Doctoral Dissertations


Youqu Shen

Keywords and Phrases

Bioactive glass; Biomaterials; Bone regeneration; Calcium phosphate; Glass conversion technique; Robocasting


"The purpose of this Ph.D. research is to investigate and improve two classes of hydroxyapatite (HA)-based biomaterials for bone repair: calcium phosphate microspheres and bioactive silicate glass scaffolds. These biomaterials were prepared with modified compositions and microstructures and then were evaluated for bone regeneration.

The open HA microspheres with dense convex surfaces and rough and porous concave surfaces were obtained by sectioning closed hollow HA microspheres. Bone regeneration with the open HA microspheres was greater than with the closed HA microsphere at 12 weeks. Hollow biphasic calcium phosphate (BCP) microspheres have been prepared with different fractions of HA and β-TCP (tricalcium phosphate) and their in vitro and in vivo reactivities determined. The BCP microspheres with higher ß-TCP/HA ratio (70/30) had faster degradation rates both in vitro and in vivo and a better capacity to regenerate bone. Moreover, the more reactive BCP microspheres were associated with significantly more blood vessel formation in the subcutaneous implants.

13-93 glass scaffolds with curved filaments stimulated a greater amount of new bone formation than straight filament scaffolds in rat calvarial defect at six weeks. Scaffolds with thin (6 ± 1 μm) HA-like surface layers were more effective at stimulating new bone formation, with the curved-filament structures again showing significant improvement in new bone growth compared to the surface-modified straight-filament structures"--Abstract, page iv.


Brow, Richard K.

Committee Member(s)

Day, D. E.
Hilmas, Greg
Huang, Yue-Wern
Semon, Julie A.


Materials Science and Engineering

Degree Name

Ph. D. in Materials Science and Engineering


The work was financially supported by the National Institutes of Health [Grant #1R15DE023987-01] and the Lasko Endowment in the Department of Materials Science and Engineering.


Missouri University of Science and Technology

Publication Date

Fall 2019

Journal article titles appearing in thesis/dissertation

  • Evaluation of open hollow hydroxyapatite microsphere on bone regeneration in rat calvarial defects
  • Hollow biphasic calcium phosphate microspheres from glass dissolution and reprecipitation; Part I: Particle formation and characterization
  • Hollow biphasic calcium phosphate microspheres from glass dissolution and reprecipitation; Part II: In vivo studies of bone regeneration and blood vessel formation
  • Evaluation of 13-93 glass scaffolds with curved filaments to enhance bone formation in rat calvarial defects


xx, 172 pages

Note about bibliography

Includes bibliographic references.


© 2019 Youqu Shen, All rights reserved.

Document Type

Dissertation - Open Access

File Type




Thesis Number

T 11649

Electronic OCLC #