Resumo:
Epoxy resins are thermosetting polymers that cure when mixed with a catalyzing agent or
"hardener”. The epoxy network formation is strongly dependent of the stoichiometry ratio
between the functional groups of the epoxy and hardener, respectively. This work describes
the physicochemical and in vitro biological properties of tree epoxy networks based on
diglycidyl ether of bisphenol-A (DGEBA) cured with triethylenetetramine (TETA),
diethylenetriamine (DETA) and 1-(2-aminoethyl)piperazine (AEP). The aim of this work was
the development of epoxy formulations that will be interesting for orthopedic applications.
The epoxy formulations were optimized by differential scanning calorimetry (DSC) for
determination of functional groups. The microhardness analyses were accomplished in the
cured and pos - cured DGEBA/TETA, DGEBA/DETA and DGEBA/AEP formulations. The
biological interactions between the obtained materials and mammalian cells (Chinese ovary
Hamster cells-CHO) and blood compatibility were studied by in vitro conditions. The
microhardness test assays showed that both, pos-cured and stoichiometric formulations
showed a largest hardness values. The hardness increase of the cured stoichiometric
DGEBA/TETA, DGEBA/DETA and DGEBA/AEP formulations relatively to the pos cured
systems, were 3.16%, 10.76% and 7.39%, respectively. These results suggests that the best
mechanical properties are obtained for the pos cured stoichiometric compositions indicating
that a more complete network DGEBA structure are obtained. The biocompatibility studies
indicate that the DGEBA/TETA, DGEBA/AEP and DGEBA/DETA epoxy networks have
low citotoxicity to mammalian cells. The protein adsorption assays onto DGEBA/TETA,
DGEBA/AEP and DGEBA/DETA surfaces showed that the epoxy networks adsorbed more
albumin than fibrinogen. However, the scanning electron microscopy indicates that the
DGEBA/TETA network adhere more blood platelets than DGEBA/AEP and DGEBA/DETA
networks, probably due to the fibrinogen adsorption. The results about platelet adhesion and
thrombus formation indicated that DGEBA/AEP and DGEBA/DETA networks exhibits good
hemocompatible behavior.
