Design principles for generating robust gene expression patterns in dynamic engineered tissues

A simple and Rapid Method for Generating Patterned Co-Cultures with Stable Interfaces

“…We quantified the extent of pattern disruption for a homotypic co-culture (Supplementary Figure S4). Pattern disruption is significantly less than what was observed using microcontact printing with the same combination of cell types (22). This limited cell-cell mixing behavior is potentially useful for multi-day experiments where the extent of cell-cell contact between the two cell types could change signaling properties and hence cellular function.…”

Light‐Patterned RNA Interference of 3D‐Cultured Human Embryonic Stem Cells

“…In contrast, the downregulation of GFP-transduced HeLa cells loaded with HGNs and irradiated on a 2D culture dish did not show distinct patterns (Figure 3b). This suggests that undifferentiated H9 cells migrate [36] within the spheroid, and neither laser irradiation nor siRNA release alters this migration.…”

Synthetic mechanobiology: engineering cellular force generation and signaling

“…[18] However, there are also a number of limitations, perhaps the most important of which is the slow dynamics of the expression system and the protein of interest. While in some scenarios, cells respond phenotypically within six hours[16,19], some systems may take as long as ten days to reach a steady-state response[19,20]. This is compounded by system-to-system variations in the kinetics of transcriptional activation, protein folding and post-translational modifications, protein transport, and protein degradation, all of which may be key to the final phenotype.…”

“…However, several approaches for spatial control of gene expression at the cell population level have been proposed. For instance, inducers and repressors can be restricted to certain areas of a cell population through microfluidic control[20], by occlusion of membrane pores[19], or by sequestration of the agent within the material scaffold[21,22]. Several factors influence the extent of control over spatial activation of gene expression and thus pattern fidelity.…”

“…Cell migration and slow delivery, induction, and expression kinetics may disrupt intended patterns. Shorter lag times between introduction of the inducer/repressor and protein expression allows for more faithful pattern formation [19]. …”