Nanophotonics, Liquid Biopsies and Extracellular Vesicles: Emerging Approaches for Tomorrow’s Diagnostics

Speaker: Tatu Rojalin, Ph.D.
Affiliation: Postdoctoral Research Scientist, UC Davis

Abstract: All cells investigated to date endogenously secrete nanoscale extracellular vesicles (nEVs) into circulation and other bodily fluids, hence offering unprecedented potential for new diagnostic strategies. Fundamentally nEVs are lipid-bilayer enveloped nanoscale assemblies (typically ~40-1000 nm in diameter), and their biomolecular makeup comprises lipids, coding and non-coding nucleic acids, biologically active peptides, carbohydrates and hormones, among others. Different types of nEVs have been found to control – or to be associated with – a myriad of homeostatic processes and numerous physiological findings implicate that nEVs can mediate pathological disorders such as cardiovascular and metabolic diseases, inflammatory diseases, neurological disorders (e.g. Alzheimer’s disease), and cancers. Interestingly, cancer cells make efficient use of their autologous nEVs that can carry cancer-specific and tissue-specific biomolecules and are capable of acting in their local environment as well as mediating endocrine-resembling effects over distances. Therefore, nEVs are powerful mediators in intra- and intercellular biochemical communication. They constitute a potential group of biomarker nanoparticles for liquid biopsies, whereby disease-specific nEVs in patient’s body fluid can be explored and characterized instead of invasive surgical procedures.  Although rich in biomolecular information, the broad compositional heterogeneity, hurdles in isolating nEV subpopulations and the low frequency of disease-associated nEVs amongst healthy nEV background in biofluids poses a great challenge in translating promising technologies into useful clinical diagnostic platforms. However, nanophotonics, for example label-free nanoplasmonic techniques, i.e. harnessing the unique interaction of light with nanoscale metallic materials, have the potential to provide completely new insights into sensitive biomedical detection and imaging of nEVs.  In his talk, Dr. Rojalin will elucidate how nanoplasmonic, light scattering and light interference-based methodologies can be used to detect and characterize nEVs. The emphasis will be on structural analysis of nEVs by surface enhanced Raman spectroscopy (SERS), refractive index determination by nanoparticle tracking analysis (NTA), and bio-layer interferometry (BLI) investigation of nEV surface interactions with specific capturing moieties. Additionally, promising novel techniques developed in Prof. Aydogan Ozcan’s laboratory will be discussed in the context of integration with nEV and liquid biopsies research; lens-free holographic microscopy [1] and deep learning assisted holographic aggregation-based assays [2]. This panel of different approaches can improve our current understanding for optimal design of devices and methods to tackle the challenges in the horizon of tomorrow’s diagnostics.

[1] McLeod, E., Ozcan, A. et al., 2015. High-Throughput and Label-Free Single Nanoparticle Sizing Based on Time-Resolved On-Chip Microscopy. ACS Nano, 9(3), pp. 3265–3273

[2] Wu, Y., Ray, A., Ozcan A. et al., 2019. Deep Learning Enables High-Throughput Analysis of Particle-Aggregation-Based Biosensors Imaged Using Holography. ACS Photonics, 6, pp. 294-301

Biography: Tatu Rojalin received his PhD in Pharmaceutical Sciences from the University of Helsinki, Finland. He did his dissertation research in the Doctoral School in Natural Sciences, Programme in Materials Research and Nanosciences, group of Pharmaceutical Biophysics. Dr. Rojalin worked for one year as a visiting PhD Scholar at the University of California, Davis before finalizing his PhD Thesis “Raman Spectroscopy and Surface Plasmon Resonance as Photonic Tools for Biopharmaceutical Applications”. His dissertation primarily addressed to the development of biophotonic technologies, applications and data analysis methods for small molecular and liposome-based drug discovery, as well as nanoscale extracellular vesicle (nEV) and Alzheimer’s disease research. Collectively, the results of his Thesis expanded on the current knowledge of how light can be effectively generated, modified and manipulated in order to engineer devices and applications that can be used to probe for biochemical and sub-cellular phenomena in modern diagnostics and drug development. Dr. Rojalin currently works as a Postdoctoral Research Scientist at the University of California, Davis, Department of Biochemistry and Molecular Medicine. His multidisciplinary expertise integrates bioengineering, materials science, biophysics and medicine, and his main avenue of research encompasses the development of cancer detection methods and instruments based on photonics, liquid biopsies, and nEVs. Dr. Rojalin’s long-term objective is to develop highly modifiable, non- or minimally invasive biosensing platforms for revolutionary diagnostics of various diseases, with the aim of transforming these platforms into widely-used, rapid, and cost-effective devices for a broad range of health systems globally regardless the level of resources available.

For more information, contact Prof. Aydogan Ozcan ()

Date(s) - May 16, 2019
1:00 pm - 2:00 pm

E-IV Tesla Room #53-125
420 Westwood Plaza - 5th Flr., Los Angeles CA 90095