Barbieri Thesis - BioMedical Materials program (BMM)

CChapter
3 – Instructive
composit tes: effect of filller
content on osteoinduction
Surface mmineralization
could play a role. At the end of the Sixties, a po olymer (i.e.
polyHEMAA)
was reporteed
to induce bone formatioon
under the skin of pigs and it was
observed tthat
the surfacce
of the poly ymer had minneralized
before
bone forma ation.
connectionn
of in vitro suurface
minera alization with mmaterial–direc
cted bone ind
been propoosed.
Osteoinnductivity
in muscle m of doggs
of titanium implants, wit
that did or did not mineraalize
in vitro in n SBF, was stuudied.
[221] A
uction has
h surfaces
Figure 7. Overview
(with sccanner)
of staine ed sections (blue
methylene/bas sic fuchsin staining)
after 12
weeks implanntation.
(a) 0% CCaP,
(b) 10% CaP P, (c) 20% CaP aand
(d) 40% CaP P implants. It can be observed
that bone forrmation
occurred only in 40% CaP
composites (dd)
while the porous
structure of 0%
CaP, 10%
CaP and 20% % CaP implants ccollapsed
(a, b an nd c): no porous architecture of th he materials is cle early visible.
64
Figgure
8. Bone ind duction in 40% CaP C after 12
weeeks
of intramusc cular implantation.
An active,
but t not yet mineraliz zed, bone formation
zone with
a definite osteob blast–seam (bla ack arrows)
covvering
an osteoid d layer (*) is visib ble. The inner
parrt
of the trabeculu um is an immatur re woven and
minneralized
bone with the typica al large and
polyygonal
osteocyte es (white arrows) .