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International Journal of Bioprinting Bioprinting with ASCs and bioactive glass

Figure 14. Gelatin release profiles from AG, 1.25G, and 2.5G scaffolds.

the glass particle dissolution and release ions to control exhibit a viscoelastic solid-like behavior (G’> G’’) that
the hydrogel viscosity and establish a window of printable improved the hydrogel recovery and enabled effortless
time for the composite hydrogel. However, borate-based extrusion 3D printing of scaffolds. AG scaffold stiffness
55
bioactive glasses dissolve rapidly and supply the dissolution increased with the addition of B3 (from 33 kPa to 73 kPa),
products (including Ca ions) to control the hydrogels and the mechanical properties showed the potential of
2+
viscosity for 3D printing without affecting their shear- the modified AG hydrogel to serve as a viable matrix for
thinning behavior. The mechanisms that are currently human ASCs. Despite the toxicity of B3 to ASCs when
adopted during bioprinting with alginate-based hydrogels added in quantities higher than 0.3 w/v % to hydrogel
include filament exposure to CaCl solution to initiate (<70% viable ASCs), lower quantities of B3 have increased
2
crosslinking and fabrication under temperature-controlled the viability in comparison to AG hydrogels without B3
environment by modifying the solvent ionic strength. 13,59 In after 7 days in culture (>80% viable ASCs). Overall, the
this study, we successfully demonstrated bioprinting with rheological modification of alginate-based hydrogels with
borate glass-modified hydrogels at room temperature. This B3 glass showed the potential for future applications in
study is the first to report the use of borate-based bioactive extrusion-based bioprinting with human ASCs.
glass to improve the extrudability of alginate-based
hydrogels with consideration of human ASC viability. Acknowledgments

4. Conclusion The authors thank Austin Martin and Jeremy Watts for
their help with rheological assessment of hydrogels and
Our research showcased the capability of B3 glass to freeze-drying hydrogels. The glass used in this study was
facilitate printing using AG hydrogel at room temperature, provided by Mo-Sci Corporation, Rolla, MO, USA.
eliminating the requirement for a temperature-controlled
setting. This improvement was analyzed not just in terms Funding
of the hydrogel’s printability at room temperature, but This research was funded by the Intelligent Systems Center
also regarding its impact on cell viability. Rheological and the Center for Biomedical Research at the Missouri
properties of an AG hydrogel were modified with the University of Science and Technology.
addition of 0.075 to 0.6 w/v % of highly resorbable B3 glass,
and scaffolds were successfully fabricated. The addition of Conflict of interest
B3 glass (0.075 and 0.15 w/v %) increased the viscosity
(from 0.2 kPa·s to 7 kPa·s) and made the AG hydrogel The authors declare no conflicts of interest.

Volume 10 Issue 2 (2024) 472 doi. 10.36922/ijb.2057