Electron microscopy to characterise nanoparticles in the biological environment

Nowadays the use of nanomaterials has led a growing interest in biomedical application as drug delivery systems for the treatment and the diagnosis of different pathologies. Different analytical techniques have been applied to characterise nanoparticles in the biological environment. However, in the attempt to describe in detail the interaction of NPs with the living systems and to detect the possible occurrence of cell damage or death, electron microscopies proved to be especially suitable and actually are irreplaceable techniques thanks to their image resolution at the nanoscale. In this review article, the attention will first be focused on the influence of features on their interaction with tissues and cells; then, the advantages and limits of transmission and scanning electron microscopy to evaluate the suitability of nanovectors as drug-delivery systems will be discussed.