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Development and characterisation of a photocurable alginate bioink for 3D bioprinting

a

b

c
Figure 15. 2% wt. methacrylate alginate with different concentration of VA-086 functionalized for 24 h. (a) 0.5 w/v % of VA-086, (b) 1 w/v %
of VA-086, (c) 1.5 w/v % of VA-086.

of 8 mW/cm . Produced disks were then assessed
2
and both Gʹ and Gʺ measured at room temperature
through a controlled frequency of 1Hz as presented in
Figures 14 and 15. In the case of alginate methacrylate
samples obtained after 8 h of reaction time, its possible
to observe that there is no significant change of both Gʹ
and Gʺ (the storage modulus is always higher than the
elastic modulus) with the increase in the photoinitiator
Figure 16. Scanning electron microscopy images of cross-linked
methacrylate alginate hydrogel structures obtained from alginate- concentration. In the case of alginate methacrylate
methacrylate at different reaction times: 8 and 24 h. samples obtained after 24 h of reaction time, results
show that by increasing the photoinitiator concentration
3.4 Viscoelastic Properties of Formed Hydrogels Gʹ and Gʺ increases. In this case, it is also possible to
observe that the difference between Gʹ and Gʺ increases
Hydrogel disks (4 mm of height and 8 mm of diameter) with the increase of photoinitiator concentration, which is
were produced using an acrylic machined mold. Samples associated with the high cross-linked density.
of 2 % w/v of alginate methacrylate obtained after The viscoelastic nature of the cross-linked disks is
both 8 and 24 h of reaction time containing different also observed from the Gʹ and Gʺ versus strain graphs.
concentrations of photoinitiator (0.5, 1, and 1.5% w/v) In this case, it is possible to observe for all samples
were polymerized during 8 min under a light intensity that, till a critical strain value, the storage modulus is

22 International Journal of Bioprinting (2019)–Volume 5, Issue 2