Non-destructive three-dimensional evaluation of biocompatible materials by microtomography using synchrotron radiation

Microtomography based on synchrotron radiation sources is a unique technique for the 3D characterization of different materials with a spatial resolution down to about 1 μm. The interface between implant materials (metals, ceramics and polymers) and biological matter is non-destructively accessible, i.e. without preparation artifacts. Since the materials exhibit different X-ray absorption, it can become impossible to visualize implant material and tissue, simultaneously. Here, we show that coating of polymer implants, which are invisible in bone tissue, does not only improve the interfacial properties but also allow the imaging of the interface in detail. Titanium implants, on the other hand, absorb the X-rays stronger than bone tissue. The difference, however, is small enough to quantify the bone formation near interface. Another advantage of microtomography with respect to classical histology is the capability to examine samples in a hydrated state. We demonstrate that ceramic hollow spheres can be imaged before sintering and fibroblasts marked by OsO₄ are visible on polymer textiles. Consequently, scaffolds of different materials designed for tissue engineering and implant coatings can be optimized on the basis of the tomograms.