Randy Carney

Surface enhanced Raman scattering of extracellular vesicles: a new toolbox for clinical diagnostics 

When cancer is detected early, treatments are more effective and survival improves. There is a critical need to develop rapid, inexpensive, sensitive, and specific new platforms that identify tumor associated features in circulating biofluids in the earliest stages. Cancer pathology is dramatically mediated by cellular vesicle transport machinery via a number of key molecules trafficked in nanoscale extracellular vesicles (EVs). Accurate detection of the cell-specific biomaterials recruited and packaged in EVs has the potential to revolutionize identification and monitoring of cancer. 

My lab develops surface enhanced Raman scattering (SERS) platforms to analyze EVs for clinical diagnostics. Using SERS platforms, we have analyzed EVs isolated from dozens of patient samples across the spectrum of ovarian, endometrial, brain, lung, and head and neck cancer. We are able to detect as few as 600 EVs/mL. Notably, our SERS platform is not dependent on isolation method used to separate EVs, nor is affected by heavy lipoprotein contamination. We have pioneered methods for automating measurement based on machine learning algorithms that simulate the expertise of trained users. Using straightforward statistical modeling of spectral data, compared to histopathology analysis, SERS analysis of native EVs yielded a sensitivity, specificity, and accuracy over 90% in all cases. We found that the EV glycocalyx carries chemical information of great diagnostic value, that when removed dramatically reduces accuracy. By combining spectral data across patient biofluids using novel post-processing analysis, we were able to achieve accuracies rivaling the best performing diagnostics platforms reported in the literature (>95% across cancers).

SERS techniques represent an emerging tool to assess and account for the high heterogeneity of EVs isolated from clinical samples in an inexpensive, rapid, and label-free assay. We will continue to innovate on SERS substrate design to maximize the ease and automation of EV analysis, with the hope to facilitate clinical translation. 

Biography: Randy Carney is an Assistant Professor of Biomedical Engineering at the University of California, Davis. He received his B.S. in Chemistry in 2008 from University of Arkansas. His M.S. at Massachusetts Institute of Technology (2010) and PhD from EPFL in Switzerland (2013) focused on the impact of nanoscale surface structure in the organic ligand coating of metal nanoparticles on cell penetration. He continued his studies as a postdoctoral fellow at UC Davis in the fields of soft nanomaterials, including exosomes and related extracellular vesicles (EVs). His group engineers platforms to examine the use of EVs as next-generation cancer biomarkers and therapeutics.