Mechanical properties and shape memory effect of 3D-printed PLA-based porous scaffolds. (April 2016)

• Record Type: Journal Article
• Authors: Senatov, F.S.; Niaza, K.V.; Zadorozhnyy, M.Yu.; Maksimkin, A.V.; Kaloshkin, S.D.; Estrin, Y.Z.
• Is Part Of: Journal of the mechanical behavior of biomedical materials. Volume 57(2016)
• Page Start: 139
• Page End: 148
• Publication Date: 2016-04
• Subjects: Polylactide -- Hydroxyapatite -- 3D-printingShape memory effect -- Scaffold -- Polymer composite; Biomedical materials -- Periodicals; Biomedical materials -- Mechanical properties -- Periodicals; Biomedical materials; Biomedical materials -- Mechanical properties; Periodicals; Electronic journals; 610.28
• DOI: 10.1016/j.jmbbm.2015.11.036
• Languages: English
• ISSNs: 1751-6161

Abstract

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. Graphical abstract: Highlights: PLA/15%HA scaffolds with recovery stress of 3.0 MPa were obtained by 3D-printing. HA particles act as nucleation centers and form an additional rigid fixed phase. HA particles inhibit growth of cracks during compression-heating-compression cycles. SME results in "self-healing" by narrowing the cracks with shape recovery of 98%. PLA/15%HA porous scaffolds may be used as self-fitting bone implants.