The development of cryo-FIBSEM techniques for the sectioning and TEM analysis of the cell-biomaterial interface

The imaging and chemical mapping of the interface between cells and biomaterials using transmission electron microscopy (TEM) has often proved to be an interesting a challenge, due to the limitations of standard specimen preparation techniques. In the past, ultramicrotomy has mainly been used to section tissue, however harder materials such as the interface between bone and implanted biomaterials have also been sectioned [1]. This has provided an effective and generally reliable methodology for the analysis of materials which are close in material hardness, However, the preparation of ultrathin samples of soft cells attached to hard materials may introduce cutting artefacts into the specimen. Also, ultramicrotomy requires cells to be chemically fixed, dehydrated and embedded in resin prior to cutting, consuming time and resources. Recently, cryo focused ion beam scanning electron microscopy (cryo-FIBSEM) coupled with cryo transfer for TEM has emerged as an alternative pathway to ultramicrotomy for the preparation of such samples.