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ORIGINAL ARTICLE

3D-printed Biomimetic Bioactive Glass Scaffolds for

Bone Regeneration in Rat Calvarial Defects

Krishna C. R. Kolan *, Yue-Wern Huang , Julie A. Semon , Ming C. Leu 1
2
2
1
1 Department of Mechanical and Aerospace Engineering, Missouri University of Science and Technology, Rolla, Missouri,
USA
2 Department of Biological Sciences, Missouri University of Science and Technology, Rolla, Missouri, USA

Abstract: The pore geometry of scaffold intended for the use in the bone repair or replacement is one of the most important
parameters in bone tissue engineering. It affects not only the mechanical properties of the scaffold but also the amount of
bone regeneration after implantation. Scaffolds with five different architectures (cubic, spherical, x, gyroid, and diamond)
at different porosities were fabricated with bioactive borate glass using the selective laser sintering (SLS) process. The
compressive strength of scaffolds with porosities ranging from 60% to 30% varied from 1.7 to 15.5 MPa. The scaffold’s
compressive strength decreased significantly (up to 90%) after 1-week immersion in simulated body fluids. Degradation of
scaffolds is dependent on porosity, in which the scaffold with the largest surface area has the largest reduction in strength.
Scaffolds with traditional cubic architecture and biomimetic diamond architecture were implanted in 4.6 mm diameter full-
thickness rat calvarial defects for 6 weeks to evaluate the bone regeneration with or without bone morphogenetic protein
2 (BMP-2). Histological analysis indicated no significant difference in bone formation in the defects treated with the two
different architectures. However, the defects treated with the diamond architecture scaffolds had more fibrous tissue formation
and thus have the potential for faster bone formation. Overall, the results indicated that borate glass scaffolds fabricated using
the SLS process have the potential for bone repair and the addition of BMP-2 significantly improves bone regeneration.

Keywords: Selective laser sintering, Bioactive borate glass, In vivo bone formation, Porosity, Pore geometry, Scaffold
architecture

*Corresponding Author: Krishna C. R. Kolan, Department of Mechanical and Aerospace Engineering, Missouri University of Science and
Technology, Rolla, Missouri, USA; kolank@mst.edu.
Received: April 2, 2020; Accepted: April 16, 2020; Published Online: April 29, 2020
Citation: Kolan KCR, Huang YW, Semon JA, et al., 2020, 3D-printed Biomimetic Bioactive Glass Scaffolds for Bone
Regeneration in Rat Calvarial Defects. Int J Bioprint, 6(2):274. DOI: 10.18063/ijb.v6i2.274

1 Introduction networks to highly resorbable glass compositions
based on B O networks as researchers have
3
2
Since the discovery of Bioglass by Dr. Hench focused on developing borate and borophosphate
®
in 1969, researchers have identified a wide range glasses for biological applications due to the
of glass and glass-ceramic compositions for bone
repair as well as soft tissue applications [1-3] . The ability to support angiogenesis and offer faster
[4]
advantage of utilizing silicate-based bioactive degradation . Several studies have investigated
glasses for bone repair is their conversion gradual replacement of SiO in silicate glass with
2
to hydroxyapatite (HA), the main mineral B O and reported the effects of glass dissolution,
2
3
constituent of bone, that can readily integrate with tissue infiltration, and cell culture compatibility
surrounding tissue . The research on bioactive of the borosilicate glasses [5,6] . Borate glass is
[2]
glasses has evolved from traditional SiO chemically less durable in comparison to silicate
2
© 2020 Kolan, et al. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International
License (http://creativecommons.org/licenses/by-nc/4.0/), permitting all non-commercial use, distribution, and reproduction in any medium, provided the
original work is properly cited.
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