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International Journal of Bioprinting Five-axis printer for hybrid 3D scaffolds

form surfaces. The evaluation criteria included geometric assembling into a fibrous network, into channels printed
accuracy of strut and pore sizes. Measurements involved with a photocurable resin to fabricate a multiscale and
assessing dimensions at half the width horizontally and multi-material structure (Figure 3). Herein, we have noted
half the height vertically. Printing accuracy is quantified as three key points of hybrid printing:
normalized deviation from the intended design. (i) Hydrogels have reduced mechanical strength and
structural support for thicker structures (a few
3. Results and discussion mm). Incorporating them within a photopolymer
3.1. Hybrid printing on planar surfaces for hard and network can improve the mechanical strength and
soft material interfaces structural support.
We first applied hybrid printing on planar surfaces by (ii) Synthetic photopolymers often lack bioactivity, and
embedding a soft peptide hydrogel, capable of self- integrating hydrogels could potentially augment the

Figure 3. Workflow and accuracy visualization for a bi-phasic soft phase scaffold on a planar surface. (a) Schematic illustration of the hybrid fabrication of
a bi-material soft phase using 3D inkjet and extrusion printing: (a, 1i) scaffold to be fabricated; (a, 2ii) slicing and G-code generation; and (a, 3iii and iv)
printing strategy for 3D inkjet printing and extrusion printing. (b) 3D inkjet-printed channels using a photopolymer. (c) Overhanging structure printed
with a peptide hydrogel as support material. Scanning electron microscopic (SEM) magnified image displaying the nanofiber network of the RADA-16
raw material state prior to printing (provided by 3D-Matrix). Magnification: ×20. Scale bar: 1 mm. (d–e) Inner structure of the channels before and after
removing the hydrogel. (f–g) Measurement positions to determine printing accuracy. (h) Printing accuracy of the struts and pores.

Volume 10 Issue 3 (2024) 593 doi: 10.36922/ijb.3189