89-91 - Polskie Stowarzyszenie Biomateriałów

2 weeks designed hernia mesh Dallop® M compared to
polypropylene hernia mesh Duramesh TM presented slight irritation;
after 4,12, 26 and 52 weeks designed polypropylene
hernia mesh Dallop® compared to polypropylene mesh
Duramesh TM presented no irritation.
- In histological evaluation in muscle tissue in all test
terms (after 2,4,12,26 and 52 weeks) designed hernia mesh
Dallop® M compared to polypropylene mesh Duramesh TM
presented no irritation.
- The process of Dallop® M integration caused the formation
of thin layer of connective tissue with fat infiltration
around the mesh fibers both in subcutaneous and muscle
tissue.
- Reaction of subcutaneous and muscle tissues in test
terms 2,4,12,26 and 52 weeks against implanted samples
of designed hernia mesh Dallop® M allows to recognize it
as fully biocompatible material i range of ISO 10993-6:2005
and PN-EN ISO 10993-6:2007.
fIg.17. microscopic view 52 weeks after implantation
of control hernia mesh duramesh tm into muscles
tissue. In the centre the round sample of mesh surrounded
by the band of fibre connective tissue, The richcell
connective tissue in the straight neighbourhood
of the fibre the rich-cell connective tissue is visible .
Stain vg. magn.560x.
References
The tests were planned and conducted in accordance with the
following standards:
- PN-EN ISO 10993-1: 2003 ‘’Biological evaluation of medical
devices- Part 1.: Evaluation and test’’;
- PN-EN ISO 10993-2: 2002 ‘’Biological evaluation of medical devices-
Part 2.: Requirements as for animal management’’;
- PN-EN ISO 30993-6:2000 ‘’ Biological evaluation of medical
devices- Part 6.: Test for local effects after implantation’’;
- ISO/DIS 10993-6, 2004-2005, Biological evaluation of medical
devices- Part 6: Test for local effects after implantation, Annex E
- PN-EN ISO 10993-6:2007 ‘’ Biological evaluation of medical
devices- Part 6.: Test for local effects after implantation’’
EffECT of TITanIum
on the sinteRing anD
mICRoSTRuCTuRE of Ti-DopeD
hyDRoxyapatite
A.ŚLóSARCZyK, A.ZIMA, Z.PASZKIEWICZ, J.SZCZEPANIAK
AGh–uniVerSity oF Science And technoloGy, Al. MicKiewi-
czA 30, 30-059 crAcow, PolAnd
[Engineering of Biomaterials, 89-91, (2009), 37]
Introduction
Calcium phosphates (CaPs): hydroxyapatite (HA
– Ca 10(PO 4) 6(OH) 2) and βTCP (βCa 3(PO 4) 2) are widely used
in hard tissue replacement in orthopaedic, maxillofacial
surgery and dentistry. Despite of very high biocompatibility
and bioactivity, due to poor mechanical strength and low
fracture toughness their medical applications are limited
to unloaded or low-loaded implants and coatings. One approach
in the design of the next generation of CaPs implants
is to dope synthetic HAp with small amounts of different
elements which affect properties of the obtained materials.
In this study we report the influence of titanium additives on
sinterability, phase composition, microstructure and flexural
strength of the Ti-modified hydroxyapatite ceramics.
materials and methods
Hydroxyapatite powders doped with various concentrations
of Ti (0.5; 1.0 and 2.0wt%) were produced by a wet
method. In such synthesis CaO, H 3PO 4 and TiCl 3 were applied
as reactants. The initial powders were pressed under
the pressure of 100 MPa to rectangular samples 8×40mm.
Samples of undoped HA were prepared for reference. All
the samples were sintered at 1250°C for 2h. The apparent
density and open porosity of the materials were measured
by Archimedes method. Phase composition of the initial
powders and sintered materials was examined by X-ray
diffraction (Philips diffractometer). The phase quantification
was made by the Rietveld method using the program
X’pert Pro Plus. The unit cell parameters for HA and αTCP
were determined. Fracture surfaces of the specimens were
studied by SEM (Hitachi S4700). Flexural strength was
measured by Instron 3345.
Results
All the CaPs materials based on Ti modified HA exhibited
lower apparent density and higher porosity (Po~9%,
Pt~10% for HA with 2 wt.% of Ti) in comparison to reference
(not-doped HA) samples (P o~4%, P t~8%). Ti negatively influenced
the densification and sinterability of the initial powders.
XRD studies showed that Ti-doped HA decomposed
partially to αTCP and a new crystalline phase, perovskite
(CaTiO 3) was formed. Ti ions partially substituted Ca ions
in HA structure which resulted in changes of HA unit cells.
SEM studies confirmed the presence of CaTiO 3 homogeneously
distributed on the surfaces and the grain boundaries of
calcium phosphate. The flexural strength of doped ceramics
decreased with increasing titanium amount from 88MPa
(undoped hydroxyapatite) to 53MPa for materials with 2wt%
addition of titanium.
Conclusions
Sintering of Ti-doped HA results in threephasic materials
composed of modified HA (with Ti in the structure), αTCP and
perovskite – CaTiO 3 (5.9wt% for the material with 2wt% of
Ti). The formation of a solid solution in the HA-TiO 2 system
was observed. Titanium additives influence phase composition,
sinterability and microstructure of HA ceramics.
acknowledgments
This work has been supported by the Polish Ministry of
Science and Higher Education. Project No R 15 003 03.