Avaliação de peças de Poli(ácido lático) (PLA) impressas para aplicações biomédicas

Abstract

Poly (lactic acid) (PLA) has attractive properties for use in the biomedical area because of its biocompatibility. PLA is biodegradable, since it is capable of being disintegrated by biological agents, being also bioreabsorbable, since the product of its degradation participates in the metabolic process of the human organism. Among the manufacturing techniques of PLA parts for biomedical applications, 3D printing stands out as promising, mainly due to the possibility of production of customized and individualized pieces, as well as production by prototyping with high level of detail. However, more studies involving the alteration of the properties of the material when in contact with biological medium are still necessary to evaluate the application of parts in implantable devices. The objective of this work was to evaluate changes in the properties of PLA parts made by 3D printing when immersed in phosphate saline solutions for periods of 7, 14 and 30 days. The samples were evaluated for mass change, chemical changes (Fourier Transform Infrared Spectroscopy - FTIR), changes in dynamic-mechanical properties (DMA), mechanical tests in 3-point bending and fatigue. The results showed a change in mass to higher values after immersion for 7 days and lower for samples immersed for 14 and 30 days. The results suggest some chemical changes and changes in glass transition temperature. In addition, among the characterizations performed, the most relevant was the fatigue test, where the material presented a mean fatigue life reduction of 56.5% and 77% of the samples submerged in phosphate saline solution when compared to the non - submerged.