3D Nanoprinting Technologies for Tissue Engineering Applications

Figure 4

Feature formation to control ECM context and geometry. (a) Defined features can be patterned at the surface or within PEGdiPDA hydrogels by rastering the focal point of a two-photon laser scanning microscope (LSM, Zeiss LSM 710) through specific geometries using region of interest software. (b) Surface feature formation can be performed on size scales relevant to the cell (~1 to 100 mm) and spatially confined to desired regions to disrupt adhesion at the front or back side of adhered cells (purple oval and yellow circle) or to disrupt adhesion at individual filopodia (red triangle). To demonstrate this strategy, feature formation was performed in the absence of cells on the order of microns (red triangle) to 100 mm (purple oval) and was monitored with confocal microscopy (3D renderings of fluorescent confocal stacks and the corresponding cross sections, green and blue lines). (c) Features were also patterned within the bulk of PEGdiPDA hydrogels to motivate the utility of this approach for directing encapsulated cells ((c)(i)) to migrate down specific channels ((c)(ii)) or for defining the geometry of the cell niche ((c)(iii)). 20 mm and 30 mm wide channels were patterned into PEGdiPDA gels ((c)(ii)) for representative channel formation, and a 45 mm wide square cylinder was patterned into a gel ((c)(iii)) as a representative change to the geometry of the cell niche. Scale bars represent 20 mm, except as noted (figures were reproduced from [31] with permission of Royal Society of Chemistry).

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