Biomedical Engineering Reference
In-Depth Information
In our previous other works,
in vitro
swelling and
in vivo
biocompatibility of radiation
crosslinked acrylamide and its co-polymers such as acrylamide (AAm) and
acrylamide/crotonic acid (AAm/CA), acrylamide/itaconic acid (AAm/IA), and
acrylamide/maleic acid (AAm/MA) hydrogels were investigated.
The radiation crosslinked AAm, AAm/CA, AAm/IA and (AAm/MA) co-polymers were
found to be well tolerated, non-toxic and highly biocompatible.
On the other hand, calcium phosphate ceramics and xenografts have been used in different
fields of medicine and dentistry. We demonstrated the effects of calcium phosphate
ceramics (Ceraform) and xenograft (Unilab Surgibone) in the field of experimentally created
critical size parietal bone defects in rats. Although Ceraform was less resorptive and not
osteoconductive properties, it could be considered as a biocompatible bone defect filling
material having a limited application alternative in dentistry and medicine. However,
xenograft seems biocompatible, osteoconductive, and could be used in a limited manner as a
filling material in osseous defects in clinical practice.
2.Toxicological effect of the water-soluble monomers
2.1 Monomers
Monomer is a molecule of any of a class of compounds, mostly organic, that can react with
other molecules of the same or other compound to form very large molecules, or polymers.
The essential feature of a monomer is polyfunctionality, the capacity to form chemical bonds
to at least two other monomer molecules. Bifunctional monomers can form only linear,
chainlike polymers, but monomers of higher functionality yield cross-linked, network
polymeric products. Toxicological effects of the monomers are changing from very low
(zero) to very high.
Some polymeric biomaterials such as hydrogels are produced by the effect of initiator such
as chemical initiator, heat, light or high energy radiation from the water soluble-monomers.
2.2 Cytotoxic effects
Biomaterial suitable for a biomedical application must be biocompatible at least on its
surface. In several previous studies, we investigated whether acrylamide, methacrylamide,
N-isopropylacrylamide, acrylic acid, 2-hydroxyethyl methacrylate, 1-vinyl-2-pyrrolidone
and ethylene glycol used in polimeric biomaterial production had cytotoxic effects (Unver
Saraydin et al., 2011). The cytotoxicity of xenograft (one of the alternative graft materials)
was also examined in vitro (Unver Saraydin et al., 2011).
The viability of cultured fibroblastic cell lines following all monomer applications except for
the ethylene glycol group were found to be decreased in all time intervals (Figure 1, 2), and
differences were statistically significant (p<0.05). In addition, the cell viability was
significantly (p<0.05) lower in the acrylamid application group when compared to the
control group. Acrylic acid demonstrated the maximum cytotoxic effect when compared to
the methacrylamide and ethylene glycol groups. On the other hand, the ethylene glycol
group showed no cytotoxicity for cells (Graphic 1).
In our study of the xenograft cytotoxic activities, the xenograft showed no cytotoxicity for
the cells (Figure 3). There was no decolorization zone around the samples. Although the
cells were directly in contact with the xenograft in the culture media, they did not show any
signs of injury and preserved their morphological characteristics and wholeness like those
seen in the controls.
