Characterization of silver nanoparticles for biomedical applications by means of quantitative analysis of TEM micrographs

In the recent years, an increasing interest has been directed toward the exploitation of silver nanoparticle technology in the development of bioactive biomaterials as well as in food and general biomedical applications. The antibacterial effect and the toxicity toward eukaryotic cells seem to be related, among others, to size and shape of such nanoparticles. A quantitative characterization of their morphology allows for a better understanding of their formation and stabilization improving their efficacy and safety in the design of the nanocomposite system. To this end, an image analysis methodology is proposed in the present paper. Starting from Transmission Electron Microscopy (TEM) images of the nanoparticles and by means of proper segmentation, the proposed automated protocol can be employed as a size calculator as well as a shape descriptor. This methodology has been applied to a silver nanoparticle-polysaccharide nanocomposite system developed for biomaterials applications [1]. This study is a first step towards the development of automatic tools that are able to quantitatively analyze TEM images overcoming the subjectivity of human visual inspection.