TY - JOUR

T1 - Bioactive glass scaffolds for bone regeneration and their hierarchical characterisation

AU - Jones, Julian R.

AU - Lin, S.

AU - Yue, S.

AU - Lee, P. D.

AU - Hanna, John V.

AU - Smith, Mark E.

AU - Newport, Robert J.

PY - 2010/12

Y1 - 2010/12

N2 - 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 μm 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.

AB - 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 μm 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.

KW - bioactive glass

KW - scaffolds

KW - tissue engineering

KW - bone regeneration

KW - NMR

KW - XRD

KW - nanostructure

KW - image analysis

KW - X-ray microtomography

U2 - 10.1243/09544119JEIM836

DO - 10.1243/09544119JEIM836

M3 - Journal article

VL - 224

SP - 1373

EP - 1387

JO - Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine

JF - Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine

SN - 0954-4119

IS - 12

ER -