title: Bioactive glass scaffolds for bone regeneration and their hierarchical characterisation.
abstract: Scaffolds are needed that can act as temporary templates for bone regeneration and actively stimulate vascularized bone growth so that bone grafting is no longer necessary. To achieve this, the scaffold must have a suitable interconnected pore network and be made of an osteogenic material. Bioactive glass is an ideal material because it rapidly bonds to bone and degrades over time, releasing soluble silica and calcium ions that are thought to stimulate osteoprogenitor cells. Melt-derived bioactive glasses, such as the original Bioglass composition, are available commercially, but porous scaffolds have been difficult to produce because Bioglass and similar compositions crystallize on sintering. Sol-gel foam scaffolds have been developed that avoid this problem. They have a hierarchical pore structure comprising interconnected macropores, with interconnect diameters in excess of the 100 microm that is thought to be needed for vascularized bone ingrowth, and an inherent nanoporosity of interconnected mesopores (2-50 nm) which is beneficial for the attachment of osteoprogenitor cells. They also have a compressive strength in the range of cancellous bone. This paper describes the optimized sol-gel foaming process and illustrates the importance of optimizing the hierarchical structure from the atomic through nano, to the macro scale with respect to biological response.
authors.affiliation: Department of Materials, Imperial College London, South Kensington Campus, London, UK. julian.r.jones@imperial.ac.uk
authors.forename: J R
authors.initials: JR
authors.lastname: Jones
authors.forename: S
authors.initials: S
authors.lastname: Lin
authors.forename: S
authors.initials: S
authors.lastname: Yue
authors.forename: P D
authors.initials: PD
authors.lastname: Lee
authors.forename: J V
authors.initials: JV
authors.lastname: Hanna
authors.forename: M E
authors.initials: ME
authors.lastname: Smith
authors.forename: R J
authors.initials: RJ
authors.lastname: Newport
mesh_terms: D000818:Animals; D001846:Bone Development / Q000502:physiology*; D001861:Bone Regeneration / Q000502:physiology*; D018786:Bone Substitutes / Q000737:chemistry*; D006801:Humans; D008420:Manufactured Materials; D023822:Tissue Engineering / Q000295:instrumentation* / Q000379:methods*; D054457:Tissue Scaffolds
chemical_list: D018786:Bone Substitutes