Structural characterisation of hypoxia-mimicking bioactive glasses

DOI: 10.1039/c3tb00408b

Authors: Jodie M. Smith (University of Kent) , Gabriel J. Cuello (Institut Laue-Langevin) , Robert J. Newport (University of Kent at Canterbury) , Richard A. Martin (University of Aston)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Journal Of Materials Chemistry B

State: Published (Approved)
Published: January 2013

Abstract: Nickel and cobalt are both known to stimulate the hypoxia-inducible factor-1 (HIF-1α), thus significantly improving blood vessel formation in tissue engineering applications. We have manufactured nickel and cobalt doped bioactive glasses to act as a controlled delivery mechanism of these ions. The resultant structural consequences have been investigated using the methods of isotopic and isomorphic substitution applied to neutron diffraction. The structural sites present will be intimately related to their release properties in physiological fluids such as plasma and saliva, and hence the bioactivity of the material. Detailed structural knowledge is therefore a prerequisite for optimising material design. Results show that nickel and cobalt adopt a mixed structural role within these bioactive glasses occupying both network-forming (tetrahedral) and network-modifying (5-fold) geometries. Two thirds of the Ni (or Co) occupies a five-fold geometry with the remaining third in a tetrahedral environment. A direct comparison of the primary structural correlations (e.g. Si–O, Ca–O, Na–O and O–Si–O) between the archetypal 45S5 Bioglass® and the Ni and Co glasses studied here reveal no significant differences. This indicates that the addition of Ni (or Co) will have no adverse effects on the existing structure, and thus on in vitro/in vivo dissolution rates and therefore bioactivity of these glasses.

Subject Areas: Materials, Chemistry, Biology and Bio-materials


Instruments: B18-Core EXAFS

Other Facilities: D4 at ILL

Added On: 15/01/2013 09:50

Documents:
c3tb00408b.pdf

Discipline Tags:

Biomaterials Chemistry Materials Science

Technical Tags:

Spectroscopy X-ray Absorption Spectroscopy (XAS) Extended X-ray Absorption Fine Structure (EXAFS) X-ray Absorption Near Edge Structure (XANES)