Jump to main content
Jump to site search

Core-Shell-Structured Nonstoichiometric Bioceramic Microspheres for Improving Osteogenic Capability


A rational design of fully interconnected porous constructs of biomaterials with controlled pore-wall bioactivity and biodegradation is of importance in the advancement of bone regenerative medicine. We hypothesize that the layered structure of hybrid bioceramics might produce time-dependent biological performances to tune osteogenic responses. We hereby developed the core-shell-structured nonstoichiometric Ca-silicate (nCSi) spheres and evaluated the effect of spatiotemporal distribution of bi-component nCSi on osteogenic capability. The alginate-based 4% Sr-, 6% Mg-, or 10 % Mg-doped nCaSi (i.e. CSi-Sr4, CSi-Mg6, CSi-Mg10) slurries were extruded into a Ca2+-rich solution through the core or shell layer of a coaxial bi-layer nozzle, and followed by drying and sintering treatments, the core-shell nCSi ceramic spheres were prepared. The improved sintering property and denser structure of CSi-Mg6 and CSi-Mg10 shells readily retarded bioactive ion release and biodegradation of CSi-Sr4@CSi-Mg6 and CSi-Sr4@CSi-Mg10 spheres compared with the CSi-Sr4@CSi-Sr4. When the spheres were implanted into the femoral bone defect in rabbits, the differences in biodegradation and bone regeneration rate in relation the microsphere scaffolds were measured at 6‒18 weeks post-implantation. The CSi-Sr4@CSi-Mg10 showed a slow biodegradation and new bone regeneration, whereas the CaSi-Sr4@CSi-Sr4 showed a much faster degradation such that a low osteogenic capacity was observed with prolongation of time. However, the CSi-Sr4@CSi-Mg6 spheres displayed expected biodegradation and osteogenic activity with time. These results confirm the slight tailoring in both doping ions and component distribution of nCSi is beneficial for adjusting the osteogenesis of core-shell spheres. By rationally choosing the foreign ion doping, this concept may represent a versatile strategy for the production of a variety of core-shell bioactive ceramics for bone regeneration and repair applications.

Back to tab navigation

Publication details

The article was received on 28 Aug 2017, accepted on 11 Oct 2017 and first published on 11 Oct 2017

Article type: Paper
DOI: 10.1039/C7TB02295F
Citation: J. Mater. Chem. B, 2017, Accepted Manuscript
  •   Request permissions

    Core-Shell-Structured Nonstoichiometric Bioceramic Microspheres for Improving Osteogenic Capability

    C. Zhuang, X. Ke, Z. Jin, L. Zhang, X. Yang, S. Xu, G. Yang, L. Xie, G. E. Prince, Z. Pan and Z. Gou, J. Mater. Chem. B, 2017, Accepted Manuscript , DOI: 10.1039/C7TB02295F

Search articles by author