In-vivo analysis of iron-gold composite nanoparticles as potential exogenous contrast agents for magnetomotive optical coherence tomography (MMOCT)

Abstract

Magnetomotive optical coherence tomography (MMOCT) is a functional modification of conventional optical coherence tomography (OCT). It utilizes the nano-scale displacement embedded magnetic nanoparticles (MNPs) and subsequent amplitude and phase changes in OCT interferogram scattered from samples. We report a new robust method for ‘phase-lock-in’ detection of MMOCT signals and subsequent imaging. We validated this method utilizing iron-gold (Fe-Au) composite nanoparticles as an exogenous contrast agent for MMOCT. High contrast and specific background-subtracted images was generated for Fe-Au MNPs targeted samples. MMOCT with MNPs imaging systems was corroborated with tissue phantoms and in-vivo swiss albino mice model with modulating external magnetic field (resonant frequency of 30 Hz). A time-dependent dynamics study of diffusion for MNPs inside the tissue of mice as a function of time and depth is also reported.