Cell Compatible Trimethoprim-Decorated Iron Oxide Nanoparticles Bind Dihydrofolate Reductase for Magnetically Modulating Focal Adhesion of Mammalian Cells

On the basis of the high affinity binding of trimethoprim (TMP) to Escherichia coli dihydrofolate reductase (eDHFR), TMP-decorated iron oxide nanoparticles bind to eDHFR with high affinity and specificity, which allows magnetic modulation of focal adhesion of mammalian cells adhered to a surface. Besides being the first example of nanoparticles that selectively bind to eDHFR, the biocompatibility of the conjugate of TMP-iron oxide nanoparticles renders a convenient and versatile platform for investigating the cellular responses to specific, mechanical perturbation of proteins via a magnetic force.