Estudo das propriedades biocompatíveis de redes epoxídicas do éter diglicidílico do bisfenol-a

Abstract

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.