title: Chitosan/bioactive glass nanoparticles scaffolds with shape memory properties.
abstract: We propose a combination of chitosan (CHT) with bioactive glass nanoparticles (BG-NPs) in order to produce CHT/BG-NPs scaffolds that combine the shape memory properties of chitosan and the biomineralization ability of BG-NPs for applications in bone regeneration. The addition of BG-NPs prepared by a sol-gel route to the CHT polymeric matrix improved the bioactivity of the nanocomposite scaffold, as seen by the precipitation of bone-like apatite layer upon immersion in simulated body fluid (SBF). Shape memory tests were carried out while the samples were immersed in varying compositions of water/ethanol mixtures. Dehydration with ethanol enables to fix a temporary shape of a deformed scaffold that recovers the initial geometry upon water uptake. The scaffolds present good shape memory properties characterized by a recovery ratio of 87.5% for CHT and 89.9% for CHT/BG-NPs and a fixity ratio of 97.2% for CHT and 98.2% for CHT/BG-NPs (for 30% compressive deformation). The applicability of such structures was demonstrated by a good geometrical accommodation of a previously compressed scaffold in a bone defect. The results indicate that the developed CHT/BG-NPs nanocomposite scaffolds have potential for being applied in bone tissue engineering.
authors.affiliation: 3B's Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence of Tissue Engineering and Regenerative Medicine, Avepark - Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017 Barco GMR, Portugal; ICVS/3B's, PT Government Associate Laboratory, Braga/Guimarães, Portugal.
authors.forename: Cristina O
authors.initials: CO
authors.lastname: Correia
authors.affiliation: 3B's Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence of Tissue Engineering and Regenerative Medicine, Avepark - Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017 Barco GMR, Portugal; ICVS/3B's, PT Government Associate Laboratory, Braga/Guimarães, Portugal.
authors.forename: Álvaro J
authors.initials: ÁJ
authors.lastname: Leite
authors.affiliation: 3B's Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence of Tissue Engineering and Regenerative Medicine, Avepark - Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017 Barco GMR, Portugal; ICVS/3B's, PT Government Associate Laboratory, Braga/Guimarães, Portugal. Electronic address: jmano@dep.uminho.pt.
authors.forename: João F
authors.initials: JF
authors.lastname: Mano
mesh_terms: D001031:Apatites / Q000737:chemistry; D001826:Body Fluids / Q000737:chemistry; D048271:Chitosan / Q000737:chemistry*; D000431:Ethanol / Q000737:chemistry; D005898:Glass / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D017550:Spectroscopy, Fourier Transform Infrared; D013314:Stress, Mechanical; D023822:Tissue Engineering; D054457:Tissue Scaffolds; D014867:Water / Q000737:chemistry; D055114:X-Ray Microtomography
chemical_list: D001031:Apatites; D014867:Water; D000431:Ethanol; D048271:Chitosan
keywords: Bioactive glass nanoparticles; Bioactivity; Biomimetic; Chitosan; Hydromechanical cyclic test; Shape memory