In vitro degradation of biodegradable polylactic acid/Mg composites: Influence of nature and crystalline degree of the polymeric matrix Articles uri icon

authors

  • CIFUENTES CUELLAR, SANDRA CAROLINA
  • Lieblich, Marcela
  • Saldaña, Laura
  • Gonzalez-Carrasco, Jose Luis
  • Benavente, Rosario

publication date

  • June 2019

volume

  • 6

International Standard Serial Number (ISSN)

  • 2589-1529

abstract

  • A deeper knowledge on the degradation pattern of a biodegradable material is required before considering it for a specific application as a bioabsorbable implant. In the last few years, composites formed by polylactic-acid reinforced with Mg-based particles have been proposed for biodegradable implants. The aim of the present work is to study the effect of the type and crystalline degree of the polymeric matrix on in vitro degradation kinetics of PLA/Mg composites. The effect of the nature of the matrix has been studied by comparing a composite with a poly-L-lactic (PLLA) matrix with another with a poly-L,D-lactic (PLDA) matrix. The influence of the crystalline degree has been studied by comparing a near amorphous with a high crystalline composite. The degradation behaviour has been determined through a joint analysis of the microstructure, the changes in mass and water intake, the pH evolution in buffered and non-buffered media, and the amount of H2 released up to 28 days of immersion. The viability of human mesenchymal stem cells (MSCs) on the composites was also evaluated. Results show that a PLDA matrix is more effective lowering the degradation rate of Mg particles than PLLA. The crystalline degree plays a major role in PLA/Mg composites degradation. The composite with the near amorphous matrix exhibited the lowest degradation rate and the highest cell viability. Whereas, cell viability decreases markedly on the high-crystalline composites, which is likely related to the accelerated release of degradation products. These data highlight the importance of matrix crystallinity on the degradation kinetics and cytocompatibility of PLA/Mg composite

keywords

  • crystallinity; cytocompatibility; hydrogen release; in vitro degradation; magnesium; polylactic acid