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International Journal of Bioprinting Photocurable pullulan-based bioink for 3D printing

Figure 8. The cytotoxicity of Pul-NB hydrogels with different DS toward L929 cells.

Figure 9. Models and photos of the 3D-printed objects using Pul-NB inks.

ability. Photo-functionalized Pul-NB ink prepared in this despite the satisfactory 3D printing of geometrical
work had a suitable viscosity for DLP, and the viscosity complicated products. This study only focused on 3D
was not affected by external factors. Considering the printing of one component bioink, without considering
printability and the printing process requirements, an other situations, such as gradient hierarchical structure
appropriate ink with Pul-NB concentration of 10 wt% was or cell-laden biphasic bioinks. Therefore, it is necessary to
employed to construct 3D-printed products. As shown study the bioink material system and printer composition
in Figure 9, four different typical patterns (cylinder, to print intricate gradient bionic structures with the best
triangular, pentagonal configuration, and superimposed performance.
cube) were fabricated. By adjusting the exposure time and
light intensity, the geometric accuracy of the products can 4. Conclusion
be accurately controlled. It is theoretically possible that the We developed a photocurable system based on the
printed products with different density and mechanical renewable pullulan (Pul-NB) using a simple synthesis
strength could be obtained by adjusting the Pul-NB strategy in water phase. Pul-NB 4 with the highest degree
concentration and the ratio of the thiol group (SH) to NB. of substitution at a concentration of 10% (w/v) has suitable
Theoretically, this Pul-NB ink can be used to print 3D rheology and mechanical properties, and the hydrogel
objects with any kind of structures, but it is still challenging network can be compressed at more than 80.0% strain.
to print products with gradient structures that mimic Due to the introduction of thiol-ene photopolymerization,
biomimetic organizations. There are still some limitations the hydrogel could recover its initial shape after unloading

Volume 9 Issue 2 (2023) 114 https://doi.org/10.18063/ijb.v9i2.657