3D PRINTING AND NANOMANUFACTURING - 3D Bioprinting and Nanotechnology in Tissue Engineering and Regenerative Medicine - page 37

by chemical modification, mixing with other degradable materials, or incorporation of adhesive
peptide sequence like the tetrapeptide Arg-Gly-Asp-Ser (RGDS) or proteins like laminin ( Hribar
et al. , 2014 ). GelMA hydrogels, made from xenogenic-modified monomers, belong to the type of
naturally derived hydrogels and are bioactive for their peptide sequences, which allow the binding of
integrin protein expressed on cell membrane ( Hribar et al. , 2014 ). Like most gelatin-based hydrogels,
GelMA hydrogels provide high water content and modifiable properties (e.g. swelling and stiffness)
based on monomer percentage. GMHA hydrogels, another naturally derived hydrogels from native
ECM component, possess superior biocompatibility and are in general nonimmunogenic like natural
FIGURE 2.8
Complex 3D cell-encapsulated scaffolds fabricated by the DOPsL system. (a and b) Bright field micrographs
of GelMA scaffolds with encapsulated NIH/3T3 cells at different time points. (c) 3D reconstruction of confocal
fluorescence micrographs of cell-scaffold interaction. (d) Cross-sections of the confocal images in (c). All scale
bars are 100 m m ( Soman et al. , 2013 ).