Page 57 - IJB-2-2

Huijun Li, Sijun Liu and Lin Li

(c) 0.5 (d) 0.35

t=0s
0.4
t=30s 0.30
Width (cm) 0.3 Height (cm) 0.25 t=0s

0.2

0.1 0.20 t=30s
0.15
0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.00 0.05 0.10 0.15 0.20 0.25 0.30
GO (wt%) GO (wt%)

Figure 7. The morphologies of the printed scaffolds for 10 wt.% alginate hydrogels filled with various GO contents at the recovery
time of (a) t = 0 second, and (b) t = 30 seconds; effect of GO content on the (c) width, and (d) height of the filament.

thus the printing quality is better for those scaffolds and easier to collapse and spread compared to the hy-
with a recovery time. At the same time, the filament drogel with a higher GO concentration. Figure 8(b)
height with a recovery time is greater than that with- illustrates the relationship between height and time
out a recovery time. As the printed scaffold comprised with varying content of GO. The heights of all scaf-
of 50 layers and the printing of each layer needed to folds decreased gradually with increment of ageing
pause every 30 seconds, however, the total printing time due to the spreading effect. The height of a scaf-
time was 1470 seconds or 24.5 minutes longer than fold with more GO was always bigger than those
that without taking a recovery time. scaffolds with lower GO contents during the observa-
From Figure 8(a), it is observed that the value of wi- tion period (20 minutes).
dth gradually increases with ageing time. Furthermore, Figure 9 shows the effects of ageing time on the
as the content of GO increases from 0 to 0.25 wt.%, width and height of the filaments for 10 wt.% alginate
the time effect becomes gentle. It is because that the hydrogels filled with various GO contents at the re-
hydrogel with a lower concentration of GO was softer covery time, t = 30 seconds. It can be found that the

International Journal of Bioprinting (2016)–Volume 2, Issue 2 63