PLA-Mg film degradation under in vitro environments supplemented with glucose and/or ketone bodies

Abstract

Materials used for the manufacture of implants may suffer alterations in their surface properties as a result of continuous contact with physiological fluids. Moreover, in biodegradable and bioabsorbable materials, such as polylactic acid (PLA), these changes may be more accentuated, and their biological response may be affected by the presence of proteins, enzymes or other compounds of an oxidizing character. This research proposes to study the degradation of PLA in a close-to-reality environment by supplementing the physiological buffer m-SBF with concentrations of glucose and ketone bodies of healthy individuals. To this end, parameters such as hydrophobicity, surface tension, topography and surface chemical composition of PLA films and PLA films doped with magnesium particles after degradation were evaluated to determine how these components influence these properties compared to degradation in standard buffer. The presence of glucose and/or ketone bodies in the degradation medium of PLA doped with magnesium particles altered the composition of the salt layers absorbed on the surface of the material due to the action of gluconate and/or hydroxybutyrate anions, which were able to coordinate with ions from the solution as well as Mg2+ cations from polymer degradation. The salt accumulation on polymeric films changes the surface mechanical response increasing the Young's modulus after degradation.