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International Journal of Bioprinting Printing organoids in peptide matrices

Figure 4. Confocal micrographs depicting immunostained organoids cultured within peptide hydrogels, indicating the presence of pan-cadherin-mediated
cell–cell junctions (green). Supplementary counterstaining highlights the cytoskeletal elements (red) and nuclei (blue). Comparative assessment of cell–
cell junction expression in biofunctional hydrogels containing FIB and LAM peptides reveals an absence of junctional complexes along both basolateral
and apical membranes. Organoids cultured under the parent (low) condition exhibit robust junctional protein expression. Abbreviations: FIB, fibrinogen-
derived peptide containing the RGD motif; LAM, laminin-derived peptide containing YIGSR. Scale bar = 100 µm.

explored in this study. In contrast, the FIB (low) peptide induce LGR5+ cells to disrupt the differentiation process.
reduces the level of LGR5 expression, pointing towards a Interestingly, we identified an overexpression of EpCAM
correlation between LGR5 expression and stiffness. in all peptide hydrogel cultures compared to Matrigel
(Figure 7c), including the cells in the 2D culture. The
We also characterized the expression of the CHGA overexpression of the EpCAM molecule could indicate a
marker corresponding to enteroendocrine cells. As stronger interaction between cells and the environment.
seen in Figure 7b, CHGA is overexpressed in LAM One possible explanation would be that the cell–matrix
(high) and 2D control, while other conditions have a interactions between the peptide hydrogels and the cells
similar expression level to that of Matrigel. These data come from a possibly synergetic relationship between the
indicate that SW1222 cells in 2D cultures have a skewed motif interaction and adhesive properties of the fibers.
differentiation to enteroendocrine cells. Hence, the use of However, further research is warranted to characterize
3D matrices within the stiffness ranges of this study may the adhesive properties of the tetrapeptide hydrogels

Volume 10 Issue 5 (2024) 352 doi: 10.36922/ijb.3033