Molecular Imaging with Genetically Programmed Nanoparticles

Abstract

Nanoparticle research has greatly benefitted medical imaging platforms by generating new signals, enhancing detection sensitivity, and expanding both clinical and preclinical applications. For magnetic resonance imaging, the fabrication of superparamagnetic iron oxide nanoparticles has provided a means of detecting cells and has paved the way for magnetic particle imaging. As the field of molecular imaging grows and enables the tracking of cells and their molecular activities so does the possibility of tracking genetically programmed biomarkers. This chapter discusses the advantages and challenges of gene-based contrast, using the bacterial magnetosome model to highlight the requirements of in vivo iron biomineralization and reporter gene expression for magnetic resonance signal detection. New information about magnetosome protein interactions in non-magnetic mammalian cells is considered in the light of design and application(s) of a rudimentary magnetosome-like nanoparticle for molecular imaging. Central to this is the hypothesis that a magnetosome root structure is defined by essential magnetosome genes, whose expression positions the biomineral in a given membrane compartment, in any cell type. The use of synthetic biology for programming multi-component structures not only broadens the scope of reporter gene expression for molecular MRI but also facilitates the tracking of cell therapies.

Exploring the host range for genetic transfer of magnetic organelle biosynthesis

“…These findings have stimulated enormous efforts within the synthetic biology community to transfer magnetosome biosynthesis into more facile hosts, and even inspired ideas to borrow genetic parts from MTB for endogenous magnetization of cells from higher organisms [21][22][23] . Heterologous magnetosome biosynthesis in other, biotechnologically relevant and more tractable hosts would also alleviate some problems associated with the challenging cultivation and limited tractability of the available native and synthetic magnetic bacterial strains 24,25 .…”