Mapping the density and mineral phase of calcium in bone at the interface with biomaterials using scanning x-ray microscopy

Abstract

Orthopaedic surgery often involves the insertion of a prosthetic implant. For successful and rapid healing, it is important for the prosthesis to make a close and well integrated bond with the bone tissue. To assist this integration, a number of “biomaterials” are on trial as components in the prosthetic implants. Much work is in progress to determine the phase, composition and density of bone mineral at the bone/biomaterial interface. It is expected that the results of this work can be used to develop synthetic calcium phosphates which can be incorporated in prosthetic implants. The composition of bone and biomaterials has been investigated using techniques such as x-ray diffraction, Infra-red, NMR and EXAFS on homogenized samples. However, these studies do not determine the spatial distribution of the bone mineral, its density, localized mineral phase or cellular integration with biomaterials. Electron microscopy with electron probe microanalysis, light and Infra-red microscopy can indicate the presence of mineral in relation to the tissue morphology, but do not give a spatial measure of the density or chemical phase of the mineral at the sub micron level.

Soft X-ray microscopes and their biological applications

“…Studies of the reaction of the body to bone implants are also being pursued (Buckley et al 1994). It appears that if the implant (often made of titanium) is coated with a well bonded layer of calcium apatite, the host makes use of this coating, and incorporates it into the remodelled bone structure.…”