Dispositivos poliméricos cardiovasculares: comportamento termomecânico e viabilidade celular Cardiovascular polymeric devices: thermomechanical behavior and cell viability

In recent decades new synthetic materials have been developed with adequate biofunctionality and biocompatibility to become a biomaterial. Biostable polymers have widespread use in the biomedical field, and many advances in polymeric biomaterials have been made in the search for improvements to cardiovascular implants. Currently, the most commonly used synthetic materials for the production of vascular grafts are PTFE and PET, due to their chemical stability after implant. In this work, a study of the thermal and mechanical properties of the commercial devices based on PET and PTFE is reported, as well as their cytotoxicity in mouse fibroblast cells, 3T3- NIH, through tests for the evaluation of cell viability (MTT test and VN). These materials showed high thermal stability (over 300 ° C), even after 270 days in vitro degradation and elastic behavior (maximal strain value of 186±22% by PET and 65±19% by PTFE). Cell viability by VN and MTT of PTFE device was more than 80%, thus, classified as non-cytotoxic. For PET device, VN test showed no cytotoxic effect, however the results obtained by MTT indicated that it causes alteration of mitochondrial function, independent of dose and time measured.