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Polyelectrolyte gelatin-chitosan hydrogel optimized for 3D bioprinting in skin tissue engineering

Figure 4. Effect of printing pressures on printed filament
widths.

filament width (Figure 5). It was observed in 2.5%

PGC hydrogels that the printed filament widths in- Figure 5. Effect of feed rates on printed filament widths.
crease to a larger extent with decreasing feed rates
when higher printing pressures were used (indicated less viscous hydrogels such as 2.5% PGC hydrogels
by the gradient of the plotted lines). Conversely, the with increasing printing pressures.
most viscous 7.5% PGC hydrogels exhibited a linear As shown in Figure 6, an optimal combination of
relationship between the feed rates and printed filament both printing pressures and feed rates is required to
widths within its suitable range of printing pressures. obtain a complete grid-like pattern. A high printing
Hence, varying feed rates has significant effect on the pressure would result in excessive material deposition,

58 International Journal of Bioprinting (2016)–Volume 2, Issue 1