Bioprinting offers the opportunity to fabricate precise 3D
tumor models to study
tumor pathophysiology and progression. However, the choice of the bioink used is important. In this study, cell behavior was studied in three mechanically and biologically different
hydrogels (
alginate,
alginate dialdehyde crosslinked with
gelatin (ADA-GEL), and
thiol-modified
hyaluronan (HA-SH crosslinked with PEGDA)) with cells from
breast cancer (MDA-MB-231 and MCF-7) and
melanoma (Mel Im and MV3), by analyzing survival, growth, and the amount of metabolically active, living cells via
WST-8 labeling. Material characteristics were analyzed by dynamic mechanical analysis. Cell lines revealed significantly increased cell numbers in low-percentage
alginate and HA-SH from day 1 to 14, while only Mel Im also revealed an increase in ADA-GEL. MCF-7 showed a preference for 1%
alginate.
Melanoma cells tended to proliferate better in ADA-GEL and HA-SH than mammary
carcinoma cells. In 1%
alginate,
breast cancer cells showed equally good proliferation compared to
melanoma cell lines. A smaller area was colonized in high-percentage
alginate-based
hydrogels. Moreover, 3%
alginate was the stiffest material, and 2.5% ADA-GEL was the softest material. The other
hydrogels were in the same range in between. Therefore, cellular responses were not only stiffness-dependent. With 1%
alginate and HA-SH, we identified matrices that enable proliferation of all tested tumor cell lines while maintaining expected
tumor heterogeneity. By adapting
hydrogels, differences could be accentuated. This opens up the possibility of understanding and analyzing
tumor heterogeneity by biofabrication.