cells in 4 × 4 × 1 mm construct).
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migrating out of the DermaMatrix constructs and through Ten days after the implantation of GFP-MPC-seeded
the 3D Matrigel layer were monitored; we found that the DLL1-DermaMatrix constructs or MPC-seeded control
number of cells migrating out of DLL1-DermaMatrix DermaMatrix constructs, an improved cell engraftment
constructs were much higher (Figure 4B). The increased was observed in the muscle tissue implanted with the
migration capacity may be beneficial for improving cell MPC-seeded DLL1-DermaMatrix constructs (Figure 5).

Volume 9 Issue 3 (2023) 305 https://doi.org/10.18063/ijb.711