The Translational Approach of Colloidal Surface-Enhanced Raman Nanoparticles— Multiplexed Biomedical Imaging and In Vivo Clearance

In this presentation, I will present our chemistry efforts to engineer surface-enhanced Raman scattering (SERS) nanoparticles for multiplexed biomedical imaging and its translation.<br/>(i) Along with the biomedical applications of SERS for molecular assays and sensing, we have utilized the high spectral resolution of SERS signals for multiplexed preclinical imaging of cancer. To gain sufficient brightness for the in vivo imaging condition, we controlled SERS nanoparticles oligomerization to produce multicore SERS nanoparticles, which displayed Raman scattering as bright as near-infrared (NIR) fluorescence. The large enhancement factor from hot-spot geometry of the multicore nanoparticles along with the NIR-resonant Raman reporters produced the SERS signals as bright as NIR fluorescence. With the multicore SERS nanoparticle palettes, we demonstrated noninvasive and five-plex ratiometric imaging of tumors in live preclinical models, which simulated the noninvasive assessment of multiple biological targets within tumors (Yu JH <i>et al</i>. ACS Nano 2021).<br/>(ii) While the colloidal SERS nanoparticles have limited their use in humans because of their inability to excrete from the body, we address this problem by creating supraparticles composed of small-sized nanoclusters. We performed the FDTD simulation of the supraparticle design, in which the maximum enhancement factor of 10^6 was achieved. Then, we chemically synthesized bright supraparticles that enabled in vivo Raman imaging of rodent models. Furthermore, the supraparticles were highly excretable, offering great potential for clinical application of the surface-enhanced Raman scattering imaging by replacing non-excretable SERS nanotags (Yu JH <i>et al</i>. bioRxiv 2022).<br/><br/>References<br/>1. Yu JH <i>et al</i>. Noninvasive and Highly Multiplexed Five-Color Tumor Imaging of Multicore Near-Infrared Resonant Surface-Enhanced Raman Nanoparticles <i>In Vivo. </i>ACS Nano<i> </i><b>2021,</b><i> 15, </i>19956-19969.<br/><i>2. Yu </i>JH<i> et al. </i>Highly Excretable Gold Supraclusters for Translatable In Vivo Raman Imaging of Tumors. bioRxiv 2022. (https://www.biorxiv.org/content/10.1101/2022.10.18.512314v1).