Comparisons of human amniotic mesenchymal stem cell viability in FDA-approved collagen-based scaffolds: Implications for engineered diaphragmatic replacement

Background/purpose: We sought to examine amniotic fluid mesenchymal stem cell (afMSC) viability within two FDA-approved collagen-based scaffolds, as a prerequisite to clinical translation of afMSC-based engineered diaphragmatic repair. Methods: Human afMSCs were seeded in a human-derived collagen hydrogel and in a bovine-derived collagen sheet at 3 matching densities. Cell viability was analyzed at 1, 3, and 5 days using an ATP-based 3D bioluminescence assay. Statistical comparisons were by ANOVA (P < 0.05). Results: There was a highly significant 3-way interaction between scaffold type, seeding density, and time in 3D culture as determinants of cell viability, clearly favoring the human hydrogel (P < 0.001). In both scaffolds, cell viabilitywas highest at the highest seeding density of 150,000 cells/mL. Time in 3Dculture impacted cell viability at the optimal seeding density in the human hydrogel, with the highest levels on days 1 (P < 0.001) and 5 (P= 0.05) with no significant effect in the bovine sheet (P = 0.39-0.96). Conclusions: Among clinically-approved cell delivery vehicles, mesenchymal stem cell viability is significantly enhanced in a collagen hydrogel when compared with a collagen sheet. Cell viability can be further optimized by seeding density and time in 3D culture. These data further support the regulatory viability of clinical trials of engineered diaphragmatic repair. (C) 2017 Elsevier Inc. All rights reserved.