Mechanical properties and shape memory effect of 3D-printed PLA-based porous scaffolds

F. S. Senatov, K. V. Niaza, M. Yu Zadorozhnyy, A. V. Maksimkin, S. D. Kaloshkin, Y. Z. Estrin

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200 Citations (Scopus)

Abstract

In the present work polylactide (PLA)/15 wt% hydroxyapatite (HA) porous scaffolds with pre-modeled structure were obtained by 3D-printing by fused filament fabrication. Composite filament was obtained by extrusion. Mechanical properties, structural characteristics and shape memory effect (SME) were studied. Direct heating was used for activation of SME. The average pore size and porosity of the scaffolds were 700. μm and 30 vol%, respectively. Dispersed particles of HA acted as nucleation centers during the ordering of PLA molecular chains and formed an additional rigid fixed phase that reduced molecular mobility, which led to a shift of the onset of recovery stress growth from 53 to 57 °C. A more rapid development of stresses was observed for PLA/HA composites with the maximum recovery stress of 3.0 MPa at 70 °C. Ceramic particles inhibited the growth of cracks during compression-heating-compression cycles when porous PLA/HA 3D-scaffolds recovered their initial shape. Shape recovery at the last cycle was about 96%. SME during heating may have resulted in "self-healing" of scaffold by narrowing the cracks. PLA/HA 3D-scaffolds were found to withstand up to three compression-heating-compression cycles without delamination. It was shown that PLA/15%HA porous scaffolds obtained by 3D-printing with shape recovery of 98% may be used as self-fitting implant for small bone defect replacement owing to SME.

Original languageEnglish
Pages (from-to)139-148
Number of pages10
JournalJournal of the Mechanical Behavior of Biomedical Materials
Volume57
DOIs
Publication statusPublished - 1 Apr 2016
Externally publishedYes

Keywords

  • 3D-printingShape memory effect
  • Hydroxyapatite
  • Polylactide
  • Polymer composite
  • Scaffold

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