Biomedical Engineering Reference
In-Depth Information
shown that baghdadite spheres induced a higher rate of new bone forma-
tion in the defects than did β-TCP spheres. Immunohistochemical analysis
showed greater expression of Col I and OPN in the baghdadite group com-
pared to the β-TCP groups (Luo et al. 2012). The results indicate that silicate
bioceramics possess excellent
in vivo
osteostimulation. It is suggested that
there are two main factors to contribute to the excellent
in vivo
osteogenesis
of silicate bioceramics. One is that the released Si ions from silicate bioceram-
ics stimulate osteogenic differentiation for bone-forming cells and further
promote
in vivo
osteogenesis and angiogenesis; the other is that their excel-
lent apatite-mineralization ability may contribute to their
in vivo
bioactivity
and in turn stimulate
in vivo
osteogeneis.
2.6 Conclusion
This chapter reviewed the research advancement of silicate system bioc-
eramics, including preparation methods, mechanical strength, apatite min-
eralization, dissolution, and
in vitro
and
in vivo
osteostimulation properties.
Their osteostimulation properties and corresponding mechanism were
highlighted. By comparing silicate bioceramics with conventional calcium
phosphate bioceramics, it is found that some silicate bioceramics have supe-
rior physicochemical and osteostimulation properties. Silicate bioceram-
ics possess two significant features: (1) silicate bioceramics could promote
osteogenic differentiation of several kinds of stem cells, including bone mar-
row stromal cells, adipose stem cells, dental pulp, and periodontal cells; and
(2) silicate bioceramics could induce
in vitro
and
in vivo
angiogenesis. It is
known that how to improve the osteogenesis and angiogenesis of biomateri-
als remain a significant challenge; silicate bioceramics may provide a new
way to solve these problems. It is widely accepted that the development of
the third generation of biomaterials is a common goal for tissue regeneration
application, which biomaterials in the human physiological environment
should stimulate the functional response to tissue cells at the molecular
level response and further promote new bone tissue formation. Silicate bio-
ceramics have been confirmed to activate cell response at the gene level and
promote new bone formation. Therefore, it is reasonable to regard silicate
bioceramics as a typical representative of the third generation of bioactive
materials. Moreover, since silicate bioceramics have a relatively wide range
of chemical composition, their physical, chemical, and biological properties
could be well optimized to satisfy the requirements of tissue regeneration.
We believe that some silicate bioceramics are promising for clinical appli-
cation in 5 years. To achieve this goal, more studies are needed: (1) the
molecular mechanism of osteostimulation by silicate bioceramics should be
further clarified by culturing stem cells; and (2) the
in vivo
osteogenesis and
Search WWH ::
Custom Search