title: Freeze extrusion fabrication of 13-93 bioactive glass scaffolds for bone repair.
abstract: A solid freeform fabrication technique, freeze extrusion fabrication (FEF), was investigated for the creation of three-dimensional bioactive glass (13-93) scaffolds with pre-designed porosity and pore architecture. An aqueous mixture of bioactive glass particles and polymeric additives with a paste-like consistency was extruded through a narrow nozzle, and deposited layer-by-layer in a cold environment according to a computer-aided design (CAD) file. Following sublimation of the ice in a freeze dryer, the construct was heated according to a controlled schedule to burn out the polymeric additives (below ~500°C), and to densify the glass phase at higher temperature (1 h at 700°C). The sintered scaffolds had a grid-like microstructure of interconnected pores, with a porosity of ~50%, pore width of ~300 μm, and dense glass filaments (struts) with a diameter or width of ~300 μm. The scaffolds showed an elastic response during mechanical testing in compression, with an average compressive strength of 140 MPa and an elastic modulus of 5-6 GPa, comparable to the values for human cortical bone. These bioactive glass scaffolds created by the FEF method could have potential application in the repair of load-bearing bones.
authors.affiliation: Department of Mechanical and Aerospace Engineering, Missouri University of Science and Technology, Rolla, MO 65409, USA.
authors.forename: Nikhil D
authors.initials: ND
authors.lastname: Doiphode
authors.forename: Tieshu
authors.initials: T
authors.lastname: Huang
authors.forename: Ming C
authors.initials: MC
authors.lastname: Leu
authors.forename: Mohamed N
authors.initials: MN
authors.lastname: Rahaman
authors.forename: Delbert E
authors.initials: DE
authors.lastname: Day
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D018786:Bone Substitutes / Q000737:chemistry; D001842:Bone and Bones / Q000378:metabolism / Q000473:pathology*; D019245:Compressive Strength; D004548:Elasticity; D017102:Fracture Healing; D005898:Glass / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D011108:Polymers / Q000737:chemistry; D016062:Porosity; D011312:Pressure; D013314:Stress, Mechanical; D013696:Temperature; D013818:Thermogravimetry; D054457:Tissue Scaffolds / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D018786:Bone Substitutes; D011108:Polymers